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freebsd-skq/sys/vm/uma_core.c

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/* -> /*- for license, minor formatting changes
2005-01-07 02:29:27 +00:00
/*-
sys: general adoption of SPDX licensing ID tags. Mainly focus on files that use BSD 2-Clause license, however the tool I was using misidentified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. No functional change intended.
2017-11-27 15:23:17 +00:00
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
* Copyright (c) 2002-2019 Jeffrey Roberson <jeff@FreeBSD.org>
Improve canonicalization of copyrights. Order copyrights by order of assertion (jeff, bmilekic, rwatson). Suggested ages ago by: bde MFC after: 1 week
2005-07-16 09:51:52 +00:00
* Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
Better align output of "show uma" by moving from displaying the basic counters of allocs/frees/use for each zone to the same statistics shown by userspace "vmstat -z". MFC after: 3 days
2006-10-26 12:55:32 +00:00
* Copyright (c) 2004-2006 Robert N. M. Watson
Improve canonicalization of copyrights. Order copyrights by order of assertion (jeff, bmilekic, rwatson). Suggested ages ago by: bde MFC after: 1 week
2005-07-16 09:51:52 +00:00
* All rights reserved.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* uma_core.c Implementation of the Universal Memory allocator
*
* This allocator is intended to replace the multitude of similar object caches
* in the standard FreeBSD kernel. The intent is to be flexible as well as
sys/vm: minor spelling fixes in comments. No functional change.
2016-05-02 20:16:29 +00:00
* efficient. A primary design goal is to return unused memory to the rest of
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
* the system. This will make the system as a whole more flexible due to the
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* ability to move memory to subsystems which most need it instead of leaving
* pools of reserved memory unused.
*
* The basic ideas stem from similar slab/zone based allocators whose algorithms
* are well known.
*
*/
/*
* TODO:
* - Improve memory usage for large allocations
* - Investigate cache size adjustments
*/
Use __FBSDID().
2003-06-11 23:50:51 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
#include "opt_ddb.h"
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include "opt_param.h"
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
#include "opt_vm.h"
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <sys/param.h>
#include <sys/systm.h>
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
#include <sys/bitset.h>
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
#include <sys/domainset.h>
call vm_lowmem hook in uma_reclaim_worker A comment near kmem_reclaim() implies that we already did that. Calling the hook is useful, because some handlers, e.g. ARC, might be able to release significant amounts of KVA. Now that we have more than one place where vm_lowmem hook is called, use this change as an opportunity to introduce flags that describe a reason for calling the hook. No handler makes use of the flags yet. Reviewed by: markj, kib MFC after: 1 week Sponsored by: Panzura Differential Revision: https://reviews.freebsd.org/D9764
2017-02-25 16:39:21 +00:00
#include <sys/eventhandler.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <sys/kernel.h>
#include <sys/types.h>
Fix arc after r326347 broke various memory limit queries. Use UMA features rather than kmem arena size to determine available memory. Initialize the UMA limit to LONG_MAX to avoid spurious wakeups on boot before the real limit is set. PR: 224330 (partial), 224080 Reviewed by: markj, avg Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13494
2018-01-02 04:35:56 +00:00
#include <sys/limits.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <sys/queue.h>
#include <sys/malloc.h>
Generate KTR trace records for uma_zalloc_arg() and uma_zfree_arg(). This doesn't trace every event of interest in UMA, but provides enough basic information to explain lock traces and sleep patterns.
2004-08-06 21:52:38 +00:00
#include <sys/ktr.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <sys/lock.h>
#include <sys/sysctl.h>
#include <sys/mutex.h>
In uma_zalloc_arg(), if we are performing a M_WAITOK allocation, ensure that td_intr_nesting_level is 0 (like malloc() does). Since malloc() calls uma we can probably remove the check in malloc() for this now. Also, perform an extra witness check in that case to make sure we don't hold any locks when performing a M_WAITOK allocation.
2002-05-20 17:54:48 +00:00
#include <sys/proc.h>
This is the much-discussed major upgrade to the random(4) device, known to you all as /dev/random. This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources. The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people. The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway. Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to. My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise. My Nomex pants are on. Let the feedback commence! Reviewed by: trasz,des(partial),imp(partial?),rwatson(partial?) Approved by: so(des)
2014-10-30 21:21:53 +00:00
#include <sys/random.h>
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
#include <sys/rwlock.h>
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
#include <sys/sbuf.h>
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
#include <sys/sched.h>
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
#include <sys/sleepqueue.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <sys/smp.h>
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
#include <sys/smr.h>
Redo r292484. Embed task(9) into zone, so that uz_maxaction is called in a context that can sleep, allowing consumers of the KPI to run their drain routines without any extra measures. Discussed with: jtl
2016-02-03 23:30:17 +00:00
#include <sys/taskqueue.h>
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
#include <sys/vmmeter.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <vm/vm.h>
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
#include <vm/vm_domainset.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <vm/vm_object.h>
#include <vm/vm_page.h>
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
#include <vm/vm_pageout.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <vm/vm_param.h>
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
#include <vm/vm_phys.h>
Allow empty NUMA memory domains to support Threadripper2 The AMD Threadripper 2990WX is basically a slightly crippled Epyc. Rather than having 4 memory controllers, one per NUMA domain, it has only 2 memory controllers enabled. This means that only 2 of the 4 NUMA domains can be populated with physical memory, and the others are empty. Add support to FreeBSD for empty NUMA domains by: - creating empty memory domains when parsing the SRAT table, rather than failing to parse the table - not running the pageout deamon threads in empty domains - adding defensive code to UMA to avoid allocating from empty domains - adding defensive code to cpuset to avoid binding to an empty domain Thanks to Jeff for suggesting this strategy. Reviewed by: alc, markj Approved by: re (gjb@) Differential Revision: https://reviews.freebsd.org/D1683
2018-10-01 14:14:21 +00:00
#include <vm/vm_pagequeue.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/uma.h>
#include <vm/uma_int.h>
Remove the temporary alignment check in free(). Implement the following checks on freed memory in the bucket path: - Slab membership - Alignment - Duplicate free This previously was only done if we skipped the buckets. This code will slow down INVARIANTS a bit, but it is smp safe. The checks were moved out of the normal path and into hooks supplied in uma_dbg.
2002-05-02 02:08:48 +00:00
#include <vm/uma_dbg.h>
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
#include <ddb/ddb.h>
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
#ifdef DEBUG_MEMGUARD
#include <vm/memguard.h>
#endif
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
#include <machine/md_var.h>
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
#ifdef INVARIANTS
#define UMA_ALWAYS_CTORDTOR 1
#else
#define UMA_ALWAYS_CTORDTOR 0
#endif
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
* This is the zone and keg from which all zones are spawned.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
static uma_zone_t kegs;
static uma_zone_t zones;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
/*
* These are the two zones from which all offpage uma_slab_ts are allocated.
*
* One zone is for slab headers that can represent a larger number of items,
* making the slabs themselves more efficient, and the other zone is for
* headers that are smaller and represent fewer items, making the headers more
* efficient.
*/
#define SLABZONE_SIZE(setsize) \
(sizeof(struct uma_hash_slab) + BITSET_SIZE(setsize) * SLAB_BITSETS)
#define SLABZONE0_SETSIZE (PAGE_SIZE / 16)
#define SLABZONE1_SETSIZE SLAB_MAX_SETSIZE
#define SLABZONE0_SIZE SLABZONE_SIZE(SLABZONE0_SETSIZE)
#define SLABZONE1_SIZE SLABZONE_SIZE(SLABZONE1_SETSIZE)
static uma_zone_t slabzones[2];
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* The initial hash tables come out of this zone so they can be allocated
* prior to malloc coming up.
*/
static uma_zone_t hashzone;
Add uma_set_align() interface, which will be called at most once during boot by MD code to indicated detected alignment preference. Rather than cache alignment being encoded in UMA consumers by defining a global alignment value of (16 - 1) in UMA_ALIGN_CACHE, UMA_ALIGN_CACHE is now a special value (-1) that causes UMA to look at registered alignment. If no preferred alignment has been selected by MD code, a default alignment of (16 - 1) will be used. Currently, no hardware platforms specify alignment; architecture maintainers will need to modify MD startup code to specify an alignment if desired. This must occur before initialization of UMA so that all UMA zones pick up the requested alignment. Reviewed by: jeff, alc Submitted by: attilio
2007-02-11 20:13:52 +00:00
/* The boot-time adjusted value for cache line alignment. */
- Merge changes to the base system to support OFED. These include a wider arg2 for sysctl, updates to vlan code, IFT_INFINIBAND, and other miscellaneous small features.
2011-03-21 09:40:01 +00:00
int uma_align_cache = 64 - 1;
Add uma_set_align() interface, which will be called at most once during boot by MD code to indicated detected alignment preference. Rather than cache alignment being encoded in UMA consumers by defining a global alignment value of (16 - 1) in UMA_ALIGN_CACHE, UMA_ALIGN_CACHE is now a special value (-1) that causes UMA to look at registered alignment. If no preferred alignment has been selected by MD code, a default alignment of (16 - 1) will be used. Currently, no hardware platforms specify alignment; architecture maintainers will need to modify MD startup code to specify an alignment if desired. This must occur before initialization of UMA so that all UMA zones pick up the requested alignment. Reviewed by: jeff, alc Submitted by: attilio
2007-02-11 20:13:52 +00:00
- Don't abuse M_DEVBUF, define a tag for UMA hashes.
2003-09-19 07:23:50 +00:00
static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
- Don't abuse M_DEVBUF, define a tag for UMA hashes.
2003-09-19 07:23:50 +00:00
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
/*
* Are we allowed to allocate buckets?
*/
static int bucketdisable = 1;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/* Linked list of all kegs in the system */
(S)LIST_HEAD_INITIALIZER takes a (S)LIST_HEAD as an argument. Fix some wrong usages. Note: this does not affect generated binaries as this argument is not used. PR: 137213 Submitted by: Eygene Ryabinkin (initial version) MFC after: 1 month
2009-12-28 22:56:30 +00:00
static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
- Add bucket size column to `show uma` DDB command. - Add `show umacache` command to show alike stats for cache-only UMA zones.
2013-11-28 19:20:49 +00:00
/* Linked list of all cache-only zones in the system */
static LIST_HEAD(,uma_zone) uma_cachezones =
LIST_HEAD_INITIALIZER(uma_cachezones);
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
/* This RW lock protects the keg list */
Start annotating global _padalign locks with __exclusive_cache_line While these locks are guarnteed to not share their respective cache lines, their current placement leaves unnecessary holes in lines which preceeded them. For instance the annotation of vm_page_queue_free_mtx allows 2 neighbour cachelines (previously separate by the lock) to be collapsed into 1. The annotation is only effective on architectures which have it implemented in their linker script (currently only amd64). Thus locks are not converted to their not-padaligned variants as to not affect the rest. MFC after: 1 week
2017-09-06 20:28:18 +00:00
static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Simplify boot pages management in UMA. It is simply a contigous virtual memory pointer and number of pages. There is no need to build a linked list here. Just increment pointer and decrement counter. The only functional difference to old allocator is that before we gave pages from topmost and down to lowest, and now we give them in normal ascending order. While here remove padalign from a mutex that is unused at runtime. Reviewed by: alc
2017-06-01 18:26:57 +00:00
/*
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
* First available virual address for boot time allocations.
Simplify boot pages management in UMA. It is simply a contigous virtual memory pointer and number of pages. There is no need to build a linked list here. Just increment pointer and decrement counter. The only functional difference to old allocator is that before we gave pages from topmost and down to lowest, and now we give them in normal ascending order. While here remove padalign from a mutex that is unused at runtime. Reviewed by: alc
2017-06-01 18:26:57 +00:00
*/
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
static vm_offset_t bootstart;
static vm_offset_t bootmem;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
static struct sx uma_reclaim_lock;
Provide mutual exclusion between zone allocation/destruction and uma_reclaim(). Reclamation code must not see half-constructed or destructed zones. Do this by bracing uma_zcreate() and uma_zdestroy() into a shared-locked sx, and take the sx exclusively in uma_reclaim(). Usually zones are not created/destroyed during the system operation, but tmpfs mounts do cause zone operations and exposed the bug. Another solution could be to only expose a new keg on uma_kegs list after the corresponding zone is fully constructed, and similar treatment for the destruction. But it probably requires more risky code rearrangement as well. Reported and tested by: pho Discussed with: avg Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2014-11-30 20:20:55 +00:00
Add sysctls for uma_kmem_{limit,total}. Reviewed by: alc, dougm, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20514
2019-06-06 16:26:58 +00:00
/*
* kmem soft limit, initialized by uma_set_limit(). Ensure that early
* allocations don't trigger a wakeup of the reclaim thread.
*/
Handle large mallocs by going directly to kmem. Taking a detour through UMA does not provide any additional value. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22563
2019-11-29 03:14:10 +00:00
unsigned long uma_kmem_limit = LONG_MAX;
Add sysctls for uma_kmem_{limit,total}. Reviewed by: alc, dougm, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20514
2019-06-06 16:26:58 +00:00
SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
"UMA kernel memory soft limit");
Handle large mallocs by going directly to kmem. Taking a detour through UMA does not provide any additional value. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22563
2019-11-29 03:14:10 +00:00
unsigned long uma_kmem_total;
Add sysctls for uma_kmem_{limit,total}. Reviewed by: alc, dougm, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20514
2019-06-06 16:26:58 +00:00
SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
"UMA kernel memory usage");
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* Is the VM done starting up? */
UMA: Don't destroy zones after the system shutdown process starts. Some kernel subsystems, notably ZFS, will destroy UMA zones from a shutdown eventhandler. This causes the zone to be drained. For slabs that are mapped into KVA this can be very expensive and so it needlessly delays the shutdown process. Add a new state to the "booted" variable, BOOT_SHUTDOWN. Once kern_reboot() starts invoking shutdown handlers, turn uma_zdestroy() into a no-op, provided that the zone does not have a custom finalization routine. PR: 242427 Reviewed by: jeff, kib, rlibby MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23066
2020-01-09 19:17:42 +00:00
static enum {
BOOT_COLD,
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
BOOT_KVA,
UMA: Don't destroy zones after the system shutdown process starts. Some kernel subsystems, notably ZFS, will destroy UMA zones from a shutdown eventhandler. This causes the zone to be drained. For slabs that are mapped into KVA this can be very expensive and so it needlessly delays the shutdown process. Add a new state to the "booted" variable, BOOT_SHUTDOWN. Once kern_reboot() starts invoking shutdown handlers, turn uma_zdestroy() into a no-op, provided that the zone does not have a custom finalization routine. PR: 242427 Reviewed by: jeff, kib, rlibby MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23066
2020-01-09 19:17:42 +00:00
BOOT_RUNNING,
BOOT_SHUTDOWN,
} booted = BOOT_COLD;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
/*
* This is the handle used to schedule events that need to happen
* outside of the allocation fast path.
*/
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
static struct callout uma_callout;
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
#define UMA_TIMEOUT 20 /* Seconds for callout interval. */
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* This structure is passed as the zone ctor arg so that I don't have to create
* a special allocation function just for zones.
*/
struct uma_zctor_args {
Const-ify the zone name argument to uma_zcreate(9). MFC after: 3 days
2012-10-26 17:51:05 +00:00
const char *name;
- Changed the size element of uma_zctor_args to be size_t instead of int. - Changed uma_zcreate to accept the size argument as a size_t intead of int. Approved by: jeff
2002-05-02 07:36:30 +00:00
size_t size;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma_ctor ctor;
uma_dtor dtor;
uma_init uminit;
uma_fini fini;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
uma_import import;
uma_release release;
void *arg;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_keg_t keg;
int align;
Convert UMA code to C99 uintXX_t types.
2013-04-09 17:43:48 +00:00
uint32_t flags;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
};
struct uma_kctor_args {
uma_zone_t zone;
size_t size;
uma_init uminit;
uma_fini fini;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
int align;
Convert UMA code to C99 uintXX_t types.
2013-04-09 17:43:48 +00:00
uint32_t flags;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
};
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
struct uma_bucket_zone {
uma_zone_t ubz_zone;
char *ubz_name;
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
int ubz_entries; /* Number of items it can hold. */
int ubz_maxsize; /* Maximum allocation size per-item. */
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
};
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
/*
* Compute the actual number of bucket entries to pack them in power
* of two sizes for more efficient space utilization.
*/
#define BUCKET_SIZE(n) \
(((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
Introduce new "256 Bucket" zone to split requests and reduce congestion on "128 Bucket" zone lock. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2014-06-12 11:57:07 +00:00
#define BUCKET_MAX BUCKET_SIZE(256)
Use literal bucket sizes for smaller buckets rather than the rounding system. Small bucket sizes already pack well even if they are an odd number of words. This prevents any potential new instances of the problem fixed in r357463 as well as making the system easier to understand. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D23494
2020-02-04 20:28:06 +00:00
#define BUCKET_MIN 2
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
struct uma_bucket_zone bucket_zones[] = {
Use literal bucket sizes for smaller buckets rather than the rounding system. Small bucket sizes already pack well even if they are an odd number of words. This prevents any potential new instances of the problem fixed in r357463 as well as making the system easier to understand. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D23494
2020-02-04 20:28:06 +00:00
/* Literal bucket sizes. */
{ NULL, "2 Bucket", 2, 4096 },
{ NULL, "4 Bucket", 4, 3072 },
{ NULL, "8 Bucket", 8, 2048 },
{ NULL, "16 Bucket", 16, 1024 },
/* Rounded down power of 2 sizes for efficiency. */
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
Introduce new "256 Bucket" zone to split requests and reduce congestion on "128 Bucket" zone lock. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2014-06-12 11:57:07 +00:00
{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
{ NULL, NULL, 0}
};
Track UMA(9) allocation failures by zone, and export via sysctl. Requested by: victor cruceru <victor dot cruceru at gmail dot com> MFC after: 1 week
2005-07-15 23:34:39 +00:00
/*
* Flags and enumerations to be passed to internal functions.
*/
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
enum zfreeskip {
SKIP_NONE = 0,
SKIP_CNT = 0x00000001,
SKIP_DTOR = 0x00010000,
SKIP_FINI = 0x00020000,
};
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* Prototypes.. */
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
void uma_startup1(vm_offset_t);
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
void uma_startup2(void);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
uma: add UMA_ZONE_CONTIG, and a default contig_alloc For now, copy the mbuf allocator. Reviewed by: jeff, markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23237
2020-02-04 22:40:11 +00:00
static void *contig_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
Fix integer truncation bug in malloc(9) A couple of internal functions used by malloc(9) and uma truncated a size_t down to an int. This could cause any number of issues (e.g. indefinite sleeps, memory corruption) if any kernel subsystem tried to allocate 2GB or more through malloc. zfs would attempt such an allocation when run on a system with 2TB or more of RAM. Note to self: When this is MFCed, sparc64 needs the same fix. Differential revision: https://reviews.freebsd.org/D2106 Reviewed by: kib Reported by: Michael Fuckner <michael@fuckner.net> Tested by: Michael Fuckner <michael@fuckner.net> MFC after: 2 weeks
2015-04-01 12:42:26 +00:00
static void page_free(void *, vm_size_t, uint8_t);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
static void pcpu_page_free(void *, vm_size_t, uint8_t);
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
static void cache_drain(uma_zone_t);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
static void bucket_drain(uma_zone_t, uma_bucket_t);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
static void bucket_cache_reclaim(uma_zone_t zone, bool);
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
static int keg_ctor(void *, int, void *, int);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
static void keg_dtor(void *, int, void *);
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
static int zone_ctor(void *, int, void *, int);
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
static void zone_dtor(void *, int, void *);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
static inline void item_dtor(uma_zone_t zone, void *item, int size,
void *udata, enum zfreeskip skip);
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
static int zero_init(void *, int, int);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
static void zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *), void *);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static void zone_timeout(uma_zone_t zone, void *);
Allow UMA hash tables to expand faster then 2x in 20 seconds. ZFS ABD allocates tons of 4KB chunks via UMA, requiring huge hash tables. With initial hash table size of only 32 elements it takes ~20 expansions or ~400 seconds to adapt to handling 220GB ZFS ARC. During that time not only the hash table is highly inefficient, but also each of those expan- sions takes significant time with the lock held, blocking operation. On my test system with 256GB of RAM and ZFS pool of 28 HDDs this change reduces time needed to first time read 240GB from ~300-400s, during which system is quite busy and unresponsive, to only ~150s with light CPU load and just 5 sub-second CPU spikes to expand the hash table. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2019-06-06 23:57:28 +00:00
static int hash_alloc(struct uma_hash *, u_int);
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
static int hash_expand(struct uma_hash *, struct uma_hash *);
static void hash_free(struct uma_hash *hash);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
static void uma_timeout(void *);
static void uma_startup3(void);
UMA: Don't destroy zones after the system shutdown process starts. Some kernel subsystems, notably ZFS, will destroy UMA zones from a shutdown eventhandler. This causes the zone to be drained. For slabs that are mapped into KVA this can be very expensive and so it needlessly delays the shutdown process. Add a new state to the "booted" variable, BOOT_SHUTDOWN. Once kern_reboot() starts invoking shutdown handlers, turn uma_zdestroy() into a no-op, provided that the zone does not have a custom finalization routine. PR: 242427 Reviewed by: jeff, kib, rlibby MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23066
2020-01-09 19:17:42 +00:00
static void uma_shutdown(void);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
static void *zone_alloc_item(uma_zone_t, void *, int, int);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
static int zone_alloc_limit(uma_zone_t zone, int count, int flags);
static void zone_free_limit(uma_zone_t zone, int count);
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
static void bucket_enable(void);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
static void bucket_init(void);
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
static void bucket_zone_drain(void);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
Convert UMA code to C99 uintXX_t types.
2013-04-09 17:43:48 +00:00
uma_fini fini, int align, uint32_t flags);
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
static int zone_import(void *, void **, int, int, int);
static void zone_release(void *, void **, int);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
static bool cache_free(uma_zone_t, uma_cache_t, void *, void *, int);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
uma: pretty print zone flags sysctl Requested by: jeff Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22748
2019-12-11 06:50:55 +00:00
static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
uma: report slab efficiency Reviewed by: jeff Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22766
2019-12-13 09:32:09 +00:00
static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
static int sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Fix an assertion introduced in r356348. On architectures without UMA_MD_SMALL_ALLOC vmem has a more complicated startup sequence that violated the new assert. Resolve this by rewriting the COLD asserts to look at the per-cpu allocation counts for evidence of api activity. Discussed with: rlibby Reviewed by: markj Reported by: lwhsu
2020-01-04 19:29:25 +00:00
static uint64_t uma_zone_get_allocs(uma_zone_t zone);
uma: multipage chicken switch Add a switch to allow disabling multipage slabs, in order to facilitate measuring memory usage and performance effects. The tunable vm.debug.uma_multipage_slabs defaults to 1 and can be set to 0 to disable. The name may change soon. Reviewed by: markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23487
2020-02-04 22:40:45 +00:00
static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD, 0,
"Memory allocation debugging");
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
#ifdef INVARIANTS
Fix an assertion introduced in r356348. On architectures without UMA_MD_SMALL_ALLOC vmem has a more complicated startup sequence that violated the new assert. Resolve this by rewriting the COLD asserts to look at the per-cpu allocation counts for evidence of api activity. Discussed with: rlibby Reviewed by: markj Reported by: lwhsu
2020-01-04 19:29:25 +00:00
static uint64_t uma_keg_get_allocs(uma_keg_t zone);
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
static u_int dbg_divisor = 1;
SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
"Debug & thrash every this item in memory allocator");
static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
&uma_dbg_cnt, "memory items debugged");
SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
&uma_skip_cnt, "memory items skipped, not debugged");
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
#endif
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
uma: move sysctl vm.uma defn out from under INVARIANTS Fix non-INVARIANTS builds after r355149. Reported by: Michael Butler <imb@protected-networks.net> Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22588
2019-11-28 04:15:16 +00:00
SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW, 0, "Universal Memory Allocator");
vm: add missing CLTFLAG_MPSAFE annotations This covers all vm/* files.
2020-01-12 05:08:57 +00:00
SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_INT,
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
vm: add missing CLTFLAG_MPSAFE annotations This covers all vm/* files.
2020-01-12 05:08:57 +00:00
SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_STRUCT,
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
static int zone_warnings = 1;
Pull in r267961 and r267973 again. Fix for issues reported will follow.
2014-06-28 03:56:17 +00:00
SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
"Warn when UMA zones becomes full");
uma: multipage chicken switch Add a switch to allow disabling multipage slabs, in order to facilitate measuring memory usage and performance effects. The tunable vm.debug.uma_multipage_slabs defaults to 1 and can be set to 0 to disable. The name may change soon. Reviewed by: markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23487
2020-02-04 22:40:45 +00:00
static int multipage_slabs = 1;
TUNABLE_INT("vm.debug.uma_multipage_slabs", &multipage_slabs);
SYSCTL_INT(_vm_debug, OID_AUTO, uma_multipage_slabs,
CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &multipage_slabs, 0,
"UMA may choose larger slab sizes for better efficiency");
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
/*
* Select the slab zone for an offpage slab with the given maximum item count.
*/
static inline uma_zone_t
slabzone(int ipers)
{
return (slabzones[ipers > SLABZONE0_SETSIZE]);
}
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
/*
* This routine checks to see whether or not it's safe to enable buckets.
*/
static void
bucket_enable(void)
{
uma: delay bucket_init() until we might actually enable buckets This helps with a bootstrapping problem in upcoming work. We don't first enable buckets until uma_startup2(), so we can delay bucket creation until then. The other two paths to bucket_enable() are both later, one in the pageout daemon (SI_SUB_KTHREAD_PAGE vs SI_SUB_VM) and one in uma_timeout() (first activated in uma_startup3()). Note that although some bucket functions are accessible before uma_startup2() (e.g. bucket_select() in zone_ctor()), none of them inspect ubz_zone. Discussed with: jeff Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22765
2019-12-13 09:32:03 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
KASSERT(booted >= BOOT_KVA, ("Bucket enable before init"));
Tweak condition for disabling allocation from per-CPU buckets in low memory situation. I've observed a situation where per-CPU allocations were disabled while there were enough free cached pages. Basically, cnt.v_free_count was sitting stable at a value lower than cnt.v_free_min and that caused massive performance drop. Reviewed by: alc MFC after: 1 week
2012-05-23 18:56:29 +00:00
bucketdisable = vm_page_count_min();
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
}
Abstract the logic to look up the uma_bucket_zone given a desired number of entries into bucket_zone_lookup(), which helps make more clear the logic of consumers of bucket zones. Annotate the behavior of bucket_init() with a comment indicating how the various data structures, including the bucket lookup tables, are initialized.
2004-11-06 11:43:30 +00:00
/*
* Initialize bucket_zones, the array of zones of buckets of various sizes.
*
* For each zone, calculate the memory required for each bucket, consisting
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
* of the header and an array of pointers.
Abstract the logic to look up the uma_bucket_zone given a desired number of entries into bucket_zone_lookup(), which helps make more clear the logic of consumers of bucket zones. Annotate the behavior of bucket_init() with a comment indicating how the various data structures, including the bucket lookup tables, are initialized.
2004-11-06 11:43:30 +00:00
*/
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
static void
bucket_init(void)
{
struct uma_bucket_zone *ubz;
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
int size;
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
Eliminate an unused variable. MFC after: 1 week
2015-04-20 16:48:21 +00:00
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
size = roundup(sizeof(struct uma_bucket), sizeof(void *));
size += sizeof(void *) * ubz->ubz_entries;
ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET |
UMA_ZONE_FIRSTTOUCH);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
}
}
Abstract the logic to look up the uma_bucket_zone given a desired number of entries into bucket_zone_lookup(), which helps make more clear the logic of consumers of bucket zones. Annotate the behavior of bucket_init() with a comment indicating how the various data structures, including the bucket lookup tables, are initialized.
2004-11-06 11:43:30 +00:00
/*
* Given a desired number of entries for a bucket, return the zone from which
* to allocate the bucket.
*/
static struct uma_bucket_zone *
bucket_zone_lookup(int entries)
{
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
struct uma_bucket_zone *ubz;
Abstract the logic to look up the uma_bucket_zone given a desired number of entries into bucket_zone_lookup(), which helps make more clear the logic of consumers of bucket zones. Annotate the behavior of bucket_init() with a comment indicating how the various data structures, including the bucket lookup tables, are initialized.
2004-11-06 11:43:30 +00:00
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
if (ubz->ubz_entries >= entries)
return (ubz);
ubz--;
return (ubz);
}
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
static struct uma_bucket_zone *
bucket_zone_max(uma_zone_t zone, int nitems)
{
struct uma_bucket_zone *ubz;
int bpcpu;
bpcpu = 2;
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
/* Count the cross-domain bucket. */
bpcpu++;
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
if (ubz->ubz_entries * bpcpu * mp_ncpus > nitems)
break;
if (ubz == &bucket_zones[0])
ubz = NULL;
else
ubz--;
return (ubz);
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
static int
bucket_select(int size)
{
struct uma_bucket_zone *ubz;
ubz = &bucket_zones[0];
if (size > ubz->ubz_maxsize)
return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
for (; ubz->ubz_entries != 0; ubz++)
if (ubz->ubz_maxsize < size)
break;
ubz--;
return (ubz->ubz_entries);
Abstract the logic to look up the uma_bucket_zone given a desired number of entries into bucket_zone_lookup(), which helps make more clear the logic of consumers of bucket zones. Annotate the behavior of bucket_init() with a comment indicating how the various data structures, including the bucket lookup tables, are initialized.
2004-11-06 11:43:30 +00:00
}
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
static uma_bucket_t
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
bucket_alloc(uma_zone_t zone, void *udata, int flags)
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
{
struct uma_bucket_zone *ubz;
uma_bucket_t bucket;
/*
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
* Don't allocate buckets early in boot.
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
*/
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if (__predict_false(booted < BOOT_KVA))
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
return (NULL);
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
/*
* To limit bucket recursion we store the original zone flags
* in a cookie passed via zalloc_arg/zfree_arg. This allows the
* NOVM flag to persist even through deep recursions. We also
* store ZFLAG_BUCKET once we have recursed attempting to allocate
* a bucket for a bucket zone so we do not allow infinite bucket
* recursion. This cookie will even persist to frees of unused
* buckets via the allocation path or bucket allocations in the
* free path.
*/
if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
udata = (void *)(uintptr_t)zone->uz_flags;
Fix bug introduced at r252226, when udata argument passed to bucket_alloc() was used without making sure first that it was really passed for us. On some of my systems this bug made user argument passed by ZFS code to uma_zalloc_arg() unexpectedly block UMA per-CPU caches for those zones.
2013-11-27 19:55:42 +00:00
else {
if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
return (NULL);
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
Fix bug introduced at r252226, when udata argument passed to bucket_alloc() was used without making sure first that it was really passed for us. On some of my systems this bug made user argument passed by ZFS code to uma_zalloc_arg() unexpectedly block UMA per-CPU caches for those zones.
2013-11-27 19:55:42 +00:00
}
uma: remove UMA_ZFLAG_CACHEONLY flag UMA_ZFLAG_CACHEONLY was essentially the same thing as UMA_ZONE_VM, but with a more confusing name. Remove the flag, make UMA_ZONE_VM an inherit flag, and replace all references. Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23516
2020-02-06 08:32:25 +00:00
if (((uintptr_t)udata & UMA_ZONE_VM) != 0)
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
flags |= M_NOVM;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
ubz = bucket_zone_lookup(zone->uz_bucket_size);
Allocating new bucket for bucket zone, never take it from the zone itself, since it will almost certanly fail. Take next bigger zone instead. This situation should not happen with original bucket zones configuration: "32 Bucket" zone uses "64 Bucket" and vice versa. But if "64 Bucket" zone lock is congested, zone may grow its bucket size and start biting itself. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2014-06-12 11:36:22 +00:00
if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
ubz++;
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
if (bucket) {
#ifdef INVARIANTS
bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
#endif
bucket->ub_cnt = 0;
bucket->ub_entries = ubz->ubz_entries;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
bucket->ub_seq = SMR_SEQ_INVALID;
CTR3(KTR_UMA, "bucket_alloc: zone %s(%p) allocated bucket %p",
zone->uz_name, zone, bucket);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
}
return (bucket);
}
static void
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
{
struct uma_bucket_zone *ubz;
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
KASSERT(bucket->ub_cnt == 0,
("bucket_free: Freeing a non free bucket."));
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
KASSERT(bucket->ub_seq == SMR_SEQ_INVALID,
("bucket_free: Freeing an SMR bucket."));
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
udata = (void *)(uintptr_t)zone->uz_flags;
Abstract the logic to look up the uma_bucket_zone given a desired number of entries into bucket_zone_lookup(), which helps make more clear the logic of consumers of bucket zones. Annotate the behavior of bucket_init() with a comment indicating how the various data structures, including the bucket lookup tables, are initialized.
2004-11-06 11:43:30 +00:00
ubz = bucket_zone_lookup(bucket->ub_entries);
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
uma_zfree_arg(ubz->ubz_zone, bucket, udata);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
}
static void
bucket_zone_drain(void)
{
struct uma_bucket_zone *ubz;
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
uma_zone_reclaim(ubz->ubz_zone, UMA_RECLAIM_DRAIN);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
/*
* Attempt to satisfy an allocation by retrieving a full bucket from one of the
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
* zone's caches. If a bucket is found the zone is not locked on return.
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
*/
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
static uma_bucket_t
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom)
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
{
uma_bucket_t bucket;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
int i;
bool dtor = false;
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
ZONE_LOCK_ASSERT(zone);
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
if ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) == NULL)
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
return (NULL);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
/* SMR Buckets can not be re-used until readers expire. */
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
bucket->ub_seq != SMR_SEQ_INVALID) {
if (!smr_poll(zone->uz_smr, bucket->ub_seq, false))
return (NULL);
bucket->ub_seq = SMR_SEQ_INVALID;
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
dtor = (zone->uz_dtor != NULL) || UMA_ALWAYS_CTORDTOR;
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
MPASS(zdom->uzd_nitems >= bucket->ub_cnt);
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
zdom->uzd_nitems -= bucket->ub_cnt;
if (zdom->uzd_imin > zdom->uzd_nitems)
zdom->uzd_imin = zdom->uzd_nitems;
zone->uz_bkt_count -= bucket->ub_cnt;
ZONE_UNLOCK(zone);
if (dtor)
for (i = 0; i < bucket->ub_cnt; i++)
item_dtor(zone, bucket->ub_bucket[i], zone->uz_size,
NULL, SKIP_NONE);
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
return (bucket);
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
/*
* Insert a full bucket into the specified cache. The "ws" parameter indicates
* whether the bucket's contents should be counted as part of the zone's working
* set.
*/
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
static void
zone_put_bucket(uma_zone_t zone, uma_zone_domain_t zdom, uma_bucket_t bucket,
const bool ws)
{
ZONE_LOCK_ASSERT(zone);
Include cache zones into zone_foreach() where appropriate. The r354367 is reverted since it is subsumed by this, more complete, approach. Suggested by: markj Reviewed by: alc. glebius, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22242
2019-11-10 09:25:19 +00:00
KASSERT(!ws || zone->uz_bkt_count < zone->uz_bkt_max,
("%s: zone %p overflow", __func__, zone));
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
zdom->uzd_nitems += bucket->ub_cnt;
if (ws && zdom->uzd_imax < zdom->uzd_nitems)
zdom->uzd_imax = zdom->uzd_nitems;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone->uz_bkt_count += bucket->ub_cnt;
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
}
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
/* Pops an item out of a per-cpu cache bucket. */
static inline void *
cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
{
void *item;
CRITICAL_ASSERT(curthread);
bucket->ucb_cnt--;
item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
#ifdef INVARIANTS
bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
#endif
cache->uc_allocs++;
return (item);
}
/* Pushes an item into a per-cpu cache bucket. */
static inline void
cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
{
CRITICAL_ASSERT(curthread);
KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
("uma_zfree: Freeing to non free bucket index."));
bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
bucket->ucb_cnt++;
cache->uc_frees++;
}
/*
* Unload a UMA bucket from a per-cpu cache.
*/
static inline uma_bucket_t
cache_bucket_unload(uma_cache_bucket_t bucket)
{
uma_bucket_t b;
b = bucket->ucb_bucket;
if (b != NULL) {
MPASS(b->ub_entries == bucket->ucb_entries);
b->ub_cnt = bucket->ucb_cnt;
bucket->ucb_bucket = NULL;
bucket->ucb_entries = bucket->ucb_cnt = 0;
}
return (b);
}
static inline uma_bucket_t
cache_bucket_unload_alloc(uma_cache_t cache)
{
return (cache_bucket_unload(&cache->uc_allocbucket));
}
static inline uma_bucket_t
cache_bucket_unload_free(uma_cache_t cache)
{
return (cache_bucket_unload(&cache->uc_freebucket));
}
static inline uma_bucket_t
cache_bucket_unload_cross(uma_cache_t cache)
{
return (cache_bucket_unload(&cache->uc_crossbucket));
}
/*
* Load a bucket into a per-cpu cache bucket.
*/
static inline void
cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
{
CRITICAL_ASSERT(curthread);
MPASS(bucket->ucb_bucket == NULL);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
MPASS(b->ub_seq == SMR_SEQ_INVALID);
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket->ucb_bucket = b;
bucket->ucb_cnt = b->ub_cnt;
bucket->ucb_entries = b->ub_entries;
}
static inline void
cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
{
cache_bucket_load(&cache->uc_allocbucket, b);
}
static inline void
cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
{
cache_bucket_load(&cache->uc_freebucket, b);
}
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
static inline void
cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
{
cache_bucket_load(&cache->uc_crossbucket, b);
}
#endif
/*
* Copy and preserve ucb_spare.
*/
static inline void
cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
{
b1->ucb_bucket = b2->ucb_bucket;
b1->ucb_entries = b2->ucb_entries;
b1->ucb_cnt = b2->ucb_cnt;
}
/*
* Swap two cache buckets.
*/
static inline void
cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
{
struct uma_cache_bucket b3;
CRITICAL_ASSERT(curthread);
cache_bucket_copy(&b3, b1);
cache_bucket_copy(b1, b2);
cache_bucket_copy(b2, &b3);
}
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
static void
zone_log_warning(uma_zone_t zone)
{
static const struct timeval warninterval = { 300, 0 };
if (!zone_warnings || zone->uz_warning == NULL)
return;
if (ratecheck(&zone->uz_ratecheck, &warninterval))
printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
}
Add a safety net to reclaim mbufs when one of the mbuf zones become exhausted. It is possible for a bug in the code (or, theoretically, even unusual network conditions) to exhaust all possible mbufs or mbuf clusters. When this occurs, things can grind to a halt fairly quickly. However, we currently do not call mb_reclaim() unless the entire system is experiencing a low-memory condition. While it is best to try to prevent exhaustion of one of the mbuf zones, it would also be useful to have a mechanism to attempt to recover from these situations by freeing "expendable" mbufs. This patch makes two changes: a) The patch adds a generic API to the UMA zone allocator to set a function that should be called when an allocation fails because the zone limit has been reached. Because of the way this function can be called, it really should do minimal work. b) The patch uses this API to try to free mbufs when an allocation fails from one of the mbuf zones because the zone limit has been reached. The function schedules a callout to run mb_reclaim(). Differential Revision: https://reviews.freebsd.org/D3864 Reviewed by: gnn Comments by: rrs, glebius MFC after: 2 weeks Sponsored by: Juniper Networks
2015-12-20 02:05:33 +00:00
static inline void
zone_maxaction(uma_zone_t zone)
{
Redo r292484. Embed task(9) into zone, so that uz_maxaction is called in a context that can sleep, allowing consumers of the KPI to run their drain routines without any extra measures. Discussed with: jtl
2016-02-03 23:30:17 +00:00
if (zone->uz_maxaction.ta_func != NULL)
taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
Add a safety net to reclaim mbufs when one of the mbuf zones become exhausted. It is possible for a bug in the code (or, theoretically, even unusual network conditions) to exhaust all possible mbufs or mbuf clusters. When this occurs, things can grind to a halt fairly quickly. However, we currently do not call mb_reclaim() unless the entire system is experiencing a low-memory condition. While it is best to try to prevent exhaustion of one of the mbuf zones, it would also be useful to have a mechanism to attempt to recover from these situations by freeing "expendable" mbufs. This patch makes two changes: a) The patch adds a generic API to the UMA zone allocator to set a function that should be called when an allocation fails because the zone limit has been reached. Because of the way this function can be called, it really should do minimal work. b) The patch uses this API to try to free mbufs when an allocation fails from one of the mbuf zones because the zone limit has been reached. The function schedules a callout to run mb_reclaim(). Differential Revision: https://reviews.freebsd.org/D3864 Reviewed by: gnn Comments by: rrs, glebius MFC after: 2 weeks Sponsored by: Juniper Networks
2015-12-20 02:05:33 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Routine called by timeout which is used to fire off some time interval
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
* based calculations. (stats, hash size, etc.)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Arguments:
* arg Unused
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
*
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* Returns:
* Nothing
*/
static void
uma_timeout(void *unused)
{
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
bucket_enable();
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_foreach(zone_timeout, NULL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* Reschedule this event */
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
/*
* Update the working set size estimate for the zone's bucket cache.
* The constants chosen here are somewhat arbitrary. With an update period of
* 20s (UMA_TIMEOUT), this estimate is dominated by zone activity over the
* last 100s.
*/
static void
zone_domain_update_wss(uma_zone_domain_t zdom)
{
long wss;
MPASS(zdom->uzd_imax >= zdom->uzd_imin);
wss = zdom->uzd_imax - zdom->uzd_imin;
zdom->uzd_imax = zdom->uzd_imin = zdom->uzd_nitems;
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zdom->uzd_wss = (4 * wss + zdom->uzd_wss) / 5;
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
* Routine to perform timeout driven calculations. This expands the
* hashes and does per cpu statistics aggregation.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* Returns nothing.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
static void
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_timeout(uma_zone_t zone, void *unused)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Include cache zones into zone_foreach() where appropriate. The r354367 is reverted since it is subsumed by this, more complete, approach. Suggested by: markj Reviewed by: alc. glebius, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22242
2019-11-10 09:25:19 +00:00
uma_keg_t keg;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
u_int slabs, pages;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
Include cache zones into zone_foreach() where appropriate. The r354367 is reverted since it is subsumed by this, more complete, approach. Suggested by: markj Reviewed by: alc. glebius, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22242
2019-11-10 09:25:19 +00:00
goto update_wss;
keg = zone->uz_keg;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
/*
* Hash zones are non-numa by definition so the first domain
* is the only one present.
*/
KEG_LOCK(keg, 0);
pages = keg->uk_domain[0].ud_pages;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* Expand the keg hash table.
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
*
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* This is done if the number of slabs is larger than the hash size.
* What I'm trying to do here is completely reduce collisions. This
* may be a little aggressive. Should I allow for two collisions max?
*/
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
if ((slabs = pages / keg->uk_ppera) > keg->uk_hash.uh_hashsize) {
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
struct uma_hash newhash;
struct uma_hash oldhash;
int ret;
/*
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
* This is so involved because allocating and freeing
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* while the keg lock is held will lead to deadlock.
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
* I have to do everything in stages and check for
* races.
*/
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_UNLOCK(keg, 0);
Allow UMA hash tables to expand faster then 2x in 20 seconds. ZFS ABD allocates tons of 4KB chunks via UMA, requiring huge hash tables. With initial hash table size of only 32 elements it takes ~20 expansions or ~400 seconds to adapt to handling 220GB ZFS ARC. During that time not only the hash table is highly inefficient, but also each of those expan- sions takes significant time with the lock held, blocking operation. On my test system with 256GB of RAM and ZFS pool of 28 HDDs this change reduces time needed to first time read 240GB from ~300-400s, during which system is quite busy and unresponsive, to only ~150s with light CPU load and just 5 sub-second CPU spikes to expand the hash table. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2019-06-06 23:57:28 +00:00
ret = hash_alloc(&newhash, 1 << fls(slabs));
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK(keg, 0);
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
if (ret) {
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
if (hash_expand(&keg->uk_hash, &newhash)) {
oldhash = keg->uk_hash;
keg->uk_hash = newhash;
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
} else
oldhash = newhash;
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_UNLOCK(keg, 0);
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
hash_free(&oldhash);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
goto update_wss;
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_UNLOCK(keg, 0);
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
Include cache zones into zone_foreach() where appropriate. The r354367 is reverted since it is subsumed by this, more complete, approach. Suggested by: markj Reviewed by: alc. glebius, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22242
2019-11-10 09:25:19 +00:00
update_wss:
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
ZONE_LOCK(zone);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
for (int i = 0; i < vm_ndomains; i++)
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
zone_domain_update_wss(&zone->uz_domain[i]);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
ZONE_UNLOCK(zone);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
/*
* Allocate and zero fill the next sized hash table from the appropriate
* backing store.
*
* Arguments:
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
* hash A new hash structure with the old hash size in uh_hashsize
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
*
* Returns:
sys/vm: minor spelling fixes in comments. No functional change.
2016-05-02 20:16:29 +00:00
* 1 on success and 0 on failure.
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
*/
Be consistent about "static" functions: if the function is marked static in its prototype, mark it static at the definition too. Inspired by: FlexeLint warning #512
2002-09-28 17:15:38 +00:00
static int
Allow UMA hash tables to expand faster then 2x in 20 seconds. ZFS ABD allocates tons of 4KB chunks via UMA, requiring huge hash tables. With initial hash table size of only 32 elements it takes ~20 expansions or ~400 seconds to adapt to handling 220GB ZFS ARC. During that time not only the hash table is highly inefficient, but also each of those expan- sions takes significant time with the lock held, blocking operation. On my test system with 256GB of RAM and ZFS pool of 28 HDDs this change reduces time needed to first time read 240GB from ~300-400s, during which system is quite busy and unresponsive, to only ~150s with light CPU load and just 5 sub-second CPU spikes to expand the hash table. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2019-06-06 23:57:28 +00:00
hash_alloc(struct uma_hash *hash, u_int size)
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
{
Fix integer math overflow in UMA hash_alloc(). 512GB of ZFS ABD ARC means abd_chunk zone of 128M 4KB items. To manage them UMA tries to allocate 2GB hash table, which size does not fit into the int variable, causing later allocation failure, which makes ARC shrink back below the 512GB, not letting it to use more RAM. With this change I easily reached >700GB ARC size on 768GB RAM machine. MFC after: 1 week Sponsored by: iXsystems, Inc.
2019-02-02 04:11:59 +00:00
size_t alloc;
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
Allow UMA hash tables to expand faster then 2x in 20 seconds. ZFS ABD allocates tons of 4KB chunks via UMA, requiring huge hash tables. With initial hash table size of only 32 elements it takes ~20 expansions or ~400 seconds to adapt to handling 220GB ZFS ARC. During that time not only the hash table is highly inefficient, but also each of those expan- sions takes significant time with the lock held, blocking operation. On my test system with 256GB of RAM and ZFS pool of 28 HDDs this change reduces time needed to first time read 240GB from ~300-400s, during which system is quite busy and unresponsive, to only ~150s with light CPU load and just 5 sub-second CPU spikes to expand the hash table. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2019-06-06 23:57:28 +00:00
KASSERT(powerof2(size), ("hash size must be power of 2"));
if (size > UMA_HASH_SIZE_INIT) {
hash->uh_hashsize = size;
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
} else {
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
UMA_ANYDOMAIN, M_WAITOK);
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
hash->uh_hashsize = UMA_HASH_SIZE_INIT;
}
if (hash->uh_slab_hash) {
bzero(hash->uh_slab_hash, alloc);
hash->uh_hashmask = hash->uh_hashsize - 1;
return (1);
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
}
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
return (0);
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
- There are an endless stream of style(9) errors in this file. Fix a few. Also catch some spelling errors.
2003-09-19 22:31:45 +00:00
* Expands the hash table for HASH zones. This is done from zone_timeout
* to reduce collisions. This must not be done in the regular allocation
* path, otherwise, we can recurse on the vm while allocating pages.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Arguments:
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
* oldhash The hash you want to expand
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
* newhash The hash structure for the new table
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Returns:
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
* Nothing
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Discussion:
*/
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
static int
hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
uma_hash_slab_t slab;
UMA: unsign some variables related to allocation in hash_alloc(). As a followup to r343673, unsign some variables related to allocation since the hashsize cannot be negative. This gives a bit more space to handle bigger allocations and avoid some implicit casting. While here also unsign uh_hashmask, it makes little sense to keep that signed. MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D19148
2019-02-12 04:33:05 +00:00
u_int hval;
u_int idx;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
if (!newhash->uh_slab_hash)
return (0);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
if (oldhash->uh_hashsize >= newhash->uh_hashsize)
return (0);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* I need to investigate hash algorithms for resizing without a
* full rehash.
*/
UMA: unsign some variables related to allocation in hash_alloc(). As a followup to r343673, unsign some variables related to allocation since the hashsize cannot be negative. This gives a bit more space to handle bigger allocations and avoid some implicit casting. While here also unsign uh_hashmask, it makes little sense to keep that signed. MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D19148
2019-02-12 04:33:05 +00:00
for (idx = 0; idx < oldhash->uh_hashsize; idx++)
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
LIST_REMOVE(slab, uhs_hlink);
hval = UMA_HASH(newhash, slab->uhs_data);
LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
slab, uhs_hlink);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
return (1);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Fix a witness warning when expanding a hash table. We were allocating the new hash while holding the lock on a zone. Fix this by doing the allocation seperately from the actual hash expansion. The lock is dropped before the allocation and reacquired before the expansion. The expansion code checks to see if we lost the race and frees the new hash if we do. We really never will lose this race because the hash expansion is single threaded via the timeout mechanism.
2002-04-14 13:47:10 +00:00
/*
* Free the hash bucket to the appropriate backing store.
*
* Arguments:
* slab_hash The hash bucket we're freeing
* hashsize The number of entries in that hash bucket
*
* Returns:
* Nothing
*/
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
static void
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
hash_free(struct uma_hash *hash)
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
{
Remove the hash_free() lock order reversal. This could have happened for several reasons before. Fixing it involved restructuring the generic hash code to require calling code to handle locking, unlocking, and freeing hashes on error conditions.
2002-05-13 04:39:28 +00:00
if (hash->uh_slab_hash == NULL)
return;
if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
else
- Don't abuse M_DEVBUF, define a tag for UMA hashes.
2003-09-19 07:23:50 +00:00
free(hash->uh_slab_hash, M_UMAHASH);
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Frees all outstanding items in a bucket
*
* Arguments:
* zone The zone to free to, must be unlocked.
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
* bucket The free/alloc bucket with items.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Returns:
* Nothing
*/
static void
bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
{
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
int i;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (bucket == NULL || bucket->ub_cnt == 0)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
return;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
bucket->ub_seq != SMR_SEQ_INVALID) {
smr_wait(zone->uz_smr, bucket->ub_seq);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
bucket->ub_seq = SMR_SEQ_INVALID;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
for (i = 0; i < bucket->ub_cnt; i++)
item_dtor(zone, bucket->ub_bucket[i],
zone->uz_size, NULL, SKIP_NONE);
}
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
if (zone->uz_fini)
for (i = 0; i < bucket->ub_cnt; i++)
zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (zone->uz_max_items > 0)
zone_free_limit(zone, bucket->ub_cnt);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
#ifdef INVARIANTS
bzero(bucket->ub_bucket, sizeof(void *) * bucket->ub_cnt);
#endif
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
bucket->ub_cnt = 0;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
/*
* Drains the per cpu caches for a zone.
*
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
* NOTE: This may only be called while the zone is being torn down, and not
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
* during normal operation. This is necessary in order that we do not have
* to migrate CPUs to drain the per-CPU caches.
*
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* Arguments:
Plug a race and a leak in UMA. 1) The race has to do with zone destruction. From the zone destructor we would lock the zone, set the working set size to 0, then unlock the zone, drain it, and then free the structure. Within the window following the working-set-size set to 0 and unlocking of the zone and the point where in zone_drain we re-acquire the zone lock, the uma timer routine could have fired off and changed the working set size to something non-zero, thereby potentially preventing us from completely freeing slabs before destroying the zone (and thus leaking them). 2) The leak has to do with zone destruction as well. When destroying a zone we would take care to free all the buckets cached in the zone, but although we would drain the pcpu cache buckets, we would not free them. This resulted in leaking a couple of bucket structures (512 bytes each) per cpu on SMP during zone destruction. While I'm here, also silence GCC warnings by turning uma_slab_alloc() from inline to real function. It's too big to be an inline. Reviewed by: JeffR
2003-07-30 18:55:15 +00:00
* zone The zone to drain, must be unlocked.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Returns:
* Nothing
*/
static void
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
cache_drain(uma_zone_t zone)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
uma_cache_t cache;
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
uma_bucket_t bucket;
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
smr_seq_t seq;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
int cpu;
/*
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
* XXX: It is safe to not lock the per-CPU caches, because we're
* tearing down the zone anyway. I.e., there will be no further use
* of the caches at this point.
*
* XXX: It would good to be able to assert that the zone is being
* torn down to prevent improper use of cache_drain().
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
seq = SMR_SEQ_INVALID;
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
seq = smr_current(zone->uz_smr);
Update several places that iterate over CPUs to use CPU_FOREACH().
2010-06-11 18:46:34 +00:00
CPU_FOREACH(cpu) {
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
cache = &zone->uz_cpu[cpu];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket = cache_bucket_unload_alloc(cache);
if (bucket != NULL) {
bucket_drain(zone, bucket);
bucket_free(zone, bucket, NULL);
}
bucket = cache_bucket_unload_free(cache);
if (bucket != NULL) {
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
bucket->ub_seq = seq;
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket_drain(zone, bucket);
bucket_free(zone, bucket, NULL);
}
bucket = cache_bucket_unload_cross(cache);
if (bucket != NULL) {
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
bucket->ub_seq = seq;
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket_drain(zone, bucket);
bucket_free(zone, bucket, NULL);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
bucket_cache_reclaim(zone, true);
- Fix a problem where we did not drain the cache of buckets in the zone when uma_reclaim() was called. This was introduced when the zone working-set algorithm was removed in favor of using the per cpu caches as the working set.
2004-02-01 06:15:17 +00:00
}
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
static void
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
cache_shrink(uma_zone_t zone, void *unused)
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
{
if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
return;
ZONE_LOCK(zone);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone->uz_bucket_size =
(zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
ZONE_UNLOCK(zone);
}
static void
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
cache_drain_safe_cpu(uma_zone_t zone, void *unused)
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
{
uma_cache_t cache;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
uma_bucket_t b1, b2, b3;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
int domain;
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
return;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
b1 = b2 = b3 = NULL;
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
critical_enter();
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
domain = PCPU_GET(domain);
else
domain = 0;
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
cache = &zone->uz_cpu[curcpu];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
b1 = cache_bucket_unload_alloc(cache);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/*
* Don't flush SMR zone buckets. This leaves the zone without a
* bucket and forces every free to synchronize().
*/
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
if ((zone->uz_flags & UMA_ZONE_SMR) == 0) {
b2 = cache_bucket_unload_free(cache);
b3 = cache_bucket_unload_cross(cache);
}
critical_exit();
ZONE_LOCK(zone);
if (b1 != NULL && b1->ub_cnt != 0) {
zone_put_bucket(zone, &zone->uz_domain[domain], b1, false);
b1 = NULL;
}
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (b2 != NULL && b2->ub_cnt != 0) {
zone_put_bucket(zone, &zone->uz_domain[domain], b2, false);
b2 = NULL;
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
}
ZONE_UNLOCK(zone);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
if (b1 != NULL)
When purging per-CPU UMA caches do not return empty buckets into the global full bucket cache to not trigger assertion if allocation happen before that global cache get purged.
2013-11-23 13:42:56 +00:00
bucket_free(zone, b1, NULL);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
if (b2 != NULL)
When purging per-CPU UMA caches do not return empty buckets into the global full bucket cache to not trigger assertion if allocation happen before that global cache get purged.
2013-11-23 13:42:56 +00:00
bucket_free(zone, b2, NULL);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
if (b3 != NULL) {
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
bucket_drain(zone, b3);
bucket_free(zone, b3, NULL);
}
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
}
/*
* Safely drain per-CPU caches of a zone(s) to alloc bucket.
* This is an expensive call because it needs to bind to all CPUs
* one by one and enter a critical section on each of them in order
* to safely access their cache buckets.
* Zone lock must not be held on call this function.
*/
static void
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
pcpu_cache_drain_safe(uma_zone_t zone)
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
{
int cpu;
/*
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
* Polite bucket sizes shrinking was not enough, shrink aggressively.
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
*/
if (zone)
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
cache_shrink(zone, NULL);
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
else
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_foreach(cache_shrink, NULL);
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
CPU_FOREACH(cpu) {
thread_lock(curthread);
sched_bind(curthread, cpu);
thread_unlock(curthread);
if (zone)
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
cache_drain_safe_cpu(zone, NULL);
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
else
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_foreach(cache_drain_safe_cpu, NULL);
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
}
thread_lock(curthread);
sched_unbind(curthread);
thread_unlock(curthread);
}
- Fix a problem where we did not drain the cache of buckets in the zone when uma_reclaim() was called. This was introduced when the zone working-set algorithm was removed in favor of using the per cpu caches as the working set.
2004-02-01 06:15:17 +00:00
/*
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
* Reclaim cached buckets from a zone. All buckets are reclaimed if the caller
* requested a drain, otherwise the per-domain caches are trimmed to either
* estimated working set size.
- Fix a problem where we did not drain the cache of buckets in the zone when uma_reclaim() was called. This was introduced when the zone working-set algorithm was removed in favor of using the per cpu caches as the working set.
2004-02-01 06:15:17 +00:00
*/
static void
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
bucket_cache_reclaim(uma_zone_t zone, bool drain)
- Fix a problem where we did not drain the cache of buckets in the zone when uma_reclaim() was called. This was introduced when the zone working-set algorithm was removed in favor of using the per cpu caches as the working set.
2004-02-01 06:15:17 +00:00
{
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_zone_domain_t zdom;
- Fix a problem where we did not drain the cache of buckets in the zone when uma_reclaim() was called. This was introduced when the zone working-set algorithm was removed in favor of using the per cpu caches as the working set.
2004-02-01 06:15:17 +00:00
uma_bucket_t bucket;
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
long target, tofree;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
int i;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
for (i = 0; i < vm_ndomains; i++) {
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
/*
* The cross bucket is partially filled and not part of
* the item count. Reclaim it individually here.
*/
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
zdom = &zone->uz_domain[i];
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
ZONE_CROSS_LOCK(zone);
bucket = zdom->uzd_cross;
zdom->uzd_cross = NULL;
ZONE_CROSS_UNLOCK(zone);
if (bucket != NULL) {
bucket_drain(zone, bucket);
bucket_free(zone, bucket, NULL);
}
/*
* Shrink the zone bucket size to ensure that the per-CPU caches
* don't grow too large.
*/
ZONE_LOCK(zone);
if (i == 0 && zone->uz_bucket_size > zone->uz_bucket_size_min)
zone->uz_bucket_size--;
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
/*
* If we were asked to drain the zone, we are done only once
* this bucket cache is empty. Otherwise, we reclaim items in
* excess of the zone's estimated working set size. If the
* difference nitems - imin is larger than the WSS estimate,
* then the estimate will grow at the end of this interval and
* we ignore the historical average.
*/
target = drain ? 0 : lmax(zdom->uzd_wss, zdom->uzd_nitems -
zdom->uzd_imin);
while (zdom->uzd_nitems > target) {
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
bucket = STAILQ_FIRST(&zdom->uzd_buckets);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
if (bucket == NULL)
break;
tofree = bucket->ub_cnt;
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zdom->uzd_nitems -= tofree;
Update the zone-global count of cached items in bucket_cache_reclaim(). This was missed in r351673. The count is used to enfore cache limits, which are rarely used. Discussed with: jeff Sponsored by: The FreeBSD Foundation
2020-02-13 23:15:21 +00:00
zone->uz_bkt_count -= tofree;
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
/*
* Shift the bounds of the current WSS interval to avoid
* perturbing the estimate.
*/
zdom->uzd_imax -= lmin(zdom->uzd_imax, tofree);
zdom->uzd_imin -= lmin(zdom->uzd_imin, tofree);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
ZONE_UNLOCK(zone);
bucket_drain(zone, bucket);
bucket_free(zone, bucket, NULL);
ZONE_LOCK(zone);
}
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
ZONE_UNLOCK(zone);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
static void
keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
{
uint8_t *mem;
int i;
uint8_t flags;
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
mem = slab_data(slab, keg);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
flags = slab->us_flags;
i = start;
if (keg->uk_fini != NULL) {
for (i--; i > -1; i--)
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
#ifdef INVARIANTS
/*
* trash_fini implies that dtor was trash_dtor. trash_fini
* would check that memory hasn't been modified since free,
* which executed trash_dtor.
* That's why we need to run uma_dbg_kskip() check here,
* albeit we don't make skip check for other init/fini
* invocations.
*/
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
keg->uk_fini != trash_fini)
#endif
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
zone_free_item(slabzone(keg->uk_ipers), slab_tohashslab(slab),
NULL, SKIP_NONE);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
uma_total_dec(PAGE_SIZE * keg->uk_ppera);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
/*
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* Frees pages from a keg back to the system. This is done on demand from
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* the pageout daemon.
*
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* Returns nothing.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
static void
keg_drain(uma_keg_t keg)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
struct slabhead freeslabs;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_domain_t dom;
Simplify keg_drain() a bit by using LIST_FOREACH_SAFE. MFC after: 1 week
2016-10-20 23:10:27 +00:00
uma_slab_t slab, tmp;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
int i, n;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
return;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
for (i = 0; i < vm_ndomains; i++) {
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
CTR4(KTR_UMA, "keg_drain %s(%p) domain %d free items: %u",
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
keg->uk_name, keg, i, dom->ud_free_items);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
dom = &keg->uk_domain[i];
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
LIST_INIT(&freeslabs);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK(keg, i);
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0) {
LIST_FOREACH(slab, &dom->ud_free_slab, us_link)
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
UMA_HASH_REMOVE(&keg->uk_hash, slab);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
}
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
n = dom->ud_free_slabs;
LIST_SWAP(&freeslabs, &dom->ud_free_slab, uma_slab, us_link);
dom->ud_free_slabs = 0;
dom->ud_free_items -= n * keg->uk_ipers;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
dom->ud_pages -= n * keg->uk_ppera;
KEG_UNLOCK(keg, i);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
LIST_FOREACH_SAFE(slab, &freeslabs, us_link, tmp)
keg_free_slab(keg, slab, keg->uk_ipers);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
}
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
static void
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zone_reclaim(uma_zone_t zone, int waitok, bool drain)
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
{
/*
* Set draining to interlock with zone_dtor() so we can release our
* locks as we go. Only dtor() should do a WAITOK call since it
* is the only call that knows the structure will still be available
* when it wakes up.
*/
ZONE_LOCK(zone);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
while (zone->uz_flags & UMA_ZFLAG_RECLAIMING) {
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
if (waitok == M_NOWAIT)
goto out;
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
msleep(zone, &zone->uz_lock, PVM, "zonedrain", 1);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zone->uz_flags |= UMA_ZFLAG_RECLAIMING;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
ZONE_UNLOCK(zone);
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
bucket_cache_reclaim(zone, drain);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
/*
* The DRAINING flag protects us from being freed while
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
* we're running. Normally the uma_rwlock would protect us but we
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* must be able to release and acquire the right lock for each keg.
*/
Include cache zones into zone_foreach() where appropriate. The r354367 is reverted since it is subsumed by this, more complete, approach. Suggested by: markj Reviewed by: alc. glebius, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22242
2019-11-10 09:25:19 +00:00
if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
keg_drain(zone->uz_keg);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
ZONE_LOCK(zone);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zone->uz_flags &= ~UMA_ZFLAG_RECLAIMING;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
wakeup(zone);
out:
ZONE_UNLOCK(zone);
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
static void
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_drain(uma_zone_t zone, void *unused)
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
{
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zone_reclaim(zone, M_NOWAIT, true);
}
static void
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_trim(uma_zone_t zone, void *unused)
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
{
zone_reclaim(zone, M_NOWAIT, false);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
* Allocate a new slab for a keg and inserts it into the partial slab list.
* The keg should be unlocked on entry. If the allocation succeeds it will
* be locked on return.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Arguments:
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
* flags Wait flags for the item initialization routine
* aflags Wait flags for the slab allocation
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Returns:
* The slab that was allocated or NULL if there is no memory and the
* caller specified M_NOWAIT.
*/
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
static uma_slab_t
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
int aflags)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uma_domain_t dom;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_alloc allocf;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_slab_t slab;
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
unsigned long size;
Convert UMA code to C99 uintXX_t types.
2013-04-09 17:43:48 +00:00
uint8_t *mem;
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
uint8_t sflags;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
int i;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
KASSERT(domain >= 0 && domain < vm_ndomains,
("keg_alloc_slab: domain %d out of range", domain));
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
allocf = keg->uk_allocf;
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
slab = NULL;
mem = NULL;
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
uma_hash_slab_t hslab;
hslab = zone_alloc_item(slabzone(keg->uk_ipers), NULL,
domain, aflags);
if (hslab == NULL)
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
goto fail;
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
slab = &hslab->uhs_slab;
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
}
- Remove bogus use of kmem_alloc that was inherited from the old zone allocator. - Properly set M_ZERO when talking to the back end page allocators for non malloc zones. This forces us to zero fill pages when they are first brought into a cache. - Properly handle M_ZERO in uma_zalloc_internal. This fixes a problem where per cpu buckets weren't always getting zeroed.
2002-06-19 20:49:44 +00:00
/*
* This reproduces the old vm_zone behavior of zero filling pages the
* first time they are added to a zone.
*
* Malloced items are zeroed in uma_zalloc.
*/
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
aflags |= M_ZERO;
- Remove bogus use of kmem_alloc that was inherited from the old zone allocator. - Properly set M_ZERO when talking to the back end page allocators for non malloc zones. This forces us to zero fill pages when they are first brought into a cache. - Properly handle M_ZERO in uma_zalloc_internal. This fixes a problem where per cpu buckets weren't always getting zeroed.
2002-06-19 20:49:44 +00:00
else
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
aflags &= ~M_ZERO;
- Remove bogus use of kmem_alloc that was inherited from the old zone allocator. - Properly set M_ZERO when talking to the back end page allocators for non malloc zones. This forces us to zero fill pages when they are first brought into a cache. - Properly handle M_ZERO in uma_zalloc_internal. This fixes a problem where per cpu buckets weren't always getting zeroed.
2002-06-19 20:49:44 +00:00
exclude kmem_alloc'ed ARC data buffers from kernel minidumps on amd64 excluding other allocations including UMA now entails the addition of a single flag to kmem_alloc or uma zone create Reviewed by: alc, avg MFC after: 2 weeks
2012-01-27 20:18:31 +00:00
if (keg->uk_flags & UMA_ZONE_NODUMP)
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
aflags |= M_NODUMP;
exclude kmem_alloc'ed ARC data buffers from kernel minidumps on amd64 excluding other allocations including UMA now entails the addition of a single flag to kmem_alloc or uma zone create Reviewed by: alc, avg MFC after: 2 weeks
2012-01-27 20:18:31 +00:00
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
/* zone is passed for legacy reasons. */
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
size = keg->uk_ppera * PAGE_SIZE;
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
mem = allocf(zone, size, domain, &sflags, aflags);
- Move the logic for dealing with the uma_boot_pages cache into the page_alloc() function from the slab_zalloc() function. This allows us to unconditionally call uz_allocf(). - In page_alloc() cleanup the boot_pages logic some. Previously memory from this cache that was not used by the time the system started was left in the cache and never used. Typically this wasn't more than a few pages, but now we will use this cache so long as memory is available.
2003-09-19 08:53:33 +00:00
if (mem == NULL) {
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
zone_free_item(slabzone(keg->uk_ipers),
slab_tohashslab(slab), NULL, SKIP_NONE);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
goto fail;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
uma_total_inc(size);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
/* For HASH zones all pages go to the same uma_domain. */
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
domain = 0;
Reduce the amount of code that runs with the zone lock held in slab_zalloc(). This allows us to run the zone initialization functions without any locks held.
2002-06-25 21:04:50 +00:00
/* Point the slab into the allocated memory */
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE))
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
slab = (uma_slab_t )(mem + keg->uk_pgoff);
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
else
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
slab_tohashslab(slab)->uhs_data = mem;
Reduce the amount of code that runs with the zone lock held in slab_zalloc(). This allows us to run the zone initialization functions without any locks held.
2002-06-25 21:04:50 +00:00
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (keg->uk_flags & UMA_ZFLAG_VTOSLAB)
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
for (i = 0; i < keg->uk_ppera; i++)
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
zone, slab);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
slab->us_freecount = keg->uk_ipers;
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
slab->us_flags = sflags;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
slab->us_domain = domain;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
BIT_FILL(keg->uk_ipers, &slab->us_free);
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
#ifdef INVARIANTS
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
#endif
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
if (keg->uk_init != NULL) {
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
for (i = 0; i < keg->uk_ipers; i++)
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
if (keg->uk_init(slab_item(slab, keg, i),
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
keg->uk_size, flags) != 0)
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
break;
if (i != keg->uk_ipers) {
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
keg_free_slab(keg, slab, i);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
goto fail;
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
}
}
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK(keg, domain);
Reduce the amount of code that runs with the zone lock held in slab_zalloc(). This allows us to run the zone initialization functions without any locks held.
2002-06-25 21:04:50 +00:00
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
slab, keg->uk_name, keg);
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (keg->uk_flags & UMA_ZFLAG_HASH)
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
/*
* If we got a slab here it's safe to mark it partially used
* and return. We assume that the caller is going to remove
* at least one item.
*/
dom = &keg->uk_domain[domain];
LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
dom->ud_pages += keg->uk_ppera;
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
dom->ud_free_items += keg->uk_ipers;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
return (slab);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
fail:
return (NULL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
- Fix MD_SMALL_ALLOC on architectures that support it. Define a new alloc function, startup_alloc(), that is used for single page allocations prior to the VM starting up. If it is used after the VM startups up, it replaces the zone's allocf pointer with either page_alloc() or uma_small_alloc() where appropriate. Pointy hat to: me Tested by: phk/amd64, me/x86
2003-09-21 07:39:16 +00:00
/*
* This function is intended to be used early on in place of page_alloc() so
* that we may use the boot time page cache to satisfy allocations before
* the VM is ready.
*/
static void *
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
- Fix MD_SMALL_ALLOC on architectures that support it. Define a new alloc function, startup_alloc(), that is used for single page allocations prior to the VM starting up. If it is used after the VM startups up, it replaces the zone's allocf pointer with either page_alloc() or uma_small_alloc() where appropriate. Pointy hat to: me Tested by: phk/amd64, me/x86
2003-09-21 07:39:16 +00:00
{
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
vm_paddr_t pa;
vm_page_t m;
Simplify boot pages management in UMA. It is simply a contigous virtual memory pointer and number of pages. There is no need to build a linked list here. Just increment pointer and decrement counter. The only functional difference to old allocator is that before we gave pages from topmost and down to lowest, and now we give them in normal ascending order. While here remove padalign from a mutex that is unused at runtime. Reviewed by: alc
2017-06-01 18:26:57 +00:00
void *mem;
int pages;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
int i;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Fix boot_pages exhaustion on machines with many domains and cores, where size of UMA zone allocation is greater than page size. In this case zone of zones can not use UMA_MD_SMALL_ALLOC, and we need to postpone switch off of this zone from startup_alloc() until full launch of VM. o Always supply number of VM zones to uma_startup_count(). On machines with UMA_MD_SMALL_ALLOC ignore it completely, unless zsize goes over a page. In the latter case account VM zones for number of allocations from the zone of zones. o Rewrite startup_alloc() so that it will immediately switch off from itself any zone that is already capable of running real alloc. In worst case scenario we may leak a single page here. See comment in uma_startup_count(). o Hardcode call to uma_startup2() into vm_mem_init(). Otherwise some extra SYSINITs, e.g. vm_page_init() may sneak in before. o While here, remove uma_boot_pages_mtx. With recent changes to boot pages calculation, we are guaranteed to use all of the boot_pages in the early single threaded stage. Reported & tested by: mav
2018-02-09 04:45:39 +00:00
pages = howmany(bytes, PAGE_SIZE);
KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
Fix boot_pages exhaustion on machines with many domains and cores, where size of UMA zone allocation is greater than page size. In this case zone of zones can not use UMA_MD_SMALL_ALLOC, and we need to postpone switch off of this zone from startup_alloc() until full launch of VM. o Always supply number of VM zones to uma_startup_count(). On machines with UMA_MD_SMALL_ALLOC ignore it completely, unless zsize goes over a page. In the latter case account VM zones for number of allocations from the zone of zones. o Rewrite startup_alloc() so that it will immediately switch off from itself any zone that is already capable of running real alloc. In worst case scenario we may leak a single page here. See comment in uma_startup_count(). o Hardcode call to uma_startup2() into vm_mem_init(). Otherwise some extra SYSINITs, e.g. vm_page_init() may sneak in before. o While here, remove uma_boot_pages_mtx. With recent changes to boot pages calculation, we are guaranteed to use all of the boot_pages in the early single threaded stage. Reported & tested by: mav
2018-02-09 04:45:39 +00:00
*pflag = UMA_SLAB_BOOT;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
m = vm_page_alloc_contig_domain(NULL, 0, domain,
malloc2vm_flags(wait) | VM_ALLOC_NOOBJ | VM_ALLOC_WIRED, pages,
(vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT);
if (m == NULL)
return (NULL);
pa = VM_PAGE_TO_PHYS(m);
for (i = 0; i < pages; i++, pa += PAGE_SIZE) {
#if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
defined(__riscv) || defined(__powerpc64__)
if ((wait & M_NODUMP) == 0)
dump_add_page(pa);
#endif
}
/* Allocate KVA and indirectly advance bootmem. */
mem = (void *)pmap_map(&bootmem, m->phys_addr,
m->phys_addr + (pages * PAGE_SIZE), VM_PROT_READ | VM_PROT_WRITE);
if ((wait & M_ZERO) != 0)
bzero(mem, pages * PAGE_SIZE);
return (mem);
}
Fix boot_pages exhaustion on machines with many domains and cores, where size of UMA zone allocation is greater than page size. In this case zone of zones can not use UMA_MD_SMALL_ALLOC, and we need to postpone switch off of this zone from startup_alloc() until full launch of VM. o Always supply number of VM zones to uma_startup_count(). On machines with UMA_MD_SMALL_ALLOC ignore it completely, unless zsize goes over a page. In the latter case account VM zones for number of allocations from the zone of zones. o Rewrite startup_alloc() so that it will immediately switch off from itself any zone that is already capable of running real alloc. In worst case scenario we may leak a single page here. See comment in uma_startup_count(). o Hardcode call to uma_startup2() into vm_mem_init(). Otherwise some extra SYSINITs, e.g. vm_page_init() may sneak in before. o While here, remove uma_boot_pages_mtx. With recent changes to boot pages calculation, we are guaranteed to use all of the boot_pages in the early single threaded stage. Reported & tested by: mav
2018-02-09 04:45:39 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
static void
startup_free(void *mem, vm_size_t bytes)
{
vm_offset_t va;
vm_page_t m;
va = (vm_offset_t)mem;
m = PHYS_TO_VM_PAGE(pmap_kextract(va));
pmap_remove(kernel_pmap, va, va + bytes);
for (; bytes != 0; bytes -= PAGE_SIZE, m++) {
#if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
defined(__riscv) || defined(__powerpc64__)
dump_drop_page(VM_PAGE_TO_PHYS(m));
#endif
vm_page_unwire_noq(m);
vm_page_free(m);
}
- Fix MD_SMALL_ALLOC on architectures that support it. Define a new alloc function, startup_alloc(), that is used for single page allocations prior to the VM starting up. If it is used after the VM startups up, it replaces the zone's allocf pointer with either page_alloc() or uma_small_alloc() where appropriate. Pointy hat to: me Tested by: phk/amd64, me/x86
2003-09-21 07:39:16 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Allocates a number of pages from the system
*
* Arguments:
* bytes The number of bytes requested
* wait Shall we wait?
*
* Returns:
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
* A pointer to the alloced memory or possibly
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* NULL if M_NOWAIT is set.
*/
static void *
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
void *p; /* Returned page */
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
*pflag = UMA_SLAB_KERNEL;
Add malloc_domainset(9) and _domainset variants to other allocator KPIs. Remove malloc_domain(9) and most other _domain KPIs added in r327900. The new functions allow the caller to specify a general NUMA domain selection policy, rather than specifically requesting an allocation from a specific domain. The latter policy tends to interact poorly with M_WAITOK, resulting in situations where a caller is blocked indefinitely because the specified domain is depleted. Most existing consumers of the _domain KPIs are converted to instead use a DOMAINSET_PREF() policy, in which we fall back to other domains to satisfy the allocation request. This change also defines a set of DOMAINSET_FIXED() policies, which only permit allocations from the specified domain. Discussed with: gallatin, jeff Reported and tested by: pho (previous version) MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17418
2018-10-30 18:26:34 +00:00
p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
return (p);
}
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
static void *
pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
struct pglist alloctail;
vm_offset_t addr, zkva;
int cpu, flags;
vm_page_t p, p_next;
#ifdef NUMA
struct pcpu *pc;
#endif
Fix pre-SI_SUB_CPU initialization of per-CPU counters. r336020 introduced pcpu_page_alloc(), replacing page_alloc() as the backend allocator for PCPU UMA zones. Unlike page_alloc(), it does not honour malloc(9) flags such as M_ZERO or M_NODUMP, so fix that. r336020 also changed counter(9) to initialize each counter using a CPU_FOREACH() loop instead of an SMP rendezvous. Before SI_SUB_CPU, smp_rendezvous() will only execute the callback on the current CPU (i.e., CPU 0), so only one counter gets zeroed. The rest are zeroed by virtue of the fact that UMA gratuitously zeroes slabs when importing them into a zone. Prior to SI_SUB_CPU, all_cpus is clear, so with r336020 we weren't zeroing vm_cnt counters during boot: the CPU_FOREACH() loop had no effect, and pcpu_page_alloc() didn't honour M_ZERO. Fix this by iterating over the full range of CPU IDs when zeroing counters, ignoring whether the corresponding bits in all_cpus are set. Reported and tested by: pho (previous version) Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D16190
2018-07-10 00:18:12 +00:00
MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
Fix pre-SI_SUB_CPU initialization of per-CPU counters. r336020 introduced pcpu_page_alloc(), replacing page_alloc() as the backend allocator for PCPU UMA zones. Unlike page_alloc(), it does not honour malloc(9) flags such as M_ZERO or M_NODUMP, so fix that. r336020 also changed counter(9) to initialize each counter using a CPU_FOREACH() loop instead of an SMP rendezvous. Before SI_SUB_CPU, smp_rendezvous() will only execute the callback on the current CPU (i.e., CPU 0), so only one counter gets zeroed. The rest are zeroed by virtue of the fact that UMA gratuitously zeroes slabs when importing them into a zone. Prior to SI_SUB_CPU, all_cpus is clear, so with r336020 we weren't zeroing vm_cnt counters during boot: the CPU_FOREACH() loop had no effect, and pcpu_page_alloc() didn't honour M_ZERO. Fix this by iterating over the full range of CPU IDs when zeroing counters, ignoring whether the corresponding bits in all_cpus are set. Reported and tested by: pho (previous version) Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D16190
2018-07-10 00:18:12 +00:00
TAILQ_INIT(&alloctail);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
Fix pre-SI_SUB_CPU initialization of per-CPU counters. r336020 introduced pcpu_page_alloc(), replacing page_alloc() as the backend allocator for PCPU UMA zones. Unlike page_alloc(), it does not honour malloc(9) flags such as M_ZERO or M_NODUMP, so fix that. r336020 also changed counter(9) to initialize each counter using a CPU_FOREACH() loop instead of an SMP rendezvous. Before SI_SUB_CPU, smp_rendezvous() will only execute the callback on the current CPU (i.e., CPU 0), so only one counter gets zeroed. The rest are zeroed by virtue of the fact that UMA gratuitously zeroes slabs when importing them into a zone. Prior to SI_SUB_CPU, all_cpus is clear, so with r336020 we weren't zeroing vm_cnt counters during boot: the CPU_FOREACH() loop had no effect, and pcpu_page_alloc() didn't honour M_ZERO. Fix this by iterating over the full range of CPU IDs when zeroing counters, ignoring whether the corresponding bits in all_cpus are set. Reported and tested by: pho (previous version) Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D16190
2018-07-10 00:18:12 +00:00
malloc2vm_flags(wait);
*pflag = UMA_SLAB_KERNEL;
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
for (cpu = 0; cpu <= mp_maxid; cpu++) {
if (CPU_ABSENT(cpu)) {
p = vm_page_alloc(NULL, 0, flags);
} else {
#ifndef NUMA
p = vm_page_alloc(NULL, 0, flags);
#else
pc = pcpu_find(cpu);
pcpu_page_alloc: guard against empty NUMA domains Some systems, such as higher end Threadripper, may have NUMA domains with no physical memory, Don't allocate from these domains. This fixes a "panic: vm_wait in early boot" on my 2990WX desktop Reviewed by: jeff Sponsored by: Netflix
2020-01-18 18:25:37 +00:00
if (__predict_false(VM_DOMAIN_EMPTY(pc->pc_domain)))
p = NULL;
else
p = vm_page_alloc_domain(NULL, 0,
pc->pc_domain, flags);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
if (__predict_false(p == NULL))
p = vm_page_alloc(NULL, 0, flags);
#endif
}
if (__predict_false(p == NULL))
goto fail;
TAILQ_INSERT_TAIL(&alloctail, p, listq);
}
if ((addr = kva_alloc(bytes)) == 0)
goto fail;
zkva = addr;
TAILQ_FOREACH(p, &alloctail, listq) {
pmap_qenter(zkva, &p, 1);
zkva += PAGE_SIZE;
}
return ((void*)addr);
Replace uses of vm_page_unwire(m, PQ_NONE) with vm_page_unwire_noq(m). These calls are not the same in general: the former will dequeue the page if it is enqueued, while the latter will just leave it alone. But, all existing uses of the former apply to unmanaged pages, which are never enqueued in the first place. No functional change intended. Reviewed by: kib MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20470
2019-06-07 18:23:29 +00:00
fail:
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
Replace uses of vm_page_unwire(m, PQ_NONE) with vm_page_unwire_noq(m). These calls are not the same in general: the former will dequeue the page if it is enqueued, while the latter will just leave it alone. But, all existing uses of the former apply to unmanaged pages, which are never enqueued in the first place. No functional change intended. Reviewed by: kib MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20470
2019-06-07 18:23:29 +00:00
vm_page_unwire_noq(p);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
vm_page_free(p);
}
return (NULL);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Allocates a number of pages from within an object
*
* Arguments:
* bytes The number of bytes requested
* wait Shall we wait?
*
* Returns:
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
* A pointer to the alloced memory or possibly
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* NULL if M_NOWAIT is set.
*/
static void *
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
int wait)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
TAILQ_HEAD(, vm_page) alloctail;
u_long npages;
Revise obj_alloc(). Most notably, use the object's lock to prevent two concurrent invocations from acquiring the same address(es). Also, in case of an incomplete allocation, free any allocated pages. In collaboration with: tegge
2003-08-03 06:08:48 +00:00
vm_offset_t retkva, zkva;
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
vm_page_t p, p_next;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_keg_t keg;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
TAILQ_INIT(&alloctail);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
keg = zone->uz_keg;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
npages = howmany(bytes, PAGE_SIZE);
while (npages > 0) {
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
p = vm_page_alloc_domain(NULL, 0, domain, VM_ALLOC_INTERRUPT |
Replace manyinstances of VM_WAIT with blocking page allocation flags similar to the kernel memory allocator. This simplifies NUMA allocation because the domain will be known at wait time and races between failure and sleeping are eliminated. This also reduces boilerplate code and simplifies callers. A wait primitive is supplied for uma zones for similar reasons. This eliminates some non-specific VM_WAIT calls in favor of more explicit sleeps that may be satisfied without new pages. Reviewed by: alc, kib, markj Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2017-11-08 02:39:37 +00:00
VM_ALLOC_WIRED | VM_ALLOC_NOOBJ |
Fix operator priority. Sponsored by: The FreeBSD Foundation
2017-11-08 23:25:05 +00:00
((wait & M_WAITOK) != 0 ? VM_ALLOC_WAITOK :
VM_ALLOC_NOWAIT));
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
if (p != NULL) {
/*
* Since the page does not belong to an object, its
* listq is unused.
*/
TAILQ_INSERT_TAIL(&alloctail, p, listq);
npages--;
continue;
}
/*
* Page allocation failed, free intermediate pages and
* exit.
*/
TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
Replace uses of vm_page_unwire(m, PQ_NONE) with vm_page_unwire_noq(m). These calls are not the same in general: the former will dequeue the page if it is enqueued, while the latter will just leave it alone. But, all existing uses of the former apply to unmanaged pages, which are never enqueued in the first place. No functional change intended. Reviewed by: kib MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20470
2019-06-07 18:23:29 +00:00
vm_page_unwire_noq(p);
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
vm_page_free(p);
}
return (NULL);
}
*flags = UMA_SLAB_PRIV;
zkva = keg->uk_kva +
atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
retkva = zkva;
TAILQ_FOREACH(p, &alloctail, listq) {
Revise obj_alloc(). Most notably, use the object's lock to prevent two concurrent invocations from acquiring the same address(es). Also, in case of an incomplete allocation, free any allocated pages. In collaboration with: tegge
2003-08-03 06:08:48 +00:00
pmap_qenter(zkva, &p, 1);
zkva += PAGE_SIZE;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
return ((void *)retkva);
}
uma: add UMA_ZONE_CONTIG, and a default contig_alloc For now, copy the mbuf allocator. Reviewed by: jeff, markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23237
2020-02-04 22:40:11 +00:00
/*
* Allocate physically contiguous pages.
*/
static void *
contig_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
*pflag = UMA_SLAB_KERNEL;
return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
bytes, wait, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Frees a number of pages to the system
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
*
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
* Arguments:
* mem A pointer to the memory to be freed
* size The size of the memory being freed
* flags The original p->us_flags field
*
* Returns:
* Nothing
*/
static void
Fix integer truncation bug in malloc(9) A couple of internal functions used by malloc(9) and uma truncated a size_t down to an int. This could cause any number of issues (e.g. indefinite sleeps, memory corruption) if any kernel subsystem tried to allocate 2GB or more through malloc. zfs would attempt such an allocation when run on a system with 2TB or more of RAM. Note to self: When this is MFCed, sparc64 needs the same fix. Differential revision: https://reviews.freebsd.org/D2106 Reviewed by: kib Reported by: Michael Fuckner <michael@fuckner.net> Tested by: Michael Fuckner <michael@fuckner.net> MFC after: 2 weeks
2015-04-01 12:42:26 +00:00
page_free(void *mem, vm_size_t size, uint8_t flags)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
- Remove bogus use of kmem_alloc that was inherited from the old zone allocator. - Properly set M_ZERO when talking to the back end page allocators for non malloc zones. This forces us to zero fill pages when they are first brought into a cache. - Properly handle M_ZERO in uma_zalloc_internal. This fixes a problem where per cpu buckets weren't always getting zeroed.
2002-06-19 20:49:44 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
if ((flags & UMA_SLAB_BOOT) != 0) {
startup_free(mem, size);
return;
}
uma: add UMA_ZONE_CONTIG, and a default contig_alloc For now, copy the mbuf allocator. Reviewed by: jeff, markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23237
2020-02-04 22:40:11 +00:00
KASSERT((flags & UMA_SLAB_KERNEL) != 0,
("UMA: page_free used with invalid flags %x", flags));
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Eliminate the arena parameter to kmem_free(). Implicitly this corrects an error in the function hypercall_memfree(), where the wrong arena was being passed to kmem_free(). Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are mapped in kmem with execute permissions. Use this flag to determine which arena the kmem virtual addresses are returned to. Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it redundant. Update the nearby comment for UMA_SLAB_KERNEL. Reviewed by: kib, markj Discussed with: jeff Approved by: re (marius) Differential Revision: https://reviews.freebsd.org/D16845
2018-08-25 19:38:08 +00:00
kmem_free((vm_offset_t)mem, size);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
/*
* Frees pcpu zone allocations
*
* Arguments:
* mem A pointer to the memory to be freed
* size The size of the memory being freed
* flags The original p->us_flags field
*
* Returns:
* Nothing
*/
static void
pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
{
vm_offset_t sva, curva;
vm_paddr_t paddr;
vm_page_t m;
MPASS(size == (mp_maxid+1)*PAGE_SIZE);
uma: pcpu_page_free needs to startup_free pages from startup_alloc After r357392, it is apparent that we do have some early-boot PCPU zones. Make it so we can safely free pages from them if they are actually used during early boot. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23496
2020-02-04 22:39:58 +00:00
if ((flags & UMA_SLAB_BOOT) != 0) {
startup_free(mem, size);
return;
}
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
sva = (vm_offset_t)mem;
for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
paddr = pmap_kextract(curva);
m = PHYS_TO_VM_PAGE(paddr);
Replace uses of vm_page_unwire(m, PQ_NONE) with vm_page_unwire_noq(m). These calls are not the same in general: the former will dequeue the page if it is enqueued, while the latter will just leave it alone. But, all existing uses of the former apply to unmanaged pages, which are never enqueued in the first place. No functional change intended. Reviewed by: kib MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20470
2019-06-07 18:23:29 +00:00
vm_page_unwire_noq(m);
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
vm_page_free(m);
}
pmap_qremove(sva, size >> PAGE_SHIFT);
kva_free(sva, size);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Zero fill initializer
*
* Arguments/Returns follow uma_init specifications
*/
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
static int
zero_init(void *mem, int size, int flags)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
bzero(mem, size);
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
return (0);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
#ifdef INVARIANTS
struct noslabbits *
slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
{
return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
}
#endif
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
/*
* Actual size of embedded struct slab (!OFFPAGE).
*/
size_t
slab_sizeof(int nitems)
{
size_t s;
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
return (roundup(s, UMA_ALIGN_PTR + 1));
}
/*
* Size of memory for embedded slabs (!OFFPAGE).
*/
size_t
slab_space(int nitems)
{
return (UMA_SLAB_SIZE - slab_sizeof(nitems));
}
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
#define UMA_FIXPT_SHIFT 31
#define UMA_FRAC_FIXPT(n, d) \
((uint32_t)(((uint64_t)(n) << UMA_FIXPT_SHIFT) / (d)))
#define UMA_FIXPT_PCT(f) \
((u_int)(((uint64_t)100 * (f)) >> UMA_FIXPT_SHIFT))
#define UMA_PCT_FIXPT(pct) UMA_FRAC_FIXPT((pct), 100)
#define UMA_MIN_EFF UMA_PCT_FIXPT(100 - UMA_MAX_WASTE)
/*
* Compute the number of items that will fit in a slab. If hdr is true, the
* item count may be limited to provide space in the slab for an inline slab
* header. Otherwise, all slab space will be provided for item storage.
*/
static u_int
slab_ipers_hdr(u_int size, u_int rsize, u_int slabsize, bool hdr)
{
u_int ipers;
u_int padpi;
/* The padding between items is not needed after the last item. */
padpi = rsize - size;
if (hdr) {
/*
* Start with the maximum item count and remove items until
* the slab header first alongside the allocatable memory.
*/
for (ipers = MIN(SLAB_MAX_SETSIZE,
(slabsize + padpi - slab_sizeof(1)) / rsize);
ipers > 0 &&
ipers * rsize - padpi + slab_sizeof(ipers) > slabsize;
ipers--)
continue;
} else {
ipers = MIN((slabsize + padpi) / rsize, SLAB_MAX_SETSIZE);
}
return (ipers);
}
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
/*
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
* Compute the number of items that will fit in a slab for a startup zone.
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
*/
int
slab_ipers(size_t size, int align)
{
int rsize;
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
rsize = roundup(size, align + 1); /* Assume no CACHESPREAD */
return (slab_ipers_hdr(size, rsize, UMA_SLAB_SIZE, true));
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
}
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
struct keg_layout_result {
u_int format;
u_int slabsize;
u_int ipers;
u_int eff;
};
static void
keg_layout_one(uma_keg_t keg, u_int rsize, u_int slabsize, u_int fmt,
struct keg_layout_result *kl)
{
u_int total;
kl->format = fmt;
kl->slabsize = slabsize;
/* Handle INTERNAL as inline with an extra page. */
if ((fmt & UMA_ZFLAG_INTERNAL) != 0) {
kl->format &= ~UMA_ZFLAG_INTERNAL;
kl->slabsize += PAGE_SIZE;
}
kl->ipers = slab_ipers_hdr(keg->uk_size, rsize, kl->slabsize,
(fmt & UMA_ZFLAG_OFFPAGE) == 0);
/* Account for memory used by an offpage slab header. */
total = kl->slabsize;
if ((fmt & UMA_ZFLAG_OFFPAGE) != 0)
total += slabzone(kl->ipers)->uz_keg->uk_rsize;
kl->eff = UMA_FRAC_FIXPT(kl->ipers * rsize, total);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
* Determine the format of a uma keg. This determines where the slab header
* will be placed (inline or offpage) and calculates ipers, rsize, and ppera.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Arguments
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
* keg The zone we should initialize
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Returns
* Nothing
*/
static void
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
keg_layout(uma_keg_t keg)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
struct keg_layout_result kl = {}, kl_tmp;
u_int fmts[2];
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
u_int alignsize;
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
u_int nfmt;
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
u_int pages;
Rework the way slab header storage space is calculated in UMA. - zone_large_init() stays pretty much the same. - zone_small_init() will try to stash the slab header in the slab page being allocated if the amount of calculated wasted space is less than UMA_MAX_WASTE (for both the UMA_ZONE_REFCNT case and regular case). If the amount of wasted space is >= UMA_MAX_WASTE, then UMA_ZONE_OFFPAGE will be set and the slab header will be allocated separately for better use of space. - uma_startup() calculates the maximum ipers required in offpage slabs (so that the offpage slab header zone(s) can be sized accordingly). The algorithm used to calculate this replaces the old calculation (which only happened to work coincidentally). We now iterate over possible object sizes, starting from the smallest one, until we determine that wastedspace calculated in zone_small_init() might end up being greater than UMA_MAX_WASTE, at which point we use the found object size to compute the maximum possible ipers. The reason this works is because: - wastedspace versus objectsize is a see-saw function with local minima all equal to zero and local maxima growing directly proportioned to objectsize. This implies that for objects up to or equal a certain objectsize, the see-saw remains entirely below UMA_MAX_WASTE, so for those objectsizes it is impossible to ever go OFFPAGE for slab headers. - ipers (items-per-slab) versus objectsize is an inversely proportional function which falls off very quickly (very large for small objectsizes). - To determine the maximum ipers we'll ever need from OFFPAGE slab headers we first find the largest objectsize for which we are guaranteed to not go offpage for and use it to compute ipers (as though we were offpage). Since the only objectsizes allowed to go offpage are bigger than the found objectsize, and since ipers vs objectsize is inversely proportional (and monotonically decreasing), then we are guaranteed that the ipers computed is always >= what we will ever need in offpage slab headers. - Define UMA_FRITM_SZ and UMA_FRITMREF_SZ to be the actual (possibly padded) size of each freelist index so that offset calculations are fixed. This might fix weird data corruption problems and certainly allows ARM to now boot to at least single-user (via simulator). Tested on i386 UP by me. Tested on sparc64 SMP by fenner. Tested on ARM simulator to single-user by cognet.
2004-07-29 15:25:40 +00:00
u_int rsize;
uma: eliminate uk_slabsize field The field was not used beyond the initial keg setup stage anyway. MFC after: 1 month (if ever)
2017-03-11 16:35:36 +00:00
u_int slabsize;
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
u_int i, j;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
(keg->uk_size <= UMA_PCPU_ALLOC_SIZE &&
(keg->uk_flags & UMA_ZONE_CACHESPREAD) == 0),
("%s: cannot configure for PCPU: keg=%s, size=%u, flags=0x%b",
__func__, keg->uk_name, keg->uk_size, keg->uk_flags,
PRINT_UMA_ZFLAGS));
uma: remove UMA_ZFLAG_CACHEONLY flag UMA_ZFLAG_CACHEONLY was essentially the same thing as UMA_ZONE_VM, but with a more confusing name. Remove the flag, make UMA_ZONE_VM an inherit flag, and replace all references. Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23516
2020-02-06 08:32:25 +00:00
KASSERT((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) == 0 ||
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
(keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0,
("%s: incompatible flags 0x%b", __func__, keg->uk_flags,
PRINT_UMA_ZFLAGS));
Revert r249590 and in case if mp_ncpus isn't initialized use MAXCPU. This allows us to init counter zone at early stage of boot. Reviewed by: kib Tested by: Lytochkin Boris <lytboris gmail.com>
2013-07-23 11:16:40 +00:00
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
alignsize = keg->uk_align + 1;
Merge from projects/counters: UMA_ZONE_PCPU zones. These zones have slab size == sizeof(struct pcpu), but request from VM enough pages to fit (uk_slabsize * mp_ncpus). An item allocated from such zone would have a separate twin for each CPU in the system, and these twins are at a distance of sizeof(struct pcpu) from each other. This magic value of distance would allow us to make some optimizations later. To address private item from a CPU simple arithmetics should be used: item = (type *)((char *)base + sizeof(struct pcpu) * curcpu) These arithmetics are available as zpcpu_get() macro in pcpu.h. To introduce non-page size slabs a new field had been added to uma_keg uk_slabsize. This shifted some frequently used fields of uma_keg to the fourth cache line on amd64. To mitigate this pessimization, uma_keg fields were a bit rearranged and least frequently used uk_name and uk_link moved down to the fourth cache line. All other fields, that are dereferenced frequently fit into first three cache lines. Sponsored by: Nginx, Inc.
2013-04-08 19:10:45 +00:00
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
/*
* Calculate the size of each allocation (rsize) according to
* alignment. If the requested size is smaller than we have
* allocation bits for we round it up.
*/
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
rsize = MAX(keg->uk_size, UMA_SMALLEST_UNIT);
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
rsize = roundup2(rsize, alignsize);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
if ((keg->uk_flags & UMA_ZONE_CACHESPREAD) != 0) {
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
/*
* We want one item to start on every align boundary in a page.
* To do this we will span pages. We will also extend the item
* by the size of align if it is an even multiple of align.
* Otherwise, it would fall on the same boundary every time.
*/
if ((rsize & alignsize) == 0)
rsize += alignsize;
slabsize = rsize * (PAGE_SIZE / alignsize);
slabsize = MIN(slabsize, rsize * SLAB_MAX_SETSIZE);
slabsize = MIN(slabsize, UMA_CACHESPREAD_MAX_SIZE);
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
slabsize = round_page(slabsize);
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
} else {
/*
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
* Start with a slab size of as many pages as it takes to
* represent a single item. We will try to fit as many
* additional items into the slab as possible.
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
*/
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
slabsize = round_page(keg->uk_size);
Handle a special case when a slab can fit only one allocation, and zone has a large alignment. With alignment taken into account uk_rsize will be greater than space in a slab. However, since we have only one item per slab, it is always naturally aligned. Code that will panic before this change with 4k page: z = uma_zcreate("test", 3984, NULL, NULL, NULL, NULL, 31, 0); uma_zalloc(z, M_WAITOK); A practical scenario to hit the panic is a machine with 56 CPUs and 2 NUMA domains, which yields in zone size of 3984. PR: 227116 MFC after: 2 weeks
2018-04-02 05:11:59 +00:00
}
Merge from projects/counters: UMA_ZONE_PCPU zones. These zones have slab size == sizeof(struct pcpu), but request from VM enough pages to fit (uk_slabsize * mp_ncpus). An item allocated from such zone would have a separate twin for each CPU in the system, and these twins are at a distance of sizeof(struct pcpu) from each other. This magic value of distance would allow us to make some optimizations later. To address private item from a CPU simple arithmetics should be used: item = (type *)((char *)base + sizeof(struct pcpu) * curcpu) These arithmetics are available as zpcpu_get() macro in pcpu.h. To introduce non-page size slabs a new field had been added to uma_keg uk_slabsize. This shifted some frequently used fields of uma_keg to the fourth cache line on amd64. To mitigate this pessimization, uma_keg fields were a bit rearranged and least frequently used uk_name and uk_link moved down to the fourth cache line. All other fields, that are dereferenced frequently fit into first three cache lines. Sponsored by: Nginx, Inc.
2013-04-08 19:10:45 +00:00
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
/* Build a list of all of the available formats for this keg. */
nfmt = 0;
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
/* Evaluate an inline slab layout. */
if ((keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0)
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
fmts[nfmt++] = 0;
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
/* TODO: vm_page-embedded slab. */
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Rework the way slab header storage space is calculated in UMA. - zone_large_init() stays pretty much the same. - zone_small_init() will try to stash the slab header in the slab page being allocated if the amount of calculated wasted space is less than UMA_MAX_WASTE (for both the UMA_ZONE_REFCNT case and regular case). If the amount of wasted space is >= UMA_MAX_WASTE, then UMA_ZONE_OFFPAGE will be set and the slab header will be allocated separately for better use of space. - uma_startup() calculates the maximum ipers required in offpage slabs (so that the offpage slab header zone(s) can be sized accordingly). The algorithm used to calculate this replaces the old calculation (which only happened to work coincidentally). We now iterate over possible object sizes, starting from the smallest one, until we determine that wastedspace calculated in zone_small_init() might end up being greater than UMA_MAX_WASTE, at which point we use the found object size to compute the maximum possible ipers. The reason this works is because: - wastedspace versus objectsize is a see-saw function with local minima all equal to zero and local maxima growing directly proportioned to objectsize. This implies that for objects up to or equal a certain objectsize, the see-saw remains entirely below UMA_MAX_WASTE, so for those objectsizes it is impossible to ever go OFFPAGE for slab headers. - ipers (items-per-slab) versus objectsize is an inversely proportional function which falls off very quickly (very large for small objectsizes). - To determine the maximum ipers we'll ever need from OFFPAGE slab headers we first find the largest objectsize for which we are guaranteed to not go offpage for and use it to compute ipers (as though we were offpage). Since the only objectsizes allowed to go offpage are bigger than the found objectsize, and since ipers vs objectsize is inversely proportional (and monotonically decreasing), then we are guaranteed that the ipers computed is always >= what we will ever need in offpage slab headers. - Define UMA_FRITM_SZ and UMA_FRITMREF_SZ to be the actual (possibly padded) size of each freelist index so that offset calculations are fixed. This might fix weird data corruption problems and certainly allows ARM to now boot to at least single-user (via simulator). Tested on i386 UP by me. Tested on sparc64 SMP by fenner. Tested on ARM simulator to single-user by cognet.
2004-07-29 15:25:40 +00:00
/*
* We can't do OFFPAGE if we're internal or if we've been
* asked to not go to the VM for buckets. If we do this we
uma: remove UMA_ZFLAG_CACHEONLY flag UMA_ZFLAG_CACHEONLY was essentially the same thing as UMA_ZONE_VM, but with a more confusing name. Remove the flag, make UMA_ZONE_VM an inherit flag, and replace all references. Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23516
2020-02-06 08:32:25 +00:00
* may end up going to the VM for slabs which we do not want
* to do if we're UMA_ZONE_VM, which clearly forbids it.
* In those cases, evaluate a pseudo-format called INTERNAL
* which has an inline slab header and one extra page to
* guarantee that it fits.
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
*
* Otherwise, see if using an OFFPAGE slab will improve our
* efficiency.
Rework the way slab header storage space is calculated in UMA. - zone_large_init() stays pretty much the same. - zone_small_init() will try to stash the slab header in the slab page being allocated if the amount of calculated wasted space is less than UMA_MAX_WASTE (for both the UMA_ZONE_REFCNT case and regular case). If the amount of wasted space is >= UMA_MAX_WASTE, then UMA_ZONE_OFFPAGE will be set and the slab header will be allocated separately for better use of space. - uma_startup() calculates the maximum ipers required in offpage slabs (so that the offpage slab header zone(s) can be sized accordingly). The algorithm used to calculate this replaces the old calculation (which only happened to work coincidentally). We now iterate over possible object sizes, starting from the smallest one, until we determine that wastedspace calculated in zone_small_init() might end up being greater than UMA_MAX_WASTE, at which point we use the found object size to compute the maximum possible ipers. The reason this works is because: - wastedspace versus objectsize is a see-saw function with local minima all equal to zero and local maxima growing directly proportioned to objectsize. This implies that for objects up to or equal a certain objectsize, the see-saw remains entirely below UMA_MAX_WASTE, so for those objectsizes it is impossible to ever go OFFPAGE for slab headers. - ipers (items-per-slab) versus objectsize is an inversely proportional function which falls off very quickly (very large for small objectsizes). - To determine the maximum ipers we'll ever need from OFFPAGE slab headers we first find the largest objectsize for which we are guaranteed to not go offpage for and use it to compute ipers (as though we were offpage). Since the only objectsizes allowed to go offpage are bigger than the found objectsize, and since ipers vs objectsize is inversely proportional (and monotonically decreasing), then we are guaranteed that the ipers computed is always >= what we will ever need in offpage slab headers. - Define UMA_FRITM_SZ and UMA_FRITMREF_SZ to be the actual (possibly padded) size of each freelist index so that offset calculations are fixed. This might fix weird data corruption problems and certainly allows ARM to now boot to at least single-user (via simulator). Tested on i386 UP by me. Tested on sparc64 SMP by fenner. Tested on ARM simulator to single-user by cognet.
2004-07-29 15:25:40 +00:00
*/
uma: remove UMA_ZFLAG_CACHEONLY flag UMA_ZFLAG_CACHEONLY was essentially the same thing as UMA_ZONE_VM, but with a more confusing name. Remove the flag, make UMA_ZONE_VM an inherit flag, and replace all references. Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23516
2020-02-06 08:32:25 +00:00
if ((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) != 0)
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
fmts[nfmt++] = UMA_ZFLAG_INTERNAL;
else
fmts[nfmt++] = UMA_ZFLAG_OFFPAGE;
Rework the way slab header storage space is calculated in UMA. - zone_large_init() stays pretty much the same. - zone_small_init() will try to stash the slab header in the slab page being allocated if the amount of calculated wasted space is less than UMA_MAX_WASTE (for both the UMA_ZONE_REFCNT case and regular case). If the amount of wasted space is >= UMA_MAX_WASTE, then UMA_ZONE_OFFPAGE will be set and the slab header will be allocated separately for better use of space. - uma_startup() calculates the maximum ipers required in offpage slabs (so that the offpage slab header zone(s) can be sized accordingly). The algorithm used to calculate this replaces the old calculation (which only happened to work coincidentally). We now iterate over possible object sizes, starting from the smallest one, until we determine that wastedspace calculated in zone_small_init() might end up being greater than UMA_MAX_WASTE, at which point we use the found object size to compute the maximum possible ipers. The reason this works is because: - wastedspace versus objectsize is a see-saw function with local minima all equal to zero and local maxima growing directly proportioned to objectsize. This implies that for objects up to or equal a certain objectsize, the see-saw remains entirely below UMA_MAX_WASTE, so for those objectsizes it is impossible to ever go OFFPAGE for slab headers. - ipers (items-per-slab) versus objectsize is an inversely proportional function which falls off very quickly (very large for small objectsizes). - To determine the maximum ipers we'll ever need from OFFPAGE slab headers we first find the largest objectsize for which we are guaranteed to not go offpage for and use it to compute ipers (as though we were offpage). Since the only objectsizes allowed to go offpage are bigger than the found objectsize, and since ipers vs objectsize is inversely proportional (and monotonically decreasing), then we are guaranteed that the ipers computed is always >= what we will ever need in offpage slab headers. - Define UMA_FRITM_SZ and UMA_FRITMREF_SZ to be the actual (possibly padded) size of each freelist index so that offset calculations are fixed. This might fix weird data corruption problems and certainly allows ARM to now boot to at least single-user (via simulator). Tested on i386 UP by me. Tested on sparc64 SMP by fenner. Tested on ARM simulator to single-user by cognet.
2004-07-29 15:25:40 +00:00
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
/*
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
* Choose a slab size and format which satisfy the minimum efficiency.
* Prefer the smallest slab size that meets the constraints.
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
*
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
* Start with a minimum slab size, to accommodate CACHESPREAD. Then,
* for small items (up to PAGE_SIZE), the iteration increment is one
* page; and for large items, the increment is one item.
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
*/
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
i = (slabsize + rsize - keg->uk_size) / MAX(PAGE_SIZE, rsize);
KASSERT(i >= 1, ("keg %s(%p) flags=0x%b slabsize=%u, rsize=%u, i=%u",
keg->uk_name, keg, keg->uk_flags, PRINT_UMA_ZFLAGS, slabsize,
rsize, i));
for ( ; ; i++) {
slabsize = (rsize <= PAGE_SIZE) ? ptoa(i) :
round_page(rsize * (i - 1) + keg->uk_size);
for (j = 0; j < nfmt; j++) {
/* Only if we have no viable format yet. */
if ((fmts[j] & UMA_ZFLAG_INTERNAL) != 0 &&
kl.ipers > 0)
continue;
keg_layout_one(keg, rsize, slabsize, fmts[j], &kl_tmp);
if (kl_tmp.eff <= kl.eff)
continue;
kl = kl_tmp;
CTR6(KTR_UMA, "keg %s layout: format %#x "
"(ipers %u * rsize %u) / slabsize %#x = %u%% eff",
keg->uk_name, kl.format, kl.ipers, rsize,
kl.slabsize, UMA_FIXPT_PCT(kl.eff));
/* Stop when we reach the minimum efficiency. */
if (kl.eff >= UMA_MIN_EFF)
break;
}
uma: multipage chicken switch Add a switch to allow disabling multipage slabs, in order to facilitate measuring memory usage and performance effects. The tunable vm.debug.uma_multipage_slabs defaults to 1 and can be set to 0 to disable. The name may change soon. Reviewed by: markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23487
2020-02-04 22:40:45 +00:00
if (kl.eff >= UMA_MIN_EFF || !multipage_slabs ||
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
slabsize >= SLAB_MAX_SETSIZE * rsize ||
(keg->uk_flags & (UMA_ZONE_PCPU | UMA_ZONE_CONTIG)) != 0)
break;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Merge from projects/counters: UMA_ZONE_PCPU zones. These zones have slab size == sizeof(struct pcpu), but request from VM enough pages to fit (uk_slabsize * mp_ncpus). An item allocated from such zone would have a separate twin for each CPU in the system, and these twins are at a distance of sizeof(struct pcpu) from each other. This magic value of distance would allow us to make some optimizations later. To address private item from a CPU simple arithmetics should be used: item = (type *)((char *)base + sizeof(struct pcpu) * curcpu) These arithmetics are available as zpcpu_get() macro in pcpu.h. To introduce non-page size slabs a new field had been added to uma_keg uk_slabsize. This shifted some frequently used fields of uma_keg to the fourth cache line on amd64. To mitigate this pessimization, uma_keg fields were a bit rearranged and least frequently used uk_name and uk_link moved down to the fourth cache line. All other fields, that are dereferenced frequently fit into first three cache lines. Sponsored by: Nginx, Inc.
2013-04-08 19:10:45 +00:00
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
pages = atop(kl.slabsize);
if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
pages *= mp_maxid + 1;
keg->uk_rsize = rsize;
keg->uk_ipers = kl.ipers;
keg->uk_ppera = pages;
keg->uk_flags |= kl.format;
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
/*
* How do we find the slab header if it is offpage or if not all item
* start addresses are in the same page? We could solve the latter
* case with vaddr alignment, but we don't.
*/
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0 ||
(keg->uk_ipers - 1) * rsize >= PAGE_SIZE) {
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((keg->uk_flags & UMA_ZONE_NOTPAGE) != 0)
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
keg->uk_flags |= UMA_ZFLAG_HASH;
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
else
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
}
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
uma: fixup some ktr messages Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23148
2020-01-14 02:13:46 +00:00
CTR6(KTR_UMA, "%s: keg=%s, flags=%#x, rsize=%u, ipers=%u, ppera=%u",
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
__func__, keg->uk_name, keg->uk_flags, rsize, keg->uk_ipers,
pages);
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
("%s: keg=%s, flags=0x%b, rsize=%u, ipers=%u, ppera=%u", __func__,
uma: grow slabs to enforce minimum memory efficiency Memory efficiency can be poor with awkward item sizes (e.g. 1/2 or 1 page size + epsilon). In order to achieve a minimum memory efficiency, select a slab size with a potentially larger number of pages if it yields a lower portion of waste. This may mean using page_alloc instead of uma_small_alloc, which could be more costly. Discussed with: jeff, mckusick Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23239
2020-02-04 22:40:34 +00:00
keg->uk_name, keg->uk_flags, PRINT_UMA_ZFLAGS, rsize,
keg->uk_ipers, pages));
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
}
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
/*
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
* Keg header ctor. This initializes all fields, locks, etc. And inserts
* the keg onto the global keg list.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Arguments/Returns follow uma_ctor specifications
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
* udata Actually uma_kctor_args
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
static int
keg_ctor(void *mem, int size, void *udata, int flags)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
struct uma_kctor_args *arg = udata;
uma_keg_t keg = mem;
uma_zone_t zone;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
int i;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
bzero(keg, size);
keg->uk_size = arg->size;
keg->uk_init = arg->uminit;
keg->uk_fini = arg->fini;
keg->uk_align = arg->align;
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
keg->uk_reserve = 0;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
keg->uk_flags = arg->flags;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
/*
* We use a global round-robin policy by default. Zones with
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
* UMA_ZONE_FIRSTTOUCH set will use first-touch instead, in which
* case the iterator is never run.
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
*/
keg->uk_dr.dr_policy = DOMAINSET_RR();
keg->uk_dr.dr_iter = 0;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/*
* The master zone is passed to us at keg-creation time.
*/
zone = arg->zone;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
keg->uk_name = zone->uz_name;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
if (arg->flags & UMA_ZONE_ZINIT)
keg->uk_init = zero_init;
- Introduce the new M_NOVM option which tells uma to only check the currently allocated slabs and bucket caches for free items. It will not go ask the vm for pages. This differs from M_NOWAIT in that it not only doesn't block, it doesn't even ask. - Add a new zcreate option ZONE_VM, that sets the BUCKETCACHE zflag. This tells uma that it should only allocate buckets out of the bucket cache, and not from the VM. It does this by using the M_NOVM option to zalloc when getting a new bucket. This is so that the VM doesn't recursively enter itself while trying to allocate buckets for vm_map_entry zones. If there are already allocated buckets when we get here we'll still use them but otherwise we'll skip it. - Use the ZONE_VM flag on vm map entries and pv entries on x86.
2002-06-17 22:02:41 +00:00
Remove UMA_ZONE_REFCNT feature, now unused. Blessed by: jeff
2016-03-01 00:33:32 +00:00
if (arg->flags & UMA_ZONE_MALLOC)
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
#ifndef SMP
keg->uk_flags &= ~UMA_ZONE_PCPU;
Merge from projects/counters: UMA_ZONE_PCPU zones. These zones have slab size == sizeof(struct pcpu), but request from VM enough pages to fit (uk_slabsize * mp_ncpus). An item allocated from such zone would have a separate twin for each CPU in the system, and these twins are at a distance of sizeof(struct pcpu) from each other. This magic value of distance would allow us to make some optimizations later. To address private item from a CPU simple arithmetics should be used: item = (type *)((char *)base + sizeof(struct pcpu) * curcpu) These arithmetics are available as zpcpu_get() macro in pcpu.h. To introduce non-page size slabs a new field had been added to uma_keg uk_slabsize. This shifted some frequently used fields of uma_keg to the fourth cache line on amd64. To mitigate this pessimization, uma_keg fields were a bit rearranged and least frequently used uk_name and uk_link moved down to the fourth cache line. All other fields, that are dereferenced frequently fit into first three cache lines. Sponsored by: Nginx, Inc.
2013-04-08 19:10:45 +00:00
#endif
uma: unify layout paths and improve efficiency Unify the keg layout selection paths (keg_small_init, keg_large_init, keg_cachespread_init), and slightly improve memory efficiecy by: - using the padding of the final item to store the slab header, - not going OFFPAGE if we have a choice unless it improves efficiency. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23048
2020-01-09 02:03:17 +00:00
keg_layout(keg);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
/*
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
* Use a first-touch NUMA policy for all kegs that pmap_extract()
* will work on with the exception of critical VM structures
* necessary for paging.
*
* Zones may override the default by specifying either.
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
*/
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
if ((keg->uk_flags &
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
(UMA_ZFLAG_HASH | UMA_ZONE_VM | UMA_ZONE_ROUNDROBIN)) == 0)
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
keg->uk_flags |= UMA_ZONE_FIRSTTOUCH;
else if ((keg->uk_flags & UMA_ZONE_FIRSTTOUCH) == 0)
keg->uk_flags |= UMA_ZONE_ROUNDROBIN;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
#endif
- Fix MD_SMALL_ALLOC on architectures that support it. Define a new alloc function, startup_alloc(), that is used for single page allocations prior to the VM starting up. If it is used after the VM startups up, it replaces the zone's allocf pointer with either page_alloc() or uma_small_alloc() where appropriate. Pointy hat to: me Tested by: phk/amd64, me/x86
2003-09-21 07:39:16 +00:00
/*
* If we haven't booted yet we need allocations to go through the
* startup cache until the vm is ready.
*/
#ifdef UMA_MD_SMALL_ALLOC
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
if (keg->uk_ppera == 1)
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
keg->uk_allocf = uma_small_alloc;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
else
When we are in UMA_STARTUP use startup_alloc() for any zone, not for internal zones only. This allows to create new zones at early stages of boot, without need to mark them as internal to UMA, which isn't always true. Reviewed by: alc
2017-06-08 21:33:19 +00:00
#endif
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
if (booted < BOOT_KVA)
keg->uk_allocf = startup_alloc;
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
else if (keg->uk_flags & UMA_ZONE_PCPU)
keg->uk_allocf = pcpu_page_alloc;
uma: add UMA_ZONE_CONTIG, and a default contig_alloc For now, copy the mbuf allocator. Reviewed by: jeff, markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23237
2020-02-04 22:40:11 +00:00
else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 && keg->uk_ppera > 1)
keg->uk_allocf = contig_alloc;
When we are in UMA_STARTUP use startup_alloc() for any zone, not for internal zones only. This allows to create new zones at early stages of boot, without need to mark them as internal to UMA, which isn't always true. Reviewed by: alc
2017-06-08 21:33:19 +00:00
else
keg->uk_allocf = page_alloc;
#ifdef UMA_MD_SMALL_ALLOC
if (keg->uk_ppera == 1)
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
keg->uk_freef = uma_small_free;
When we are in UMA_STARTUP use startup_alloc() for any zone, not for internal zones only. This allows to create new zones at early stages of boot, without need to mark them as internal to UMA, which isn't always true. Reviewed by: alc
2017-06-08 21:33:19 +00:00
else
Correct an error in r222163. Unless UMA_MD_SMALL_ALLOC is defined, startup_alloc() must be used until uma_startup2() is called. Reported by: jh
2011-05-22 17:46:16 +00:00
#endif
Back pcpu zone with domain correct pages - Change pcpu zone consumers to use a stride size of PAGE_SIZE. (defined as UMA_PCPU_ALLOC_SIZE to make future identification easier) - Allocate page from the correct domain for a given cpu. - Don't initialize pc_domain to non-zero value if NUMA is not defined There are some misconceptions surrounding this field. It is the _VM_ NUMA domain and should only ever correspond to valid domain values as understood by the VM. The former slab size of sizeof(struct pcpu) was somewhat arbitrary. The new value is PAGE_SIZE because that's the smallest granularity which the VM can allocate a slab for a given domain. If you have fewer than PAGE_SIZE/8 counters on your system there will be some memory wasted, but this is obviously something where you want the cache line to be coming from the correct domain. Reviewed by: jeff Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D15933
2018-07-06 02:06:03 +00:00
if (keg->uk_flags & UMA_ZONE_PCPU)
keg->uk_freef = pcpu_page_free;
else
When we are in UMA_STARTUP use startup_alloc() for any zone, not for internal zones only. This allows to create new zones at early stages of boot, without need to mark them as internal to UMA, which isn't always true. Reviewed by: alc
2017-06-08 21:33:19 +00:00
keg->uk_freef = page_free;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/*
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
* Initialize keg's locks.
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
*/
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
for (i = 0; i < vm_ndomains; i++)
KEG_LOCK_INIT(keg, i, (arg->flags & UMA_ZONE_MTXCLASS));
Add a new zone flag UMA_ZONE_MTXCLASS. This puts the zone in it's own mutex class. Currently this is only used for kmapentzone because kmapents are are potentially allocated when freeing memory. This is not dangerous though because no other allocations will be done while holding the kmapentzone lock.
2002-04-29 23:45:41 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* If we're putting the slab header in the actual page we need to
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
* figure out where in each page it goes. See slab_sizeof
* definition.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE)) {
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
size_t shsize;
shsize = slab_sizeof(keg->uk_ipers);
keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
Rework the way slab header storage space is calculated in UMA. - zone_large_init() stays pretty much the same. - zone_small_init() will try to stash the slab header in the slab page being allocated if the amount of calculated wasted space is less than UMA_MAX_WASTE (for both the UMA_ZONE_REFCNT case and regular case). If the amount of wasted space is >= UMA_MAX_WASTE, then UMA_ZONE_OFFPAGE will be set and the slab header will be allocated separately for better use of space. - uma_startup() calculates the maximum ipers required in offpage slabs (so that the offpage slab header zone(s) can be sized accordingly). The algorithm used to calculate this replaces the old calculation (which only happened to work coincidentally). We now iterate over possible object sizes, starting from the smallest one, until we determine that wastedspace calculated in zone_small_init() might end up being greater than UMA_MAX_WASTE, at which point we use the found object size to compute the maximum possible ipers. The reason this works is because: - wastedspace versus objectsize is a see-saw function with local minima all equal to zero and local maxima growing directly proportioned to objectsize. This implies that for objects up to or equal a certain objectsize, the see-saw remains entirely below UMA_MAX_WASTE, so for those objectsizes it is impossible to ever go OFFPAGE for slab headers. - ipers (items-per-slab) versus objectsize is an inversely proportional function which falls off very quickly (very large for small objectsizes). - To determine the maximum ipers we'll ever need from OFFPAGE slab headers we first find the largest objectsize for which we are guaranteed to not go offpage for and use it to compute ipers (as though we were offpage). Since the only objectsizes allowed to go offpage are bigger than the found objectsize, and since ipers vs objectsize is inversely proportional (and monotonically decreasing), then we are guaranteed that the ipers computed is always >= what we will ever need in offpage slab headers. - Define UMA_FRITM_SZ and UMA_FRITMREF_SZ to be the actual (possibly padded) size of each freelist index so that offset calculations are fixed. This might fix weird data corruption problems and certainly allows ARM to now boot to at least single-user (via simulator). Tested on i386 UP by me. Tested on sparc64 SMP by fenner. Tested on ARM simulator to single-user by cognet.
2004-07-29 15:25:40 +00:00
/*
* The only way the following is possible is if with our
* UMA_ALIGN_PTR adjustments we are now bigger than
* UMA_SLAB_SIZE. I haven't checked whether this is
* mathematically possible for all cases, so we make
* sure here anyway.
*/
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
For not offpage zones the slab is placed at the end of page. Keg's uk_pgoff is calculated to guarantee that struct uma_slab is placed at pointer size alignment. Calculation of real struct uma_slab size is done in keg_ctor() and yet again in keg_large_init(), to check if we need an extra page. This calculation can actually be performed at compile time. - Add SIZEOF_UMA_SLAB macro to calculate size of struct uma_slab placed at an end of a page with alignment requirement. - Use SIZEOF_UMA_SLAB in keg_ctor() and in keg_large_init(). This is a not a functional change. - Use SIZEOF_UMA_SLAB in UMA_SLAB_SPACE definition and in keg_small_init(). This is a potential bugfix, but in reality I don't think there are any systems affected, since compiler aligns struct uma_slab anyway.
2018-11-28 19:17:27 +00:00
("zone %s ipers %d rsize %d size %d slab won't fit",
zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (keg->uk_flags & UMA_ZFLAG_HASH)
Allow UMA hash tables to expand faster then 2x in 20 seconds. ZFS ABD allocates tons of 4KB chunks via UMA, requiring huge hash tables. With initial hash table size of only 32 elements it takes ~20 expansions or ~400 seconds to adapt to handling 220GB ZFS ARC. During that time not only the hash table is highly inefficient, but also each of those expan- sions takes significant time with the lock held, blocking operation. On my test system with 256GB of RAM and ZFS pool of 28 HDDs this change reduces time needed to first time read 240GB from ~300-400s, during which system is quite busy and unresponsive, to only ~150s with light CPU load and just 5 sub-second CPU spikes to expand the hash table. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2019-06-06 23:57:28 +00:00
hash_alloc(&keg->uk_hash, 0);
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
uma: fixup some ktr messages Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23148
2020-01-14 02:13:46 +00:00
CTR3(KTR_UMA, "keg_ctor %p zone %s(%p)", keg, zone->uz_name, zone);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wlock(&uma_rwlock);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wunlock(&uma_rwlock);
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
return (0);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
static void
zone_kva_available(uma_zone_t zone, void *unused)
{
uma_keg_t keg;
if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
return;
KEG_GET(zone, keg);
uma: add UMA_ZONE_CONTIG, and a default contig_alloc For now, copy the mbuf allocator. Reviewed by: jeff, markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23237
2020-02-04 22:40:11 +00:00
if (keg->uk_allocf == startup_alloc) {
/* Switch to the real allocator. */
if (keg->uk_flags & UMA_ZONE_PCPU)
keg->uk_allocf = pcpu_page_alloc;
else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 &&
keg->uk_ppera > 1)
keg->uk_allocf = contig_alloc;
else
keg->uk_allocf = page_alloc;
}
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
}
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
static void
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_alloc_counters(uma_zone_t zone, void *unused)
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
{
zone->uz_allocs = counter_u64_alloc(M_WAITOK);
zone->uz_frees = counter_u64_alloc(M_WAITOK);
zone->uz_fails = counter_u64_alloc(M_WAITOK);
}
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static void
zone_alloc_sysctl(uma_zone_t zone, void *unused)
{
uma_zone_domain_t zdom;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uma_domain_t dom;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
uma_keg_t keg;
struct sysctl_oid *oid, *domainoid;
Fix two problems with r355149. The sysctl name collision code assumed that zones would never be freed. In the case of tmpfs this was not true. While here test for the right bit to disable the keg related sysctls for zones that don't have kegs. Reported by: pho Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22655
2019-12-08 01:55:23 +00:00
int domains, i, cnt;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static const char *nokeg = "cache zone";
char *c;
/*
* Make a sysctl safe copy of the zone name by removing
* any special characters and handling dups by appending
* an index.
*/
if (zone->uz_namecnt != 0) {
Fix two problems with r355149. The sysctl name collision code assumed that zones would never be freed. In the case of tmpfs this was not true. While here test for the right bit to disable the keg related sysctls for zones that don't have kegs. Reported by: pho Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22655
2019-12-08 01:55:23 +00:00
/* Count the number of decimal digits and '_' separator. */
for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
cnt /= 10;
zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
M_UMA, M_WAITOK);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
zone->uz_namecnt);
} else
zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
for (c = zone->uz_ctlname; *c != '\0'; c++)
if (strchr("./\\ -", *c) != NULL)
*c = '_';
/*
* Basic parameters at the root.
*/
zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
OID_AUTO, zone->uz_ctlname, CTLFLAG_RD, NULL, "");
oid = zone->uz_oid;
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
uma: pretty print zone flags sysctl Requested by: jeff Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22748
2019-12-11 06:50:55 +00:00
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_flags, "A",
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
"Allocator configuration flags");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
"Desired per-cpu cache size");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
"Maximum allowed per-cpu cache size");
/*
* keg if present.
*/
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
domains = vm_ndomains;
else
domains = 1;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
"keg", CTLFLAG_RD, NULL, "");
keg = zone->uz_keg;
Fix two problems with r355149. The sysctl name collision code assumed that zones would never be freed. In the case of tmpfs this was not true. While here test for the right bit to disable the keg related sysctls for zones that don't have kegs. Reported by: pho Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22655
2019-12-08 01:55:23 +00:00
if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"name", CTLFLAG_RD, keg->uk_name, "Keg name");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
"Real object size with alignment");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
"pages per-slab allocation");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
"items available per-slab");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"align", CTLFLAG_RD, &keg->uk_align, 0,
"item alignment mask");
uma: report slab efficiency Reviewed by: jeff Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22766
2019-12-13 09:32:09 +00:00
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
keg, 0, sysctl_handle_uma_slab_efficiency, "I",
"Slab utilization (100 - internal fragmentation %)");
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(oid),
OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
for (i = 0; i < domains; i++) {
dom = &keg->uk_domain[i];
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD,
NULL, "");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"pages", CTLFLAG_RD, &dom->ud_pages, 0,
"Total pages currently allocated from VM");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
"free_items", CTLFLAG_RD, &dom->ud_free_items, 0,
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
"items free in the slab layer");
}
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
} else
SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"name", CTLFLAG_RD, nokeg, "Keg name");
/*
* Information about zone limits.
*/
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
"limit", CTLFLAG_RD, NULL, "");
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"items", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_items, "QU",
"current number of allocated items if limit is set");
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
"Maximum number of cached items");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
"Number of threads sleeping at limit");
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
"Total zone limit sleeps");
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_max", CTLFLAG_RD, &zone->uz_bkt_max, 0,
"Maximum number of items in the bucket cache");
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_cnt", CTLFLAG_RD, &zone->uz_bkt_count, 0,
"Number of items in the bucket cache");
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
/*
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
* Per-domain zone information.
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
*/
domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
OID_AUTO, "domain", CTLFLAG_RD, NULL, "");
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0)
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
domains = 1;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
for (i = 0; i < domains; i++) {
zdom = &zone->uz_domain[i];
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
OID_AUTO, VM_DOMAIN(i)->vmd_name, CTLFLAG_RD, NULL, "");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"nitems", CTLFLAG_RD, &zdom->uzd_nitems,
"number of items in this domain");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"imax", CTLFLAG_RD, &zdom->uzd_imax,
"maximum item count in this period");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"imin", CTLFLAG_RD, &zdom->uzd_imin,
"minimum item count in this period");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"wss", CTLFLAG_RD, &zdom->uzd_wss,
"Working set size");
}
/*
* General statistics.
*/
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
"stats", CTLFLAG_RD, NULL, "");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
zone, 1, sysctl_handle_uma_zone_cur, "I",
"Current number of allocated items");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_allocs, "QU",
"Total allocation calls");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_frees, "QU",
"Total free calls");
SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"fails", CTLFLAG_RD, &zone->uz_fails,
"Number of allocation failures");
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"xdomain", CTLFLAG_RD, &zone->uz_xdomain, 0,
"Free calls from the wrong domain");
}
struct uma_zone_count {
const char *name;
int count;
};
static void
zone_count(uma_zone_t zone, void *arg)
{
struct uma_zone_count *cnt;
cnt = arg;
Fix two problems with r355149. The sysctl name collision code assumed that zones would never be freed. In the case of tmpfs this was not true. While here test for the right bit to disable the keg related sysctls for zones that don't have kegs. Reported by: pho Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22655
2019-12-08 01:55:23 +00:00
/*
* Some zones are rapidly created with identical names and
* destroyed out of order. This can lead to gaps in the count.
* Use one greater than the maximum observed for this name.
*/
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
if (strcmp(zone->uz_name, cnt->name) == 0)
Fix two problems with r355149. The sysctl name collision code assumed that zones would never be freed. In the case of tmpfs this was not true. While here test for the right bit to disable the keg related sysctls for zones that don't have kegs. Reported by: pho Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22655
2019-12-08 01:55:23 +00:00
cnt->count = MAX(cnt->count,
zone->uz_namecnt + 1);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
}
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
static void
zone_update_caches(uma_zone_t zone)
{
int i;
for (i = 0; i <= mp_maxid; i++) {
cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
}
}
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/*
* Zone header ctor. This initializes all fields, locks, etc.
*
* Arguments/Returns follow uma_ctor specifications
* udata Actually uma_zctor_args
*/
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
static int
zone_ctor(void *mem, int size, void *udata, int flags)
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
{
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
struct uma_zone_count cnt;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
struct uma_zctor_args *arg = udata;
uma_zone_t zone = mem;
uma_zone_t z;
uma_keg_t keg;
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
int i;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
bzero(zone, size);
zone->uz_name = arg->name;
zone->uz_ctor = arg->ctor;
zone->uz_dtor = arg->dtor;
zone->uz_init = NULL;
zone->uz_fini = NULL;
Add a new column to the output of vmstat -z to indicate the number of times the system was forced to sleep when requesting a new allocation. Expand the debugger hook, db_show_uma, to display these results as well. This has proven to be very useful in out of memory situations when it is not known why systems have become sluggish or fail in odd ways. Reviewed by: rwatson alc Approved by: scottl (mentor) peter Obtained from: Yahoo Inc.
2010-06-15 19:28:37 +00:00
zone->uz_sleeps = 0;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
zone->uz_xdomain = 0;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone->uz_bucket_size = 0;
zone->uz_bucket_size_min = 0;
zone->uz_bucket_size_max = BUCKET_MAX;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
zone->uz_flags = (arg->flags & UMA_ZONE_SMR);
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
zone->uz_warning = NULL;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
/* The domain structures follow the cpu structures. */
uma: fix zone domain overlaying pcpu cache with disabled cpus UMA zone structures have two arrays at the end which are sized according to the machine: an array of CPU count length, and an array of NUMA domain count length. The CPU counting was wrong in the case where some CPUs are disabled (when mp_ncpus != mp_maxid + 1), and this caused the second array to be overlaid with the first. Reported by: olivier Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23318
2020-01-23 04:56:38 +00:00
zone->uz_domain =
(struct uma_zone_domain *)&zone->uz_cpu[mp_maxid + 1];
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone->uz_bkt_max = ULONG_MAX;
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
timevalclear(&zone->uz_ratecheck);
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
/* Count the number of duplicate names. */
cnt.name = arg->name;
cnt.count = 0;
zone_foreach(zone_count, &cnt);
zone->uz_namecnt = cnt.count;
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
ZONE_CROSS_LOCK_INIT(zone);
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
for (i = 0; i < vm_ndomains; i++)
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
STAILQ_INIT(&zone->uz_domain[i].uzd_buckets);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
#ifdef INVARIANTS
if (arg->uminit == trash_init && arg->fini == trash_fini)
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
#endif
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
/*
* This is a pure cache zone, no kegs.
*/
if (arg->import) {
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KASSERT((arg->flags & UMA_ZFLAG_CACHE) != 0,
("zone_ctor: Import specified for non-cache zone."));
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
zone->uz_flags = arg->flags;
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
zone->uz_size = arg->size;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
zone->uz_import = arg->import;
zone->uz_release = arg->release;
zone->uz_arg = arg->arg;
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wlock(&uma_rwlock);
- Add bucket size column to `show uma` DDB command. - Add `show umacache` command to show alike stats for cache-only UMA zones.
2013-11-28 19:20:49 +00:00
LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wunlock(&uma_rwlock);
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
goto out;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
}
/*
* Use the regular zone/keg/slab allocator.
*/
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
zone->uz_import = zone_import;
zone->uz_release = zone_release;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
zone->uz_arg = zone;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
keg = arg->keg;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
if (arg->flags & UMA_ZONE_SECONDARY) {
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
("Secondary zone requested UMA_ZFLAG_INTERNAL"));
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
zone->uz_init = arg->uminit;
zone->uz_fini = arg->fini;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
zone->uz_flags |= UMA_ZONE_SECONDARY;
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wlock(&uma_rwlock);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
ZONE_LOCK(zone);
LIST_FOREACH(z, &keg->uk_zones, uz_link) {
if (LIST_NEXT(z, uz_link) == NULL) {
LIST_INSERT_AFTER(z, zone, uz_link);
break;
}
}
ZONE_UNLOCK(zone);
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wunlock(&uma_rwlock);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
} else if (keg == NULL) {
if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
arg->align, arg->flags)) == NULL)
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
return (ENOMEM);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
} else {
struct uma_kctor_args karg;
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
int error;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/* We should only be here from uma_startup() */
karg.size = arg->size;
karg.uminit = arg->uminit;
karg.fini = arg->fini;
karg.align = arg->align;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
karg.flags = (arg->flags & ~UMA_ZONE_SMR);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
karg.zone = zone;
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
flags);
if (error)
return (error);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
/* Inherit properties from the keg. */
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone->uz_keg = keg;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
zone->uz_size = keg->uk_size;
zone->uz_flags |= (keg->uk_flags &
(UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
out:
UMA: Don't destroy zones after the system shutdown process starts. Some kernel subsystems, notably ZFS, will destroy UMA zones from a shutdown eventhandler. This causes the zone to be drained. For slabs that are mapped into KVA this can be very expensive and so it needlessly delays the shutdown process. Add a new state to the "booted" variable, BOOT_SHUTDOWN. Once kern_reboot() starts invoking shutdown handlers, turn uma_zdestroy() into a no-op, provided that the zone does not have a custom finalization routine. PR: 242427 Reviewed by: jeff, kib, rlibby MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23066
2020-01-09 19:17:42 +00:00
if (__predict_true(booted >= BOOT_RUNNING)) {
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_alloc_counters(zone, NULL);
zone_alloc_sysctl(zone, NULL);
} else {
zone->uz_allocs = EARLY_COUNTER;
zone->uz_frees = EARLY_COUNTER;
zone->uz_fails = EARLY_COUNTER;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/* Caller requests a private SMR context. */
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
zone->uz_smr = smr_create(zone->uz_name);
Add a UMA zone flag to disable the use of buckets. This allows the creation of zones which don't do any caching in front of the keg. If the zone is a cache zone, this means that UMA will not attempt any memory allocations when allocating an item from the backend. This is intended for use after a panic by netdump, but likely has other applications. Reviewed by: kib MFC after: 2 weeks Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D15184
2018-04-24 20:05:45 +00:00
KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
(UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
("Invalid zone flag combination"));
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
if (arg->flags & UMA_ZFLAG_INTERNAL)
zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
zone->uz_bucket_size = BUCKET_MAX;
else if ((arg->flags & UMA_ZONE_MINBUCKET) != 0)
zone->uz_bucket_size_max = zone->uz_bucket_size = BUCKET_MIN;
else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
zone->uz_bucket_size = 0;
Add a UMA zone flag to disable the use of buckets. This allows the creation of zones which don't do any caching in front of the keg. If the zone is a cache zone, this means that UMA will not attempt any memory allocations when allocating an item from the backend. This is intended for use after a panic by netdump, but likely has other applications. Reviewed by: kib MFC after: 2 weeks Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D15184
2018-04-24 20:05:45 +00:00
else
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone->uz_bucket_size = bucket_select(zone->uz_size);
zone->uz_bucket_size_min = zone->uz_bucket_size;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
zone_update_caches(zone);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
return (0);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
/*
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
* Keg header dtor. This frees all data, destroys locks, frees the hash
* table and removes the keg from the global list.
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
*
* Arguments/Returns follow uma_dtor specifications
* udata unused
*/
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
static void
keg_dtor(void *arg, int size, void *udata)
{
uma_keg_t keg;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uint32_t free, pages;
int i;
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
keg = (uma_keg_t)arg;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
free = pages = 0;
for (i = 0; i < vm_ndomains; i++) {
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
free += keg->uk_domain[i].ud_free_items;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
pages += keg->uk_domain[i].ud_pages;
KEG_LOCK_FINI(keg, i);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
uma: report leaks more accurately Previously UMA had some false negatives in the leak report at keg destruction time, where it only reported leaks if there were free items in the slab layer (rather than allocated items), which notably would not be true for single-item slabs (large items). Now, report a leak if there are any allocated pages, and calculate and report the number of allocated items rather than free items. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23275
2020-01-23 04:56:34 +00:00
if (pages != 0)
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
printf("Freed UMA keg (%s) was not empty (%u items). "
" Lost %u pages of memory.\n",
keg->uk_name ? keg->uk_name : "",
uma: report leaks more accurately Previously UMA had some false negatives in the leak report at keg destruction time, where it only reported leaks if there were free items in the slab layer (rather than allocated items), which notably would not be true for single-item slabs (large items). Now, report a leak if there are any allocated pages, and calculate and report the number of allocated items rather than free items. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23275
2020-01-23 04:56:34 +00:00
pages / keg->uk_ppera * keg->uk_ipers - free, pages);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
hash_free(&keg->uk_hash);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
/*
* Zone header dtor.
*
* Arguments/Returns follow uma_dtor specifications
* udata unused
*/
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
static void
zone_dtor(void *arg, int size, void *udata)
{
uma_zone_t zone;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_keg_t keg;
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
zone = (uma_zone_t)arg;
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
sysctl_remove_oid(zone->uz_oid, 1, 1);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
cache_drain(zone);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wlock(&uma_rwlock);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
LIST_REMOVE(zone, uz_link);
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wunlock(&uma_rwlock);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
/*
* XXX there are some races here where
* the zone can be drained but zone lock
* released and then refilled before we
* remove it... we dont care for now
*/
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
zone_reclaim(zone, M_WAITOK, true);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
/*
for a cache-only zone the destructor tries to destroy a non-existent keg Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D19835
2019-04-12 12:46:25 +00:00
* We only destroy kegs from non secondary/non cache zones.
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
*/
for a cache-only zone the destructor tries to destroy a non-existent keg Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D19835
2019-04-12 12:46:25 +00:00
if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
keg = zone->uz_keg;
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wlock(&uma_rwlock);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
LIST_REMOVE(keg, uk_link);
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_wunlock(&uma_rwlock);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
zone_free_item(kegs, keg, NULL, SKIP_NONE);
- Replace the local maxcpu with mp_maxid. Previously, if mp_maxid was equal to MAXCPU, we would overrun the pcpu_mtx array because maxcpu was calculated incorrectly. - Add some more debugging code so that memory leaks at the time of uma_zdestroy() are more easily diagnosed. Approved by: re (rwatson)
2003-11-30 08:04:01 +00:00
}
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
counter_u64_free(zone->uz_allocs);
counter_u64_free(zone->uz_frees);
counter_u64_free(zone->uz_fails);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
free(zone->uz_ctlname, M_UMA);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
ZONE_LOCK_FINI(zone);
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
ZONE_CROSS_LOCK_FINI(zone);
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
}
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
static void
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *arg), void *arg)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_keg_t keg;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma_zone_t zone;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
LIST_FOREACH(keg, &uma_kegs, uk_link) {
LIST_FOREACH(zone, &keg->uk_zones, uz_link)
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zfunc(zone, arg);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
Include cache zones into zone_foreach() where appropriate. The r354367 is reverted since it is subsumed by this, more complete, approach. Suggested by: markj Reviewed by: alc. glebius, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22242
2019-11-10 09:25:19 +00:00
LIST_FOREACH(zone, &uma_cachezones, uz_link)
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zfunc(zone, arg);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
/*
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
* Traverses every zone in the system and calls a callback
*
* Arguments:
* zfunc A pointer to a function which accepts a zone
* as an argument.
*
* Returns:
* Nothing
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
*/
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
static void
zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
{
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
rw_rlock(&uma_rwlock);
zone_foreach_unlocked(zfunc, arg);
rw_runlock(&uma_rwlock);
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
}
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
/*
* Initialize the kernel memory allocator. This is done after pages can be
* allocated but before general KVA is available.
*/
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
void
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
uma_startup1(vm_offset_t virtual_avail)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
struct uma_zctor_args args;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
size_t ksize, zsize, size;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_keg_t masterkeg;
uintptr_t m;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
uint8_t pflag;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
bootstart = bootmem = virtual_avail;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
rw_init(&uma_rwlock, "UMA lock");
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
sx_init(&uma_reclaim_lock, "umareclaim");
ksize = sizeof(struct uma_keg) +
(sizeof(struct uma_domain) * vm_ndomains);
ksize = roundup(ksize, UMA_SUPER_ALIGN);
zsize = sizeof(struct uma_zone) +
(sizeof(struct uma_cache) * (mp_maxid + 1)) +
(sizeof(struct uma_zone_domain) * vm_ndomains);
zsize = roundup(zsize, UMA_SUPER_ALIGN);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
/* Allocate the zone of zones, zone of kegs, and zone of zones keg. */
size = (zsize * 2) + ksize;
m = (uintptr_t)startup_alloc(NULL, size, 0, &pflag, M_NOWAIT | M_ZERO);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
zones = (uma_zone_t)m;
Fix uma boot pages calculations on NUMA machines that also don't have MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt of zones while here. This was already correct because uz_cpu strongly aligned the zone structure but the specified alignment did not match reality and involved redundant defines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23046
2020-01-06 02:51:19 +00:00
m += zsize;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
kegs = (uma_zone_t)m;
Fix uma boot pages calculations on NUMA machines that also don't have MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt of zones while here. This was already correct because uz_cpu strongly aligned the zone structure but the specified alignment did not match reality and involved redundant defines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23046
2020-01-06 02:51:19 +00:00
m += zsize;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
masterkeg = (uma_keg_t)m;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/* "manually" create the initial zone */
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
memset(&args, 0, sizeof(args));
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.name = "UMA Kegs";
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
args.size = ksize;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.ctor = keg_ctor;
args.dtor = keg_dtor;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
args.uminit = zero_init;
args.fini = NULL;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
args.keg = masterkeg;
Fix uma boot pages calculations on NUMA machines that also don't have MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt of zones while here. This was already correct because uz_cpu strongly aligned the zone structure but the specified alignment did not match reality and involved redundant defines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23046
2020-01-06 02:51:19 +00:00
args.align = UMA_SUPER_ALIGN - 1;
- Fix the silly flag situation in UMA. Remove redundant ZFLAG/ZONE flags by accepting the user supplied flags directly. Previously this was not done so that flags for the same field would not be defined in two different files. Add comments in each header instructing future developers on how now to shoot their feet. - Fix a test for !OFFPAGE which should have been a test for HASH. This would have caused a panic if we had ever destructed a malloc zone. This also opens up the possibility that other zones could use the vsetobj() method rather than a hash.
2003-09-19 08:37:44 +00:00
args.flags = UMA_ZFLAG_INTERNAL;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
zone_ctor(kegs, zsize, &args, M_WAITOK);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.name = "UMA Zones";
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
args.size = zsize;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.ctor = zone_ctor;
args.dtor = zone_dtor;
args.uminit = zero_init;
args.fini = NULL;
args.keg = NULL;
Fix uma boot pages calculations on NUMA machines that also don't have MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt of zones while here. This was already correct because uz_cpu strongly aligned the zone structure but the specified alignment did not match reality and involved redundant defines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23046
2020-01-06 02:51:19 +00:00
args.align = UMA_SUPER_ALIGN - 1;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.flags = UMA_ZFLAG_INTERNAL;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
zone_ctor(zones, zsize, &args, M_WAITOK);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
/* Now make zones for slab headers */
slabzones[0] = uma_zcreate("UMA Slabs 0", SLABZONE0_SIZE,
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
slabzones[1] = uma_zcreate("UMA Slabs 1", SLABZONE1_SIZE,
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
hashzone = uma_zcreate("UMA Hash",
sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
bucket_init();
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
smr_init();
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
}
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
#ifndef UMA_MD_SMALL_ALLOC
extern void vm_radix_reserve_kva(void);
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
#endif
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
/*
* Advertise the availability of normal kva allocations and switch to
* the default back-end allocator. Marks the KVA we consumed on startup
* as used in the map.
*/
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
void
- Split UMA_ZFLAG_OFFPAGE into UMA_ZFLAG_OFFPAGE and UMA_ZFLAG_HASH. - Remove all instances of the mallochash. - Stash the slab pointer in the vm page's object pointer when allocating from the kmem_obj. - Use the overloaded object pointer to find slabs for malloced memory.
2002-09-18 08:26:30 +00:00
uma_startup2(void)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
Some architectures with DMAP still consume boot kva. Simplify the test for claiming kva in uma_startup2() to handle this. Reported by: bdragon
2020-01-23 03:37:35 +00:00
if (bootstart != bootmem) {
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
vm_map_lock(kernel_map);
(void)vm_map_insert(kernel_map, NULL, 0, bootstart, bootmem,
VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
vm_map_unlock(kernel_map);
}
#ifndef UMA_MD_SMALL_ALLOC
/* Set up radix zone to use noobj_alloc. */
vm_radix_reserve_kva();
Fix boot_pages exhaustion on machines with many domains and cores, where size of UMA zone allocation is greater than page size. In this case zone of zones can not use UMA_MD_SMALL_ALLOC, and we need to postpone switch off of this zone from startup_alloc() until full launch of VM. o Always supply number of VM zones to uma_startup_count(). On machines with UMA_MD_SMALL_ALLOC ignore it completely, unless zsize goes over a page. In the latter case account VM zones for number of allocations from the zone of zones. o Rewrite startup_alloc() so that it will immediately switch off from itself any zone that is already capable of running real alloc. In worst case scenario we may leak a single page here. See comment in uma_startup_count(). o Hardcode call to uma_startup2() into vm_mem_init(). Otherwise some extra SYSINITs, e.g. vm_page_init() may sneak in before. o While here, remove uma_boot_pages_mtx. With recent changes to boot pages calculation, we are guaranteed to use all of the boot_pages in the early single threaded stage. Reported & tested by: mav
2018-02-09 04:45:39 +00:00
#endif
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
booted = BOOT_KVA;
zone_foreach_unlocked(zone_kva_available, NULL);
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
bucket_enable();
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
/*
* Finish our initialization steps.
*/
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
static void
uma_startup3(void)
{
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
#ifdef INVARIANTS
TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
uma_skip_cnt = counter_u64_alloc(M_WAITOK);
#endif
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
zone_foreach_unlocked(zone_alloc_counters, NULL);
zone_foreach_unlocked(zone_alloc_sysctl, NULL);
CALLOUT_MPSAFE has lost its meaning since r141428, i.e., for more than ten years for head. However, it is continuously misused as the mpsafe argument for callout_init(9). Deprecate the flag and clean up callout_init() calls to make them more consistent. Differential Revision: https://reviews.freebsd.org/D2613 Reviewed by: jhb MFC after: 2 weeks
2015-05-22 17:05:21 +00:00
callout_init(&uma_callout, 1);
- Remove the working-set algorithm. Instead, use the per cpu buckets as the working set cache. This has several advantages. Firstly, we never touch the per cpu queues now in the timeout handler. This removes one more reason for having per cpu locks. Secondly, it reduces the size of the zone by 8 bytes, bringing it under 200 bytes for a single proc x86 box. This tidies up other logic as well. - The 'destroy' flag no longer needs to be passed to zone_drain() since it always frees everything in the zone's slabs. - cache_drain() is now only called from zone_dtor() and so it destroys by default. It also does not need the destroy parameter now.
2003-09-19 23:27:46 +00:00
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
booted = BOOT_RUNNING;
UMA: Don't destroy zones after the system shutdown process starts. Some kernel subsystems, notably ZFS, will destroy UMA zones from a shutdown eventhandler. This causes the zone to be drained. For slabs that are mapped into KVA this can be very expensive and so it needlessly delays the shutdown process. Add a new state to the "booted" variable, BOOT_SHUTDOWN. Once kern_reboot() starts invoking shutdown handlers, turn uma_zdestroy() into a no-op, provided that the zone does not have a custom finalization routine. PR: 242427 Reviewed by: jeff, kib, rlibby MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23066
2020-01-09 19:17:42 +00:00
EVENTHANDLER_REGISTER(shutdown_post_sync, uma_shutdown, NULL,
EVENTHANDLER_PRI_FIRST);
}
static void
uma_shutdown(void)
{
booted = BOOT_SHUTDOWN;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
static uma_keg_t
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
Convert UMA code to C99 uintXX_t types.
2013-04-09 17:43:48 +00:00
int align, uint32_t flags)
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
{
struct uma_kctor_args args;
args.size = size;
args.uminit = uminit;
args.fini = fini;
Add uma_set_align() interface, which will be called at most once during boot by MD code to indicated detected alignment preference. Rather than cache alignment being encoded in UMA consumers by defining a global alignment value of (16 - 1) in UMA_ALIGN_CACHE, UMA_ALIGN_CACHE is now a special value (-1) that causes UMA to look at registered alignment. If no preferred alignment has been selected by MD code, a default alignment of (16 - 1) will be used. Currently, no hardware platforms specify alignment; architecture maintainers will need to modify MD startup code to specify an alignment if desired. This must occur before initialization of UMA so that all UMA zones pick up the requested alignment. Reviewed by: jeff, alc Submitted by: attilio
2007-02-11 20:13:52 +00:00
args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.flags = flags;
args.zone = zone;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
Followup on r302393 by cperciva, improving calculation of boot pages required for UMA startup. o Introduce another stage of UMA startup, which is entered after vm_page_startup() finishes. After this stage we don't yet enable buckets, but we can ask VM for pages. Rename stages to meaningful names while here. New list of stages: BOOT_COLD, BOOT_STRAPPED, BOOT_PAGEALLOC, BOOT_BUCKETS, BOOT_RUNNING. Enabling page alloc earlier allows us to dramatically reduce number of boot pages required. What is more important number of zones becomes consistent across different machines, as no MD allocations are done before the BOOT_PAGEALLOC stage. Now only UMA internal zones actually need to use startup_alloc(), however that may change, so vm_page_startup() provides its need for early zones as argument. o Introduce uma_startup_count() function, to avoid code duplication. The functions calculates sizes of zones zone and kegs zone, and calculates how many pages UMA will need to bootstrap. It counts not only of zone structures, but also of kegs, slabs and hashes. o Hide uma_startup_foo() declarations from public file. o Provide several DIAGNOSTIC printfs on boot_pages usage. o Bugfix: when calculating zone of zones size use (mp_maxid + 1) instead of mp_ncpus. Use resulting number not only in the size argument to zone_ctor() but also as args.size. Reviewed by: imp, gallatin (earlier version) Differential Revision: https://reviews.freebsd.org/D14054
2018-02-06 04:16:00 +00:00
/* Public functions */
Add uma_set_align() interface, which will be called at most once during boot by MD code to indicated detected alignment preference. Rather than cache alignment being encoded in UMA consumers by defining a global alignment value of (16 - 1) in UMA_ALIGN_CACHE, UMA_ALIGN_CACHE is now a special value (-1) that causes UMA to look at registered alignment. If no preferred alignment has been selected by MD code, a default alignment of (16 - 1) will be used. Currently, no hardware platforms specify alignment; architecture maintainers will need to modify MD startup code to specify an alignment if desired. This must occur before initialization of UMA so that all UMA zones pick up the requested alignment. Reviewed by: jeff, alc Submitted by: attilio
2007-02-11 20:13:52 +00:00
/* See uma.h */
void
uma_set_align(int align)
{
if (align != UMA_ALIGN_CACHE)
uma_align_cache = align;
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* See uma.h */
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
uma_zone_t
Const-ify the zone name argument to uma_zcreate(9). MFC after: 3 days
2012-10-26 17:51:05 +00:00
uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
Convert UMA code to C99 uintXX_t types.
2013-04-09 17:43:48 +00:00
uma_init uminit, uma_fini fini, int align, uint32_t flags)
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
struct uma_zctor_args args;
Provide mutual exclusion between zone allocation/destruction and uma_reclaim(). Reclamation code must not see half-constructed or destructed zones. Do this by bracing uma_zcreate() and uma_zdestroy() into a shared-locked sx, and take the sx exclusively in uma_reclaim(). Usually zones are not created/destroyed during the system operation, but tmpfs mounts do cause zone operations and exposed the bug. Another solution could be to only expose a new keg on uma_kegs list after the corresponding zone is fully constructed, and similar treatment for the destruction. But it probably requires more risky code rearrangement as well. Reported and tested by: pho Discussed with: avg Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2014-11-30 20:20:55 +00:00
uma_zone_t res;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Assert that the align parameter to uma_zcreate() is valid. Reviewed by: kib MFC after: 1 week Sponsored by: DARPA / AFRL Differential Revision: https://reviews.freebsd.org/D10100
2017-04-04 16:26:46 +00:00
KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
align, name));
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* This stuff is essential for the zone ctor */
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
memset(&args, 0, sizeof(args));
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
args.name = name;
args.size = size;
args.ctor = ctor;
args.dtor = dtor;
args.uminit = uminit;
args.fini = fini;
If INVARIANTS is specified, add ctor/dtor to junk memory if they are unspecified... Submitted by: Suresh Gumpula at Netapp Differential Revision: https://reviews.freebsd.org/D2725
2015-06-25 20:44:46 +00:00
#ifdef INVARIANTS
/*
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
* Inject procedures which check for memory use after free if we are
* allowed to scramble the memory while it is not allocated. This
* requires that: UMA is actually able to access the memory, no init
* or fini procedures, no dependency on the initial value of the
* memory, and no (legitimate) use of the memory after free. Note,
* the ctor and dtor do not need to be empty.
If INVARIANTS is specified, add ctor/dtor to junk memory if they are unspecified... Submitted by: Suresh Gumpula at Netapp Differential Revision: https://reviews.freebsd.org/D2725
2015-06-25 20:44:46 +00:00
*/
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOTOUCH |
UMA_ZONE_NOFREE))) && uminit == NULL && fini == NULL) {
If INVARIANTS is specified, add ctor/dtor to junk memory if they are unspecified... Submitted by: Suresh Gumpula at Netapp Differential Revision: https://reviews.freebsd.org/D2725
2015-06-25 20:44:46 +00:00
args.uminit = trash_init;
args.fini = trash_fini;
}
#endif
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
args.align = align;
args.flags = flags;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.keg = NULL;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
sx_slock(&uma_reclaim_lock);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
sx_sunlock(&uma_reclaim_lock);
Provide mutual exclusion between zone allocation/destruction and uma_reclaim(). Reclamation code must not see half-constructed or destructed zones. Do this by bracing uma_zcreate() and uma_zdestroy() into a shared-locked sx, and take the sx exclusively in uma_reclaim(). Usually zones are not created/destroyed during the system operation, but tmpfs mounts do cause zone operations and exposed the bug. Another solution could be to only expose a new keg on uma_kegs list after the corresponding zone is fully constructed, and similar treatment for the destruction. But it probably requires more risky code rearrangement as well. Reported and tested by: pho Discussed with: avg Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2014-11-30 20:20:55 +00:00
return (res);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
/* See uma.h */
uma_zone_t
uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_zone_t master)
{
struct uma_zctor_args args;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_keg_t keg;
Provide mutual exclusion between zone allocation/destruction and uma_reclaim(). Reclamation code must not see half-constructed or destructed zones. Do this by bracing uma_zcreate() and uma_zdestroy() into a shared-locked sx, and take the sx exclusively in uma_reclaim(). Usually zones are not created/destroyed during the system operation, but tmpfs mounts do cause zone operations and exposed the bug. Another solution could be to only expose a new keg on uma_kegs list after the corresponding zone is fully constructed, and similar treatment for the destruction. But it probably requires more risky code rearrangement as well. Reported and tested by: pho Discussed with: avg Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2014-11-30 20:20:55 +00:00
uma_zone_t res;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
keg = master->uz_keg;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
memset(&args, 0, sizeof(args));
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.name = name;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
args.size = keg->uk_size;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
args.ctor = ctor;
args.dtor = dtor;
args.uminit = zinit;
args.fini = zfini;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
args.align = keg->uk_align;
args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
args.keg = keg;
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
sx_slock(&uma_reclaim_lock);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
Simplify VM and UMA startup by eliminating boot pages. Instead use careful ordering to allocate early pages in the same way boot pages were but only as needed. After the KVA allocator has started up we allocate the KVA that we consumed during boot. This also makes the boot pages freeable since they have vm_page structures allocated with the rest of memory. Parts of this patch were written and tested by markj. Reviewed by: glebius, markj Differential Revision: https://reviews.freebsd.org/D23102
2020-01-16 05:01:21 +00:00
sx_sunlock(&uma_reclaim_lock);
Provide mutual exclusion between zone allocation/destruction and uma_reclaim(). Reclamation code must not see half-constructed or destructed zones. Do this by bracing uma_zcreate() and uma_zdestroy() into a shared-locked sx, and take the sx exclusively in uma_reclaim(). Usually zones are not created/destroyed during the system operation, but tmpfs mounts do cause zone operations and exposed the bug. Another solution could be to only expose a new keg on uma_kegs list after the corresponding zone is fully constructed, and similar treatment for the destruction. But it probably requires more risky code rearrangement as well. Reported and tested by: pho Discussed with: avg Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2014-11-30 20:20:55 +00:00
return (res);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
}
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
/* See uma.h */
uma_zone_t
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_import zimport,
uma_release zrelease, void *arg, int flags)
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
{
struct uma_zctor_args args;
memset(&args, 0, sizeof(args));
args.name = name;
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
args.size = size;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
args.ctor = ctor;
args.dtor = dtor;
args.uminit = zinit;
args.fini = zfini;
args.import = zimport;
args.release = zrelease;
args.arg = arg;
args.align = 0;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
args.flags = flags | UMA_ZFLAG_CACHE;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
}
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
/* See uma.h */
void
uma_zdestroy(uma_zone_t zone)
{
Further UMA statistics related changes: - Add a new uma_zfree_internal() flag, ZFREE_STATFREE, which causes it to to update the zone's uz_frees statistic. Previously, the statistic was updated unconditionally. - Use the flag in situations where a "real" free occurs: i.e., one where the caller is freeing an allocated item, to be differentiated from situations where uma_zfree_internal() is used to tear down the item during slab teardown in order to invoke its fini() method. Also use the flag when UMA is freeing its internal objects. - When exchanging a bucket with the zone from the per-CPU cache when freeing an item, flush cache statistics back to the zone (since the zone lock and critical section are both held) to match the allocation case. MFC after: 3 days
2005-07-20 18:47:42 +00:00
UMA: Don't destroy zones after the system shutdown process starts. Some kernel subsystems, notably ZFS, will destroy UMA zones from a shutdown eventhandler. This causes the zone to be drained. For slabs that are mapped into KVA this can be very expensive and so it needlessly delays the shutdown process. Add a new state to the "booted" variable, BOOT_SHUTDOWN. Once kern_reboot() starts invoking shutdown handlers, turn uma_zdestroy() into a no-op, provided that the zone does not have a custom finalization routine. PR: 242427 Reviewed by: jeff, kib, rlibby MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23066
2020-01-09 19:17:42 +00:00
/*
* Large slabs are expensive to reclaim, so don't bother doing
* unnecessary work if we're shutting down.
*/
if (booted == BOOT_SHUTDOWN &&
zone->uz_fini == NULL && zone->uz_release == zone_release)
return;
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_slock(&uma_reclaim_lock);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
zone_free_item(zones, zone, NULL, SKIP_NONE);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_sunlock(&uma_reclaim_lock);
Implement uma_zdestroy(). It's prototype changed slightly. I decided that I didn't like the wait argument and that if you were removing a zone it had better be empty. Also, I broke out part of hash_expand and made a seperate hash_free() for use in uma_zdestroy.
2002-04-08 04:48:58 +00:00
}
Replace manyinstances of VM_WAIT with blocking page allocation flags similar to the kernel memory allocator. This simplifies NUMA allocation because the domain will be known at wait time and races between failure and sleeping are eliminated. This also reduces boilerplate code and simplifies callers. A wait primitive is supplied for uma zones for similar reasons. This eliminates some non-specific VM_WAIT calls in favor of more explicit sleeps that may be satisfied without new pages. Reviewed by: alc, kib, markj Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2017-11-08 02:39:37 +00:00
void
uma_zwait(uma_zone_t zone)
{
void *item;
item = uma_zalloc_arg(zone, NULL, M_WAITOK);
uma_zfree(zone, item);
}
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
void *
uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
{
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
void *item, *pcpu_item;
Fix uma_zalloc_pcpu_arg() operation in case of !SMP build. Reviewed by: mjg Sponsored by: DARPA, AFRL
2018-06-21 11:43:54 +00:00
#ifdef SMP
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
int i;
MPASS(zone->uz_flags & UMA_ZONE_PCPU);
Fix uma_zalloc_pcpu_arg() operation in case of !SMP build. Reviewed by: mjg Sponsored by: DARPA, AFRL
2018-06-21 11:43:54 +00:00
#endif
Fix pre-SI_SUB_CPU initialization of per-CPU counters. r336020 introduced pcpu_page_alloc(), replacing page_alloc() as the backend allocator for PCPU UMA zones. Unlike page_alloc(), it does not honour malloc(9) flags such as M_ZERO or M_NODUMP, so fix that. r336020 also changed counter(9) to initialize each counter using a CPU_FOREACH() loop instead of an SMP rendezvous. Before SI_SUB_CPU, smp_rendezvous() will only execute the callback on the current CPU (i.e., CPU 0), so only one counter gets zeroed. The rest are zeroed by virtue of the fact that UMA gratuitously zeroes slabs when importing them into a zone. Prior to SI_SUB_CPU, all_cpus is clear, so with r336020 we weren't zeroing vm_cnt counters during boot: the CPU_FOREACH() loop had no effect, and pcpu_page_alloc() didn't honour M_ZERO. Fix this by iterating over the full range of CPU IDs when zeroing counters, ignoring whether the corresponding bits in all_cpus are set. Reported and tested by: pho (previous version) Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D16190
2018-07-10 00:18:12 +00:00
item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
if (item == NULL)
return (NULL);
pcpu_item = zpcpu_base_to_offset(item);
if (flags & M_ZERO) {
Fix uma_zalloc_pcpu_arg() operation in case of !SMP build. Reviewed by: mjg Sponsored by: DARPA, AFRL
2018-06-21 11:43:54 +00:00
#ifdef SMP
Fix pre-SI_SUB_CPU initialization of per-CPU counters. r336020 introduced pcpu_page_alloc(), replacing page_alloc() as the backend allocator for PCPU UMA zones. Unlike page_alloc(), it does not honour malloc(9) flags such as M_ZERO or M_NODUMP, so fix that. r336020 also changed counter(9) to initialize each counter using a CPU_FOREACH() loop instead of an SMP rendezvous. Before SI_SUB_CPU, smp_rendezvous() will only execute the callback on the current CPU (i.e., CPU 0), so only one counter gets zeroed. The rest are zeroed by virtue of the fact that UMA gratuitously zeroes slabs when importing them into a zone. Prior to SI_SUB_CPU, all_cpus is clear, so with r336020 we weren't zeroing vm_cnt counters during boot: the CPU_FOREACH() loop had no effect, and pcpu_page_alloc() didn't honour M_ZERO. Fix this by iterating over the full range of CPU IDs when zeroing counters, ignoring whether the corresponding bits in all_cpus are set. Reported and tested by: pho (previous version) Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D16190
2018-07-10 00:18:12 +00:00
for (i = 0; i <= mp_maxid; i++)
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
bzero(zpcpu_get_cpu(pcpu_item, i), zone->uz_size);
Fix uma_zalloc_pcpu_arg() operation in case of !SMP build. Reviewed by: mjg Sponsored by: DARPA, AFRL
2018-06-21 11:43:54 +00:00
#else
bzero(item, zone->uz_size);
#endif
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
}
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
return (pcpu_item);
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
}
/*
* A stub while both regular and pcpu cases are identical.
*/
void
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
uma_zfree_pcpu_arg(uma_zone_t zone, void *pcpu_item, void *udata)
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
{
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
void *item;
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
Eliminate a spurious panic on non-SMP systems (occurred on shutdown/reboot).
2018-06-22 20:22:26 +00:00
#ifdef SMP
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
MPASS(zone->uz_flags & UMA_ZONE_PCPU);
Eliminate a spurious panic on non-SMP systems (occurred on shutdown/reboot).
2018-06-22 20:22:26 +00:00
#endif
Store offset into zpcpu allocations in the per-cpu area. This shorten zpcpu_get and allows more optimizations. Reviewed by: jeff Differential Revision: https://reviews.freebsd.org/D23570
2020-02-12 11:11:22 +00:00
item = zpcpu_offset_to_base(pcpu_item);
uma: implement provisional api for per-cpu zones Per-cpu zone allocations are very rarely done compared to regular zones. The intent is to avoid pessimizing the latter case with per-cpu specific code. In particular contrary to the claim in r334824, M_ZERO is sometimes being used for such zones. But the zeroing method is completely different and braching on it in the fast path for regular zones is a waste of time.
2018-06-08 21:40:03 +00:00
uma_zfree_arg(zone, item, udata);
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
static inline void *
item_ctor(uma_zone_t zone, int uz_flags, int size, void *udata, int flags,
void *item)
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
{
#ifdef INVARIANTS
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
bool skipdbg;
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
skipdbg = uma_dbg_zskip(zone, item);
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
zone->uz_ctor != trash_ctor)
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
trash_ctor(item, size, udata, flags);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
#endif
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/* Check flags before loading ctor pointer. */
if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0) &&
__predict_false(zone->uz_ctor != NULL) &&
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
zone->uz_ctor(item, size, udata, flags) != 0) {
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
counter_u64_add(zone->uz_fails, 1);
zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
return (NULL);
}
#ifdef INVARIANTS
if (!skipdbg)
uma_dbg_alloc(zone, NULL, item);
#endif
if (flags & M_ZERO)
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
bzero(item, size);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
return (item);
}
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
static inline void
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
item_dtor(uma_zone_t zone, void *item, int size, void *udata,
enum zfreeskip skip)
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
{
#ifdef INVARIANTS
bool skipdbg;
skipdbg = uma_dbg_zskip(zone, item);
if (skip == SKIP_NONE && !skipdbg) {
if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
uma_dbg_free(zone, udata, item);
else
uma_dbg_free(zone, NULL, item);
}
#endif
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
if (__predict_true(skip < SKIP_DTOR)) {
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
if (zone->uz_dtor != NULL)
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
zone->uz_dtor(item, size, udata);
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
#ifdef INVARIANTS
if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
zone->uz_dtor != trash_dtor)
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
trash_dtor(item, size, udata);
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
#endif
}
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
#if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS)
#define UMA_ZALLOC_DEBUG
static int
uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
int error;
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
error = 0;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
#ifdef WITNESS
Remove uma_zalloc_arg() hack, which coerced M_WAITOK to M_NOWAIT when allocations were made using improper flags in interrupt context. Replace with a simple WITNESS warning call. This restores the invariant that M_WAITOK allocations will always succeed or die horribly trying, which is relied on by many UMA consumers. MFC after: 3 weeks Discussed with: jhb
2007-01-10 21:04:43 +00:00
if (flags & M_WAITOK) {
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
"uma_zalloc_debug: zone \"%s\"", zone->uz_name);
In uma_zalloc_arg(), if we are performing a M_WAITOK allocation, ensure that td_intr_nesting_level is 0 (like malloc() does). Since malloc() calls uma we can probably remove the check in malloc() for this now. Also, perform an extra witness check in that case to make sure we don't hold any locks when performing a M_WAITOK allocation.
2002-05-20 17:54:48 +00:00
}
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
#endif
#ifdef INVARIANTS
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
KASSERT((flags & M_EXEC) == 0,
("uma_zalloc_debug: called with M_EXEC"));
Don't make assertions about td_critnest when the scheduler is stopped. A panicking thread always executes with a critical section held, so any attempt to allocate or free memory while dumping will otherwise cause a second panic. This can occur, for example, if xpt_polled_action() completes non-dump I/O that was pending at the time of the panic. The fact that this can occur is itself a bug, but asserting in this case does little but reduce the reliability of kernel dumps. Suggested by: kib Reported by: pho
2015-12-11 20:05:07 +00:00
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
("uma_zalloc_debug: called within spinlock or critical section"));
KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0,
("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO"));
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
#endif
Consistently enforce the restriction against calling malloc/free when in a critical section. uma_zalloc_arg()/uma_zalloc_free() may acquire a sleepable lock on the zone. The malloc() family of functions may call uma_zalloc_arg() or uma_zalloc_free(). The malloc(9) man page currently claims that free() will never sleep. It also implies that the malloc() family of functions will not sleep when called with M_NOWAIT. However, it is more correct to say that these functions will not sleep indefinitely. Indeed, they may acquire a sleepable lock. However, a developer may overlook this restriction because the WITNESS check that catches attempts to call the malloc() family of functions within a critical section is inconsistenly applied. This change clarifies the language of the malloc(9) man page to clarify the restriction against calling the malloc() family of functions while in a critical section or holding a spin lock. It also adds KASSERTs at appropriate points to make the enforcement of this restriction more consistent. PR: 204633 Differential Revision: https://reviews.freebsd.org/D4197 Reviewed by: markj Approved by: gnn (mentor) Sponsored by: Juniper Networks
2015-11-19 14:04:53 +00:00
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
#ifdef DEBUG_MEMGUARD
Fix LINT build with MEMGUARD.
2020-01-31 02:03:22 +00:00
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && memguard_cmp_zone(zone)) {
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
void *item;
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
item = memguard_alloc(zone->uz_size, flags);
if (item != NULL) {
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
error = EJUSTRETURN;
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
if (zone->uz_init != NULL &&
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
zone->uz_init(item, zone->uz_size, flags) != 0) {
*itemp = NULL;
return (error);
}
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
if (zone->uz_ctor != NULL &&
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
zone->uz_ctor(item, zone->uz_size, udata,
flags) != 0) {
uma: trash memory when ctor/dtor supplied too On INVARIANTS kernels, UMA has a use-after-free detection mechanism. This mechanism previously required that all of the ctor/dtor/uminit/fini arguments to uma_zcreate() be NULL in order to function. Now, it only requires that uminit and fini be NULL; now, the trash ctor and dtor will be called in addition to any supplied ctor or dtor. Also do a little refactoring for readability of the resulting logic. This enables use-after-free detection for more zones, and will allow for simplification of some callers that worked around the previous restriction (see kern_mbuf.c). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20722
2019-11-27 19:49:55 +00:00
counter_u64_add(zone->uz_fails, 1);
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
zone->uz_fini(item, zone->uz_size);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
*itemp = NULL;
return (error);
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
*itemp = item;
return (error);
Make memguard(9) capable to guard uma(9) allocations.
2011-10-12 18:08:28 +00:00
}
/* This is unfortunate but should not be fatal. */
}
#endif
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
return (error);
}
static int
uma_zfree_debug(uma_zone_t zone, void *item, void *udata)
{
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zfree_debug: called with spinlock or critical section held"));
#ifdef DEBUG_MEMGUARD
Fix LINT build with MEMGUARD.
2020-01-31 02:03:22 +00:00
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && is_memguard_addr(item)) {
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if (zone->uz_dtor != NULL)
zone->uz_dtor(item, zone->uz_size, udata);
if (zone->uz_fini != NULL)
zone->uz_fini(item, zone->uz_size);
memguard_free(item);
return (EJUSTRETURN);
}
#endif
return (0);
}
#endif
static __noinline void *
uma_zalloc_single(uma_zone_t zone, void *udata, int flags)
{
int domain;
/*
* We can not get a bucket so try to return a single item.
*/
if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
domain = PCPU_GET(domain);
else
domain = UMA_ANYDOMAIN;
return (zone_alloc_item(zone, udata, domain, flags));
}
/* See uma.h */
void *
uma_zalloc_smr(uma_zone_t zone, int flags)
{
uma_cache_bucket_t bucket;
uma_cache_t cache;
void *item;
int size, uz_flags;
#ifdef UMA_ZALLOC_DEBUG
KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
("uma_zalloc_arg: called with non-SMR zone.\n"));
if (uma_zalloc_debug(zone, &item, NULL, flags) == EJUSTRETURN)
return (item);
#endif
critical_enter();
do {
cache = &zone->uz_cpu[curcpu];
bucket = &cache->uc_allocbucket;
size = cache_uz_size(cache);
uz_flags = cache_uz_flags(cache);
if (__predict_true(bucket->ucb_cnt != 0)) {
item = cache_bucket_pop(cache, bucket);
critical_exit();
return (item_ctor(zone, uz_flags, size, NULL, flags,
item));
}
} while (cache_alloc(zone, cache, NULL, flags));
critical_exit();
return (uma_zalloc_single(zone, NULL, flags));
}
/* See uma.h */
void *
uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
{
uma_cache_bucket_t bucket;
uma_cache_t cache;
void *item;
int size, uz_flags;
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
/* This is the fast path allocation */
CTR3(KTR_UMA, "uma_zalloc_arg zone %s(%p) flags %d", zone->uz_name,
zone, flags);
#ifdef UMA_ZALLOC_DEBUG
KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("uma_zalloc_arg: called with SMR zone.\n"));
if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
return (item);
#endif
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
/*
* If possible, allocate from the per-CPU cache. There are two
* requirements for safe access to the per-CPU cache: (1) the thread
* accessing the cache must not be preempted or yield during access,
* and (2) the thread must not migrate CPUs without switching which
* cache it accesses. We rely on a critical section to prevent
* preemption and migration. We release the critical section in
* order to acquire the zone mutex if we are unable to allocate from
* the current cache; when we re-acquire the critical section, we
* must detect and handle migration if it has occurred.
*/
critical_enter();
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
do {
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
cache = &zone->uz_cpu[curcpu];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket = &cache->uc_allocbucket;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
size = cache_uz_size(cache);
uz_flags = cache_uz_flags(cache);
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (__predict_true(bucket->ucb_cnt != 0)) {
item = cache_bucket_pop(cache, bucket);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
critical_exit();
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
return (item_ctor(zone, uz_flags, size, udata, flags,
item));
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
}
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
} while (cache_alloc(zone, cache, udata, flags));
critical_exit();
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
return (uma_zalloc_single(zone, udata, flags));
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
}
/*
* Replenish an alloc bucket and possibly restore an old one. Called in
* a critical section. Returns in a critical section.
*
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
* A false return value indicates an allocation failure.
* A true return value indicates success and the caller should retry.
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
*/
static __noinline bool
cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
{
uma_zone_domain_t zdom;
uma_bucket_t bucket;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
int domain;
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
bool lockfail;
CRITICAL_ASSERT(curthread);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
/*
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
* If we have run out of items in our alloc bucket see
* if we can switch with the free bucket.
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
*
* SMR Zones can't re-use the free bucket until the sequence has
* expired.
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
*/
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 &&
cache->uc_freebucket.ucb_cnt != 0) {
cache_bucket_swap(&cache->uc_freebucket,
&cache->uc_allocbucket);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
return (true);
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
/*
* Discard any empty allocation bucket while we hold no locks.
*/
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket = cache_bucket_unload_alloc(cache);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
critical_exit();
if (bucket != NULL)
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
bucket_free(zone, bucket, udata);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
/* Short-circuit for zones without buckets and low memory. */
if (zone->uz_bucket_size == 0 || bucketdisable) {
critical_enter();
return (false);
}
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
/*
* Attempt to retrieve the item from the per-CPU cache has failed, so
* we must go back to the zone. This requires the zone lock, so we
* must drop the critical section, then re-acquire it when we go back
* to the cache. Since the critical section is released, we may be
* preempted or migrate. As such, make sure not to maintain any
* thread-local state specific to the cache from prior to releasing
* the critical section.
*/
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
lockfail = 0;
if (ZONE_TRYLOCK(zone) == 0) {
/* Record contention to size the buckets. */
ZONE_LOCK(zone);
lockfail = 1;
}
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
/* See if we lost the race to fill the cache. */
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
critical_enter();
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
cache = &zone->uz_cpu[curcpu];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (cache->uc_allocbucket.ucb_bucket != NULL) {
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
ZONE_UNLOCK(zone);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
return (true);
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
/*
* Check the zone's cache of buckets.
*/
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH) {
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
domain = PCPU_GET(domain);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
zdom = &zone->uz_domain[domain];
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
} else {
domain = UMA_ANYDOMAIN;
zdom = &zone->uz_domain[0];
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
if ((bucket = zone_fetch_bucket(zone, zdom)) != NULL) {
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
KASSERT(bucket->ub_cnt != 0,
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
("uma_zalloc_arg: Returning an empty bucket."));
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
cache_bucket_load_alloc(cache, bucket);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
return (true);
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
}
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
/* We are no longer associated with this CPU. */
critical_exit();
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
/*
* We bump the uz count when the cache size is insufficient to
* handle the working set.
*/
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
zone->uz_bucket_size++;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
ZONE_UNLOCK(zone);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
* Fill a bucket and attempt to use it as the alloc bucket.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
bucket = zone_alloc_bucket(zone, udata, domain, flags);
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
zone->uz_name, zone, bucket);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (bucket == NULL) {
critical_enter();
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
return (false);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
/*
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
* See if we lost the race or were migrated. Cache the
* initialized bucket to make this less likely or claim
* the memory directly.
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
*/
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
ZONE_LOCK(zone);
critical_enter();
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
cache = &zone->uz_cpu[curcpu];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (cache->uc_allocbucket.ucb_bucket == NULL &&
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0 ||
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
domain == PCPU_GET(domain))) {
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
cache_bucket_load_alloc(cache, bucket);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
zdom->uzd_imax += bucket->ub_cnt;
} else if (zone->uz_bkt_count >= zone->uz_bkt_max) {
critical_exit();
ZONE_UNLOCK(zone);
bucket_drain(zone, bucket);
bucket_free(zone, bucket, udata);
critical_enter();
return (true);
} else
zone_put_bucket(zone, zdom, bucket, false);
ZONE_UNLOCK(zone);
return (true);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
}
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
void *
uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
{
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
Remove the Yarrow PRNG algorithm option in accordance with due notice given in random(4). This includes updating of the relevant man pages, and no-longer-used harvesting parameters. Ensure that the pseudo-unit-test still does something useful, now also with the "other" algorithm instead of Yarrow. PR: 230870 Reviewed by: cem Approved by: so(delphij,gtetlow) Approved by: re(marius) Differential Revision: https://reviews.freebsd.org/D16898
2018-08-26 12:51:46 +00:00
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
/* This is the fast path allocation */
uma: fixup some ktr messages Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23148
2020-01-14 02:13:46 +00:00
CTR4(KTR_UMA, "uma_zalloc_domain zone %s(%p) domain %d flags %d",
zone->uz_name, zone, domain, flags);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
if (flags & M_WAITOK) {
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"uma_zalloc_domain: zone \"%s\"", zone->uz_name);
}
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zalloc_domain: called with spinlock or critical section held"));
return (zone_alloc_item(zone, udata, domain, flags));
}
/*
* Find a slab with some space. Prefer slabs that are partially used over those
* that are totally full. This helps to reduce fragmentation.
*
* If 'rr' is 1, search all domains starting from 'domain'. Otherwise check
* only 'domain'.
*/
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
static uma_slab_t
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
keg_first_slab(uma_keg_t keg, int domain, bool rr)
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
{
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_domain_t dom;
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
uma_slab_t slab;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
int start;
KASSERT(domain >= 0 && domain < vm_ndomains,
("keg_first_slab: domain %d out of range", domain));
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK_ASSERT(keg, domain);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
slab = NULL;
start = domain;
do {
dom = &keg->uk_domain[domain];
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
if ((slab = LIST_FIRST(&dom->ud_part_slab)) != NULL)
return (slab);
if ((slab = LIST_FIRST(&dom->ud_free_slab)) != NULL) {
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
LIST_REMOVE(slab, us_link);
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
dom->ud_free_slabs--;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
return (slab);
}
if (rr)
domain = (domain + 1) % vm_ndomains;
} while (domain != start);
return (NULL);
}
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
/*
* Fetch an existing slab from a free or partial list. Returns with the
* keg domain lock held if a slab was found or unlocked if not.
*/
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
static uma_slab_t
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
{
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uma_slab_t slab;
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
uint32_t reserve;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
/* HASH has a single free list. */
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
domain = 0;
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK(keg, domain);
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
if (keg->uk_domain[domain].ud_free_items <= reserve ||
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
(slab = keg_first_slab(keg, domain, rr)) == NULL) {
KEG_UNLOCK(keg, domain);
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
return (NULL);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
}
return (slab);
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
}
static uma_slab_t
keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
{
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
struct vm_domainset_iter di;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_slab_t slab;
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
int aflags, domain;
bool rr;
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
restart:
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
/*
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
* Use the keg's policy if upper layers haven't already specified a
* domain (as happens with first-touch zones).
*
* To avoid races we run the iterator with the keg lock held, but that
* means that we cannot allow the vm_domainset layer to sleep. Thus,
* clear M_WAITOK and handle low memory conditions locally.
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
*/
rr = rdomain == UMA_ANYDOMAIN;
if (rr) {
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
aflags = (flags & ~M_WAITOK) | M_NOWAIT;
vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
&aflags);
} else {
aflags = flags;
domain = rdomain;
}
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
for (;;) {
slab = keg_fetch_free_slab(keg, domain, rr, flags);
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
if (slab != NULL)
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
return (slab);
/*
* M_NOVM means don't ask at all!
*/
if (flags & M_NOVM)
break;
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
if (slab != NULL)
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
return (slab);
Fix a bug with _NUMA domains introduced in r339686. When M_NOWAIT is specified there was no loop termination condition in keg_fetch_slab(). Reported by: pho Reviewed by: markj
2019-12-25 19:26:35 +00:00
if (!rr && (flags & M_WAITOK) == 0)
break;
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
if (rr && vm_domainset_iter_policy(&di, &domain) != 0) {
if ((flags & M_WAITOK) != 0) {
vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
goto restart;
}
break;
Allow empty NUMA memory domains to support Threadripper2 The AMD Threadripper 2990WX is basically a slightly crippled Epyc. Rather than having 4 memory controllers, one per NUMA domain, it has only 2 memory controllers enabled. This means that only 2 of the 4 NUMA domains can be populated with physical memory, and the others are empty. Add support to FreeBSD for empty NUMA domains by: - creating empty memory domains when parsing the SRAT table, rather than failing to parse the table - not running the pageout deamon threads in empty domains - adding defensive code to UMA to avoid allocating from empty domains - adding defensive code to cpuset to avoid binding to an empty domain Thanks to Jeff for suggesting this strategy. Reviewed by: alc, markj Approved by: re (gjb@) Differential Revision: https://reviews.freebsd.org/D1683
2018-10-01 14:14:21 +00:00
}
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
}
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
/*
* We might not have been able to get a slab but another cpu
* could have while we were unlocked. Check again before we
* fail.
*/
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL)
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
return (slab);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
return (NULL);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Plug a race and a leak in UMA. 1) The race has to do with zone destruction. From the zone destructor we would lock the zone, set the working set size to 0, then unlock the zone, drain it, and then free the structure. Within the window following the working-set-size set to 0 and unlocking of the zone and the point where in zone_drain we re-acquire the zone lock, the uma timer routine could have fired off and changed the working set size to something non-zero, thereby potentially preventing us from completely freeing slabs before destroying the zone (and thus leaking them). 2) The leak has to do with zone destruction as well. When destroying a zone we would take care to free all the buckets cached in the zone, but although we would drain the pcpu cache buckets, we would not free them. This resulted in leaking a couple of bucket structures (512 bytes each) per cpu on SMP during zone destruction. While I'm here, also silence GCC warnings by turning uma_slab_alloc() from inline to real function. It's too big to be an inline. Reviewed by: JeffR
2003-07-30 18:55:15 +00:00
static void *
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
{
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_domain_t dom;
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
void *item;
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
int freei;
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK_ASSERT(keg, slab->us_domain);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
dom = &keg->uk_domain[slab->us_domain];
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
item = slab_item(slab, keg, freei);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
slab->us_freecount--;
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
dom->ud_free_items--;
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
/*
* Move this slab to the full list. It must be on the partial list, so
* we do not need to update the free slab count. In particular,
* keg_fetch_slab() always returns slabs on the partial list.
*/
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
if (slab->us_freecount == 0) {
LIST_REMOVE(slab, us_link);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
}
return (item);
}
static int
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
zone_import(void *arg, void **bucket, int max, int domain, int flags)
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
{
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uma_domain_t dom;
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
uma_zone_t zone;
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
uma_slab_t slab;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_keg_t keg;
Wrap the declaration and assignment of "stripe" with #ifdef NUMA declarations as not all targets are NUMA aware. Found with gcc. Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D16113
2018-07-07 13:37:44 +00:00
#ifdef NUMA
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
int stripe;
Wrap the declaration and assignment of "stripe" with #ifdef NUMA declarations as not all targets are NUMA aware. Found with gcc. Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D16113
2018-07-07 13:37:44 +00:00
#endif
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
int i;
- Introduce the new M_NOVM option which tells uma to only check the currently allocated slabs and bucket caches for free items. It will not go ask the vm for pages. This differs from M_NOWAIT in that it not only doesn't block, it doesn't even ask. - Add a new zcreate option ZONE_VM, that sets the BUCKETCACHE zflag. This tells uma that it should only allocate buckets out of the bucket cache, and not from the VM. It does this by using the M_NOVM option to zalloc when getting a new bucket. This is so that the VM doesn't recursively enter itself while trying to allocate buckets for vm_map_entry zones. If there are already allocated buckets when we get here we'll still use them but otherwise we'll skip it. - Use the ZONE_VM flag on vm map entries and pv entries on x86.
2002-06-17 22:02:41 +00:00
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
zone = arg;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
slab = NULL;
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
keg = zone->uz_keg;
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
/* Try to keep the buckets totally full */
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
for (i = 0; i < max; ) {
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
break;
Wrap the declaration and assignment of "stripe" with #ifdef NUMA declarations as not all targets are NUMA aware. Found with gcc. Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D16113
2018-07-07 13:37:44 +00:00
#ifdef NUMA
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
stripe = howmany(max, vm_ndomains);
Wrap the declaration and assignment of "stripe" with #ifdef NUMA declarations as not all targets are NUMA aware. Found with gcc. Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D16113
2018-07-07 13:37:44 +00:00
#endif
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
dom = &keg->uk_domain[slab->us_domain];
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
while (slab->us_freecount && i < max) {
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
bucket[i++] = slab_alloc_item(keg, slab);
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
if (dom->ud_free_items <= keg->uk_reserve)
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
break;
Move VM_NUMA_ALLOC and DEVICE_NUMA under the single global config option NUMA. Sponsored by: Netflix, Dell/EMC Isilon Discussed with: jhb
2018-01-14 03:36:03 +00:00
#ifdef NUMA
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
/*
* If the zone is striped we pick a new slab for every
* N allocations. Eliminating this conditional will
* instead pick a new domain for each bucket rather
* than stripe within each bucket. The current option
* produces more fragmentation and requires more cpu
* time but yields better distribution.
*/
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0 &&
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
vm_ndomains > 1 && --stripe == 0)
break;
#endif
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
}
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_UNLOCK(keg, slab->us_domain);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
/* Don't block if we allocated any successfully. */
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
flags &= ~M_WAITOK;
flags |= M_NOWAIT;
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
return i;
}
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
static int
zone_alloc_limit_hard(uma_zone_t zone, int count, int flags)
{
uint64_t old, new, total, max;
/*
* The hard case. We're going to sleep because there were existing
* sleepers or because we ran out of items. This routine enforces
* fairness by keeping fifo order.
*
* First release our ill gotten gains and make some noise.
*/
for (;;) {
zone_free_limit(zone, count);
zone_log_warning(zone);
zone_maxaction(zone);
if (flags & M_NOWAIT)
return (0);
/*
* We need to allocate an item or set ourself as a sleeper
* while the sleepq lock is held to avoid wakeup races. This
* is essentially a home rolled semaphore.
*/
sleepq_lock(&zone->uz_max_items);
old = zone->uz_items;
do {
MPASS(UZ_ITEMS_SLEEPERS(old) < UZ_ITEMS_SLEEPERS_MAX);
/* Cache the max since we will evaluate twice. */
max = zone->uz_max_items;
if (UZ_ITEMS_SLEEPERS(old) != 0 ||
UZ_ITEMS_COUNT(old) >= max)
new = old + UZ_ITEMS_SLEEPER;
else
new = old + MIN(count, max - old);
} while (atomic_fcmpset_64(&zone->uz_items, &old, new) == 0);
/* We may have successfully allocated under the sleepq lock. */
if (UZ_ITEMS_SLEEPERS(new) == 0) {
sleepq_release(&zone->uz_max_items);
return (new - old);
}
/*
* This is in a different cacheline from uz_items so that we
* don't constantly invalidate the fastpath cacheline when we
* adjust item counts. This could be limited to toggling on
* transitions.
*/
atomic_add_32(&zone->uz_sleepers, 1);
atomic_add_64(&zone->uz_sleeps, 1);
/*
* We have added ourselves as a sleeper. The sleepq lock
* protects us from wakeup races. Sleep now and then retry.
*/
sleepq_add(&zone->uz_max_items, NULL, "zonelimit", 0, 0);
sleepq_wait(&zone->uz_max_items, PVM);
/*
* After wakeup, remove ourselves as a sleeper and try
* again. We no longer have the sleepq lock for protection.
*
* Subract ourselves as a sleeper while attempting to add
* our count.
*/
atomic_subtract_32(&zone->uz_sleepers, 1);
old = atomic_fetchadd_64(&zone->uz_items,
-(UZ_ITEMS_SLEEPER - count));
/* We're no longer a sleeper. */
old -= UZ_ITEMS_SLEEPER;
/*
* If we're still at the limit, restart. Notably do not
* block on other sleepers. Cache the max value to protect
* against changes via sysctl.
*/
total = UZ_ITEMS_COUNT(old);
max = zone->uz_max_items;
if (total >= max)
continue;
/* Truncate if necessary, otherwise wake other sleepers. */
if (total + count > max) {
zone_free_limit(zone, total + count - max);
count = max - total;
} else if (total + count < max && UZ_ITEMS_SLEEPERS(old) != 0)
wakeup_one(&zone->uz_max_items);
return (count);
}
}
/*
* Allocate 'count' items from our max_items limit. Returns the number
* available. If M_NOWAIT is not specified it will sleep until at least
* one item can be allocated.
*/
static int
zone_alloc_limit(uma_zone_t zone, int count, int flags)
{
uint64_t old;
uint64_t max;
max = zone->uz_max_items;
MPASS(max > 0);
/*
* We expect normal allocations to succeed with a simple
* fetchadd.
*/
old = atomic_fetchadd_64(&zone->uz_items, count);
if (__predict_true(old + count <= max))
return (count);
/*
* If we had some items and no sleepers just return the
* truncated value. We have to release the excess space
* though because that may wake sleepers who weren't woken
* because we were temporarily over the limit.
*/
if (old < max) {
zone_free_limit(zone, (old + count) - max);
return (max - old);
}
return (zone_alloc_limit_hard(zone, count, flags));
}
/*
* Free a number of items back to the limit.
*/
static void
zone_free_limit(uma_zone_t zone, int count)
{
uint64_t old;
MPASS(count > 0);
/*
* In the common case we either have no sleepers or
* are still over the limit and can just return.
*/
old = atomic_fetchadd_64(&zone->uz_items, -count);
if (__predict_true(UZ_ITEMS_SLEEPERS(old) == 0 ||
UZ_ITEMS_COUNT(old) - count >= zone->uz_max_items))
return;
/*
* Moderate the rate of wakeups. Sleepers will continue
* to generate wakeups if necessary.
*/
wakeup_one(&zone->uz_max_items);
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
static uma_bucket_t
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
{
uma_bucket_t bucket;
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
int maxbucket, cnt;
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
uma: fixup some ktr messages Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23148
2020-01-14 02:13:46 +00:00
CTR3(KTR_UMA, "zone_alloc_bucket zone %s(%p) domain %d", zone->uz_name,
zone, domain);
Allow empty NUMA memory domains to support Threadripper2 The AMD Threadripper 2990WX is basically a slightly crippled Epyc. Rather than having 4 memory controllers, one per NUMA domain, it has only 2 memory controllers enabled. This means that only 2 of the 4 NUMA domains can be populated with physical memory, and the others are empty. Add support to FreeBSD for empty NUMA domains by: - creating empty memory domains when parsing the SRAT table, rather than failing to parse the table - not running the pageout deamon threads in empty domains - adding defensive code to UMA to avoid allocating from empty domains - adding defensive code to cpuset to avoid binding to an empty domain Thanks to Jeff for suggesting this strategy. Reviewed by: alc, markj Approved by: re (gjb@) Differential Revision: https://reviews.freebsd.org/D1683
2018-10-01 14:14:21 +00:00
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
/* Avoid allocs targeting empty domains. */
if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
domain = UMA_ANYDOMAIN;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (zone->uz_max_items > 0)
maxbucket = zone_alloc_limit(zone, zone->uz_bucket_size,
M_NOWAIT);
else
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
maxbucket = zone->uz_bucket_size;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (maxbucket == 0)
return (false);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
/* Don't wait for buckets, preserve caller's NOVM setting. */
bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
if (bucket == NULL) {
cnt = 0;
goto out;
}
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
MIN(maxbucket, bucket->ub_entries), domain, flags);
Rework most of the bucket allocation and free code so that per cpu locks are never held across blocking operations. Also, fix two other lock order reversals that were exposed by jhb's witness change. The free path previously had a bug that would cause it to skip the free bucket list in some cases and go straight to allocating a new bucket. This has been fixed as well. These changes made the bucket handling code much cleaner and removed quite a few lock operations. This should be marginally faster now. It is now possible to call malloc w/o Giant and avoid any witness warnings. This still isn't entirely safe though because malloc_type statistics are not protected by any lock.
2002-04-08 02:42:55 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/*
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
* Initialize the memory if necessary.
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
*/
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
int i;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
for (i = 0; i < bucket->ub_cnt; i++)
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
flags) != 0)
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
break;
/*
* If we couldn't initialize the whole bucket, put the
* rest back onto the freelist.
*/
if (i != bucket->ub_cnt) {
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
bucket->ub_cnt - i);
Fix a INVARIANTS-only bug introduced in Revision 1.104: IF INVARIANTS is defined, and in the rare case that we have allocated some objects from the slab and at least one initializer on at least one of those objects failed, and we need to fail the allocation and push the uninitialized items back into the slab caches -- in that scenario, we would fail to [re]set the bucket cache's ub_bucket item references to NULL, which would eventually trigger a KASSERT.
2004-10-27 21:19:35 +00:00
#ifdef INVARIANTS
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
bzero(&bucket->ub_bucket[i],
sizeof(void *) * (bucket->ub_cnt - i));
Fix a INVARIANTS-only bug introduced in Revision 1.104: IF INVARIANTS is defined, and in the rare case that we have allocated some objects from the slab and at least one initializer on at least one of those objects failed, and we need to fail the allocation and push the uninitialized items back into the slab caches -- in that scenario, we would fail to [re]set the bucket cache's ub_bucket item references to NULL, which would eventually trigger a KASSERT.
2004-10-27 21:19:35 +00:00
#endif
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
bucket->ub_cnt = i;
}
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
cnt = bucket->ub_cnt;
Don't count bucket allocation failures for UMA zones as their own failures. There are good reasons for this to happen, such as recursion prevention, etc. and they are not fatal since buckets are just an optimization mechanism. Real bucket allocation failures are any way counted by the bucket zones themselves, and we don't need double accounting there.
2013-11-27 20:16:18 +00:00
if (bucket->ub_cnt == 0) {
bucket_free(zone, bucket, udata);
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
counter_u64_add(zone->uz_fails, 1);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
bucket = NULL;
}
out:
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (zone->uz_max_items > 0 && cnt < maxbucket)
zone_free_limit(zone, maxbucket - cnt);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
return (bucket);
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
}
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
* Allocates a single item from a zone.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Arguments
* zone The zone to alloc for.
* udata The data to be passed to the constructor.
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
* domain The domain to allocate from or UMA_ANYDOMAIN.
Back out M_* changes, per decision of the TRB. Approved by: trb
2003-02-19 05:47:46 +00:00
* flags M_WAITOK, M_NOWAIT, M_ZERO.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*
* Returns
* NULL if there is no memory and M_NOWAIT is set
- Now that uma_zalloc_internal is not the fast path don't be so fussy about extra function calls. Refactor uma_zalloc_internal into seperate functions for finding the most appropriate slab, filling buckets, allocating single items, and pulling items off of slabs. This makes the code significantly cleaner. - This also fixes the "Returning an empty bucket." panic that a few people have seen. Tested On: alpha, x86
2002-10-24 07:59:03 +00:00
* An item if successful
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
static void *
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
void *item;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (zone->uz_max_items > 0 && zone_alloc_limit(zone, 1, flags) == 0)
return (NULL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
/* Avoid allocs targeting empty domains. */
if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
domain = UMA_ANYDOMAIN;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
goto fail_cnt;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/*
* We have to call both the zone's init (not the keg's init)
* and the zone's ctor. This is because the item is going from
* a keg slab directly to the user, and the user is expecting it
* to be both zone-init'd as well as zone-ctor'd.
*/
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
if (zone->uz_init != NULL) {
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
if (zone->uz_init(item, zone->uz_size, flags) != 0) {
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
goto fail_cnt;
* Add a "how" argument to uma_zone constructors and initialization functions so that they know whether the allocation is supposed to be able to sleep or not. * Allow uma_zone constructors and initialation functions to return either success or error. Almost all of the ones in the tree currently return success unconditionally, but mbuf is a notable exception: the packet zone constructor wants to be able to fail if it cannot suballocate an mbuf cluster, and the mbuf allocators want to be able to fail in general in a MAC kernel if the MAC mbuf initializer fails. This fixes the panics people are seeing when they run out of memory for mbuf clusters. * Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing the default. Both bmilekic and jeff have reviewed the changes made to make failable zone allocations work.
2004-08-02 00:18:36 +00:00
}
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata, flags,
item);
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
if (item == NULL)
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
goto fail;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
counter_u64_add(zone->uz_allocs, 1);
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
zone->uz_name, zone);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
return (item);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
Refactor uma_zalloc_arg(). It is a mess of gotos and code which doesn't make sense after many partial refactors. Attempt to make a smaller cache footprint for the fast path. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22470
2019-11-26 22:17:02 +00:00
fail_cnt:
counter_u64_add(zone->uz_fails, 1);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
fail:
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (zone->uz_max_items > 0)
zone_free_limit(zone, 1);
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
zone->uz_name, zone);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
return (NULL);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/* See uma.h */
void
uma_zfree_smr(uma_zone_t zone, void *item)
{
uma_cache_t cache;
uma_cache_bucket_t bucket;
int domain, itemdomain, uz_flags;
#ifdef UMA_ZALLOC_DEBUG
KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
("uma_zfree_smr: called with non-SMR zone.\n"));
KASSERT(item != NULL, ("uma_zfree_smr: Called with NULL pointer."));
if (uma_zfree_debug(zone, item, NULL) == EJUSTRETURN)
return;
#endif
cache = &zone->uz_cpu[curcpu];
uz_flags = cache_uz_flags(cache);
domain = itemdomain = 0;
#ifdef NUMA
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
itemdomain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
#endif
critical_enter();
do {
cache = &zone->uz_cpu[curcpu];
/* SMR Zones must free to the free bucket. */
bucket = &cache->uc_freebucket;
#ifdef NUMA
domain = PCPU_GET(domain);
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
domain != itemdomain) {
bucket = &cache->uc_crossbucket;
}
#endif
if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
cache_bucket_push(cache, bucket, item);
critical_exit();
return;
}
} while (cache_free(zone, cache, NULL, item, itemdomain));
critical_exit();
/*
* If nothing else caught this, we'll just do an internal free.
*/
zone_free_item(zone, item, NULL, SKIP_NONE);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* See uma.h */
void
uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
{
uma_cache_t cache;
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
uma_cache_bucket_t bucket;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
int domain, itemdomain, uz_flags;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Make the UMA harvesting go away completely if not wanted. Default to "not wanted". Provide and document the RANDOM_ENABLE_UMA option. Change RANDOM_FAST to RANDOM_UMA to clarify the harvesting. Remove RANDOM_DEBUG option, replace with SDT probes. These will be of use to folks measuring the harvesting effect when deciding whether to use RANDOM_ENABLE_UMA. Requested by: scottl and others. Approved by: so (/dev/random blanket) Differential Revision: https://reviews.freebsd.org/D3197
2015-08-22 12:59:05 +00:00
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
Remove the Yarrow PRNG algorithm option in accordance with due notice given in random(4). This includes updating of the relevant man pages, and no-longer-used harvesting parameters. Ensure that the pseudo-unit-test still does something useful, now also with the "other" algorithm instead of Yarrow. PR: 230870 Reviewed by: cem Approved by: so(delphij,gtetlow) Approved by: re(marius) Differential Revision: https://reviews.freebsd.org/D16898
2018-08-26 12:51:46 +00:00
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
This is the much-discussed major upgrade to the random(4) device, known to you all as /dev/random. This code has had an extensive rewrite and a good series of reviews, both by the author and other parties. This means a lot of code has been simplified. Pluggable structures for high-rate entropy generators are available, and it is most definitely not the case that /dev/random can be driven by only a hardware souce any more. This has been designed out of the device. Hardware sources are stirred into the CSPRNG (Yarrow, Fortuna) like any other entropy source. Pluggable modules may be written by third parties for additional sources. The harvesting structures and consequently the locking have been simplified. Entropy harvesting is done in a more general way (the documentation for this will follow). There is some GREAT entropy to be had in the UMA allocator, but it is disabled for now as messing with that is likely to annoy many people. The venerable (but effective) Yarrow algorithm, which is no longer supported by its authors now has an alternative, Fortuna. For now, Yarrow is retained as the default algorithm, but this may be changed using a kernel option. It is intended to make Fortuna the default algorithm for 11.0. Interested parties are encouraged to read ISBN 978-0-470-47424-2 "Cryptography Engineering" By Ferguson, Schneier and Kohno for Fortuna's gory details. Heck, read it anyway. Many thanks to Arthur Mesh who did early grunt work, and who got caught in the crossfire rather more than he deserved to. My thanks also to folks who helped me thresh this out on whiteboards and in the odd "Hallway track", or otherwise. My Nomex pants are on. Let the feedback commence! Reviewed by: trasz,des(partial),imp(partial?),rwatson(partial?) Approved by: so(des)
2014-10-30 21:21:53 +00:00
uma: fixup some ktr messages Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23148
2020-01-14 02:13:46 +00:00
CTR2(KTR_UMA, "uma_zfree_arg zone %s(%p)", zone->uz_name, zone);
Generate KTR trace records for uma_zalloc_arg() and uma_zfree_arg(). This doesn't trace every event of interest in UMA, but provides enough basic information to explain lock traces and sleep patterns.
2004-08-06 21:52:38 +00:00
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
#ifdef UMA_ZALLOC_DEBUG
KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("uma_zfree_arg: called with SMR zone.\n"));
if (uma_zfree_debug(zone, item, udata) == EJUSTRETURN)
return;
#endif
uma_zfree(zone, NULL) should do nothing, to match free(9). Noticed by: Ron Steinke <rsteinke at isilon dot com> MFC after: 3 days
2010-10-19 16:06:00 +00:00
/* uma_zfree(..., NULL) does nothing, to match free(9). */
if (item == NULL)
return;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
/*
* We are accessing the per-cpu cache without a critical section to
* fetch size and flags. This is acceptable, if we are preempted we
* will simply read another cpu's line.
*/
cache = &zone->uz_cpu[curcpu];
uz_flags = cache_uz_flags(cache);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if (UMA_ALWAYS_CTORDTOR ||
__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0))
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
Fix the calculation that determines uz_maxpages. It was off for large zones. Fortunately we have no large zones with maximums specified yet, so it wasn't breaking anything. Implement blocking when a zone exceeds the maximum and M_WAITOK is specified. Previously this just failed like the old zone allocator did. The old zone allocator didn't support WAITOK/NOWAIT though so we should do what we advertise. While I was in there I cleaned up some more zalloc logic to further simplify that code path and reduce redundant code. This was needed to make the blocking work properly anyway.
2002-04-14 01:56:25 +00:00
/*
* The race here is acceptable. If we miss it we'll just have to wait
* a little longer for the limits to be reset.
*/
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
if (zone->uz_sleepers > 0)
goto zfree_item;
}
Fix the calculation that determines uz_maxpages. It was off for large zones. Fortunately we have no large zones with maximums specified yet, so it wasn't breaking anything. Implement blocking when a zone exceeds the maximum and M_WAITOK is specified. Previously this just failed like the old zone allocator did. The old zone allocator didn't support WAITOK/NOWAIT though so we should do what we advertise. While I was in there I cleaned up some more zalloc logic to further simplify that code path and reduce redundant code. This was needed to make the blocking work properly anyway.
2002-04-14 01:56:25 +00:00
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
/*
* If possible, free to the per-CPU cache. There are two
* requirements for safe access to the per-CPU cache: (1) the thread
* accessing the cache must not be preempted or yield during access,
* and (2) the thread must not migrate CPUs without switching which
* cache it accesses. We rely on a critical section to prevent
* preemption and migration. We release the critical section in
* order to acquire the zone mutex if we are unable to free to the
* current cache; when we re-acquire the critical section, we must
* detect and handle migration if it has occurred.
*/
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
domain = itemdomain = 0;
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
itemdomain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
#endif
Modify UMA to use critical sections to protect per-CPU caches, rather than mutexes, which offers lower overhead on both UP and SMP. When allocating from or freeing to the per-cpu cache, without INVARIANTS enabled, we now no longer perform any mutex operations, which offers a 1%-3% performance improvement in a variety of micro-benchmarks. We rely on critical sections to prevent (a) preemption resulting in reentrant access to UMA on a single CPU, and (b) migration of the thread during access. In the event we need to go back to the zone for a new bucket, we release the critical section to acquire the global zone mutex, and must re-acquire the critical section and re-evaluate which cache we are accessing in case migration has occured, or circumstances have changed in the current cache. Per-CPU cache statistics are now gathered lock-free by the sysctl, which can result in small races in statistics reporting for caches. Reviewed by: bmilekic, jeff (somewhat) Tested by: rwatson, kris, gnn, scottl, mike at sentex dot net, others
2005-04-29 18:56:36 +00:00
critical_enter();
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
do {
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
cache = &zone->uz_cpu[curcpu];
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/*
* Try to free into the allocbucket first to give LIFO
* ordering for cache-hot datastructures. Spill over
* into the freebucket if necessary. Alloc will swap
* them if one runs dry.
*/
bucket = &cache->uc_allocbucket;
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
domain = PCPU_GET(domain);
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
domain != itemdomain) {
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
bucket = &cache->uc_crossbucket;
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
} else
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
#endif
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if (bucket->ucb_cnt >= bucket->ucb_entries)
bucket = &cache->uc_freebucket;
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
cache_bucket_push(cache, bucket, item);
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
critical_exit();
return;
}
} while (cache_free(zone, cache, udata, item, itemdomain));
critical_exit();
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
/*
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
* If nothing else caught this, we'll just do an internal free.
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
*/
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
zfree_item:
zone_free_item(zone, item, udata, SKIP_DTOR);
}
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
/*
* sort crossdomain free buckets to domain correct buckets and cache
* them.
*/
static void
zone_free_cross(uma_zone_t zone, uma_bucket_t bucket, void *udata)
{
struct uma_bucketlist fullbuckets;
uma_zone_domain_t zdom;
uma_bucket_t b;
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
smr_seq_t seq;
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
void *item;
int domain;
CTR3(KTR_UMA,
"uma_zfree: zone %s(%p) draining cross bucket %p",
zone->uz_name, zone, bucket);
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
STAILQ_INIT(&fullbuckets);
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
/*
* To avoid having ndomain * ndomain buckets for sorting we have a
* lock on the current crossfree bucket. A full matrix with
* per-domain locking could be used if necessary.
*/
ZONE_CROSS_LOCK(zone);
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
/*
* It is possible for buckets to arrive here out of order so we fetch
* the current smr seq rather than accepting the bucket's.
*/
seq = SMR_SEQ_INVALID;
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
seq = smr_current(zone->uz_smr);
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
while (bucket->ub_cnt > 0) {
item = bucket->ub_bucket[bucket->ub_cnt - 1];
domain = _vm_phys_domain(pmap_kextract((vm_offset_t)item));
zdom = &zone->uz_domain[domain];
if (zdom->uzd_cross == NULL) {
zdom->uzd_cross = bucket_alloc(zone, udata, M_NOWAIT);
if (zdom->uzd_cross == NULL)
break;
}
Fix a case where ub_seq would fail to be set if the cross bucket was flushed due to memory pressure. Reviewed by: markj Differential Revision: http://reviews.freebsd.org/D23614
2020-02-13 20:58:51 +00:00
b = zdom->uzd_cross;
b->ub_bucket[b->ub_cnt++] = item;
b->ub_seq = seq;
if (b->ub_cnt == b->ub_entries) {
STAILQ_INSERT_HEAD(&fullbuckets, b, ub_link);
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
zdom->uzd_cross = NULL;
}
bucket->ub_cnt--;
}
ZONE_CROSS_UNLOCK(zone);
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
if (!STAILQ_EMPTY(&fullbuckets)) {
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
ZONE_LOCK(zone);
Use STAILQ instead of TAILQ for bucket lists. We only need FIFO behavior and this is more space efficient. Stop queueing recently used buckets to the head of the list. If the bucket goes to a different processor the cache coherency will be more expensive. We already try to encourage cache-hot behavior in the per-cpu layer. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D23493
2020-02-04 02:41:24 +00:00
while ((b = STAILQ_FIRST(&fullbuckets)) != NULL) {
STAILQ_REMOVE_HEAD(&fullbuckets, ub_link);
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
if (zone->uz_bkt_count >= zone->uz_bkt_max) {
ZONE_UNLOCK(zone);
bucket_drain(zone, b);
bucket_free(zone, b, udata);
ZONE_LOCK(zone);
} else {
domain = _vm_phys_domain(
pmap_kextract(
(vm_offset_t)b->ub_bucket[0]));
zdom = &zone->uz_domain[domain];
zone_put_bucket(zone, zdom, b, true);
}
}
ZONE_UNLOCK(zone);
}
if (bucket->ub_cnt != 0)
bucket_drain(zone, bucket);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
bucket->ub_seq = SMR_SEQ_INVALID;
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
bucket_free(zone, bucket, udata);
}
#endif
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
static void
zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
int domain, int itemdomain)
{
uma_zone_domain_t zdom;
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
/*
* Buckets coming from the wrong domain will be entirely for the
* only other domain on two domain systems. In this case we can
* simply cache them. Otherwise we need to sort them back to
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
* correct domains.
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
*/
if (domain != itemdomain && vm_ndomains > 2) {
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
zone_free_cross(zone, bucket, udata);
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
return;
Mechanical whitespace cleanup.
2004-01-30 16:26:29 +00:00
}
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
#endif
Sort cross-domain frees into per-domain buckets before inserting these onto their respective bucket lists. This is a several order of magnitude improvement in contention on the keg lock under heavy free traffic while requiring only an additional bucket per-domain worth of memory. Discussed with: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22830
2020-01-04 07:56:28 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
* Attempt to save the bucket in the zone's domain bucket cache.
*
* We bump the uz count when the cache size is insufficient to
* handle the working set.
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
*/
Grow UMA zone bucket size also on lock congestion during item free. Lock congestion is the same, whether it happens on alloc or free, so handle it equally. Now that we have back pressure, there is no problem to grow buckets a bit faster. Any way growth is much slower then in 9.x.
2013-11-19 10:17:10 +00:00
if (ZONE_TRYLOCK(zone) == 0) {
/* Record contention to size the buckets. */
ZONE_LOCK(zone);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
if (zone->uz_bucket_size < zone->uz_bucket_size_max)
zone->uz_bucket_size++;
Grow UMA zone bucket size also on lock congestion during item free. Lock congestion is the same, whether it happens on alloc or free, so handle it equally. Now that we have back pressure, there is no problem to grow buckets a bit faster. Any way growth is much slower then in 9.x.
2013-11-19 10:17:10 +00:00
}
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
CTR3(KTR_UMA,
"uma_zfree: zone %s(%p) putting bucket %p on free list",
zone->uz_name, zone, bucket);
/* ub_cnt is pointing to the last free item */
KASSERT(bucket->ub_cnt == bucket->ub_entries,
("uma_zfree: Attempting to insert partial bucket onto the full list.\n"));
if (zone->uz_bkt_count >= zone->uz_bkt_max) {
ZONE_UNLOCK(zone);
bucket_drain(zone, bucket);
bucket_free(zone, bucket, udata);
} else {
zdom = &zone->uz_domain[itemdomain];
zone_put_bucket(zone, zdom, bucket, true);
ZONE_UNLOCK(zone);
}
}
/*
* Populate a free or cross bucket for the current cpu cache. Free any
* existing full bucket either to the zone cache or back to the slab layer.
*
* Enters and returns in a critical section. false return indicates that
* we can not satisfy this free in the cache layer. true indicates that
* the caller should retry.
*/
static __noinline bool
cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, void *item,
int itemdomain)
{
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
uma_cache_bucket_t cbucket;
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
uma_bucket_t newbucket, bucket;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
int domain;
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
CRITICAL_ASSERT(curthread);
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if (zone->uz_bucket_size == 0)
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
return false;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
cache = &zone->uz_cpu[curcpu];
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
newbucket = NULL;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
/*
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
* FIRSTTOUCH domains need to free to the correct zdom. When
* enabled this is the zdom of the item. The bucket is the
* cross bucket if the current domain and itemdomain do not match.
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
*/
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
cbucket = &cache->uc_freebucket;
#ifdef NUMA
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0) {
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
domain = PCPU_GET(domain);
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if (domain != itemdomain) {
cbucket = &cache->uc_crossbucket;
if (cbucket->ucb_cnt != 0)
atomic_add_64(&zone->uz_xdomain,
cbucket->ucb_cnt);
}
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
} else
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
#endif
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
itemdomain = domain = 0;
bucket = cache_bucket_unload(cbucket);
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
Release the second critical section in uma_zfree_arg() slightly earlier. It is only needed when removing a full bucket from the per-CPU cache. The bucket cache (uz_buckets) is protected by the zone mutex and thus the critical section can be released before inserting into that list. MFC after: 1 week
2016-07-20 01:01:50 +00:00
/* We are no longer associated with this CPU. */
critical_exit();
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/*
* Don't let SMR zones operate without a free bucket. Force
* a synchronize and re-use this one. We will only degrade
* to a synchronize every bucket_size items rather than every
* item if we fail to allocate a bucket.
*/
if ((zone->uz_flags & UMA_ZONE_SMR) != 0) {
if (bucket != NULL)
bucket->ub_seq = smr_advance(zone->uz_smr);
newbucket = bucket_alloc(zone, udata, M_NOWAIT);
if (newbucket == NULL && bucket != NULL) {
bucket_drain(zone, bucket);
newbucket = bucket;
bucket = NULL;
}
} else if (!bucketdisable)
newbucket = bucket_alloc(zone, udata, M_NOWAIT);
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
if (bucket != NULL)
zone_free_bucket(zone, bucket, udata, domain, itemdomain);
critical_enter();
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
if ((bucket = newbucket) == NULL)
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
return (false);
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
cache = &zone->uz_cpu[curcpu];
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
#ifdef NUMA
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
/*
* Check to see if we should be populating the cross bucket. If it
* is already populated we will fall through and attempt to populate
* the free bucket.
*/
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0) {
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
domain = PCPU_GET(domain);
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (domain != itemdomain &&
cache->uc_crossbucket.ucb_bucket == NULL) {
cache_bucket_load_cross(cache, bucket);
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
return (true);
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
}
}
#endif
Grow UMA zone bucket size also on lock congestion during item free. Lock congestion is the same, whether it happens on alloc or free, so handle it equally. Now that we have back pressure, there is no problem to grow buckets a bit faster. Any way growth is much slower then in 9.x.
2013-11-19 10:17:10 +00:00
/*
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
* We may have lost the race to fill the bucket or switched CPUs.
Grow UMA zone bucket size also on lock congestion during item free. Lock congestion is the same, whether it happens on alloc or free, so handle it equally. Now that we have back pressure, there is no problem to grow buckets a bit faster. Any way growth is much slower then in 9.x.
2013-11-19 10:17:10 +00:00
*/
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
if (cache->uc_freebucket.ucb_bucket != NULL) {
Refine UMA bucket allocation to reduce space consumption and improve performance. - Always free to the alloc bucket if there is space. This gives LIFO allocation order to improve hot-cache performance. This also allows for zones with a single bucket per-cpu rather than a pair if the entire working set fits in one bucket. - Enable per-cpu caches of buckets. To prevent recursive bucket allocation one bucket zone still has per-cpu caches disabled. - Pick the initial bucket size based on a table driven maximum size per-bucket rather than the number of items per-page. This gives more sane initial sizes. - Only grow the bucket size when we face contention on the zone lock, this causes bucket sizes to grow more slowly. - Adjust the number of items per-bucket to account for the header space. This packs the buckets more efficiently per-page while making them not quite powers of two. - Eliminate the per-zone free bucket list. Always return buckets back to the bucket zone. This ensures that as zones grow into larger bucket sizes they eventually discard the smaller sizes. It persists fewer buckets in the system. The locking is slightly trickier. - Only switch buckets in zalloc, not zfree, this eliminates pathological cases where we ping-pong between two buckets. - Ensure that the thread that fills a new bucket gets to allocate from it to give a better upper bound on allocation time. Sponsored by: EMC / Isilon Storage Division
2013-06-18 04:50:20 +00:00
critical_exit();
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
bucket_free(zone, bucket, udata);
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
critical_enter();
} else
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
cache_bucket_load_free(cache, bucket);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Refactor uma_zfree_arg into several functions to make control flow more clear and icache usage cleaner. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22491
2019-11-27 23:19:06 +00:00
return (true);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
void
uma_zfree_domain(uma_zone_t zone, void *item, void *udata)
{
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
Remove the Yarrow PRNG algorithm option in accordance with due notice given in random(4). This includes updating of the relevant man pages, and no-longer-used harvesting parameters. Ensure that the pseudo-unit-test still does something useful, now also with the "other" algorithm instead of Yarrow. PR: 230870 Reviewed by: cem Approved by: so(delphij,gtetlow) Approved by: re(marius) Differential Revision: https://reviews.freebsd.org/D16898
2018-08-26 12:51:46 +00:00
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma: fixup some ktr messages Reviewed by: markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23148
2020-01-14 02:13:46 +00:00
CTR2(KTR_UMA, "uma_zfree_domain zone %s(%p)", zone->uz_name, zone);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zfree_domain: called with spinlock or critical section held"));
/* uma_zfree(..., NULL) does nothing, to match free(9). */
if (item == NULL)
return;
zone_free_item(zone, item, udata, SKIP_NONE);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
static void
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
uma_keg_t keg;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_domain_t dom;
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
int freei;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
keg = zone->uz_keg;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK_ASSERT(keg, slab->us_domain);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* Do we need to remove from any lists? */
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
dom = &keg->uk_domain[slab->us_domain];
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
if (slab->us_freecount + 1 == keg->uk_ipers) {
Revert last commit, I have no idea what happened.
2003-06-09 22:51:36 +00:00
LIST_REMOVE(slab, us_link);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
dom->ud_free_slabs++;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
} else if (slab->us_freecount == 0) {
LIST_REMOVE(slab, us_link);
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
/* Slab management. */
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
freei = slab_item_index(slab, keg, item);
Use a precise bit count for the slab free items in UMA. This significantly shrinks embedded slab structures. Reviewed by: markj, rlibby (prior version) Differential Revision: https://reviews.freebsd.org/D22584
2019-12-02 22:44:34 +00:00
BIT_SET(keg->uk_ipers, freei, &slab->us_free);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
slab->us_freecount++;
- Convert the slab free item list from a linked array of indices to a bitmap using sys/bitset. This is much simpler, has lower space overhead and is cheaper in most cases. - Use a second bitmap for invariants asserts and improve the quality of the asserts as well as the number of erroneous conditions that we will catch. - Drastically simplify sizing code. Special case refcnt zones since they will be going away. - Update stale comments. Sponsored by: EMC / Isilon Storage Division
2013-06-13 21:05:38 +00:00
/* Keg statistics. */
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
dom->ud_free_items++;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
}
static void
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
zone_release(void *arg, void **bucket, int cnt)
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
{
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
struct mtx *lock;
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
uma_zone_t zone;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
uma_slab_t slab;
uma_keg_t keg;
uint8_t *mem;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
void *item;
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
int i;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Fix the signature for zone_import and zone_release These are cast to uma_import and uma_release functions. Use the signature for these in the zone functions. This was found with an experimental Kernel CFI. It will complain if the signature is different than what a function pointer expects. The simplest way to fix these is to correct the signature. Reviewed by: rlibby Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D22671
2019-12-04 18:40:05 +00:00
zone = arg;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
keg = zone->uz_keg;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
lock = NULL;
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (__predict_false((zone->uz_flags & UMA_ZFLAG_HASH) != 0))
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
lock = KEG_LOCK(keg, 0);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
for (i = 0; i < cnt; i++) {
item = bucket[i];
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (__predict_true((zone->uz_flags & UMA_ZFLAG_VTOSLAB) != 0)) {
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
slab = vtoslab((vm_offset_t)item);
} else {
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((zone->uz_flags & UMA_ZFLAG_HASH) != 0)
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
slab = hash_sfind(&keg->uk_hash, mem);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
else
slab = (uma_slab_t)(mem + keg->uk_pgoff);
}
if (lock != KEG_LOCKPTR(keg, slab->us_domain)) {
if (lock != NULL)
mtx_unlock(lock);
lock = KEG_LOCK(keg, slab->us_domain);
}
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
slab_free_item(zone, slab, item);
Fix the calculation that determines uz_maxpages. It was off for large zones. Fortunately we have no large zones with maximums specified yet, so it wasn't breaking anything. Implement blocking when a zone exceeds the maximum and M_WAITOK is specified. Previously this just failed like the old zone allocator did. The old zone allocator didn't support WAITOK/NOWAIT though so we should do what we advertise. While I was in there I cleaned up some more zalloc logic to further simplify that code path and reduce redundant code. This was needed to make the blocking work properly anyway.
2002-04-14 01:56:25 +00:00
}
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
if (lock != NULL)
mtx_unlock(lock);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
/*
* Frees a single item to any zone.
*
* Arguments:
* zone The zone to free to
* item The item we're freeing
* udata User supplied data for the dtor
* skip Skip dtors and finis
*/
static void
zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
{
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/*
* If a free is sent directly to an SMR zone we have to
* synchronize immediately because the item can instantly
* be reallocated. This should only happen in degenerate
* cases when no memory is available for per-cpu caches.
*/
if ((zone->uz_flags & UMA_ZONE_SMR) != 0 && skip == SKIP_NONE)
smr_synchronize(zone->uz_smr);
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
item_dtor(zone, item, zone->uz_size, udata, skip);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
if (skip < SKIP_FINI && zone->uz_fini)
zone->uz_fini(item, zone->uz_size);
zone->uz_release(zone->uz_arg, &item, 1);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
if (skip & SKIP_CNT)
return;
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
counter_u64_add(zone->uz_frees, 1);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (zone->uz_max_items > 0)
zone_free_limit(zone, 1);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
}
Add uma_zone_set_max() to add enforced limits to non vm obj backed zones.
2002-03-20 05:28:34 +00:00
/* See uma.h */
Change uma_zone_set_max to return the effective value of "nitems" after rounding. The same value can also be obtained with uma_zone_get_max, but this change avoids a caller having to make two back-to-back calls. Sponsored by: FreeBSD Foundation Reviewed by: gnn, jhb
2010-10-16 04:41:45 +00:00
int
Add uma_zone_set_max() to add enforced limits to non vm obj backed zones.
2002-03-20 05:28:34 +00:00
uma_zone_set_max(uma_zone_t zone, int nitems)
{
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
struct uma_bucket_zone *ubz;
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
int count;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
/*
* XXX This can misbehave if the zone has any allocations with
* no limit and a limit is imposed. There is currently no
* way to clear a limit.
*/
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
ZONE_LOCK(zone);
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
ubz = bucket_zone_max(zone, nitems);
count = ubz != NULL ? ubz->ubz_entries : 0;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone->uz_bucket_size_max = zone->uz_bucket_size = count;
if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
zone->uz_bucket_size_min = zone->uz_bucket_size_max;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone->uz_max_items = nitems;
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
zone->uz_flags |= UMA_ZFLAG_LIMIT;
zone_update_caches(zone);
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
/* We may need to wake waiters. */
wakeup(&zone->uz_max_items);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
ZONE_UNLOCK(zone);
return (nitems);
}
/* See uma.h */
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
void
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
uma_zone_set_maxcache(uma_zone_t zone, int nitems)
{
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
struct uma_bucket_zone *ubz;
int bpcpu;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
ZONE_LOCK(zone);
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
ubz = bucket_zone_max(zone, nitems);
if (ubz != NULL) {
bpcpu = 2;
UMA NUMA flag day. UMA_ZONE_NUMA was a source of confusion. Make the names more consistent with other NUMA features as UMA_ZONE_FIRSTTOUCH and UMA_ZONE_ROUNDROBIN. The system will now pick a select a default depending on kernel configuration. API users need only specify one if they want to override the default. Remove the UMA_XDOMAIN and UMA_FIRSTTOUCH kernel options and key only off of NUMA. XDOMAIN is now fast enough in all cases to enable whenever NUMA is. Reviewed by: markj Discussed with: rlibby Differential Revision: https://reviews.freebsd.org/D22831
2020-01-04 18:48:13 +00:00
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
/* Count the cross-domain bucket. */
bpcpu++;
nitems -= ubz->ubz_entries * bpcpu * mp_ncpus;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone->uz_bucket_size_max = ubz->ubz_entries;
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
} else {
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
Revise the page cache size policy. In r353734 the use of the page caches was limited to systems with a relatively large amount of RAM per CPU. This was to mitigate some issues reported with the system not able to keep up with memory pressure in cases where it had been able to do so prior to the addition of the direct free pool cache. This change re-enables those caches. The change modifies uma_zone_set_maxcache(), which was introduced specifically for the page cache zones. Rather than using it to limit only the full bucket cache, have it also set uz_count_max to provide an upper bound on the per-CPU cache size that is consistent with the number of items requested. Remove its return value since it has no use. Enable the page cache zones unconditionally, and limit them to 0.1% of the domain's pages. The limit can be overridden by the vm.pgcache_zone_max tunable as before. Change the item size parameter passed to uma_zcache_create() to the correct size, and stop setting UMA_ZONE_MAXBUCKET. This allows the page cache buckets to be adaptively sized, like the rest of UMA's caches. This also causes the initial bucket size to be small, so only systems which benefit from large caches will get them. Reviewed by: gallatin, jeff MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22393
2019-11-22 16:30:47 +00:00
}
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
zone->uz_bucket_size_min = zone->uz_bucket_size_max;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone->uz_bkt_max = nitems;
ZONE_UNLOCK(zone);
Add uma_zone_set_max() to add enforced limits to non vm obj backed zones.
2002-03-20 05:28:34 +00:00
}
Add uma_zone_get_max() to obtain the effective limit after a call to uma_zone_set_max(). The UMA zone limit is not exactly set to the value supplied but rounded up to completely fill the backing store increment (a page normally). This can lead to surprising situations where the number of elements allocated from UMA is higher than the supplied limit value. The new get function reads back the effective value so that the supplied limit value can be adjusted to the real limit. Reviewed by: jeffr MFC after: 1 week
2010-08-16 14:24:00 +00:00
/* See uma.h */
int
uma_zone_get_max(uma_zone_t zone)
{
int nitems;
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
nitems = atomic_load_64(&zone->uz_max_items);
Add uma_zone_get_max() to obtain the effective limit after a call to uma_zone_set_max(). The UMA zone limit is not exactly set to the value supplied but rounded up to completely fill the backing store increment (a page normally). This can lead to surprising situations where the number of elements allocated from UMA is higher than the supplied limit value. The new get function reads back the effective value so that the supplied limit value can be adjusted to the real limit. Reviewed by: jeffr MFC after: 1 week
2010-08-16 14:24:00 +00:00
return (nitems);
}
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
/* See uma.h */
void
uma_zone_set_warning(uma_zone_t zone, const char *warning)
{
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
ZONE_ASSERT_COLD(zone);
Implemented uma_zone_set_warning(9) function that sets a warning, which will be printed once the given zone becomes full and cannot allocate an item. The warning will not be printed more often than every five minutes. All UMA warnings can be globally turned off by setting sysctl/tunable vm.zone_warnings to 0. Discussed on: arch Obtained from: WHEEL Systems MFC after: 2 weeks
2012-12-07 22:27:13 +00:00
zone->uz_warning = warning;
}
Add a safety net to reclaim mbufs when one of the mbuf zones become exhausted. It is possible for a bug in the code (or, theoretically, even unusual network conditions) to exhaust all possible mbufs or mbuf clusters. When this occurs, things can grind to a halt fairly quickly. However, we currently do not call mb_reclaim() unless the entire system is experiencing a low-memory condition. While it is best to try to prevent exhaustion of one of the mbuf zones, it would also be useful to have a mechanism to attempt to recover from these situations by freeing "expendable" mbufs. This patch makes two changes: a) The patch adds a generic API to the UMA zone allocator to set a function that should be called when an allocation fails because the zone limit has been reached. Because of the way this function can be called, it really should do minimal work. b) The patch uses this API to try to free mbufs when an allocation fails from one of the mbuf zones because the zone limit has been reached. The function schedules a callout to run mb_reclaim(). Differential Revision: https://reviews.freebsd.org/D3864 Reviewed by: gnn Comments by: rrs, glebius MFC after: 2 weeks Sponsored by: Juniper Networks
2015-12-20 02:05:33 +00:00
/* See uma.h */
void
uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
{
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
ZONE_ASSERT_COLD(zone);
Redo r292484. Embed task(9) into zone, so that uz_maxaction is called in a context that can sleep, allowing consumers of the KPI to run their drain routines without any extra measures. Discussed with: jtl
2016-02-03 23:30:17 +00:00
TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
Add a safety net to reclaim mbufs when one of the mbuf zones become exhausted. It is possible for a bug in the code (or, theoretically, even unusual network conditions) to exhaust all possible mbufs or mbuf clusters. When this occurs, things can grind to a halt fairly quickly. However, we currently do not call mb_reclaim() unless the entire system is experiencing a low-memory condition. While it is best to try to prevent exhaustion of one of the mbuf zones, it would also be useful to have a mechanism to attempt to recover from these situations by freeing "expendable" mbufs. This patch makes two changes: a) The patch adds a generic API to the UMA zone allocator to set a function that should be called when an allocation fails because the zone limit has been reached. Because of the way this function can be called, it really should do minimal work. b) The patch uses this API to try to free mbufs when an allocation fails from one of the mbuf zones because the zone limit has been reached. The function schedules a callout to run mb_reclaim(). Differential Revision: https://reviews.freebsd.org/D3864 Reviewed by: gnn Comments by: rrs, glebius MFC after: 2 weeks Sponsored by: Juniper Networks
2015-12-20 02:05:33 +00:00
}
- Simplify implementation of uma_zone_get_max. - Add uma_zone_get_cur which returns the current approximate occupancy of a zone. This is useful for providing stats via sysctl amongst other things. Sponsored by: FreeBSD Foundation Reviewed by: gnn, jhb MFC after: 2 weeks
2010-10-16 04:14:45 +00:00
/* See uma.h */
int
uma_zone_get_cur(uma_zone_t zone)
{
int64_t nitems;
u_int i;
The fix in r356353 was insufficient. Not every architecture returns 0 for EARLY_COUNTER. Only amd64 seems to. Suggested by: markj Reported by: lwhsu Reviewed by: markj PR: 243117
2020-01-05 22:54:25 +00:00
nitems = 0;
if (zone->uz_allocs != EARLY_COUNTER && zone->uz_frees != EARLY_COUNTER)
nitems = counter_u64_fetch(zone->uz_allocs) -
counter_u64_fetch(zone->uz_frees);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
CPU_FOREACH(i)
nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs) -
atomic_load_64(&zone->uz_cpu[i].uc_frees);
- Simplify implementation of uma_zone_get_max. - Add uma_zone_get_cur which returns the current approximate occupancy of a zone. This is useful for providing stats via sysctl amongst other things. Sponsored by: FreeBSD Foundation Reviewed by: gnn, jhb MFC after: 2 weeks
2010-10-16 04:14:45 +00:00
return (nitems < 0 ? 0 : nitems);
}
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static uint64_t
uma_zone_get_allocs(uma_zone_t zone)
{
uint64_t nitems;
u_int i;
The fix in r356353 was insufficient. Not every architecture returns 0 for EARLY_COUNTER. Only amd64 seems to. Suggested by: markj Reported by: lwhsu Reviewed by: markj PR: 243117
2020-01-05 22:54:25 +00:00
nitems = 0;
if (zone->uz_allocs != EARLY_COUNTER)
nitems = counter_u64_fetch(zone->uz_allocs);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
CPU_FOREACH(i)
nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
return (nitems);
}
static uint64_t
uma_zone_get_frees(uma_zone_t zone)
{
uint64_t nitems;
u_int i;
The fix in r356353 was insufficient. Not every architecture returns 0 for EARLY_COUNTER. Only amd64 seems to. Suggested by: markj Reported by: lwhsu Reviewed by: markj PR: 243117
2020-01-05 22:54:25 +00:00
nitems = 0;
if (zone->uz_frees != EARLY_COUNTER)
nitems = counter_u64_fetch(zone->uz_frees);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
CPU_FOREACH(i)
nitems += atomic_load_64(&zone->uz_cpu[i].uc_frees);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
return (nitems);
}
Fix an assertion introduced in r356348. On architectures without UMA_MD_SMALL_ALLOC vmem has a more complicated startup sequence that violated the new assert. Resolve this by rewriting the COLD asserts to look at the per-cpu allocation counts for evidence of api activity. Discussed with: rlibby Reviewed by: markj Reported by: lwhsu
2020-01-04 19:29:25 +00:00
#ifdef INVARIANTS
/* Used only for KEG_ASSERT_COLD(). */
static uint64_t
uma_keg_get_allocs(uma_keg_t keg)
{
uma_zone_t z;
uint64_t nitems;
nitems = 0;
LIST_FOREACH(z, &keg->uk_zones, uz_link)
nitems += uma_zone_get_allocs(z);
return (nitems);
}
#endif
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
/* See uma.h */
void
uma_zone_set_init(uma_zone_t zone, uma_init uminit)
{
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_keg_t keg;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KEG_ASSERT_COLD(keg);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
keg->uk_init = uminit;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
/* See uma.h */
void
uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
{
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_keg_t keg;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KEG_ASSERT_COLD(keg);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
keg->uk_fini = fini;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
}
/* See uma.h */
void
uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
{
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
ZONE_ASSERT_COLD(zone);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
zone->uz_init = zinit;
}
/* See uma.h */
void
uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
{
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
ZONE_ASSERT_COLD(zone);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
zone->uz_fini = zfini;
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* See uma.h */
void
uma_zone_set_freef(uma_zone_t zone, uma_free freef)
{
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
uma_keg_t keg;
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KEG_ASSERT_COLD(keg);
- Add a new UMA API: uma_zcache_create(). This makes a zone without any backing memory that is only a container for per-cpu caches of arbitrary pointer items. These zones have no kegs. - Convert the regular keg based allocator to use the new import/release functions. - Move some stats to be atomics since they would require excessive zone locking/unlocking with the new import/release paradigm. Make zone_free_item simpler now that callers can manage more stats. - Check for these cache-only zones in the public APIs and debugging code by checking zone_first_keg() against NULL. Sponsored by: EMC / Isilong Storage Division
2013-06-17 03:43:47 +00:00
keg->uk_freef = freef;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
/* See uma.h */
void
uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
{
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
uma_keg_t keg;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KEG_ASSERT_COLD(keg);
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
keg->uk_allocf = allocf;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Implement a safe memory reclamation feature that is tightly coupled with UMA. This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is a unique algorithm. This has 3x the performance of epoch in a write heavy workload with less than half of the read side cost. The memory overhead is significantly lessened by limiting the free-to-use latency. A synthetic test uses 1/20th of the memory vs Epoch. There is significant further discussion in the comments and code review. This code should be considered experimental. I will write a man page after it has settled. After further validation the VM will begin using this feature to permit lockless page lookups. Both markj and cperciva tested on arm64 at large core counts to verify fences on weaker ordering architectures. I will commit a stress testing tool in a follow-up. Reviewed by: mmacy, markj, rlibby, hselasky Discussed with: sbahara Differential Revision: https://reviews.freebsd.org/D22586
2020-01-31 00:49:51 +00:00
/* See uma.h */
void
uma_zone_set_smr(uma_zone_t zone, smr_t smr)
{
ZONE_ASSERT_COLD(zone);
zone->uz_flags |= UMA_ZONE_SMR;
zone->uz_smr = smr;
zone_update_caches(zone);
}
smr_t
uma_zone_get_smr(uma_zone_t zone)
{
return (zone->uz_smr);
}
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
/* See uma.h */
void
uma_zone_reserve(uma_zone_t zone, int items)
{
uma_keg_t keg;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KEG_ASSERT_COLD(keg);
- Resolve bucket recursion issues by passing a cookie with zone flags through bucket_alloc() to uma_zalloc_arg() and uma_zfree_arg(). - Make some smaller buckets for large zones to further reduce memory waste. - Implement uma_zone_reserve(). This holds aside a number of items only for callers who specify M_USE_RESERVE. buckets will never be filled from reserve allocations. Sponsored by: EMC / Isilon Storage Division
2013-06-26 00:57:38 +00:00
keg->uk_reserve = items;
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/* See uma.h */
int
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
uma_zone_reserve_kva(uma_zone_t zone, int count)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_keg_t keg;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
vm_offset_t kva;
Avoid sign extension of value passed to kva_alloc from uma_zone_reserve_kva Fixes "panic: vm_radix_reserve_kva: unable to reserve KVA" caused by sign extention of "pages * UMA_SLAB_SIZE" value passed to kva_alloc() which takes unsigned long argument. In the erroneus case that triggered this bug, the number of pages to allocate in uma_zone_reserve_kva() was 0x8ebe6, that gave the total number of bytes to allocate equal to 0x8ebe6000 (int). This was then sign extended in kva_alloc() to 0xffffffff8ebe6000 (unsigned long). Reviewed by: alc, kib Submitted by: Zbigniew Bodek <zbb@semihalf.com> Obtained from: Semihalf Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D3346
2015-08-10 17:16:49 +00:00
u_int pages;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
KEG_ASSERT_COLD(keg);
ZONE_ASSERT_COLD(zone);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Fix uma boot pages calculations on NUMA machines that also don't have MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt of zones while here. This was already correct because uz_cpu strongly aligned the zone structure but the specified alignment did not match reality and involved redundant defines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23046
2020-01-06 02:51:19 +00:00
pages = howmany(count, keg->uk_ipers) * keg->uk_ppera;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
#ifdef UMA_MD_SMALL_ALLOC
if (keg->uk_ppera > 1) {
#else
if (1) {
#endif
uma: fix pages <-> items conversions at several places Those places were not taking into account uk_ppera. At present one allocation is always used by one slab, so uk_ppera must be used to convert between pages and slabs. uk_ipers is used to convert between slabs and items. MFC after: 1 month (if ever)
2017-03-11 16:43:38 +00:00
kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
if (kva == 0)
return (0);
} else
kva = 0;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
ZONE_LOCK(zone);
MPASS(keg->uk_kva == 0);
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
keg->uk_kva = kva;
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
keg->uk_offset = 0;
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
zone->uz_max_items = pages * keg->uk_ipers;
Merge from vmc-playground branch: Replace the sub-optimal uma_zone_set_obj() primitive with more modern uma_zone_reserve_kva(). The new primitive reserves before hand the necessary KVA space to cater the zone allocations and allocates pages with ALLOC_NOOBJ. More specifically: - uma_zone_reserve_kva() does not need an object to cater the backend allocator. - uma_zone_reserve_kva() can cater M_WAITOK requests, in order to serve zones which need to do uma_prealloc() too. - When possible, uma_zone_reserve_kva() uses directly the direct-mapping by uma_small_alloc() rather than relying on the KVA / offset combination. The removal of the object attribute allows 2 further changes: 1) _vm_object_allocate() becomes static within vm_object.c 2) VM_OBJECT_LOCK_INIT() is removed. This function is replaced by direct calls to mtx_init() as there is no need to export it anymore and the calls aren't either homogeneous anymore: there are now small differences between arguments passed to mtx_init(). Sponsored by: EMC / Isilon storage division Reviewed by: alc (which also offered almost all the comments) Tested by: pho, jhb, davide
2013-02-26 23:35:27 +00:00
#ifdef UMA_MD_SMALL_ALLOC
keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
#else
keg->uk_allocf = noobj_alloc;
#endif
Further reduce the cacheline footprint of fast allocations by duplicating the zone size and flags fields in the per-cpu caches. This allows fast alloctions to proceed only touching the single per-cpu cacheline and simplifies the common case when no ctor/dtor is specified. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22826
2019-12-25 20:57:24 +00:00
keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
zone_update_caches(zone);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
ZONE_UNLOCK(zone);
- Add a per-zone lock for zones without kegs. - Be more explicit about zone vs keg locking. This functionally changes almost nothing. - Add a size parameter to uma_zcache_create() so we can size the buckets. - Pass the zone to bucket_alloc() so it can modify allocation flags as appropriate. - Fix a bug in zone_alloc_bucket() where I missed an address of operator in a failure case. (Found by pho) Sponsored by: EMC / Isilon Storage Division
2013-06-20 19:08:12 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
return (1);
}
/* See uma.h */
void
uma_prealloc(uma_zone_t zone, int items)
{
Fix some problems that manifest when NUMA domain 0 is empty. - In uma_prealloc(), we need to check for an empty domain before the first allocation attempt, not after. Fix this by switching uma_prealloc() to use a vm_domainset iterator, which addresses the secondary issue of using a signed domain identifier in round-robin iteration. - Don't automatically create a page daemon for domain 0. - In domainset_empty_vm(), recompute ds_cnt and ds_order after excluding empty domains; otherwise we may frequently specify an empty domain when calling in to the page allocator, wasting CPU time. Convert DOMAINSET_PREF() policies for empty domains to round-robin. - When freeing bootstrap pages, don't count them towards the per-domain total page counts for now: some vm_phys segments are created before the SRAT is parsed and are thus always identified as being in domain 0 even when they are not. Then, when bootstrap pages are freed, they are added to a domain that we had previously thought was empty. Until this is corrected, we simply exclude them from the per-domain page count. Reported and tested by: Rajesh Kumar <rajfbsd@gmail.com> Reviewed by: gallatin MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17704
2018-10-30 17:57:40 +00:00
struct vm_domainset_iter di;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uma_domain_t dom;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
uma_slab_t slab;
Bring in mbuma to replace mballoc. mbuma is an Mbuf & Cluster allocator built on top of a number of extensions to the UMA framework, all included herein. Extensions to UMA worth noting: - Better layering between slab <-> zone caches; introduce Keg structure which splits off slab cache away from the zone structure and allows multiple zones to be stacked on top of a single Keg (single type of slab cache); perhaps we should look into defining a subset API on top of the Keg for special use by malloc(9), for example. - UMA_ZONE_REFCNT zones can now be added, and reference counters automagically allocated for them within the end of the associated slab structures. uma_find_refcnt() does a kextract to fetch the slab struct reference from the underlying page, and lookup the corresponding refcnt. mbuma things worth noting: - integrates mbuf & cluster allocations with extended UMA and provides caches for commonly-allocated items; defines several zones (two primary, one secondary) and two kegs. - change up certain code paths that always used to do: m_get() + m_clget() to instead just use m_getcl() and try to take advantage of the newly defined secondary Packet zone. - netstat(1) and systat(1) quickly hacked up to do basic stat reporting but additional stats work needs to be done once some other details within UMA have been taken care of and it becomes clearer to how stats will work within the modified framework. From the user perspective, one implication is that the NMBCLUSTERS compile-time option is no longer used. The maximum number of clusters is still capped off according to maxusers, but it can be made unlimited by setting the kern.ipc.nmbclusters boot-time tunable to zero. Work should be done to write an appropriate sysctl handler allowing dynamic tuning of kern.ipc.nmbclusters at runtime. Additional things worth noting/known issues (READ): - One report of 'ips' (ServeRAID) driver acting really slow in conjunction with mbuma. Need more data. Latest report is that ips is equally sucking with and without mbuma. - Giant leak in NFS code sometimes occurs, can't reproduce but currently analyzing; brueffer is able to reproduce but THIS IS NOT an mbuma-specific problem and currently occurs even WITHOUT mbuma. - Issues in network locking: there is at least one code path in the rip code where one or more locks are acquired and we end up in m_prepend() with M_WAITOK, which causes WITNESS to whine from within UMA. Current temporary solution: force all UMA allocations to be M_NOWAIT from within UMA for now to avoid deadlocks unless WITNESS is defined and we can determine with certainty that we're not holding any locks when we're M_WAITOK. - I've seen at least one weird socketbuffer empty-but- mbuf-still-attached panic. I don't believe this to be related to mbuma but please keep your eyes open, turn on debugging, and capture crash dumps. This change removes more code than it adds. A paper is available detailing the change and considering various performance issues, it was presented at BSDCan2004: http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf Please read the paper for Future Work and implementation details, as well as credits. Testing and Debugging: rwatson, brueffer, Ketrien I. Saihr-Kesenchedra, ... Reviewed by: Lots of people (for different parts)
2004-05-31 21:46:06 +00:00
uma_keg_t keg;
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
int aflags, domain, slabs;
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
KEG_GET(zone, keg);
Fix uma boot pages calculations on NUMA machines that also don't have MD_UMA_SMALL_ALLOC. This is unusual but not impossible. Fix the alignemnt of zones while here. This was already correct because uz_cpu strongly aligned the zone structure but the specified alignment did not match reality and involved redundant defines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23046
2020-01-06 02:51:19 +00:00
slabs = howmany(items, keg->uk_ipers);
Use a vm_domainset iterator in keg_fetch_slab(). Previously, it used a hand-rolled round-robin iterator. This meant that the minskip logic in r338507 didn't apply to UMA allocations, and also meant that we would call vm_wait() for individual domains rather than permitting an allocation from any domain with sufficient free pages. Discussed with: jeff Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17420
2018-10-24 16:41:47 +00:00
while (slabs-- > 0) {
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
aflags = M_NOWAIT;
vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
&aflags);
for (;;) {
slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
aflags);
if (slab != NULL) {
dom = &keg->uk_domain[slab->us_domain];
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
/*
* keg_alloc_slab() always returns a slab on the
* partial list.
*/
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
LIST_REMOVE(slab, us_link);
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
us_link);
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
dom->ud_free_slabs++;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_UNLOCK(keg, slab->us_domain);
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
break;
}
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
if (vm_domainset_iter_policy(&di, &domain) != 0)
Correct uma_prealloc()'s use of domainset iterators after r339925. The iterator should be reinitialized after every successful slab allocation. A request to advance the iterator is interpreted as an allocation failure, so a sufficiently large preallocation would cause the iterator to believe that all domains were exhausted, resulting in a sleep with the keg lock held. [1] Also, keg_alloc_slab() should pass the unmodified wait flag to the item initialization routine, which may use it to perform allocations from other zones. Reported and tested by: slavah Diagnosed by: kib [1] Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation
2019-01-23 18:58:15 +00:00
vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask);
}
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
}
/* See uma.h */
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
void
uma_reclaim(int req)
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
{
The vmem callback to reclaim kmem arena address space on low or fragmented conditions currently just wakes up the pagedaemon. The kmem arena is significantly smaller then the total available physical memory, which means that there are loads where kmem arena space could be exhausted, while there is a lot of pages available still. The woken up pagedaemon sees vm_pages_needed != 0, verifies the condition vm_paging_needed() which is false, clears the pass and returns back to sleep, not calling neither uma_reclaim() nor lowmem handler. To handle low kmem arena conditions, create additional pagedaemon thread which calls uma_reclaim() directly. The thread sleeps on the dedicated channel and kmem_reclaim() wakes the thread in addition to the pagedaemon. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2015-05-09 20:08:36 +00:00
As old prophecy says, some day UMA_DEBUG printfs shall be made CTRs.
2017-06-01 18:36:52 +00:00
CTR0(KTR_UMA, "UMA: vm asked us to release pages!");
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_xlock(&uma_reclaim_lock);
Add a mechanism to disable buckets when the v_free_count drops below v_free_min. This should help performance in memory starved situations.
2002-04-08 06:20:34 +00:00
bucket_enable();
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
switch (req) {
case UMA_RECLAIM_TRIM:
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_foreach(zone_trim, NULL);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
break;
case UMA_RECLAIM_DRAIN:
case UMA_RECLAIM_DRAIN_CPU:
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_foreach(zone_drain, NULL);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
if (req == UMA_RECLAIM_DRAIN_CPU) {
pcpu_cache_drain_safe(NULL);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_foreach(zone_drain, NULL);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
}
break;
default:
panic("unhandled reclamation request %d", req);
Implement mechanism to safely but slowly purge UMA per-CPU caches. This is a last resort for very low memory condition in case other measures to free memory were ineffective. Sequentially cycle through all CPUs and extract per-CPU cache buckets into zone cache from where they can be freed.
2013-11-19 10:51:46 +00:00
}
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
/*
* Some slabs may have been freed but this zone will be visited early
* we visit again so that we can free pages that are empty once other
* zones are drained. We have to do the same for buckets.
*/
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
zone_drain(slabzones[0], NULL);
zone_drain(slabzones[1], NULL);
- Initialize a pool of bucket zones so that we waste less space on zones that don't cache as many items. - Introduce the bucket_alloc(), bucket_free() functions to wrap bucket allocation. These functions select the appropriate bucket zone to allocate from or free to. - Rename ub_ptr to ub_cnt to reflect a change in its use. ub_cnt now reflects the count of free items in the bucket. This gets rid of many unnatural subtractions by 1 throughout the code. - Add ub_entries which reflects the number of entries possibly held in a bucket.
2003-09-19 06:26:45 +00:00
bucket_zone_drain();
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_xunlock(&uma_reclaim_lock);
This is the first part of the new kernel memory allocator. This replaces malloc(9) and vm_zone with a slab like allocator. Reviewed by: arch@
2002-03-19 09:11:49 +00:00
}
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
static volatile int uma_reclaim_needed;
The vmem callback to reclaim kmem arena address space on low or fragmented conditions currently just wakes up the pagedaemon. The kmem arena is significantly smaller then the total available physical memory, which means that there are loads where kmem arena space could be exhausted, while there is a lot of pages available still. The woken up pagedaemon sees vm_pages_needed != 0, verifies the condition vm_paging_needed() which is false, clears the pass and returns back to sleep, not calling neither uma_reclaim() nor lowmem handler. To handle low kmem arena conditions, create additional pagedaemon thread which calls uma_reclaim() directly. The thread sleeps on the dedicated channel and kmem_reclaim() wakes the thread in addition to the pagedaemon. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2015-05-09 20:08:36 +00:00
void
uma_reclaim_wakeup(void)
{
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
wakeup(uma_reclaim);
The vmem callback to reclaim kmem arena address space on low or fragmented conditions currently just wakes up the pagedaemon. The kmem arena is significantly smaller then the total available physical memory, which means that there are loads where kmem arena space could be exhausted, while there is a lot of pages available still. The woken up pagedaemon sees vm_pages_needed != 0, verifies the condition vm_paging_needed() which is false, clears the pass and returns back to sleep, not calling neither uma_reclaim() nor lowmem handler. To handle low kmem arena conditions, create additional pagedaemon thread which calls uma_reclaim() directly. The thread sleeps on the dedicated channel and kmem_reclaim() wakes the thread in addition to the pagedaemon. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2015-05-09 20:08:36 +00:00
}
void
uma_reclaim_worker(void *arg __unused)
{
for (;;) {
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_xlock(&uma_reclaim_lock);
Perform all accesses to uma_reclaim_needed using atomic(9) KPI. Reviewed by: alc, jhb Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D13534
2017-12-19 10:06:55 +00:00
while (atomic_load_int(&uma_reclaim_needed) == 0)
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
hz);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
sx_xunlock(&uma_reclaim_lock);
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
Perform all accesses to uma_reclaim_needed using atomic(9) KPI. Reviewed by: alc, jhb Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D13534
2017-12-19 10:06:55 +00:00
atomic_store_int(&uma_reclaim_needed, 0);
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
/* Don't fire more than once per-second. */
pause("umarclslp", hz);
The vmem callback to reclaim kmem arena address space on low or fragmented conditions currently just wakes up the pagedaemon. The kmem arena is significantly smaller then the total available physical memory, which means that there are loads where kmem arena space could be exhausted, while there is a lot of pages available still. The woken up pagedaemon sees vm_pages_needed != 0, verifies the condition vm_paging_needed() which is false, clears the pass and returns back to sleep, not calling neither uma_reclaim() nor lowmem handler. To handle low kmem arena conditions, create additional pagedaemon thread which calls uma_reclaim() directly. The thread sleeps on the dedicated channel and kmem_reclaim() wakes the thread in addition to the pagedaemon. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2015-05-09 20:08:36 +00:00
}
}
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
/* See uma.h */
void
uma_zone_reclaim(uma_zone_t zone, int req)
{
switch (req) {
case UMA_RECLAIM_TRIM:
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_trim(zone, NULL);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
break;
case UMA_RECLAIM_DRAIN:
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_drain(zone, NULL);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
break;
case UMA_RECLAIM_DRAIN_CPU:
pcpu_cache_drain_safe(zone);
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
zone_drain(zone, NULL);
Extend uma_reclaim() to permit different reclamation targets. The page daemon periodically invokes uma_reclaim() to reclaim cached items from each zone when the system is under memory pressure. This is important since the size of these caches is unbounded by default. However it also results in bursts of high latency when allocating from heavily used zones as threads miss in the per-CPU caches and must access the keg in order to allocate new items. With r340405 we maintain an estimate of each zone's usage of its (per-NUMA domain) cache of full buckets. Start making use of this estimate to avoid reclaiming the entire cache when under memory pressure. In particular, introduce TRIM, DRAIN and DRAIN_CPU verbs for uma_reclaim() and uma_zone_reclaim(). When trimming, only items in excess of the estimate are reclaimed. Draining a zone reclaims all of the cached full buckets (the previous behaviour of uma_reclaim()), and may further drain the per-CPU caches in extreme cases. Now, when under memory pressure, the page daemon will trim zones rather than draining them. As a result, heavily used zones do not incur bursts of bucket cache misses following reclamation, but large, unused caches will be reclaimed as before. Reviewed by: jeff Tested by: pho (an earlier version) MFC after: 2 months Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D16667
2019-09-01 22:22:43 +00:00
break;
default:
panic("unhandled reclamation request %d", req);
}
}
- Add a new function uma_zone_exhausted() to see if a zone is full. - Add a printf in swp_pager_meta_build() to warn if the swapzone becomes exhausted so that there's at least a warning before a box that runs out of swapzone space before running out of swap space deadlocks. MFC after: 1 week Reviwed by: alc
2007-01-05 19:09:01 +00:00
/* See uma.h */
int
uma_zone_exhausted(uma_zone_t zone)
{
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
return (atomic_load_32(&zone->uz_sleepers) > 0);
Fix for problems that occur when all mbuf clusters migrate to the mbuf packet zone. Cluster allocations fail when this happens. Also processes that may have blocked on cluster allocations will never be woken up. Thanks to rwatson for an overview of the issue and pointers to the mbuma paper and his tool to dump out UMA zones. Reviewed by: andre@
2007-01-25 01:05:23 +00:00
}
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
unsigned long
uma_limit(void)
{
return (uma_kmem_limit);
}
void
uma_set_limit(unsigned long limit)
{
uma_kmem_limit = limit;
}
unsigned long
uma_size(void)
{
Remove the volatile qualifer from uma_kmem_total. No functional change intended. Reviewed by: alc, dougm, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20514
2019-06-06 16:23:44 +00:00
return (atomic_load_long(&uma_kmem_total));
Fix arc after r326347 broke various memory limit queries. Use UMA features rather than kmem arena size to determine available memory. Initialize the UMA limit to LONG_MAX to avoid spurious wakeups on boot before the real limit is set. PR: 224330 (partial), 224080 Reviewed by: markj, avg Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13494
2018-01-02 04:35:56 +00:00
}
long
uma_avail(void)
{
Remove the volatile qualifer from uma_kmem_total. No functional change intended. Reviewed by: alc, dougm, kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20514
2019-06-06 16:23:44 +00:00
return (uma_kmem_limit - uma_size());
Eliminate kmem_arena and kmem_object in preparation for further NUMA commits. The arena argument to kmem_*() is now only used in an assert. A follow-up commit will remove the argument altogether before we freeze the API for the next release. This replaces the hard limit on kmem size with a soft limit imposed by UMA. When the soft limit is exceeded we periodically wakeup the UMA reclaim thread to attempt to shrink KVA. On 32bit architectures this should behave much more gracefully as we exhaust KVA. On 64bit the limits are likely never hit. Reviewed by: markj, kib (some objections) Discussed with: alc Tested by: pho Sponsored by: Netflix / Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D13187
2017-11-28 23:40:54 +00:00
}
Fix build of uma_core.c when DDB is not compiled into the kernel by making uma_zone_sumstat() ifdef DDB, as it's only used with DDB now. Submitted by: Wolfram Fenske <Wolfram.Fenske at Student.Uni-Magdeburg.DE>
2006-07-18 01:13:18 +00:00
#ifdef DDB
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
/*
* Generate statistics across both the zone and its per-cpu cache's. Return
* desired statistics if the pointer is non-NULL for that statistic.
*
* Note: does not update the zone statistics, as it can't safely clear the
* per-CPU cache statistic.
*
*/
static void
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
{
uma_cache_t cache;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
uint64_t allocs, frees, sleeps, xdomain;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
int cachefree, cpu;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
allocs = frees = sleeps = xdomain = 0;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
cachefree = 0;
Update several places that iterate over CPUs to use CPU_FOREACH().
2010-06-11 18:46:34 +00:00
CPU_FOREACH(cpu) {
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
cache = &z->uz_cpu[cpu];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
cachefree += cache->uc_allocbucket.ucb_cnt;
cachefree += cache->uc_freebucket.ucb_cnt;
xdomain += cache->uc_crossbucket.ucb_cnt;
cachefree += cache->uc_crossbucket.ucb_cnt;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
allocs += cache->uc_allocs;
frees += cache->uc_frees;
}
Make uz_allocs, uz_frees and uz_fails counter(9). This removes some atomic updates and reduces amount of data protected by zone lock. During startup point these fields to EARLY_COUNTER. After startup allocate them for all early zones. Tested by: pho
2019-01-15 18:24:34 +00:00
allocs += counter_u64_fetch(z->uz_allocs);
frees += counter_u64_fetch(z->uz_frees);
Add a new column to the output of vmstat -z to indicate the number of times the system was forced to sleep when requesting a new allocation. Expand the debugger hook, db_show_uma, to display these results as well. This has proven to be very useful in out of memory situations when it is not known why systems have become sluggish or fail in odd ways. Reviewed by: rwatson alc Approved by: scottl (mentor) peter Obtained from: Yahoo Inc.
2010-06-15 19:28:37 +00:00
sleeps += z->uz_sleeps;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
xdomain += z->uz_xdomain;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
if (cachefreep != NULL)
*cachefreep = cachefree;
if (allocsp != NULL)
*allocsp = allocs;
if (freesp != NULL)
*freesp = frees;
Add a new column to the output of vmstat -z to indicate the number of times the system was forced to sleep when requesting a new allocation. Expand the debugger hook, db_show_uma, to display these results as well. This has proven to be very useful in out of memory situations when it is not known why systems have become sluggish or fail in odd ways. Reviewed by: rwatson alc Approved by: scottl (mentor) peter Obtained from: Yahoo Inc.
2010-06-15 19:28:37 +00:00
if (sleepsp != NULL)
*sleepsp = sleeps;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
if (xdomainp != NULL)
*xdomainp = xdomain;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
}
Fix build of uma_core.c when DDB is not compiled into the kernel by making uma_zone_sumstat() ifdef DDB, as it's only used with DDB now. Submitted by: Wolfram Fenske <Wolfram.Fenske at Student.Uni-Magdeburg.DE>
2006-07-18 01:13:18 +00:00
#endif /* DDB */
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
static int
sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
{
uma_keg_t kz;
uma_zone_t z;
int count;
count = 0;
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_rlock(&uma_rwlock);
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
count++;
}
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
LIST_FOREACH(z, &uma_cachezones, uz_link)
count++;
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_runlock(&uma_rwlock);
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
return (sysctl_handle_int(oidp, &count, 0, req));
}
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
static void
uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
struct uma_percpu_stat *ups, bool internal)
{
uma_zone_domain_t zdom;
uma_cache_t cache;
int i;
for (i = 0; i < vm_ndomains; i++) {
zdom = &z->uz_domain[i];
uth->uth_zone_free += zdom->uzd_nitems;
}
uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
uth->uth_frees = counter_u64_fetch(z->uz_frees);
uth->uth_fails = counter_u64_fetch(z->uz_fails);
uth->uth_sleeps = z->uz_sleeps;
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
uth->uth_xdomain = z->uz_xdomain;
Avoid reloading bucket pointers in uma_vm_zone_stats(). The correctness of per-CPU cache accounting in that function is dependent on reading per-CPU pointers exactly once. Ensure that the compiler does not emit multiple loads of those pointers. Reported and tested by: pho Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22081
2019-10-22 14:20:06 +00:00
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
/*
Avoid reloading bucket pointers in uma_vm_zone_stats(). The correctness of per-CPU cache accounting in that function is dependent on reading per-CPU pointers exactly once. Ensure that the compiler does not emit multiple loads of those pointers. Reported and tested by: pho Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D22081
2019-10-22 14:20:06 +00:00
* While it is not normally safe to access the cache bucket pointers
* while not on the CPU that owns the cache, we only allow the pointers
* to be exchanged without the zone lock held, not invalidated, so
* accept the possible race associated with bucket exchange during
* monitoring. Use atomic_load_ptr() to ensure that the bucket pointers
* are loaded only once.
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
*/
for (i = 0; i < mp_maxid + 1; i++) {
bzero(&ups[i], sizeof(*ups));
if (internal || CPU_ABSENT(i))
continue;
cache = &z->uz_cpu[i];
Optimize fast path allocations by storing bucket headers in the per-cpu cache area. This allows us to check on bucket space for all per-cpu buckets with a single cacheline access and fewer branches. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22825
2019-12-25 20:50:53 +00:00
ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
ups[i].ups_allocs = cache->uc_allocs;
ups[i].ups_frees = cache->uc_frees;
}
}
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
static int
sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
{
struct uma_stream_header ush;
struct uma_type_header uth;
For vm_zone_stats() sysctl handler, do not drain sbuf calling copyout(9) while owning zone lock. Despite old value sysctl buffer is wired, spurious faults might still occur. Note that we still own the uma_rwlock there, but this lock does not participate in sensitive lock orders. Reported and tested by: pho (as part of the larger patch) Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-03-24 13:48:53 +00:00
struct uma_percpu_stat *ups;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
struct sbuf sbuf;
uma_keg_t kz;
uma_zone_t z;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
uint64_t items;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uint32_t kfree, pages;
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
int count, error, i;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
Explicitly wire the user buffer rather than doing it implicitly in sbuf_new_for_sysctl(9). This allows using an sbuf with a SYSCTL_OUT drain for extremely large amounts of data where the caller knows that appropriate references are held, and sleeping is not an issue. Inspired by: rwatson
2011-01-27 00:34:12 +00:00
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
Set the SBUF_INCLUDENUL flag in sbuf_new_for_sysctl() so that sysctl strings returned to userland include the nulterm byte. Some uses of sbuf_new_for_sysctl() write binary data rather than strings; clear the SBUF_INCLUDENUL flag after calling sbuf_new_for_sysctl() in those cases. (Note that the sbuf code still automatically adds a nulterm byte in sbuf_finish(), but since it's not included in the length it won't get copied to userland along with the binary data.) Remove explicit adding of a nulterm byte in a couple places now that it gets done automatically by the sbuf drain code. PR: 195668
2015-03-14 17:08:28 +00:00
sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
For vm_zone_stats() sysctl handler, do not drain sbuf calling copyout(9) while owning zone lock. Despite old value sysctl buffer is wired, spurious faults might still occur. Note that we still own the uma_rwlock there, but this lock does not participate in sensitive lock orders. Reported and tested by: pho (as part of the larger patch) Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-03-24 13:48:53 +00:00
ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
Revert r212370, as it causes a LOR on powerpc. powerpc does a few unexpected things in copyout(9) and so wiring the user buffer is not sufficient to perform a copyout(9) while holding a random mutex. Requested by: nwhitehorn
2010-09-13 18:48:23 +00:00
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
count = 0;
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_rlock(&uma_rwlock);
Revert r212370, as it causes a LOR on powerpc. powerpc does a few unexpected things in copyout(9) and so wiring the user buffer is not sufficient to perform a copyout(9) while holding a random mutex. Requested by: nwhitehorn
2010-09-13 18:48:23 +00:00
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
count++;
Revert r212370, as it causes a LOR on powerpc. powerpc does a few unexpected things in copyout(9) and so wiring the user buffer is not sufficient to perform a copyout(9) while holding a random mutex. Requested by: nwhitehorn
2010-09-13 18:48:23 +00:00
}
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
LIST_FOREACH(z, &uma_cachezones, uz_link)
count++;
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
/*
* Insert stream header.
*/
bzero(&ush, sizeof(ush));
ush.ush_version = UMA_STREAM_VERSION;
Use mp_maxid in preference to MAXCPU when creating exports of UMA per-CPU cache statistics. UMA sizes the cache array based on the number of CPUs at boot (mp_maxid + 1), and iterating based on MAXCPU could read off the end of the array (into the next zone). Reported by: yongari MFC after: 1 week
2005-07-16 11:03:06 +00:00
ush.ush_maxcpus = (mp_maxid + 1);
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
ush.ush_count = count;
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
LIST_FOREACH(kz, &uma_kegs, uk_link) {
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
kfree = pages = 0;
for (i = 0; i < vm_ndomains; i++) {
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
kfree += kz->uk_domain[i].ud_free_items;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
pages += kz->uk_domain[i].ud_pages;
}
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
LIST_FOREACH(z, &kz->uk_zones, uz_link) {
bzero(&uth, sizeof(uth));
ZONE_LOCK(z);
Rename UMA_MAX_NAME to UTH_MAX_NAME, since it's a maximum in the monitoring API, which might or might not be the same as the internal maximum (currently none). Export flag information on UMA zones -- in particular, whether or not this is a secondary zone, and so the keg free count should be considered in that light. MFC after: 1 day
2005-07-25 00:47:32 +00:00
strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
uth.uth_align = kz->uk_align;
uth.uth_size = kz->uk_size;
uth.uth_rsize = kz->uk_rsize;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
if (z->uz_max_items > 0) {
items = UZ_ITEMS_COUNT(z->uz_items);
uth.uth_pages = (items / kz->uk_ipers) *
Only do uz_items accounting for zones that have a limit set in uz_max_items. This reduces amount of locking required for these zones. Also, for cache only zones (UMA_ZFLAG_CACHE) accounting uz_items wasn't correct at all, since they may allocate items directly from their backing store and then free them via UMA underflowing uz_items. Tested by: pho
2019-01-15 18:32:26 +00:00
kz->uk_ppera;
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
} else
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uth.uth_pages = pages;
Remove harmless leftover from code that cycles over zone's kegs. Just use + instead of +=. There is no functional change.
2019-01-15 18:49:31 +00:00
uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
kz->uk_ppera;
uth.uth_limit = z->uz_max_items;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
uth.uth_keg_free = kfree;
Rename UMA_MAX_NAME to UTH_MAX_NAME, since it's a maximum in the monitoring API, which might or might not be the same as the internal maximum (currently none). Export flag information on UMA zones -- in particular, whether or not this is a secondary zone, and so the keg free count should be considered in that light. MFC after: 1 day
2005-07-25 00:47:32 +00:00
/*
* A zone is secondary is it is not the first entry
* on the keg's zone list.
*/
- Make the keg abstraction more complete. Permit a zone to have multiple backend kegs so it may source compatible memory from multiple backends. This is useful for cases such as NUMA or different layouts for the same memory type. - Provide a new api for adding new backend kegs to secondary zones. - Provide a new flag for adjusting the layout of zones to stagger allocations better across cache lines. Sponsored by: Nokia
2009-01-25 09:11:24 +00:00
if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
Rename UMA_MAX_NAME to UTH_MAX_NAME, since it's a maximum in the monitoring API, which might or might not be the same as the internal maximum (currently none). Export flag information on UMA zones -- in particular, whether or not this is a secondary zone, and so the keg free count should be considered in that light. MFC after: 1 day
2005-07-25 00:47:32 +00:00
(LIST_FIRST(&kz->uk_zones) != z))
uth.uth_zone_flags = UTH_ZONE_SECONDARY;
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
uma_vm_zone_stats(&uth, z, &sbuf, ups,
kz->uk_flags & UMA_ZFLAG_INTERNAL);
Move the unlocking of the zone mutex in sysctl_vm_zone_stats() so that it covers the following of the uc_alloc/freebucket cache pointers. Originally, I felt that the race wasn't helped by holding the mutex, hence a comment in the code and not holding it across the cache access. However, it does improve consistency, as while it doesn't prevent bucket exchange, it does prevent bucket pointer invalidation. So a race in gathering cache free space statistics still can occur, but not one that follows an invalid bucket pointer, if the mutex is held. Submitted by: yongari MFC after: 1 week
2005-07-16 09:40:34 +00:00
ZONE_UNLOCK(z);
For vm_zone_stats() sysctl handler, do not drain sbuf calling copyout(9) while owning zone lock. Despite old value sysctl buffer is wired, spurious faults might still occur. Note that we still own the uma_rwlock there, but this lock does not participate in sensitive lock orders. Reported and tested by: pho (as part of the larger patch) Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-03-24 13:48:53 +00:00
(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
for (i = 0; i < mp_maxid + 1; i++)
(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
}
}
Report cache zones in UMA stats sysctl, that 'vmstat -z' uses. This should had been part of r251826.
2019-02-07 03:32:45 +00:00
LIST_FOREACH(z, &uma_cachezones, uz_link) {
bzero(&uth, sizeof(uth));
ZONE_LOCK(z);
strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
uth.uth_size = z->uz_size;
uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
ZONE_UNLOCK(z);
(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
for (i = 0; i < mp_maxid + 1; i++)
(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
}
Change the UMA mutex into a rwlock Acquire the lock in read mode when just needed to ensure the stability of the keg list. The UMA lock may be held for a long time (relatively speaking) in uma_reclaim() on machines with lots of zones/kegs. If the uma_timeout() would fire during that period, subsequent callouts on that CPU may be significantly delayed. Reviewed by: jhb
2014-10-05 21:34:56 +00:00
rw_runlock(&uma_rwlock);
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
For vm_zone_stats() sysctl handler, do not drain sbuf calling copyout(9) while owning zone lock. Despite old value sysctl buffer is wired, spurious faults might still occur. Note that we still own the uma_rwlock there, but this lock does not participate in sensitive lock orders. Reported and tested by: pho (as part of the larger patch) Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-03-24 13:48:53 +00:00
free(ups, M_TEMP);
Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator statistics via a binary structure stream: - Add structure 'uma_stream_header', which defines a stream version, definition of MAXCPUs used in the stream, and the number of zone records in the stream. - Add structure 'uma_type_header', which defines the name, alignment, size, resource allocation limits, current pages allocated, preferred bucket size, and central zone + keg statistics. - Add structure 'uma_percpu_stat', which, for each per-CPU cache, includes the number of allocations and frees, as well as the number of free items in the cache. - When the sysctl is queried, return a stream header, followed by a series of type descriptions, each consisting of a type header followed by a series of MAXCPUs uma_percpu_stat structures holding per-CPU allocation information. Typical values of MAXCPU will be 1 (UP compiled kernel) and 16 (SMP compiled kernel). This query mechanism allows user space monitoring tools to extract memory allocation statistics in a machine-readable form, and to do so at a per-CPU granularity, allowing monitoring of allocation patterns across CPUs in order to better understand the distribution of work and memory flow over multiple CPUs. While here, also export the number of UMA zones as a sysctl vm.uma_count, in order to assist in sizing user swpace buffers to receive the stream. A follow-up commit of libmemstat(3), a library to monitor kernel memory allocation, will occur in the next few days. This change directly supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats rather than separately maintained mbuf allocator statistics. MFC after: 1 week
2005-07-14 16:35:13 +00:00
return (error);
}
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
Provide macros that allow easily export uma(9) zone limits and current usage via sysctl(9): SYSCTL_UMA_MAX() SYSCTL_ADD_UMA_MAX() SYSCTL_UMA_CUR() SYSCTL_ADD_UMA_CUR() Sponsored by: Nginx, Inc.
2014-02-07 14:29:03 +00:00
int
sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = *(uma_zone_t *)arg1;
UMA zone limit can be lowered, so remove protection against from the sysctl_handle_uma_zone_max(). Sponsored by: Nginx, Inc.
2015-04-10 06:56:49 +00:00
int error, max;
Provide macros that allow easily export uma(9) zone limits and current usage via sysctl(9): SYSCTL_UMA_MAX() SYSCTL_ADD_UMA_MAX() SYSCTL_UMA_CUR() SYSCTL_ADD_UMA_CUR() Sponsored by: Nginx, Inc.
2014-02-07 14:29:03 +00:00
UMA zone limit can be lowered, so remove protection against from the sysctl_handle_uma_zone_max(). Sponsored by: Nginx, Inc.
2015-04-10 06:56:49 +00:00
max = uma_zone_get_max(zone);
Provide macros that allow easily export uma(9) zone limits and current usage via sysctl(9): SYSCTL_UMA_MAX() SYSCTL_ADD_UMA_MAX() SYSCTL_UMA_CUR() SYSCTL_ADD_UMA_CUR() Sponsored by: Nginx, Inc.
2014-02-07 14:29:03 +00:00
error = sysctl_handle_int(oidp, &max, 0, req);
if (error || !req->newptr)
return (error);
uma_zone_set_max(zone, max);
return (0);
}
int
sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
{
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
uma_zone_t zone;
Provide macros that allow easily export uma(9) zone limits and current usage via sysctl(9): SYSCTL_UMA_MAX() SYSCTL_ADD_UMA_MAX() SYSCTL_UMA_CUR() SYSCTL_ADD_UMA_CUR() Sponsored by: Nginx, Inc.
2014-02-07 14:29:03 +00:00
int cur;
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
/*
* Some callers want to add sysctls for global zones that
* may not yet exist so they pass a pointer to a pointer.
*/
if (arg2 == 0)
zone = *(uma_zone_t *)arg1;
else
zone = arg1;
Provide macros that allow easily export uma(9) zone limits and current usage via sysctl(9): SYSCTL_UMA_MAX() SYSCTL_ADD_UMA_MAX() SYSCTL_UMA_CUR() SYSCTL_ADD_UMA_CUR() Sponsored by: Nginx, Inc.
2014-02-07 14:29:03 +00:00
cur = uma_zone_get_cur(zone);
return (sysctl_handle_int(oidp, &cur, 0, req));
}
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
static int
sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = arg1;
uint64_t cur;
cur = uma_zone_get_allocs(zone);
return (sysctl_handle_64(oidp, &cur, 0, req));
}
static int
sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = arg1;
uint64_t cur;
cur = uma_zone_get_frees(zone);
return (sysctl_handle_64(oidp, &cur, 0, req));
}
uma: pretty print zone flags sysctl Requested by: jeff Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22748
2019-12-11 06:50:55 +00:00
static int
sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
uma_zone_t zone = arg1;
int error;
sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
if (zone->uz_flags != 0)
sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
else
sbuf_printf(&sbuf, "0");
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
uma: report slab efficiency Reviewed by: jeff Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22766
2019-12-13 09:32:09 +00:00
static int
sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
{
uma_keg_t keg = arg1;
int avail, effpct, total;
total = keg->uk_ppera * PAGE_SIZE;
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
uma: split slabzone into two sizes By allowing more items per slab, we can improve memory efficiency for small allocs. If we were just to increase the bitmap size of the slabzone, we would then waste slabzone memory. So, split slabzone into two zones, one especially for 8-byte allocs (512 per slab). The practical effect should be reduced memory usage for counter(9). Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23149
2020-01-14 02:14:15 +00:00
total += slabzone(keg->uk_ipers)->uz_keg->uk_rsize;
uma: report slab efficiency Reviewed by: jeff Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22766
2019-12-13 09:32:09 +00:00
/*
* We consider the client's requested size and alignment here, not the
* real size determination uk_rsize, because we also adjust the real
* size for internal implementation reasons (max bitset size).
*/
avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
avail *= mp_maxid + 1;
effpct = 100 * avail / total;
return (sysctl_handle_int(oidp, &effpct, 0, req));
}
Use atomics for the zone limit and sleeper count. This relies on the sleepq to serialize sleepers. This patch retains the existing sleep/wakeup paradigm to limit 'thundering herd' wakeups. It resolves a missing wakeup in one case but otherwise should be bug for bug compatible. In particular, there are still various races surrounding adjusting the limit via sysctl that are now documented. Discussed with: markj Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22827
2020-01-04 03:04:46 +00:00
static int
sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = arg1;
uint64_t cur;
cur = UZ_ITEMS_COUNT(atomic_load_64(&zone->uz_items));
return (sysctl_handle_64(oidp, &cur, 0, req));
}
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
#ifdef INVARIANTS
static uma_slab_t
uma_dbg_getslab(uma_zone_t zone, void *item)
{
uma_slab_t slab;
uma_keg_t keg;
uint8_t *mem;
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
/*
* It is safe to return the slab here even though the
* zone is unlocked because the item's allocation state
* essentially holds a reference.
*/
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
return (NULL);
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if (zone->uz_flags & UMA_ZFLAG_VTOSLAB)
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
return (vtoslab((vm_offset_t)mem));
keg = zone->uz_keg;
uma: reorganize flags - Garbage collect UMA_ZONE_PAGEABLE & UMA_ZONE_STATIC. - Move flag VTOSLAB from public to private. - Introduce public NOTPAGE flag and make HASH private. - Introduce public NOTOUCH flag and make OFFPAGE private. - Update man page. The net effect of this should be to make the contract with clients more clear. Clients should choose constraints, UMA will figure out how to implement them. This also breaks the confusing double meaning of OFFPAGE. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D23016
2020-01-09 02:03:03 +00:00
if ((keg->uk_flags & UMA_ZFLAG_HASH) == 0)
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
return ((uma_slab_t)(mem + keg->uk_pgoff));
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_LOCK(keg, 0);
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
slab = hash_sfind(&keg->uk_hash, mem);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
KEG_UNLOCK(keg, 0);
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
return (slab);
}
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
static bool
uma_dbg_zskip(uma_zone_t zone, void *mem)
{
Use a separate lock for the zone and keg. This provides concurrency between populating buckets from the slab layer and fetching full buckets from the zone layer. Eliminate some nonsense locking patterns where we lock to fetch a single variable. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22828
2020-01-04 03:15:34 +00:00
if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
return (true);
o Move zone limit from keg level up to zone level. This means that now two zones sharing a keg may have different limits. Now this is going to work: zone = uma_zcreate(); uma_zone_set_max(zone, limit); zone2 = uma_zsecond_create(zone); uma_zone_set_max(zone2, limit2); Kegs no longer have uk_maxpages field, but zones have uz_items. When set, it may be rounded up to minimum possible CPU bucket cache size. For small limits bucket cache can also be reconfigured to be smaller. Counter uz_items is updated whenever items transition from keg to a bucket cache or directly to a consumer. If zone has uz_maxitems set and it is reached, then we are going to sleep. o Since new limits don't play well with multi-keg zones, remove them. The idea of multi-keg zones was introduced exactly 10 years ago, and never have had a practical usage. In discussion with Jeff we came to a wild agreement that if we ever want to reintroduce the idea of a smart allocator that would be able to choose between two (or more) totally different backing stores, that choice should be made one level higher than UMA, e.g. in malloc(9) or in mget(), or whatever and choice should be controlled by the caller. o Sleeping code is improved to account number of sleepers and wake them one by one, to avoid thundering herd problem. o Flag UMA_ZONE_NOBUCKETCACHE removed, instead uma_zone_set_maxcache() KPI added. Having no bucket cache basically means setting maxcache to 0. o Now with many fields added and many removed (no multi-keg zones!) make sure that struct uma_zone is perfectly aligned. Reviewed by: markj, jeff Tested by: pho Differential Revision: https://reviews.freebsd.org/D17773
2019-01-15 00:02:06 +00:00
return (uma_dbg_kskip(zone->uz_keg, mem));
UMA memory debugging enabled with INVARIANTS consists of two things: trashing freed memory and checking that allocated memory is properly trashed, and also of keeping a bitset of freed items. Trashing/checking creates a lot of CPU cache poisoning, while keeping debugging bitsets consistent creates a lot of contention on UMA zone lock(s). The performance difference between INVARIANTS kernel and normal one is mostly attributed to UMA debugging, rather than to all KASSERT checks in the kernel. Add loader tunable vm.debug.divisor that allows either to turn off UMA debugging completely, or turn it on only for a fraction of allocations, while still running all KASSERTs in kernel. That allows to run INVARIANTS kernels in production environments without reducing load by orders of magnitude, but still doing useful extra checks. Default value is 1, meaning debug every allocation. Value of 0 would disable UMA debugging completely. Values above 1 enable debugging only for every N-th item. It isn't possible to strictly follow the number, but still amount of debugging is reduced roughly by (N-1)/N percent. Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D15199
2018-06-08 00:15:08 +00:00
}
static bool
uma_dbg_kskip(uma_keg_t keg, void *mem)
{
uintptr_t idx;
if (dbg_divisor == 0)
return (true);
if (dbg_divisor == 1)
return (false);
idx = (uintptr_t)mem >> PAGE_SHIFT;
if (keg->uk_ipers > 1) {
idx *= keg->uk_ipers;
idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
}
if ((idx / dbg_divisor) * dbg_divisor != idx) {
counter_u64_add(uma_skip_cnt, 1);
return (true);
}
counter_u64_add(uma_dbg_cnt, 1);
return (false);
}
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
/*
* Set up the slab's freei data such that uma_dbg_free can function.
*
*/
static void
uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
int freei;
if (slab == NULL) {
slab = uma_dbg_getslab(zone, item);
if (slab == NULL)
panic("uma: item %p did not belong to zone %s\n",
item, zone->uz_name);
}
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
keg = zone->uz_keg;
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
freei = slab_item_index(slab, keg, item);
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
if (BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n",
item, zone, zone->uz_name, slab, freei);
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
BIT_SET_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
}
/*
* Verifies freed addresses. Checks for alignment, valid slab membership
* and duplicate frees.
*
*/
static void
uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
int freei;
if (slab == NULL) {
slab = uma_dbg_getslab(zone, item);
if (slab == NULL)
panic("uma: Freed item %p did not belong to zone %s\n",
item, zone->uz_name);
}
Garbage collect the mostly unused us_keg field. Use appropriately named union members in vm_page.h to store the zone and slab. Remove some nearby dead code. Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D22564
2019-11-28 07:49:25 +00:00
keg = zone->uz_keg;
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
freei = slab_item_index(slab, keg, item);
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
if (freei >= keg->uk_ipers)
panic("Invalid free of %p from zone %p(%s) slab %p(%d)\n",
item, zone, zone->uz_name, slab, freei);
Use a variant slab structure for offpage zones. This saves space in embedded slabs but also is an opportunity to tidy up code and add accessor inlines. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22609
2019-12-08 01:15:06 +00:00
if (slab_item(slab, keg, freei) != item)
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n",
item, zone, zone->uz_name, slab, freei);
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
if (!BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)))
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n",
item, zone, zone->uz_name, slab, freei);
uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff (previous version), markj (previous version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759
2019-12-14 05:21:56 +00:00
BIT_CLR_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg));
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
}
#endif /* INVARIANTS */
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
#ifdef DDB
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
static int64_t
get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
Fix braino in r353429 cy@ points out that I got parameter order backwards between definition and invocation of the helper function. He is totally correct. The earlier version of this patch predated the XFree column so this is one I introduced, rather than the original author. Submitted by: cy Reported by: cy X-MFC-With: r353429
2019-10-11 06:02:03 +00:00
uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
{
uint64_t frees;
int i;
if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
*allocs = counter_u64_fetch(z->uz_allocs);
frees = counter_u64_fetch(z->uz_frees);
*sleeps = z->uz_sleeps;
*cachefree = 0;
*xdomain = 0;
} else
uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
xdomain);
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
for (i = 0; i < vm_ndomains; i++) {
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
*cachefree += z->uz_domain[i].uzd_nitems;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
(LIST_FIRST(&kz->uk_zones) != z)))
Reduce lock hold time in keg_drain(). Maintain a count of free slabs in the per-domain keg structure and use that to clear the free slab list in constant time for most cases. This helps minimize lock contention induced by reclamation, in preparation for proactive trimming of excesses of free memory. Reviewed by: jeff, rlibby Tested by: pho Differential Revision: https://reviews.freebsd.org/D23532
2020-02-11 20:06:33 +00:00
*cachefree += kz->uk_domain[i].ud_free_items;
Use per-domain keg locks. This provides both a lock and separate space accounting for each NUMA domain. Independent keg domain locks are important with cross-domain frees. Hashed zones are non-numa and use a single keg lock to protect the hash table. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D22829
2020-01-04 03:30:08 +00:00
}
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
*used = *allocs - frees;
return (((int64_t)*used + *cachefree) * kz->uk_size);
}
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
DB_SHOW_COMMAND(uma, db_show_uma)
{
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
const char *fmt_hdr, *fmt_entry;
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
uma_keg_t kz;
uma_zone_t z;
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
uint64_t allocs, used, sleeps, xdomain;
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
long cachefree;
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
/* variables for sorting */
uma_keg_t cur_keg;
uma_zone_t cur_zone, last_zone;
int64_t cur_size, last_size, size;
int ties;
/* /i option produces machine-parseable CSV output */
if (modif[0] == 'i') {
fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
} else {
fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
}
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
"Sleeps", "Bucket", "Total Mem", "XFree");
/* Sort the zones with largest size first. */
last_zone = NULL;
last_size = INT64_MAX;
for (;;) {
cur_zone = NULL;
cur_size = -1;
ties = 0;
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link) {
/*
* In the case of size ties, print out zones
* in the order they are encountered. That is,
* when we encounter the most recently output
* zone, we have already printed all preceding
* ties, and we must print all following ties.
*/
if (z == last_zone) {
ties = 1;
continue;
}
size = get_uma_stats(kz, z, &allocs, &used,
&sleeps, &cachefree, &xdomain);
if (size > cur_size && size < last_size + ties)
{
cur_size = size;
cur_zone = z;
cur_keg = kz;
}
}
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
}
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
if (cur_zone == NULL)
break;
size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
&sleeps, &cachefree, &xdomain);
db_printf(fmt_entry, cur_zone->uz_name,
(uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
(uintmax_t)allocs, (uintmax_t)sleeps,
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
(unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
xdomain);
ddb: Add CSV option, sorting to 'show (malloc|uma)' Add /i option for machine-parseable CSV output. This allows ready copy/ pasting into more sophisticated tooling outside of DDB. Add total zone size ("Memory Use") as a new column for UMA. For both, sort the displayed list on size (print the largest zones/types first). This is handy for quickly diagnosing "where has my memory gone?" at a high level. Submitted by: Emily Pettigrew <Emily.Pettigrew AT isilon.com> (earlier version) Sponsored by: Dell EMC Isilon
2019-10-11 01:31:31 +00:00
if (db_pager_quit)
return;
last_zone = cur_zone;
last_size = cur_size;
Add a "show uma" command to DDB, which prints out the current stats for available UMA zones. Quite useful for post-mortem debugging of memory leaks without a dump device configured on a panicked box. MFC after: 2 weeks
2005-10-20 16:39:33 +00:00
}
}
- Add bucket size column to `show uma` DDB command. - Add `show umacache` command to show alike stats for cache-only UMA zones.
2013-11-28 19:20:49 +00:00
DB_SHOW_COMMAND(umacache, db_show_umacache)
{
uma_zone_t z;
Implement NUMA support in uma(9) and malloc(9). Allocations from specific domains can be done by the _domain() API variants. UMA also supports a first-touch policy via the NUMA zone flag. The slab layer is now segregated by VM domains and is precise. It handles iteration for round-robin directly. The per-cpu cache layer remains a mix of domains according to where memory is allocated and freed. Well behaved clients can achieve perfect locality with no performance penalty. The direct domain allocation functions have to visit the slab layer and so require per-zone locks which come at some expense. Reviewed by: Attilio (a slightly older version) Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon
2018-01-12 23:25:05 +00:00
uint64_t allocs, frees;
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
long cachefree;
int i;
- Add bucket size column to `show uma` DDB command. - Add `show umacache` command to show alike stats for cache-only UMA zones.
2013-11-28 19:20:49 +00:00
db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
"Requests", "Bucket");
LIST_FOREACH(z, &uma_cachezones, uz_link) {
Add two new kernel options to control memory locality on NUMA hardware. - UMA_XDOMAIN enables an additional per-cpu bucket for freed memory that was freed on a different domain from where it was allocated. This is only used for UMA_ZONE_NUMA (first-touch) zones. - UMA_FIRSTTOUCH sets the default UMA policy to be first-touch for all zones. This tries to maintain locality for kernel memory. Reviewed by: gallatin, alc, kib Tested by: pho, gallatin Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20929
2019-08-06 21:50:34 +00:00
uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
Add accounting to per-domain UMA full bucket caches. In particular, track the current size of the cache and maintain an estimate of its working set size. This will be used to decide how much to shrink various caches when the kernel attempts to reclaim pages. As a secondary effect, it makes statistics aggregation (done by, e.g., vmstat -z) cheaper since sysctl_vm_zone_stats() no longer needs to iterate over lists of cached buckets. Discussed with: alc, glebius, jeff Tested by: pho (previous version) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D16666
2018-11-13 19:44:40 +00:00
for (i = 0; i < vm_ndomains; i++)
cachefree += z->uz_domain[i].uzd_nitems;
db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
- Add bucket size column to `show uma` DDB command. - Add `show umacache` command to show alike stats for cache-only UMA zones.
2013-11-28 19:20:49 +00:00
z->uz_name, (uintmax_t)z->uz_size,
(intmax_t)(allocs - frees), cachefree,
Implement a sysctl tree for uma zones to assist in debugging and provide more statistcs than are exported via the ABI stable vmstat interface. Rename uz_count to uz_bucket_size because even I was confused by the name after returning to the source years later. Reviewed by: rlibby Differential Revision: https://reviews.freebsd.org/D22554
2019-11-28 00:19:09 +00:00
(uintmax_t)allocs, z->uz_bucket_size);
- Add bucket size column to `show uma` DDB command. - Add `show umacache` command to show alike stats for cache-only UMA zones.
2013-11-28 19:20:49 +00:00
if (db_pager_quit)
return;
}
}
Move uma_dbg_alloc() and uma_dbg_free() into uma_core.c, which allows to make uma_dbg.h not depend on uma_int.h, which allows to uninclude uma_int.h from the mbuf(9) allocator.
2016-02-03 22:02:36 +00:00
#endif /* DDB */
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