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freebsd-skq/sys/vm/swap_pager.c

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/* -> /*- for license, minor formatting changes
2005-01-07 02:29:27 +00:00
/*-
spdx: initial adoption of licensing ID tags. 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. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point. Initially, only tag files that use BSD 4-Clause "Original" license. RelNotes: yes Differential Revision: https://reviews.freebsd.org/D13133
2017-11-18 14:26:50 +00:00
* SPDX-License-Identifier: BSD-4-Clause
*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* Copyright (c) 1998 Matthew Dillon,
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
* Copyright (c) 1994 John S. Dyson
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* Copyright (c) 1990 University of Utah.
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
* Copyright (c) 1982, 1986, 1989, 1993
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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, 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.
* 3. All advertising materials mentioning features or use of this software
Revert spelling mistake I made in the previous commit Requested by: Alan and Bruce
2000-03-27 20:41:17 +00:00
* must display the following acknowledgement:
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* New Swap System
* Matthew Dillon
*
* Radix Bitmap 'blists'.
*
* - The new swapper uses the new radix bitmap code. This should scale
* to arbitrarily small or arbitrarily large swap spaces and an almost
* arbitrary degree of fragmentation.
*
* Features:
*
* - on the fly reallocation of swap during putpages. The new system
* does not try to keep previously allocated swap blocks for dirty
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* pages.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* - on the fly deallocation of swap
*
* - No more garbage collection required. Unnecessarily allocated swap
* blocks only exist for dirty vm_page_t's now and these are already
* cycled (in a high-load system) by the pager. We also do on-the-fly
* removal of invalidated swap blocks when a page is destroyed
* or renamed.
*
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
* from: Utah $Hdr: swap_pager.c 1.4 91/04/30$
*
* @(#)swap_pager.c 8.9 (Berkeley) 3/21/94
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
* @(#)vm_swap.c 8.5 (Berkeley) 2/17/94
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Use __FBSDID().
2003-06-11 23:50:51 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#include "opt_vm.h"
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/param.h>
Separate the struct bio related stuff out of <sys/buf.h> into <sys/bio.h>. <sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall not be made a nested include according to bdes teachings on the subject of nested includes. Diskdrivers and similar stuff below specfs::strategy() should no longer need to include <sys/buf.> unless they need caching of data. Still a few bogus uses of struct buf to track down. Repocopy by: peter
2000-05-05 09:59:14 +00:00
#include <sys/bio.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/blist.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/buf.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/conf.h>
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#include <sys/disk.h>
swap_pager.c reserves 2 blocks for a bsd label. Change that 2 to the expression howmany(BBSIZE, PAGE_SIZE), where BBSIZE is the size of the boot block area. That can be less than 2 if PAGE_SIZE is big. swapon(8) has an option to trim (delete) all the blocks of a device at startup. However, if the first of those blocks is a bsd label, then trimming those blocks is destructive. Change swapon to leave the first BBSIZE bytes untrimmed. Update manual pages to reflect changes in how swapon and how it may be used, espeically in association with savecore. Reviewed by: alc Approved by: markj (mentor) MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D21191
2019-08-15 02:30:44 +00:00
#include <sys/disklabel.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/eventhandler.h>
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#include <sys/fcntl.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/lock.h>
#include <sys/kernel.h>
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#include <sys/mount.h>
#include <sys/namei.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <sys/malloc.h>
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
#include <sys/pctrie.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/priv.h>
#include <sys/proc.h>
Add accounting for most of the memory-related resources. Sponsored by: The FreeBSD Foundation Reviewed by: kib (earlier version)
2011-04-05 20:23:59 +00:00
#include <sys/racct.h>
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
#include <sys/resource.h>
#include <sys/resourcevar.h>
Switch vm_object lock to be a rwlock. * VM_OBJECT_LOCK and VM_OBJECT_UNLOCK are mapped to write operations * VM_OBJECT_SLEEP() is introduced as a general purpose primitve to get a sleep operation using a VM_OBJECT_LOCK() as protection * The approach must bear with vm_pager.h namespace pollution so many files require including directly rwlock.h
2013-02-20 10:38:34 +00:00
#include <sys/rwlock.h>
To analyze the allocation of swap blocks by blist functions, add a method for analyzing the radix tree structures and reporting on the number, and sizes, of maximal intervals of free blocks. The report includes the number of maximal intervals, and also the number of them in each of several size ranges, from small (size 1, or 3 to 4) to large (28657 to 46367) with size boundaries defined by Fibonacci numbers. The report is written in the test tool with the 's' command, or in a running kernel by sysctl. The analysis of the radix tree frequently computes the position of the lone bit set in a u_daddr_t, a computation that also appears in leaf allocation. That computation has been moved into a function of its own, and optimized for cases where an inlined machine instruction can replace the usual binary search. Submitted by: Doug Moore <dougm@rice.edu> MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D11906
2017-09-10 17:46:03 +00:00
#include <sys/sbuf.h>
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
#include <sys/sysctl.h>
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#include <sys/sysproto.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/systm.h>
With Alfred's permission, remove vm_mtx in favor of a fine-grained approach (this commit is just the first stage). Also add various GIANT_ macros to formalize the removal of Giant, making it easy to test in a more piecemeal fashion. These macros will allow us to test fine-grained locks to a degree before removing Giant, and also after, and to remove Giant in a piecemeal fashion via sysctl's on those subsystems which the authors believe can operate without Giant.
2001-07-04 16:20:28 +00:00
#include <sys/sx.h>
Implement a low-memory deadlock solution. Removed most of the hacks that were trying to deal with low-memory situations prior to now. The new code is based on the concept that I/O must be able to function in a low memory situation. All major modules related to I/O (except networking) have been adjusted to allow allocation out of the system reserve memory pool. These modules now detect a low memory situation but rather then block they instead continue to operate, then return resources to the memory pool instead of cache them or leave them wired. Code has been added to stall in a low-memory situation prior to a vnode being locked. Thus situations where a process blocks in a low-memory condition while holding a locked vnode have been reduced to near nothing. Not only will I/O continue to operate, but many prior deadlock conditions simply no longer exist. Implement a number of VFS/BIO fixes (found by Ian): in biodone(), bogus-page replacement code, the loop was not properly incrementing loop variables prior to a continue statement. We do not believe this code can be hit anyway but we aren't taking any chances. We'll turn the whole section into a panic (as it already is in brelse()) after the release is rolled. In biodone(), the foff calculation was incorrectly clamped to the iosize, causing the wrong foff to be calculated for pages in the case of an I/O error or biodone() called without initiating I/O. The problem always caused a panic before. Now it doesn't. The problem is mainly an issue with NFS. Fixed casts for ~PAGE_MASK. This code worked properly before only because the calculations use signed arithmatic. Better to properly extend PAGE_MASK first before inverting it for the 64 bit masking op. In brelse(), the bogus_page fixup code was improperly throwing away the original contents of 'm' when it did the j-loop to fix the bogus pages. The result was that it would potentially invalidate parts of the *WRONG* page(!), leading to corruption. There may still be cases where a background bitmap write is being duplicated, causing potential corruption. We have identified a potentially serious bug related to this but the fix is still TBD. So instead this patch contains a KASSERT to detect the problem and panic the machine rather then continue to corrupt the filesystem. The problem does not occur very often.. it is very hard to reproduce, and it may or may not be the cause of the corruption people have reported. Review by: (VFS/BIO: mckusick, Ian Dowse <iedowse@maths.tcd.ie>) Testing by: (VM/Deadlock) Paul Saab <ps@yahoo-inc.com>
2000-11-18 23:06:26 +00:00
#include <sys/vmmeter.h>
Extract eventfilter declarations to sys/_eventfilter.h This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h" in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header pollution substantially. EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c files into appropriate headers (e.g., sys/proc.h, powernv/opal.h). As a side effect of reduced header pollution, many .c files and headers no longer contain needed definitions. The remainder of the patch addresses adding appropriate includes to fix those files. LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by sys/mutex.h since r326106 (but silently protected by header pollution prior to this change). No functional change (intended). Of course, any out of tree modules that relied on header pollution for sys/eventhandler.h, sys/lock.h, or sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.
2019-05-20 00:38:23 +00:00
#include <sys/vnode.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now contains the userspace and user<->kernel API and definitions, with all in-kernel interfaces moved to mac_framework.h, which is now included across most of the kernel instead. This change is the first step in a larger cleanup and sweep of MAC Framework interfaces in the kernel, and will not be MFC'd. Obtained from: TrustedBSD Project Sponsored by: SPARTA
2006-10-22 11:52:19 +00:00
#include <security/mac/mac_framework.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <vm/vm.h>
- If swap metadata does not fit into the KVM, reduce the number of struct swblock entries by dividing the number of the entries by 2 until the swap metadata fits. - Reject swapon(2) upon failure of swap_zone allocation. This is just a temporary fix. Better solutions include: (suggested by: dillon) o reserving swap in SWAP_META_PAGES chunks, and o swapping the swblock structures themselves. Reviewed by: alfred, dillon
2000-12-13 10:01:00 +00:00
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
Untangled the vm.h include file spaghetti.
1995-12-07 12:48:31 +00:00
#include <vm/vm_object.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <vm/vm_page.h>
Untangled the vm.h include file spaghetti.
1995-12-07 12:48:31 +00:00
#include <vm/vm_pager.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <vm/vm_pageout.h>
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#include <vm/vm_param.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
#include <vm/swap_pager.h>
Untangled the vm.h include file spaghetti.
1995-12-07 12:48:31 +00:00
#include <vm/vm_extern.h>
Remove references to vm_zone.h and switch over to the new uma API.
2002-03-20 04:02:59 +00:00
#include <vm/uma.h>
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
#include <geom/geom.h>
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
/*
Halve the memory being internally allocated by the blist allocator. In short, half of the memory that is allocated to implement the radix tree is wasted because we did not change "u_daddr_t" to be a 64-bit unsigned int when we changed "daddr_t" to be a 64-bit (signed) int. (See r96849 and r96851.) Reviewed by: kib, markj Tested by: pho MFC after: 5 days Differential Revision: https://reviews.freebsd.org/D11028
2017-06-05 17:14:16 +00:00
* MAX_PAGEOUT_CLUSTER must be a power of 2 between 1 and 64.
* The 64-page limit is due to the radix code (kern/subr_blist.c).
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
*/
#ifndef MAX_PAGEOUT_CLUSTER
Increase the pageout cluster size to 32 pages. Decouple the pageout cluster size from the size of the hash table entry used by the swap pager for mapping (object, pindex) to a block on the swap device(s), and keep the size of a hash table entry at its current size. Eliminate a pointless macro. Reviewed by: kib, markj (an earlier version) MFC after: 4 weeks Differential Revision: https://reviews.freebsd.org/D11305
2017-06-24 17:10:33 +00:00
#define MAX_PAGEOUT_CLUSTER 32
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
#endif
#if !defined(SWB_NPAGES)
#define SWB_NPAGES MAX_PAGEOUT_CLUSTER
#endif
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
#define SWAP_META_PAGES PCTRIE_COUNT
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
/*
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
* A swblk structure maps each page index within a
* SWAP_META_PAGES-aligned and sized range to the address of an
* on-disk swap block (or SWAPBLK_NONE). The collection of these
* mappings for an entire vm object is implemented as a pc-trie.
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
*/
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
struct swblk {
vm_pindex_t p;
daddr_t d[SWAP_META_PAGES];
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
};
Move the definition of M_VMPGDATA to the swap pager, where the only remaining uses are.
2011-01-18 04:54:43 +00:00
static MALLOC_DEFINE(M_VMPGDATA, "vm_pgdata", "swap pager private data");
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
static struct mtx sw_dev_mtx;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
static TAILQ_HEAD(, swdevt) swtailq = TAILQ_HEAD_INITIALIZER(swtailq);
static struct swdevt *swdevhd; /* Allocate from here next */
static int nswapdev; /* Number of swap devices */
int swap_pager_avail;
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
static struct sx swdev_syscall_lock; /* serialize swap(on|off) */
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
static u_long swap_reserved;
static u_long swap_total;
static int sysctl_page_shift(SYSCTL_HANDLER_ARGS);
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
static SYSCTL_NODE(_vm_stats, OID_AUTO, swap, CTLFLAG_RD, 0, "VM swap stats");
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
SYSCTL_PROC(_vm, OID_AUTO, swap_reserved, CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE,
&swap_reserved, 0, sysctl_page_shift, "A",
Add sysctl documentation strings. The descriptions are derived from tuning(7). One of the descriptions references tuning(7) because it is too complex to adequatly describe here (it is not a simple boolean sysctl) and users should be warned to that. Reviewed by: alc, kib Approved by: gnn (mentor)
2009-11-02 16:56:59 +00:00
"Amount of swap storage needed to back all allocated anonymous memory.");
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
SYSCTL_PROC(_vm, OID_AUTO, swap_total, CTLTYPE_U64 | CTLFLAG_RD | CTLFLAG_MPSAFE,
&swap_total, 0, sysctl_page_shift, "A",
"Total amount of available swap storage.");
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
static int overcommit = 0;
Add OID for the vm.overcommit sysctl. This makes it possible to remove one call to sysctl(2) from jemalloc startup code. (That also requires changes to jemalloc, but I plan to push those to upstream first.) Reviewed by: kib MFC after: 2 weeks Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D12745
2017-10-22 10:35:29 +00:00
SYSCTL_INT(_vm, VM_OVERCOMMIT, overcommit, CTLFLAG_RW, &overcommit, 0,
Add sysctl documentation strings. The descriptions are derived from tuning(7). One of the descriptions references tuning(7) because it is too complex to adequatly describe here (it is not a simple boolean sysctl) and users should be warned to that. Reviewed by: alc, kib Approved by: gnn (mentor)
2009-11-02 16:56:59 +00:00
"Configure virtual memory overcommit behavior. See tuning(7) "
"for details.");
Add sysctl OIDs showing the actual size and capacity of the swap zone. MFC after: 1 week
2014-04-26 12:18:17 +00:00
static unsigned long swzone;
SYSCTL_ULONG(_vm, OID_AUTO, swzone, CTLFLAG_RD, &swzone, 0,
"Actual size of swap metadata zone");
static unsigned long swap_maxpages;
SYSCTL_ULONG(_vm, OID_AUTO, swap_maxpages, CTLFLAG_RD, &swap_maxpages, 0,
"Maximum amount of swap supported");
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
static counter_u64_t swap_free_deferred;
SYSCTL_COUNTER_U64(_vm_stats_swap, OID_AUTO, free_deferred,
CTLFLAG_RD, &swap_free_deferred,
"Number of pages that deferred freeing swap space");
static counter_u64_t swap_free_completed;
SYSCTL_COUNTER_U64(_vm_stats_swap, OID_AUTO, free_completed,
CTLFLAG_RD, &swap_free_completed,
"Number of deferred frees completed");
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
/* bits from overcommit */
#define SWAP_RESERVE_FORCE_ON (1 << 0)
#define SWAP_RESERVE_RLIMIT_ON (1 << 1)
#define SWAP_RESERVE_ALLOW_NONWIRED (1 << 2)
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
static int
sysctl_page_shift(SYSCTL_HANDLER_ARGS)
{
uint64_t newval;
u_long value = *(u_long *)arg1;
newval = ((uint64_t)value) << PAGE_SHIFT;
return (sysctl_handle_64(oidp, &newval, 0, req));
}
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
int
swap_reserve(vm_ooffset_t incr)
{
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
return (swap_reserve_by_cred(incr, curthread->td_ucred));
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
}
int
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
swap_reserve_by_cred(vm_ooffset_t incr, struct ucred *cred)
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
{
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
u_long r, s, prev, pincr;
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
int res, error;
static int curfail;
static struct timeval lastfail;
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
struct uidinfo *uip;
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
uip = cred->cr_ruidinfo;
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
KASSERT((incr & PAGE_MASK) == 0, ("%s: incr: %ju & PAGE_MASK", __func__,
(uintmax_t)incr));
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
All the racct_*() calls need to happen with the proc locked. Fixing this won't happen before 9.0. This commit adds "#ifdef RACCT" around all the "PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order to avoid useless locking/unlocking in kernels built without "options RACCT".
2011-07-06 20:06:44 +00:00
#ifdef RACCT
Add kern.racct.enable tunable and RACCT_DISABLED config option. The point of this is to be able to add RACCT (with RACCT_DISABLED) to GENERIC, to avoid having to rebuild the kernel to use rctl(8). Differential Revision: https://reviews.freebsd.org/D2369 Reviewed by: kib@ MFC after: 1 month Relnotes: yes Sponsored by: The FreeBSD Foundation
2015-04-29 10:23:02 +00:00
if (racct_enable) {
PROC_LOCK(curproc);
error = racct_add(curproc, RACCT_SWAP, incr);
PROC_UNLOCK(curproc);
if (error != 0)
return (0);
}
All the racct_*() calls need to happen with the proc locked. Fixing this won't happen before 9.0. This commit adds "#ifdef RACCT" around all the "PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order to avoid useless locking/unlocking in kernels built without "options RACCT".
2011-07-06 20:06:44 +00:00
#endif
Add accounting for most of the memory-related resources. Sponsored by: The FreeBSD Foundation Reviewed by: kib (earlier version)
2011-04-05 20:23:59 +00:00
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
pincr = atop(incr);
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
res = 0;
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
prev = atomic_fetchadd_long(&swap_reserved, pincr);
r = prev + pincr;
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
if (overcommit & SWAP_RESERVE_ALLOW_NONWIRED) {
Make v_wire_count a per-cpu counter(9) counter. This eliminates a significant source of cache line contention from vm_page_alloc(). Use accessors and vm_page_unwire_noq() so that the mechanism can be easily changed in the future. Reviewed by: markj Discussed with: kib, glebius Tested by: pho (earlier version) Sponsored by: Netflix, Dell/EMC Isilon Differential Revision: https://reviews.freebsd.org/D14273
2018-02-12 22:53:00 +00:00
s = vm_cnt.v_page_count - vm_cnt.v_free_reserved -
vm_wire_count();
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
} else
s = 0;
s += swap_total;
if ((overcommit & SWAP_RESERVE_FORCE_ON) == 0 || r <= s ||
(error = priv_check(curthread, PRIV_VM_SWAP_NOQUOTA)) == 0) {
res = 1;
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
} else {
prev = atomic_fetchadd_long(&swap_reserved, -pincr);
if (prev < pincr)
panic("swap_reserved < incr on overcommit fail");
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
}
if (res) {
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
prev = atomic_fetchadd_long(&uip->ui_vmsize, pincr);
Remove spurious call to priv_check(PRIV_VM_SWAP_NOQUOTA). Call priv_check(PRIV_VM_SWAP_NORLIMIT) only when per-uid limit is actually exceed. Both changes aim at calling priv_check(9) only for the cases when privilege is actually exercised by the process. Reported and tested by: rwatson Reviewed by: alc MFC after: 3 days
2009-10-18 12:55:39 +00:00
if ((overcommit & SWAP_RESERVE_RLIMIT_ON) != 0 &&
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
prev + pincr > lim_cur(curthread, RLIMIT_SWAP) &&
priv_check(curthread, PRIV_VM_SWAP_NORLIMIT)) {
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
res = 0;
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
prev = atomic_fetchadd_long(&uip->ui_vmsize, -pincr);
if (prev < pincr)
panic("uip->ui_vmsize < incr on overcommit fail");
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
}
}
if (!res && ppsratecheck(&lastfail, &curfail, 1)) {
printf("uid %d, pid %d: swap reservation for %jd bytes failed\n",
Fix printf. Submitted by: az MFC after: 1 week
2011-12-12 10:04:04 +00:00
uip->ui_uid, curproc->p_pid, incr);
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
}
All the racct_*() calls need to happen with the proc locked. Fixing this won't happen before 9.0. This commit adds "#ifdef RACCT" around all the "PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order to avoid useless locking/unlocking in kernels built without "options RACCT".
2011-07-06 20:06:44 +00:00
#ifdef RACCT
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
if (racct_enable && !res) {
Add accounting for most of the memory-related resources. Sponsored by: The FreeBSD Foundation Reviewed by: kib (earlier version)
2011-04-05 20:23:59 +00:00
PROC_LOCK(curproc);
racct_sub(curproc, RACCT_SWAP, incr);
PROC_UNLOCK(curproc);
}
All the racct_*() calls need to happen with the proc locked. Fixing this won't happen before 9.0. This commit adds "#ifdef RACCT" around all the "PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order to avoid useless locking/unlocking in kernels built without "options RACCT".
2011-07-06 20:06:44 +00:00
#endif
Add accounting for most of the memory-related resources. Sponsored by: The FreeBSD Foundation Reviewed by: kib (earlier version)
2011-04-05 20:23:59 +00:00
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
return (res);
}
void
swap_reserve_force(vm_ooffset_t incr)
{
struct uidinfo *uip;
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
u_long pincr;
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
KASSERT((incr & PAGE_MASK) == 0, ("%s: incr: %ju & PAGE_MASK", __func__,
(uintmax_t)incr));
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
Add accounting for most of the memory-related resources. Sponsored by: The FreeBSD Foundation Reviewed by: kib (earlier version)
2011-04-05 20:23:59 +00:00
PROC_LOCK(curproc);
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
#ifdef RACCT
if (racct_enable)
racct_add_force(curproc, RACCT_SWAP, incr);
All the racct_*() calls need to happen with the proc locked. Fixing this won't happen before 9.0. This commit adds "#ifdef RACCT" around all the "PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order to avoid useless locking/unlocking in kernels built without "options RACCT".
2011-07-06 20:06:44 +00:00
#endif
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
pincr = atop(incr);
atomic_add_long(&swap_reserved, pincr);
uip = curproc->p_ucred->cr_ruidinfo;
atomic_add_long(&uip->ui_vmsize, pincr);
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
PROC_UNLOCK(curproc);
}
void
swap_release(vm_ooffset_t decr)
{
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
struct ucred *cred;
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
PROC_LOCK(curproc);
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
cred = curproc->p_ucred;
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
swap_release_by_cred(decr, cred);
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
PROC_UNLOCK(curproc);
}
void
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
swap_release_by_cred(vm_ooffset_t decr, struct ucred *cred)
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
{
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
u_long prev, pdecr;
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
struct uidinfo *uip;
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Replace pointer to "struct uidinfo" with pointer to "struct ucred" in "struct vm_object". This is required to make it possible to account for per-jail swap usage. Reviewed by: kib@ Tested by: pho@ Sponsored by: FreeBSD Foundation
2010-12-02 17:37:16 +00:00
uip = cred->cr_ruidinfo;
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
KASSERT((decr & PAGE_MASK) == 0, ("%s: decr: %ju & PAGE_MASK", __func__,
(uintmax_t)decr));
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
pdecr = atop(decr);
prev = atomic_fetchadd_long(&swap_reserved, -pdecr);
if (prev < pdecr)
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
panic("swap_reserved < decr");
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
prev = atomic_fetchadd_long(&uip->ui_vmsize, -pdecr);
if (prev < pdecr)
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
printf("negative vmsize for uid = %d\n", uip->ui_uid);
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
#ifdef RACCT
if (racct_enable)
racct_sub_cred(cred, RACCT_SWAP, decr);
#endif
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
}
Make the swap_pager_full variable static. r290920 removed the use of the variable from vm/vm_pageout.c. Submitted by: ota@j.email.ne.jp PR: 221356 MFC after: 1 week
2017-08-30 09:44:05 +00:00
static int swap_pager_full = 2; /* swap space exhaustion (task killing) */
1. Statically initialize swap_pager_full and swap_pager_almost_full to the full state. (When swap is added their state will change appropriately.) 2. Set swap_pager_full and swap_pager_almost_full to the full state when the last swap device is removed. Combined these changes eliminate nonsense messages from the kernel on swap- less machines. Item 2 submitted by: Divacky Roman <xdivac02@stud.fit.vutbr.cz> Prodding by: phk
2004-01-24 21:31:06 +00:00
static int swap_pager_almost_full = 1; /* swap space exhaustion (w/hysteresis)*/
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
static struct mtx swbuf_mtx; /* to sync nsw_wcount_async */
static int nsw_wcount_async; /* limit async write buffers */
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
static int nsw_wcount_async_max;/* assigned maximum */
static int nsw_cluster_max; /* maximum VOP I/O allowed */
Another mega commit to staticize things.
1995-12-14 09:55:16 +00:00
Instead of reading, validating and adjusting value of the vm.swap_async_max in the main swapper work cycle, do it in the sysctl handler. This removes extra mutex acquisition from the main cycle and makes the sysctl knob return error on an invalid value, instead of accepting and fixing it. Reviewed by: kib Sponsored by: Netflix Sponsored by: Nginx, Inc.
2015-05-02 20:27:37 +00:00
static int sysctl_swap_async_max(SYSCTL_HANDLER_ARGS);
Mark swap-related proc sysctls as not requiring Giant. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:28:23 +00:00
SYSCTL_PROC(_vm, OID_AUTO, swap_async_max, CTLTYPE_INT | CTLFLAG_RW |
CTLFLAG_MPSAFE, NULL, 0, sysctl_swap_async_max, "I",
"Maximum running async swap ops");
To analyze the allocation of swap blocks by blist functions, add a method for analyzing the radix tree structures and reporting on the number, and sizes, of maximal intervals of free blocks. The report includes the number of maximal intervals, and also the number of them in each of several size ranges, from small (size 1, or 3 to 4) to large (28657 to 46367) with size boundaries defined by Fibonacci numbers. The report is written in the test tool with the 's' command, or in a running kernel by sysctl. The analysis of the radix tree frequently computes the position of the lone bit set in a u_daddr_t, a computation that also appears in leaf allocation. That computation has been moved into a function of its own, and optimized for cases where an inlined machine instruction can replace the usual binary search. Submitted by: Doug Moore <dougm@rice.edu> MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D11906
2017-09-10 17:46:03 +00:00
static int sysctl_swap_fragmentation(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_vm, OID_AUTO, swap_fragmentation, CTLTYPE_STRING | CTLFLAG_RD |
CTLFLAG_MPSAFE, NULL, 0, sysctl_swap_fragmentation, "A",
"Swap Fragmentation Info");
Instead of reading, validating and adjusting value of the vm.swap_async_max in the main swapper work cycle, do it in the sysctl handler. This removes extra mutex acquisition from the main cycle and makes the sysctl knob return error on an invalid value, instead of accepting and fixing it. Reviewed by: kib Sponsored by: Netflix Sponsored by: Nginx, Inc.
2015-05-02 20:27:37 +00:00
With Alfred's permission, remove vm_mtx in favor of a fine-grained approach (this commit is just the first stage). Also add various GIANT_ macros to formalize the removal of Giant, making it easy to test in a more piecemeal fashion. These macros will allow us to test fine-grained locks to a degree before removing Giant, and also after, and to remove Giant in a piecemeal fashion via sysctl's on those subsystems which the authors believe can operate without Giant.
2001-07-04 16:20:28 +00:00
static struct sx sw_alloc_sx;
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* "named" and "unnamed" anon region objects. Try to reduce the overhead
* of searching a named list by hashing it just a little.
*/
Another mega commit to staticize things.
1995-12-14 09:55:16 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
#define NOBJLISTS 8
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
#define NOBJLIST(handle) \
Use devtoname to print dev_t's instead of casting them to u_long for misprinting with %lx. Cast pointers to intptr_t instead of casting them to long. Cosmetic.
1999-08-23 23:55:03 +00:00
(&swap_pager_object_list[((int)(intptr_t)handle >> 4) & (NOBJLISTS-1)])
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
static struct pagerlst swap_pager_object_list[NOBJLISTS];
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
static uma_zone_t swwbuf_zone;
static uma_zone_t swrbuf_zone;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
static uma_zone_t swblk_zone;
static uma_zone_t swpctrie_zone;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* pagerops for OBJT_SWAP - "swap pager". Some ops are also global procedure
* calls hooked from other parts of the VM system and do not appear here.
* (see vm/swap_pager.h).
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
*/
Fixed recent staticizations. Some protypes for static functions were left in headers and not staticized.
1995-11-16 09:51:22 +00:00
static vm_object_t
Remove __P.
2002-03-19 22:20:14 +00:00
swap_pager_alloc(void *handle, vm_ooffset_t size,
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
vm_prot_t prot, vm_ooffset_t offset, struct ucred *);
Remove __P.
2002-03-19 22:20:14 +00:00
static void swap_pager_dealloc(vm_object_t object);
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
static int swap_pager_getpages(vm_object_t, vm_page_t *, int, int *,
int *);
static int swap_pager_getpages_async(vm_object_t, vm_page_t *, int, int *,
int *, pgo_getpages_iodone_t, void *);
Staticize swap_pager_putpages() Eliminate a lot of checkes to make sure requests are not cross-device which is unnecessary with the new layout. We know a sequential request cannot possibly be cross-device because there is a reserved page between the devices. Remove a couple of comments which no longer are relevant.
2003-08-06 12:08:27 +00:00
static void swap_pager_putpages(vm_object_t, vm_page_t *, int, boolean_t, int *);
Make swap_pager_haspages() static; remove unused function prototypes.
2003-06-20 20:20:06 +00:00
static boolean_t
swap_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before, int *after);
Remove __P.
2002-03-19 22:20:14 +00:00
static void swap_pager_init(void);
static void swap_pager_unswapped(vm_page_t);
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
static void swap_pager_swapoff(struct swdevt *sp);
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
static void swap_pager_update_writecount(vm_object_t object,
vm_offset_t start, vm_offset_t end);
static void swap_pager_release_writecount(vm_object_t object,
vm_offset_t start, vm_offset_t end);
Another mega commit to staticize things.
1995-12-14 09:55:16 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
struct pagerops swappagerops = {
Use sparse struct initialization for struct pagerops. Mark our buffers B_KEEPGIANT before sending them downstream. Remove swap_pager_strategy implementation.
2003-08-05 06:54:56 +00:00
.pgo_init = swap_pager_init, /* early system initialization of pager */
.pgo_alloc = swap_pager_alloc, /* allocate an OBJT_SWAP object */
.pgo_dealloc = swap_pager_dealloc, /* deallocate an OBJT_SWAP object */
.pgo_getpages = swap_pager_getpages, /* pagein */
Merge from projects/sendfile: o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc.
2014-11-23 12:01:52 +00:00
.pgo_getpages_async = swap_pager_getpages_async, /* pagein (async) */
Use sparse struct initialization for struct pagerops. Mark our buffers B_KEEPGIANT before sending them downstream. Remove swap_pager_strategy implementation.
2003-08-05 06:54:56 +00:00
.pgo_putpages = swap_pager_putpages, /* pageout */
.pgo_haspage = swap_pager_haspage, /* get backing store status for page */
.pgo_pageunswapped = swap_pager_unswapped, /* remove swap related to page */
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
.pgo_update_writecount = swap_pager_update_writecount,
.pgo_release_writecount = swap_pager_release_writecount,
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
};
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* swap_*() routines are externally accessible. swp_*() routines are
* internal.
*/
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
static int nswap_lowat = 128; /* in pages, swap_pager_almost_full warn */
static int nswap_hiwat = 512; /* in pages, swap_pager_almost_full warn */
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
After r118390, the variable "dmmax" was neither the correct strip size nor the correct maximum block size. Moreover, after r318995, it serves no purpose except to provide information to user space through a read- sysctl. This change eliminates the variable "dmmax" but retains the sysctl. It also corrects the value returned by the sysctl. Reviewed by: kib, markj MFC after: 3 days
2017-05-27 21:46:00 +00:00
SYSCTL_INT(_vm, OID_AUTO, dmmax, CTLFLAG_RD, &nsw_cluster_max, 0,
"Maximum size of a swap block in pages");
o Export dmmax ("Maximum size of a swap block") using SYSCTL_INT. This removes a reason that systat requires setgid kmem. More to come.
2000-11-20 00:39:04 +00:00
Remove all but one of the inlines here, this reduces the code size by 2032 bytes and has no measurable impact on performance.
2003-07-22 20:54:26 +00:00
static void swp_sizecheck(void);
Remove __P.
2002-03-19 22:20:14 +00:00
static void swp_pager_async_iodone(struct buf *bp);
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
static bool swp_pager_swblk_empty(struct swblk *sb, int start, int limit);
Add a helper function for testing a swap block and freeing it if empty. Submitted by: ota_j.email.ne.jp Approved by: alc, kib, dougm Differential Revision: https://reviews.freebsd.org/D22402
2019-11-17 18:38:37 +00:00
static void swp_pager_free_empty_swblk(vm_object_t, struct swblk *sb);
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
static int swapongeom(struct vnode *);
Continue the objectification of the swapdev backends: Remove the vnode and dev_t fields and replace them with a void *. Introduce separate strategy functions for devices and regular (NFS) vnodes. For devices we don't need the vnode v_numoutput stuff. Add a generic swaponsomething() function to add a swapdevice and split the remainder of swaponvp() into swaponvp() and swapondev() which calls this backend.
2003-08-30 11:33:25 +00:00
static int swaponvp(struct thread *, struct vnode *, u_long);
When MAC is enabled in the kernel, fix a panic triggered by a locking assertion hit in swapoff_one() when we un-mount a swap partition. We should be using curthread where we used thread0 before. This change also replaces the thread argument with a credential argument, as the MAC framework only requires the cred. It should be noted that this allows the machine to be rebooted without panicing with "cannot differ from curthread or NULL" when MAC is enabled. Submitted by: rwatson Reviewed by: attilio MFC after: 2 weeks
2008-01-08 14:58:41 +00:00
static int swapoff_one(struct swdevt *sp, struct ucred *cred);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Swap bitmap functions
*/
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
static void swp_pager_freeswapspace(daddr_t blk, daddr_t npages);
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
static daddr_t swp_pager_getswapspace(int *npages, int limit);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Metadata functions
*/
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
static daddr_t swp_pager_meta_build(vm_object_t, vm_pindex_t, daddr_t);
Fix argument type and microoptimize swp_pager_meta_free(). The count argument natural type if vm_pindex_t, but due to the loop organization, it has to be signed type to detect the termination condition. Replace this logic by using distinguished counter for the processed pages, and terminate loop when the counter exceeds the argument. Completely process one swblock for all relevant indexes instead of doing relookup in hash when incrementing page index on the loop step. Do not drop hash mutex around iterations. Noted and reviewed by: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-24 09:57:31 +00:00
static void swp_pager_meta_free(vm_object_t, vm_pindex_t, vm_pindex_t);
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
static void swp_pager_meta_transfer(vm_object_t src, vm_object_t dst,
vm_pindex_t pindex, vm_pindex_t count);
Remove __P.
2002-03-19 22:20:14 +00:00
static void swp_pager_meta_free_all(vm_object_t);
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
static daddr_t swp_pager_meta_lookup(vm_object_t, vm_pindex_t);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
static void
swp_pager_init_freerange(daddr_t *start, daddr_t *num)
{
*start = SWAPBLK_NONE;
*num = 0;
}
static void
swp_pager_update_freerange(daddr_t *start, daddr_t *num, daddr_t addr)
{
if (*start + *num == addr) {
(*num)++;
} else {
swp_pager_freeswapspace(*start, *num);
*start = addr;
*num = 1;
}
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
static void *
swblk_trie_alloc(struct pctrie *ptree)
{
return (uma_zalloc(swpctrie_zone, M_NOWAIT | (curproc == pageproc ?
M_USE_RESERVE : 0)));
}
static void
swblk_trie_free(struct pctrie *ptree, void *node)
{
uma_zfree(swpctrie_zone, node);
}
PCTRIE_DEFINE(SWAP, swblk, p, swblk_trie_alloc, swblk_trie_free);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* SWP_SIZECHECK() - update swap_pager_full indication
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
*
Reviewed by: Alan Cox <alc@cs.rice.edu> Fix problem w/ low-swap/low-memory handling as reported by Bruce Evans.
1999-02-21 08:30:49 +00:00
* update the swap_pager_almost_full indication and warn when we are
* about to run out of swap space, using lowat/hiwat hysteresis.
*
* Clear swap_pager_full ( task killing ) indication when lowat is met.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* No restrictions on call
* This routine may not block.
*/
Remove all but one of the inlines here, this reduces the code size by 2032 bytes and has no measurable impact on performance.
2003-07-22 20:54:26 +00:00
static void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swp_sizecheck(void)
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
{
Introduce a global lock for the vm subsystem (vm_mtx). vm_mtx does not recurse and is required for most low level vm operations. faults can not be taken without holding Giant. Memory subsystems can now call the base page allocators safely. Almost all atomic ops were removed as they are covered under the vm mutex. Alpha and ia64 now need to catch up to i386's trap handlers. FFS and NFS have been tested, other filesystems will need minor changes (grabbing the vm lock when twiddling page properties). Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
if (swap_pager_avail < nswap_lowat) {
Reviewed by: Alan Cox <alc@cs.rice.edu> Fix problem w/ low-swap/low-memory handling as reported by Bruce Evans.
1999-02-21 08:30:49 +00:00
if (swap_pager_almost_full == 0) {
"out of space" -> "out of swap space".
1996-01-31 13:14:21 +00:00
printf("swap_pager: out of swap space\n");
Reviewed by: Alan Cox <alc@cs.rice.edu> Fix problem w/ low-swap/low-memory handling as reported by Bruce Evans.
1999-02-21 08:30:49 +00:00
swap_pager_almost_full = 1;
Add hysteresis to the 'swap_pager_getswapspace; failed' console message. Also widen the hysteresis levels a little ( these really should be dynamically configured ).
1999-02-06 07:22:21 +00:00
}
Reviewed by: Alan Cox <alc@cs.rice.edu> Fix problem w/ low-swap/low-memory handling as reported by Bruce Evans.
1999-02-21 08:30:49 +00:00
} else {
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
swap_pager_full = 0;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
if (swap_pager_avail > nswap_hiwat)
Reviewed by: Alan Cox <alc@cs.rice.edu> Fix problem w/ low-swap/low-memory handling as reported by Bruce Evans.
1999-02-21 08:30:49 +00:00
swap_pager_almost_full = 0;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* SWAP_PAGER_INIT() - initialize the swap pager!
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* Expected to be started from system init. NOTE: This code is run
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* before much else so be careful what you depend on. Most of the VM
* system has yet to be initialized at this point.
*/
staticize.
1995-11-14 20:53:20 +00:00
static void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swap_pager_init(void)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* Initialize object lists
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
int i;
for (i = 0; i < NOBJLISTS; ++i)
TAILQ_INIT(&swap_pager_object_list[i]);
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_init(&sw_dev_mtx, "swapdev", NULL, MTX_DEF);
Explicitely initialize sw_alloc_sx. Currently it is not initialized but works due to zeroed out bss on startup. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 1 week Approved by: re (hrs)
2016-06-13 03:39:16 +00:00
sx_init(&sw_alloc_sx, "swspsx");
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_init(&swdev_syscall_lock, "swsysc");
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
static void
swap_pager_counters(void)
{
swap_free_deferred = counter_u64_alloc(M_WAITOK);
swap_free_completed = counter_u64_alloc(M_WAITOK);
}
SYSINIT(swap_counters, SI_SUB_CPU, SI_ORDER_ANY, swap_pager_counters, NULL);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* SWAP_PAGER_SWAP_INIT() - swap pager initialization from pageout process
*
* Expected to be started from pageout process once, prior to entering
* its main loop.
*/
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swap_pager_swap_init(void)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Add sysctl OIDs showing the actual size and capacity of the swap zone. MFC after: 1 week
2014-04-26 12:18:17 +00:00
unsigned long n, n2;
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* Number of in-transit swap bp operations. Don't
* exhaust the pbufs completely. Make sure we
* initialize workable values (0 will work for hysteresis
* but it isn't very efficient).
*
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
* The nsw_cluster_max is constrained by the bp->b_pages[]
A style-related change, r349791, made unclear the meaning of a comment. Rewrite that comment to improve its clarity. Reported by: cem Reviewed by: alc, cem Approved by: kib, markj (mentors, implicit) Differential Revision: https://reviews.freebsd.org/D20871
2019-07-07 06:57:04 +00:00
* array, which has MAXPHYS / PAGE_SIZE entries, and our locally
* defined MAX_PAGEOUT_CLUSTER. Also be aware that swap ops are
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* constrained by the swap device interleave stripe size.
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* Currently we hardwire nsw_wcount_async to 4. This limit is
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
* designed to prevent other I/O from having high latencies due to
* our pageout I/O. The value 4 works well for one or two active swap
* devices but is probably a little low if you have more. Even so,
* a higher value would probably generate only a limited improvement
* with three or four active swap devices since the system does not
* typically have to pageout at extreme bandwidths. We will want
* at least 2 per swap devices, and 4 is a pretty good value if you
* have one NFS swap device due to the command/ack latency over NFS.
* So it all works out pretty well.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Fix style(9) violations involving division by PAGE_SIZE. Reviewed by: alc Approved by: markj (mentor) Differential Revision: https://reviews.freebsd.org/D20847
2019-07-06 15:55:16 +00:00
nsw_cluster_max = min(MAXPHYS / PAGE_SIZE, MAX_PAGEOUT_CLUSTER);
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
nsw_wcount_async = 4;
nsw_wcount_async_max = nsw_wcount_async;
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
mtx_init(&swbuf_mtx, "async swbuf mutex", NULL, MTX_DEF);
swwbuf_zone = pbuf_zsecond_create("swwbuf", nswbuf / 4);
swrbuf_zone = pbuf_zsecond_create("swrbuf", nswbuf / 2);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
Allow to create swap zone larger than v_page_count / 2. If user configured the maxswapzone tunable, just take the literal value for the initial zone sizing attempt. Before, it was only possible to reduce the zone by the tunable. While there, correct the message which was not correct when zone creation rounded the size up. Reported by: jmg Reviewed by: markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D18381
2018-12-01 16:50:12 +00:00
* Initialize our zone, taking the user's requested size or
* estimating the number we need based on the number of pages
* in the system.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
Allow to create swap zone larger than v_page_count / 2. If user configured the maxswapzone tunable, just take the literal value for the initial zone sizing attempt. Before, it was only possible to reduce the zone by the tunable. While there, correct the message which was not correct when zone creation rounded the size up. Reported by: jmg Reviewed by: markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D18381
2018-12-01 16:50:12 +00:00
n = maxswzone != 0 ? maxswzone / sizeof(struct swblk) :
vm_cnt.v_page_count / 2;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
swpctrie_zone = uma_zcreate("swpctrie", pctrie_node_size(), NULL, NULL,
Passing UMA_ZONE_NOFREE to uma_zcreate() for swpctrie_zone and swblk_zone is redundant, because uma_zone_reserve_kva() is performed on both zones and it sets this same flag on the zone. (Moreover, the implementation of the swap pager does not itself require these zones to be UMA_ZONE_NOFREE.) Reviewed by: kib, markj Approved by: re (gjb) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D17296
2018-09-24 16:49:02 +00:00
pctrie_zone_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (swpctrie_zone == NULL)
panic("failed to create swap pctrie zone.");
swblk_zone = uma_zcreate("swblk", sizeof(struct swblk), NULL, NULL,
Passing UMA_ZONE_NOFREE to uma_zcreate() for swpctrie_zone and swblk_zone is redundant, because uma_zone_reserve_kva() is performed on both zones and it sets this same flag on the zone. (Moreover, the implementation of the swap pager does not itself require these zones to be UMA_ZONE_NOFREE.) Reviewed by: kib, markj Approved by: re (gjb) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D17296
2018-09-24 16:49:02 +00:00
NULL, NULL, _Alignof(struct swblk) - 1, UMA_ZONE_VM);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (swblk_zone == NULL)
panic("failed to create swap blk zone.");
Revert previous commit, which was performed in the wrong tree.
2012-09-04 21:06:53 +00:00
n2 = n;
Fixups for the initial allocation by dillon: 1) allocate fewer buckets 2) when failing to allocate swap zone, keep reducing the zone by a third rather than a half in order to reduce the chance of allocating way too little. I also moved around some code for readability. Suggested by: dillon Reviewed by: dillon
2001-08-02 07:54:58 +00:00
do {
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (uma_zone_reserve_kva(swblk_zone, n))
Fixups for the initial allocation by dillon: 1) allocate fewer buckets 2) when failing to allocate swap zone, keep reducing the zone by a third rather than a half in order to reduce the chance of allocating way too little. I also moved around some code for readability. Suggested by: dillon Reviewed by: dillon
2001-08-02 07:54:58 +00:00
break;
/*
* if the allocation failed, try a zone two thirds the
* size of the previous attempt.
*/
n -= ((n + 2) / 3);
} while (n > 0);
Evaluate the real size of the sblk_zone. Submitted by: ota@j.email.ne.jp PR: 221356 Reviewed by: alc, markj MFC after: 1 week Differential revision: https://reviews.freebsd.org/D12660
2017-10-13 16:23:05 +00:00
/*
* Often uma_zone_reserve_kva() cannot reserve exactly the
* requested size. Account for the difference when
* calculating swap_maxpages.
*/
n = uma_zone_get_max(swblk_zone);
Do not report reduction of swap zone if it was not. After r324600 we see the actual reservation. Reported by: jkim Sponsored by: The FreeBSD Foundation MFC after: 1 week
2017-10-18 07:27:43 +00:00
if (n < n2)
Allow to create swap zone larger than v_page_count / 2. If user configured the maxswapzone tunable, just take the literal value for the initial zone sizing attempt. Before, it was only possible to reduce the zone by the tunable. While there, correct the message which was not correct when zone creation rounded the size up. Reported by: jmg Reviewed by: markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D18381
2018-12-01 16:50:12 +00:00
printf("Swap blk zone entries changed from %lu to %lu.\n",
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
n2, n);
swapon_check_swzone(): use already calculated static variables. Submitted by: ota@j.email.ne.jp MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22065
2019-10-17 13:49:47 +00:00
/* absolute maximum we can handle assuming 100% efficiency */
Add sysctl OIDs showing the actual size and capacity of the swap zone. MFC after: 1 week
2014-04-26 12:18:17 +00:00
swap_maxpages = n * SWAP_META_PAGES;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
swzone = n * sizeof(struct swblk);
if (!uma_zone_reserve_kva(swpctrie_zone, n))
printf("Cannot reserve swap pctrie zone, "
"reduce kern.maxswzone.\n");
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
}
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
static vm_object_t
swap_pager_alloc_init(void *handle, struct ucred *cred, vm_ooffset_t size,
vm_ooffset_t offset)
{
vm_object_t object;
if (cred != NULL) {
if (!swap_reserve_by_cred(size, cred))
return (NULL);
crhold(cred);
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
/*
* The un_pager.swp.swp_blks trie is initialized by
* vm_object_allocate() to ensure the correct order of
* visibility to other threads.
*/
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
object = vm_object_allocate(OBJT_SWAP, OFF_TO_IDX(offset +
PAGE_MASK + size));
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
object->un_pager.swp.writemappings = 0;
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
object->handle = handle;
if (cred != NULL) {
object->cred = cred;
object->charge = size;
}
return (object);
}
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWAP_PAGER_ALLOC() - allocate a new OBJT_SWAP VM object and instantiate
* its metadata structures.
*
* This routine is called from the mmap and fork code to create a new
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
* OBJT_SWAP object.
o Replace GIANT_REQUIRED in swap_pager_alloc() by the acquisition and release of Giant. (Annotate as MPSAFE.)
2002-06-22 08:03:21 +00:00
*
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
* This routine must ensure that no live duplicate is created for
* the named object request, which is protected against by
* holding the sw_alloc_sx lock in case handle != NULL.
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
*/
staticize.
1995-11-14 20:53:20 +00:00
static vm_object_t
Fixed two potentially serious classes of bugs: 1) The vnode pager wasn't properly tracking the file size due to "size" being page rounded in some cases and not in others. This sometimes resulted in corrupted files. First noticed by Terry Lambert. Fixed by changing the "size" pager_alloc parameter to be a 64bit byte value (as opposed to a 32bit page index) and changing the pagers and their callers to deal with this properly. 2) Fixed a bogus type cast in round_page() and trunc_page() that caused some 64bit offsets and sizes to be scrambled. Removing the cast required adding casts at a few dozen callers. There may be problems with other bogus casts in close-by macros. A quick check seemed to indicate that those were okay, however.
1998-10-13 08:24:45 +00:00
swap_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
vm_ooffset_t offset, struct ucred *cred)
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
{
vm_object_t object;
Simplify the various pager allocation routines by computing the desired object size once and assigning that value to a local variable.
2004-01-04 20:55:15 +00:00
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
if (handle != NULL) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Reference existing named region or allocate new one. There
* should not be a race here against swp_pager_meta_build()
* as called from vm_page_remove() in regards to the lookup
* of the handle.
*/
With Alfred's permission, remove vm_mtx in favor of a fine-grained approach (this commit is just the first stage). Also add various GIANT_ macros to formalize the removal of Giant, making it easy to test in a more piecemeal fashion. These macros will allow us to test fine-grained locks to a degree before removing Giant, and also after, and to remove Giant in a piecemeal fashion via sysctl's on those subsystems which the authors believe can operate without Giant.
2001-07-04 16:20:28 +00:00
sx_xlock(&sw_alloc_sx);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
object = vm_pager_object_lookup(NOBJLIST(handle), handle);
Consider a scenario in which one processor, call it Pt, is performing vm_object_terminate() on a device-backed object at the same time that another processor, call it Pa, is performing dev_pager_alloc() on the same device. The problem is that vm_pager_object_lookup() should not be allowed to return a doomed object, i.e., an object with OBJ_DEAD set, but it does. In detail, the unfortunate sequence of events is: Pt in vm_object_terminate() holds the doomed object's lock and sets OBJ_DEAD on the object. Pa in dev_pager_alloc() holds dev_pager_sx and calls vm_pager_object_lookup(), which returns the doomed object. Next, Pa calls vm_object_reference(), which requires the doomed object's lock, so Pa waits for Pt to release the doomed object's lock. Pt proceeds to the point in vm_object_terminate() where it releases the doomed object's lock. Pa is now able to complete vm_object_reference() because it can now complete the acquisition of the doomed object's lock. So, now the doomed object has a reference count of one! Pa releases dev_pager_sx and returns the doomed object from dev_pager_alloc(). Pt now acquires dev_pager_mtx, removes the doomed object from dev_pager_object_list, releases dev_pager_mtx, and finally calls uma_zfree with the doomed object. However, the doomed object is still in use by Pa. Repeating my key point, vm_pager_object_lookup() must not return a doomed object. Moreover, the test for the object's state, i.e., doomed or not, and the increment of the object's reference count should be carried out atomically. Reviewed by: kib Approved by: re (kensmith) MFC after: 3 weeks
2007-08-05 21:04:32 +00:00
if (object == NULL) {
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
object = swap_pager_alloc_init(handle, cred, size,
offset);
if (object != NULL) {
TAILQ_INSERT_TAIL(NOBJLIST(object->handle),
object, pager_object_list);
Implement global and per-uid accounting of the anonymous memory. Add rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved for the uid. The accounting information (charge) is associated with either map entry, or vm object backing the entry, assuming the object is the first one in the shadow chain and entry does not require COW. Charge is moved from entry to object on allocation of the object, e.g. during the mmap, assuming the object is allocated, or on the first page fault on the entry. It moves back to the entry on forks due to COW setup. The per-entry granularity of accounting makes the charge process fair for processes that change uid during lifetime, and decrements charge for proper uid when region is unmapped. The interface of vm_pager_allocate(9) is extended by adding struct ucred *, that is used to charge appropriate uid when allocation if performed by kernel, e.g. md(4). Several syscalls, among them is fork(2), may now return ENOMEM when global or per-uid limits are enforced. In collaboration with: pho Reviewed by: alc Approved by: re (kensmith)
2009-06-23 20:45:22 +00:00
}
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
}
With Alfred's permission, remove vm_mtx in favor of a fine-grained approach (this commit is just the first stage). Also add various GIANT_ macros to formalize the removal of Giant, making it easy to test in a more piecemeal fashion. These macros will allow us to test fine-grained locks to a degree before removing Giant, and also after, and to remove Giant in a piecemeal fashion via sysctl's on those subsystems which the authors believe can operate without Giant.
2001-07-04 16:20:28 +00:00
sx_xunlock(&sw_alloc_sx);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
} else {
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
object = swap_pager_alloc_init(handle, cred, size, offset);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
NOTE: libkvm, w, ps, 'top', and any other utility which depends on struct proc or any VM system structure will have to be rebuilt!!! Much needed overhaul of the VM system. Included in this first round of changes: 1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages, haspage, and sync operations are supported. The haspage interface now provides information about clusterability. All pager routines now take struct vm_object's instead of "pagers". 2) Improved data structures. In the previous paradigm, there is constant confusion caused by pagers being both a data structure ("allocate a pager") and a collection of routines. The idea of a pager structure has escentially been eliminated. Objects now have types, and this type is used to index the appropriate pager. In most cases, items in the pager structure were duplicated in the object data structure and thus were unnecessary. In the few cases that remained, a un_pager structure union was created in the object to contain these items. 3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now be removed. For instance, vm_object_enter(), vm_object_lookup(), vm_object_remove(), and the associated object hash list were some of the things that were removed. 4) simple_lock's removed. Discussion with several people reveals that the SMP locking primitives used in the VM system aren't likely the mechanism that we'll be adopting. Even if it were, the locking that was in the code was very inadequate and would have to be mostly re-done anyway. The locking in a uni-processor kernel was a no-op but went a long way toward making the code difficult to read and debug. 5) Places that attempted to kludge-up the fact that we don't have kernel thread support have been fixed to reflect the reality that we are really dealing with processes, not threads. The VM system didn't have complete thread support, so the comments and mis-named routines were just wrong. We now use tsleep and wakeup directly in the lock routines, for instance. 6) Where appropriate, the pagers have been improved, especially in the pager_alloc routines. Most of the pager_allocs have been rewritten and are now faster and easier to maintain. 7) The pagedaemon pageout clustering algorithm has been rewritten and now tries harder to output an even number of pages before and after the requested page. This is sort of the reverse of the ideal pagein algorithm and should provide better overall performance. 8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup have been removed. Some other unnecessary casts have also been removed. 9) Some almost useless debugging code removed. 10) Terminology of shadow objects vs. backing objects straightened out. The fact that the vm_object data structure escentially had this backwards really confused things. The use of "shadow" and "backing object" throughout the code is now internally consistent and correct in the Mach terminology. 11) Several minor bug fixes, including one in the vm daemon that caused 0 RSS objects to not get purged as intended. 12) A "default pager" has now been created which cleans up the transition of objects to the "swap" type. The previous checks throughout the code for swp->pg_data != NULL were really ugly. This change also provides the rudiments for future backing of "anonymous" memory by something other than the swap pager (via the vnode pager, for example), and it allows the decision about which of these pagers to use to be made dynamically (although will need some additional decision code to do this, of course). 13) (dyson) MAP_COPY has been deprecated and the corresponding "copy object" code has been removed. MAP_COPY was undocumented and non- standard. It was furthermore broken in several ways which caused its behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will continue to work correctly, but via the slightly different semantics of MAP_PRIVATE. 14) (dyson) Sharing maps have been removed. It's marginal usefulness in a threads design can be worked around in other ways. Both #12 and #13 were done to simplify the code and improve readability and maintain- ability. (As were most all of these changes) TODO: 1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing this will reduce the vnode pager to a mere fraction of its current size. 2) Rewrite vm_fault and the swap/vnode pagers to use the clustering information provided by the new haspage pager interface. This will substantially reduce the overhead by eliminating a large number of VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be improved to provide both a "behind" and "ahead" indication of contiguousness. 3) Implement the extended features of pager_haspage in swap_pager_haspage(). It currently just says 0 pages ahead/behind. 4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps via a much more general mechanism that could also be used for disk striping of regular filesystems. 5) Do something to improve the architecture of vm_object_collapse(). The fact that it makes calls into the swap pager and knows too much about how the swap pager operates really bothers me. It also doesn't allow for collapsing of non-swap pager objects ("unnamed" objects backed by other pagers).
1995-07-13 08:48:48 +00:00
return (object);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWAP_PAGER_DEALLOC() - remove swap metadata from object
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* The swap backing for the object is destroyed. The code is
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* designed such that we can reinstantiate it later, but this
* routine is typically called only when the entire object is
* about to be destroyed.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* The object must be locked.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
static void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swap_pager_dealloc(vm_object_t object)
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
{
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
VM_OBJECT_ASSERT_WLOCKED(object);
KASSERT((object->flags & OBJ_DEAD) != 0, ("dealloc of reachable obj"));
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Remove from list right away so lookups will fail if we block for
* pageout completion.
*/
Store the bottom of the shadow chain in OBJ_ANON object->handle member. The handle value is stable for all shadow objects in the inheritance chain. This allows to avoid descending the shadow chain to get to the bottom of it in vm_map_entry_set_vnode_text(), and eliminate corresponding object relocking which appeared to be contending. Change vm_object_allocate_anon() and vm_object_shadow() to handle more of the cred/charge initialization for the new shadow object, in addition to set up the handle. Reported by: jeff Reviewed by: alc (previous version), jeff (previous version) Tested by: pho Sponsored by: The FreeBSD Foundation Differrential revision: https://reviews.freebsd.org/D22541
2019-12-01 20:43:04 +00:00
if ((object->flags & OBJ_ANON) == 0 && object->handle != NULL) {
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
VM_OBJECT_WUNLOCK(object);
sx_xlock(&sw_alloc_sx);
TAILQ_REMOVE(NOBJLIST(object->handle), object,
pager_object_list);
sx_xunlock(&sw_alloc_sx);
VM_OBJECT_WLOCK(object);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
vm_object_pip_wait(object, "swpdea");
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* Free all remaining metadata. We only bother to free it from
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* the swap meta data. We do not attempt to free swapblk's still
* associated with vm_page_t's for this object. We do not care
* if paging is still in progress on some objects.
*/
swp_pager_meta_free_all(object);
Place VM objects on the object list when created and never remove them. This is ok since objects come from a NOFREE zone and allows objects to be locked while traversing the object list without triggering a LOR. Ensure that objects on the list are marked DEAD while free or stillborn, and that they have a refcount of zero. This required updating most of the pagers to explicitly mark an object as dead when deallocating it. (Only the vnode pager did this previously.) Differential Revision: https://reviews.freebsd.org/D2423 Reviewed by: alc, kib (earlier version) MFC after: 2 weeks Sponsored by: Norse Corp, Inc.
2015-05-08 19:43:37 +00:00
object->handle = NULL;
object->type = OBJT_DEAD;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/************************************************************************
* SWAP PAGER BITMAP ROUTINES *
************************************************************************/
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWP_PAGER_GETSWAPSPACE() - allocate raw swap space
*
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
* Allocate swap for up to the requested number of pages, and at
* least a minimum number of pages. The starting swap block number
* (a page index) is returned or SWAPBLK_NONE if the allocation
* failed.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* Also has the side effect of advising that somebody made a mistake
* when they configured swap and didn't configure enough.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* This routine may not sleep.
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
*
* We allocate in round-robin fashion from the configured devices.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
Remove all but one of the inlines here, this reduces the code size by 2032 bytes and has no measurable impact on performance.
2003-07-22 20:54:26 +00:00
static daddr_t
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
swp_pager_getswapspace(int *io_npages, int limit)
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
{
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
daddr_t blk;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
struct swdevt *sp;
A new parameter to blist_alloc specifies an upper bound on the size of the allocation request, so that the blocks allocated are from the next set of free blocks big enough to satisfy the minimum requirements of the request, and the number of blocks allocated are as many as possible, up to the specified maximum. The implementation of swp_pager_getswapspace uses this parameter to ask for a number of blocks between the new halved request size and the previous failed request size. Thus a request for 32 blocks may fail, but instead of getting only 16 blocks instead, the caller asks for 16 to 31 next, and might get 19 or 27, which is closer to what they originally wanted. I expect this to lead to bigger block allocations and less block fragmentation, at least in some cases. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20001
2019-05-11 16:15:13 +00:00
int mpages, npages;
Support running with inadequate swap space. Additionally, the code will complain with a suggestion of increasing it.
1997-12-24 15:05:25 +00:00
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
blk = SWAPBLK_NONE;
Change blist_next_leaf_alloc so that it can examine more than one leaf after the one where the possible block allocation begins, and allocate a larger number of blocks than the current limit. This does not affect the limit on minimum allocation size, which still cannot exceed BLIST_MAX_ALLOC. Use this change to modify swp_pager_getswapspace and its callers, so that they can allocate more than BLIST_MAX_ALLOC blocks if they are available. Tested by: pho Approved by: markj (mentor) Differential Revision: https://reviews.freebsd.org/D20579
2019-07-06 06:15:03 +00:00
mpages = *io_npages;
npages = imin(BLIST_MAX_ALLOC, mpages);
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
sp = swdevhd;
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
while (!TAILQ_EMPTY(&swtailq)) {
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
if (sp == NULL)
sp = TAILQ_FIRST(&swtailq);
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
if ((sp->sw_flags & SW_CLOSING) == 0)
A new parameter to blist_alloc specifies an upper bound on the size of the allocation request, so that the blocks allocated are from the next set of free blocks big enough to satisfy the minimum requirements of the request, and the number of blocks allocated are as many as possible, up to the specified maximum. The implementation of swp_pager_getswapspace uses this parameter to ask for a number of blocks between the new halved request size and the previous failed request size. Thus a request for 32 blocks may fail, but instead of getting only 16 blocks instead, the caller asks for 16 to 31 next, and might get 19 or 27, which is closer to what they originally wanted. I expect this to lead to bigger block allocations and less block fragmentation, at least in some cases. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20001
2019-05-11 16:15:13 +00:00
blk = blist_alloc(sp->sw_blist, &npages, mpages);
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
if (blk != SWAPBLK_NONE)
break;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
sp = TAILQ_NEXT(sp, sw_list);
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
if (swdevhd == sp) {
if (npages <= limit)
break;
A new parameter to blist_alloc specifies an upper bound on the size of the allocation request, so that the blocks allocated are from the next set of free blocks big enough to satisfy the minimum requirements of the request, and the number of blocks allocated are as many as possible, up to the specified maximum. The implementation of swp_pager_getswapspace uses this parameter to ask for a number of blocks between the new halved request size and the previous failed request size. Thus a request for 32 blocks may fail, but instead of getting only 16 blocks instead, the caller asks for 16 to 31 next, and might get 19 or 27, which is closer to what they originally wanted. I expect this to lead to bigger block allocations and less block fragmentation, at least in some cases. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20001
2019-05-11 16:15:13 +00:00
mpages = npages - 1;
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
npages >>= 1;
}
Fixed bugs in accounting of swap space that resulted in the pager thinking it was out of space when it really wasn't. Submitted by: John Dyson
1994-11-13 15:36:48 +00:00
}
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
if (blk != SWAPBLK_NONE) {
*io_npages = npages;
blk += sp->sw_first;
sp->sw_used += npages;
swap_pager_avail -= npages;
swp_sizecheck();
swdevhd = TAILQ_NEXT(sp, sw_list);
} else {
if (swap_pager_full != 2) {
printf("swp_pager_getswapspace(%d): failed\n",
*io_npages);
swap_pager_full = 2;
swap_pager_almost_full = 1;
}
swdevhd = NULL;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
}
- Synchronize access to swdevhd using sw_dev_mtx. - Use swp_sizecheck() rather than assignment to swap_pager_full in swaponsomething().
2003-10-30 07:11:06 +00:00
mtx_unlock(&sw_dev_mtx);
- Remove a number of extra newlines that do not belong here according to style(9) - Minor space adjustment in cases where we have "( ", " )", if(), return(), while(), for(), etc. - Add /* SYMBOL */ after a few #endifs. Reviewed by: alc
2002-03-10 21:52:48 +00:00
return (blk);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Use swp_pager_isondev() throughout. Submitted by: ota@j.email.ne.jp Change swp_pager_isondev()'s return type to bool. Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D16712
2018-11-19 17:17:23 +00:00
static bool
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
swp_pager_isondev(daddr_t blk, struct swdevt *sp)
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
{
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
return (blk >= sp->sw_first && blk < sp->sw_end);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
}
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
static void
swp_pager_strategy(struct buf *bp)
{
struct swdevt *sp;
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
TAILQ_FOREACH(sp, &swtailq, sw_list) {
Use swp_pager_isondev() throughout. Submitted by: ota@j.email.ne.jp Change swp_pager_isondev()'s return type to bool. Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D16712
2018-11-19 17:17:23 +00:00
if (swp_pager_isondev(bp->b_blkno, sp)) {
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_unlock(&sw_dev_mtx);
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
if ((sp->sw_flags & SW_UNMAPPED) != 0 &&
unmapped_buf_allowed) {
bp->b_data = unmapped_buf;
bp->b_offset = 0;
} else {
pmap_qenter((vm_offset_t)bp->b_data,
&bp->b_pages[0], bp->b_bcount / PAGE_SIZE);
}
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
sp->sw_strategy(bp, sp);
return;
}
}
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
panic("Swapdev not found");
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
}
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* SWP_PAGER_FREESWAPSPACE() - free raw swap space
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* This routine returns the specified swap blocks back to the bitmap.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* This routine may not sleep.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
Remove all but one of the inlines here, this reduces the code size by 2032 bytes and has no measurable impact on performance.
2003-07-22 20:54:26 +00:00
static void
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
swp_pager_freeswapspace(daddr_t blk, daddr_t npages)
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
{
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
struct swdevt *sp;
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
if (npages == 0)
return;
- Synchronize access to the swdevt's sw_blist with sw_dev_mtx. - Remove several instances of GIANT_REQUIRED.
2003-10-30 09:12:43 +00:00
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
Use swp_pager_isondev() throughout. Submitted by: ota@j.email.ne.jp Change swp_pager_isondev()'s return type to bool. Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D16712
2018-11-19 17:17:23 +00:00
if (swp_pager_isondev(blk, sp)) {
- Synchronize access to the swdevt's sw_blist with sw_dev_mtx. - Remove several instances of GIANT_REQUIRED.
2003-10-30 09:12:43 +00:00
sp->sw_used -= npages;
/*
* If we are attempting to stop swapping on
* this device, we don't want to mark any
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* blocks free lest they be reused.
- Synchronize access to the swdevt's sw_blist with sw_dev_mtx. - Remove several instances of GIANT_REQUIRED.
2003-10-30 09:12:43 +00:00
*/
if ((sp->sw_flags & SW_CLOSING) == 0) {
blist_free(sp->sw_blist, blk - sp->sw_first,
npages);
swap_pager_avail += npages;
swp_sizecheck();
}
mtx_unlock(&sw_dev_mtx);
return;
}
}
panic("Swapdev not found");
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
To analyze the allocation of swap blocks by blist functions, add a method for analyzing the radix tree structures and reporting on the number, and sizes, of maximal intervals of free blocks. The report includes the number of maximal intervals, and also the number of them in each of several size ranges, from small (size 1, or 3 to 4) to large (28657 to 46367) with size boundaries defined by Fibonacci numbers. The report is written in the test tool with the 's' command, or in a running kernel by sysctl. The analysis of the radix tree frequently computes the position of the lone bit set in a u_daddr_t, a computation that also appears in leaf allocation. That computation has been moved into a function of its own, and optimized for cases where an inlined machine instruction can replace the usual binary search. Submitted by: Doug Moore <dougm@rice.edu> MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D11906
2017-09-10 17:46:03 +00:00
/*
* SYSCTL_SWAP_FRAGMENTATION() - produce raw swap space stats
*/
static int
sysctl_swap_fragmentation(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
struct swdevt *sp;
const char *devname;
int error;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (vn_isdisk(sp->sw_vp, NULL))
devname = devtoname(sp->sw_vp->v_rdev);
else
devname = "[file]";
sbuf_printf(&sbuf, "\nFree space on device %s:\n", devname);
blist_stats(sp->sw_blist, &sbuf);
}
mtx_unlock(&sw_dev_mtx);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWAP_PAGER_FREESPACE() - frees swap blocks associated with a page
* range within an object.
*
* This is a globally accessible routine.
*
* This routine removes swapblk assignments from swap metadata.
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* The external callers of this routine typically have already destroyed
* or renamed vm_page_t's associated with this range in the object so
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* we should be ok.
o Change the locking scheme for swp_bcount. It can now be accessed with a write lock on the object containing it OR with a read lock on the object containing it along with the swhash_mtx. o Remove some duplicate assertions for swap_pager_freespace() and swap_pager_unswapped() but keep the object locking references for documentation. Sponsored by: EMC / Isilon storage division Reviewed by: alc
2013-05-28 22:07:23 +00:00
*
* The object must be locked.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swap_pager_freespace(vm_object_t object, vm_pindex_t start, vm_size_t size)
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
{
Introduce a global lock for the vm subsystem (vm_mtx). vm_mtx does not recurse and is required for most low level vm operations. faults can not be taken without holding Giant. Memory subsystems can now call the base page allocators safely. Almost all atomic ops were removed as they are covered under the vm mutex. Alpha and ia64 now need to catch up to i386's trap handlers. FFS and NFS have been tested, other filesystems will need minor changes (grabbing the vm lock when twiddling page properties). Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
swp_pager_meta_free(object, start, size);
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
}
/*
* SWAP_PAGER_RESERVE() - reserve swap blocks in object
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* Assigns swap blocks to the specified range within the object. The
Fix typo in comment. MFC after: 3 days
2013-07-09 13:22:30 +00:00
* swap blocks are not zeroed. Any previous swap assignment is destroyed.
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
*
* Returns 0 on success, -1 on failure.
*/
int
swap_pager_reserve(vm_object_t object, vm_pindex_t start, vm_size_t size)
{
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
daddr_t addr, blk, n_free, s_free;
int i, j, n;
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_init_freerange(&s_free, &n_free);
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WLOCK(object);
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
for (i = 0; i < size; i += n) {
Change blist_next_leaf_alloc so that it can examine more than one leaf after the one where the possible block allocation begins, and allocate a larger number of blocks than the current limit. This does not affect the limit on minimum allocation size, which still cannot exceed BLIST_MAX_ALLOC. Use this change to modify swp_pager_getswapspace and its callers, so that they can allocate more than BLIST_MAX_ALLOC blocks if they are available. Tested by: pho Approved by: markj (mentor) Differential Revision: https://reviews.freebsd.org/D20579
2019-07-06 06:15:03 +00:00
n = size - i;
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
blk = swp_pager_getswapspace(&n, 1);
if (blk == SWAPBLK_NONE) {
swp_pager_meta_free(object, start, i);
VM_OBJECT_WUNLOCK(object);
return (-1);
}
for (j = 0; j < n; ++j) {
addr = swp_pager_meta_build(object,
start + i + j, blk + j);
if (addr != SWAPBLK_NONE)
swp_pager_update_freerange(&s_free, &n_free,
addr);
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
}
}
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_freeswapspace(s_free, n_free);
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WUNLOCK(object);
- Remove a number of extra newlines that do not belong here according to style(9) - Minor space adjustment in cases where we have "( ", " )", if(), return(), while(), for(), etc. - Add /* SYMBOL */ after a few #endifs. Reviewed by: alc
2002-03-10 21:52:48 +00:00
return (0);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
static bool
swp_pager_xfer_source(vm_object_t srcobject, vm_object_t dstobject,
vm_pindex_t pindex, daddr_t addr)
{
daddr_t dstaddr;
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
KASSERT(srcobject->type == OBJT_SWAP,
("%s: Srcobject not swappable", __func__));
if (dstobject->type == OBJT_SWAP &&
swp_pager_meta_lookup(dstobject, pindex) != SWAPBLK_NONE) {
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
/* Caller should destroy the source block. */
return (false);
}
/*
* Destination has no swapblk and is not resident, transfer source.
* swp_pager_meta_build() can sleep.
*/
vm_object_pip_add(srcobject, 1);
VM_OBJECT_WUNLOCK(srcobject);
vm_object_pip_add(dstobject, 1);
dstaddr = swp_pager_meta_build(dstobject, pindex, addr);
KASSERT(dstaddr == SWAPBLK_NONE,
("Unexpected destination swapblk"));
vm_object_pip_wakeup(dstobject);
VM_OBJECT_WLOCK(srcobject);
vm_object_pip_wakeup(srcobject);
return (true);
}
Initial support for MADV_FREE, support for pages that we don't care about the contents anymore. This gives us alot of the advantage of freeing individual pages through munmap, but with almost none of the overhead.
1996-05-23 00:45:58 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWAP_PAGER_COPY() - copy blocks from source pager to destination pager
* and destroy the source.
*
* Copy any valid swapblks from the source to the destination. In
* cases where both the source and destination have a valid swapblk,
* we keep the destination's.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* This routine is allowed to sleep. It may sleep allocating metadata
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* indirectly through swp_pager_meta_build() or if paging is still in
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* progress on the source.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* The source object contains no vm_page_t's (which is just as well)
*
* The source object is of type OBJT_SWAP.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* The source and destination objects must be locked.
* Both object locks may temporarily be released.
Initial support for MADV_FREE, support for pages that we don't care about the contents anymore. This gives us alot of the advantage of freeing individual pages through munmap, but with almost none of the overhead.
1996-05-23 00:45:58 +00:00
*/
void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swap_pager_copy(vm_object_t srcobject, vm_object_t dstobject,
vm_pindex_t offset, int destroysource)
Initial support for MADV_FREE, support for pages that we don't care about the contents anymore. This gives us alot of the advantage of freeing individual pages through munmap, but with almost none of the overhead.
1996-05-23 00:45:58 +00:00
{
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
Hide the details for the assertion for VM_OBJECT_LOCK operations. Rename current VM_OBJECT_LOCK_ASSERT(foo, RA_WLOCKED) into VM_OBJECT_ASSERT_WLOCKED(foo) Sponsored by: EMC / Isilon storage division Requested by: alc
2013-02-21 21:54:53 +00:00
VM_OBJECT_ASSERT_WLOCKED(srcobject);
VM_OBJECT_ASSERT_WLOCKED(dstobject);
Introduce a global lock for the vm subsystem (vm_mtx). vm_mtx does not recurse and is required for most low level vm operations. faults can not be taken without holding Giant. Memory subsystems can now call the base page allocators safely. Almost all atomic ops were removed as they are covered under the vm mutex. Alpha and ia64 now need to catch up to i386's trap handlers. FFS and NFS have been tested, other filesystems will need minor changes (grabbing the vm lock when twiddling page properties). Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00
swap_pager.c: Fixed long standing bug in freeing swap space during object collapses. Fixed 'out of space' messages from printing out too often. Modified to use new kmem_malloc() calling convention. Implemented an additional stat in the swap pager struct to count the amount of space allocated to that pager. This may be removed at some point in the future. Minimized unnecessary wakeups. vm_fault.c: Don't try to collect fault stats on 'swapped' processes - there aren't any upages to store the stats in. Changed read-ahead policy (again!). vm_glue.c: Be sure to gain a reference to the process's map before swapping. Be sure to lose it when done. kern_malloc.c: Added the ability to specify if allocations are at interrupt time or are 'safe'; this affects what types of pages can be allocated. vm_map.c: Fixed a variety of map lock problems; there's still a lurking bug that will eventually bite. vm_object.c: Explicitly initialize the object fields rather than bzeroing the struct. Eliminated the 'rcollapse' code and folded it's functionality into the "real" collapse routine. Moved an object_unlock() so that the backing_object is protected in the qcollapse routine. Make sure nobody fools with the backing_object when we're destroying it. Added some diagnostic code which can be called from the debugger that looks through all the internal objects and makes certain that they all belong to someone. vm_page.c: Fixed a rather serious logic bug that would result in random system crashes. Changed pagedaemon wakeup policy (again!). vm_pageout.c: Removed unnecessary page rotations on the inactive queue. Changed the number of pages to explicitly free to just free_reserved level. Submitted by: John Dyson
1995-02-02 09:09:15 +00:00
/*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* If destroysource is set, we remove the source object from the
* swap_pager internal queue now.
swap_pager.c: Fixed long standing bug in freeing swap space during object collapses. Fixed 'out of space' messages from printing out too often. Modified to use new kmem_malloc() calling convention. Implemented an additional stat in the swap pager struct to count the amount of space allocated to that pager. This may be removed at some point in the future. Minimized unnecessary wakeups. vm_fault.c: Don't try to collect fault stats on 'swapped' processes - there aren't any upages to store the stats in. Changed read-ahead policy (again!). vm_glue.c: Be sure to gain a reference to the process's map before swapping. Be sure to lose it when done. kern_malloc.c: Added the ability to specify if allocations are at interrupt time or are 'safe'; this affects what types of pages can be allocated. vm_map.c: Fixed a variety of map lock problems; there's still a lurking bug that will eventually bite. vm_object.c: Explicitly initialize the object fields rather than bzeroing the struct. Eliminated the 'rcollapse' code and folded it's functionality into the "real" collapse routine. Moved an object_unlock() so that the backing_object is protected in the qcollapse routine. Make sure nobody fools with the backing_object when we're destroying it. Added some diagnostic code which can be called from the debugger that looks through all the internal objects and makes certain that they all belong to someone. vm_page.c: Fixed a rather serious logic bug that would result in random system crashes. Changed pagedaemon wakeup policy (again!). vm_pageout.c: Removed unnecessary page rotations on the inactive queue. Changed the number of pages to explicitly free to just free_reserved level. Submitted by: John Dyson
1995-02-02 09:09:15 +00:00
*/
Store the bottom of the shadow chain in OBJ_ANON object->handle member. The handle value is stable for all shadow objects in the inheritance chain. This allows to avoid descending the shadow chain to get to the bottom of it in vm_map_entry_set_vnode_text(), and eliminate corresponding object relocking which appeared to be contending. Change vm_object_allocate_anon() and vm_object_shadow() to handle more of the cred/charge initialization for the new shadow object, in addition to set up the handle. Reported by: jeff Reviewed by: alc (previous version), jeff (previous version) Tested by: pho Sponsored by: The FreeBSD Foundation Differrential revision: https://reviews.freebsd.org/D22541
2019-12-01 20:43:04 +00:00
if (destroysource && (srcobject->flags & OBJ_ANON) == 0 &&
srcobject->handle != NULL) {
Fix inconsistent locking of the swap pager named objects list. Right now, all modifications of the list are locked by sw_alloc_mtx. But initial lookup of the object by the handle in swap_pager_alloc() is not protected by sw_alloc_mtx, which means that vm_pager_object_lookup() could follow freed pointer. Create a new named swap object with the OBJT_SWAP type, instead of OBJT_DEFAULT. With this change, swp_pager_meta_build() never need to upgrade named OBJT_DEFAULT to OBJT_SWAP (in the other place, we do not forbid for client code to create named OBJT_DEFAULT objects at all). That change allows to remove sw_alloc_mtx and make the list locked by sw_alloc_sx lock. Update swap_pager_copy() to new locking mode. Create helper swap_pager_alloc_init() to consolidate named and anonymous swap objects creation, while a caller ensures that the neccesary locks are held around the helper. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Approved by: re (hrs)
2016-06-13 03:42:46 +00:00
vm_object_pip_add(srcobject, 1);
VM_OBJECT_WUNLOCK(srcobject);
vm_object_pip_add(dstobject, 1);
VM_OBJECT_WUNLOCK(dstobject);
sx_xlock(&sw_alloc_sx);
TAILQ_REMOVE(NOBJLIST(srcobject->handle), srcobject,
pager_object_list);
sx_xunlock(&sw_alloc_sx);
VM_OBJECT_WLOCK(dstobject);
vm_object_pip_wakeup(dstobject);
VM_OBJECT_WLOCK(srcobject);
vm_object_pip_wakeup(srcobject);
swap_pager.c: Fixed long standing bug in freeing swap space during object collapses. Fixed 'out of space' messages from printing out too often. Modified to use new kmem_malloc() calling convention. Implemented an additional stat in the swap pager struct to count the amount of space allocated to that pager. This may be removed at some point in the future. Minimized unnecessary wakeups. vm_fault.c: Don't try to collect fault stats on 'swapped' processes - there aren't any upages to store the stats in. Changed read-ahead policy (again!). vm_glue.c: Be sure to gain a reference to the process's map before swapping. Be sure to lose it when done. kern_malloc.c: Added the ability to specify if allocations are at interrupt time or are 'safe'; this affects what types of pages can be allocated. vm_map.c: Fixed a variety of map lock problems; there's still a lurking bug that will eventually bite. vm_object.c: Explicitly initialize the object fields rather than bzeroing the struct. Eliminated the 'rcollapse' code and folded it's functionality into the "real" collapse routine. Moved an object_unlock() so that the backing_object is protected in the qcollapse routine. Make sure nobody fools with the backing_object when we're destroying it. Added some diagnostic code which can be called from the debugger that looks through all the internal objects and makes certain that they all belong to someone. vm_page.c: Fixed a rather serious logic bug that would result in random system crashes. Changed pagedaemon wakeup policy (again!). vm_pageout.c: Removed unnecessary page rotations on the inactive queue. Changed the number of pages to explicitly free to just free_reserved level. Submitted by: John Dyson
1995-02-02 09:09:15 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
Previously, swap_pager_copy() freed swap blocks one at at time, via swp_pager_meta_ctl(), with no opportunity to recognize freeing of consecutive blocks and free fewer block ranges. To open that opportunity, this change removes the SWM_FREE option from swp_pager_meta_ctl(), and compels the caller to do the freeing when a valid block address is returned. In swap_pager_copy(), these frees are aggregated, so that a sequence of them can be done at one time. The only other caller to swp_pager_meta_ctl() that passed SWM_FREE, swp_pager_unswapped(), is also modified to handle its single free explicitly. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib (an earlier version) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13290
2017-12-31 04:01:47 +00:00
* Transfer source to destination.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
swp_pager_meta_transfer(srcobject, dstobject, offset, dstobject->size);
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* Free left over swap blocks in source.
*
sys/vm: minor spelling fixes in comments. No functional change.
2016-05-02 20:16:29 +00:00
* We have to revert the type to OBJT_DEFAULT so we do not accidentally
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* double-remove the object from the swap queues.
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (destroysource) {
swp_pager_meta_free_all(srcobject);
/*
* Reverting the type is not necessary, the caller is going
* to destroy srcobject directly, but I'm doing it here
Spelling
2000-03-26 15:20:23 +00:00
* for consistency since we've removed the object from its
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* queues.
*/
srcobject->type = OBJT_DEFAULT;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
}
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWAP_PAGER_HASPAGE() - determine if we have good backing store for
* the requested page.
*
* We determine whether good backing store exists for the requested
* page and return TRUE if it does, FALSE if it doesn't.
*
* If TRUE, we also try to determine how much valid, contiguous backing
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
* store exists before and after the requested page.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
Make swap_pager_haspages() static; remove unused function prototypes.
2003-06-20 20:20:06 +00:00
static boolean_t
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
swap_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
int *after)
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
{
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
daddr_t blk, blk0;
int i;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
o Change the locking scheme for swp_bcount. It can now be accessed with a write lock on the object containing it OR with a read lock on the object containing it along with the swhash_mtx. o Remove some duplicate assertions for swap_pager_freespace() and swap_pager_unswapped() but keep the object locking references for documentation. Sponsored by: EMC / Isilon storage division Reviewed by: alc
2013-05-28 22:07:23 +00:00
VM_OBJECT_ASSERT_LOCKED(object);
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
KASSERT(object->type == OBJT_SWAP,
("%s: object not swappable", __func__));
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* do we have good backing store at the requested index ?
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
*/
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
blk0 = swp_pager_meta_lookup(object, pindex);
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
if (blk0 == SWAPBLK_NONE) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (before)
*before = 0;
if (after)
*after = 0;
return (FALSE);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* find backwards-looking contiguous good backing store
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (before != NULL) {
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
for (i = 1; i < SWB_NPAGES; i++) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (i > pindex)
break;
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
blk = swp_pager_meta_lookup(object, pindex - i);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (blk != blk0 - i)
break;
}
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
*before = i - 1;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* find forward-looking contiguous good backing store
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (after != NULL) {
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
for (i = 1; i < SWB_NPAGES; i++) {
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
blk = swp_pager_meta_lookup(object, pindex + i);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (blk != blk0 + i)
break;
Allow the fault code to use additional clustering info from both bmap and the swap pager. Improved fault clustering performance.
1995-09-04 04:44:26 +00:00
}
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
*after = i - 1;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
return (TRUE);
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
}
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* SWAP_PAGER_PAGE_UNSWAPPED() - remove swap backing store related to page
*
* This removes any associated swap backing store, whether valid or
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* not, from the page.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* This routine is typically called when a page is made dirty, at
* which point any associated swap can be freed. MADV_FREE also
* calls us in a special-case situation
*
* NOTE!!! If the page is clean and the swap was valid, the caller
* should make the page dirty before calling this routine. This routine
* does NOT change the m->dirty status of the page. Also: MADV_FREE
* depends on it.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* This routine may not sleep.
o Change the locking scheme for swp_bcount. It can now be accessed with a write lock on the object containing it OR with a read lock on the object containing it along with the swhash_mtx. o Remove some duplicate assertions for swap_pager_freespace() and swap_pager_unswapped() but keep the object locking references for documentation. Sponsored by: EMC / Isilon storage division Reviewed by: alc
2013-05-28 22:07:23 +00:00
*
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
* The object containing the page may be locked.
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
*/
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
static void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swap_pager_unswapped(vm_page_t m)
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
{
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
struct swblk *sb;
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
vm_object_t obj;
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
/*
* Handle enqueing deferred frees first. If we do not have the
* object lock we wait for the page daemon to clear the space.
*/
obj = m->object;
if (!VM_OBJECT_WOWNED(obj)) {
VM_PAGE_OBJECT_BUSY_ASSERT(m);
/*
* The caller is responsible for synchronization but we
* will harmlessly handle races. This is typically provided
* by only calling unswapped() when a page transitions from
* clean to dirty.
*/
if ((m->a.flags & (PGA_SWAP_SPACE | PGA_SWAP_FREE)) ==
PGA_SWAP_SPACE) {
vm_page_aflag_set(m, PGA_SWAP_FREE);
counter_u64_add(swap_free_deferred, 1);
}
return;
}
if ((m->a.flags & PGA_SWAP_FREE) != 0)
counter_u64_add(swap_free_completed, 1);
vm_page_aflag_clear(m, PGA_SWAP_FREE | PGA_SWAP_SPACE);
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
/*
* The meta data only exists if the object is OBJT_SWAP
* and even then might not be allocated yet.
*/
KASSERT(m->object->type == OBJT_SWAP,
("Free object not swappable"));
sb = SWAP_PCTRIE_LOOKUP(&m->object->un_pager.swp.swp_blks,
rounddown(m->pindex, SWAP_META_PAGES));
if (sb == NULL)
return;
if (sb->d[m->pindex % SWAP_META_PAGES] == SWAPBLK_NONE)
return;
swp_pager_freeswapspace(sb->d[m->pindex % SWAP_META_PAGES], 1);
sb->d[m->pindex % SWAP_META_PAGES] = SWAPBLK_NONE;
swp_pager_free_empty_swblk(m->object, sb);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
/*
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
* swap_pager_getpages() - bring pages in from swap
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
* Attempt to page in the pages in array "ma" of length "count". The
* caller may optionally specify that additional pages preceding and
* succeeding the specified range be paged in. The number of such pages
* is returned in the "rbehind" and "rahead" parameters, and they will
* be in the inactive queue upon return.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
* The pages in "ma" must be busied and will remain busied upon return.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Another mega commit to staticize things.
1995-12-14 09:55:16 +00:00
static int
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
swap_pager_getpages(vm_object_t object, vm_page_t *ma, int count, int *rbehind,
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
int *rahead)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
struct buf *bp;
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
vm_page_t bm, mpred, msucc, p;
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
vm_pindex_t pindex;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
daddr_t blk;
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
int i, maxahead, maxbehind, reqcount;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
reqcount = count;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
/*
* Determine the final number of read-behind pages and
* allocate them BEFORE releasing the object lock. Otherwise,
* there can be a problematic race with vm_object_split().
* Specifically, vm_object_split() might first transfer pages
* that precede ma[0] in the current object to a new object,
* and then this function incorrectly recreates those pages as
* read-behind pages in the current object.
*/
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
KASSERT(object->type == OBJT_SWAP,
("%s: object not swappable", __func__));
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
if (!swap_pager_haspage(object, ma[0]->pindex, &maxbehind, &maxahead))
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
return (VM_PAGER_FAIL);
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
Add vm object locking to various pagers' "get pages" methods, i386 stack management functions, and a u area management function.
2003-06-13 03:02:28 +00:00
/*
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
* Clip the readahead and readbehind ranges to exclude resident pages.
Add vm object locking to various pagers' "get pages" methods, i386 stack management functions, and a u area management function.
2003-06-13 03:02:28 +00:00
*/
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
if (rahead != NULL) {
Respect the caller's hints when performing swap readahead. The pager getpages interface allows the caller to bound the number of readahead and readbehind pages, and vm_fault_hold() makes use of this feature. These bounds were ignored after r305056, causing the swap pager to potentially page in more than the specified number of pages. Reported and reviewed by: alc X-MFC with: r305056
2016-09-04 00:25:49 +00:00
KASSERT(reqcount - 1 <= maxahead,
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
("page count %d extends beyond swap block", reqcount));
Respect the caller's hints when performing swap readahead. The pager getpages interface allows the caller to bound the number of readahead and readbehind pages, and vm_fault_hold() makes use of this feature. These bounds were ignored after r305056, causing the swap pager to potentially page in more than the specified number of pages. Reported and reviewed by: alc X-MFC with: r305056
2016-09-04 00:25:49 +00:00
*rahead = imin(*rahead, maxahead - (reqcount - 1));
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
pindex = ma[reqcount - 1]->pindex;
msucc = TAILQ_NEXT(ma[reqcount - 1], listq);
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
if (msucc != NULL && msucc->pindex - pindex - 1 < *rahead)
*rahead = msucc->pindex - pindex - 1;
}
if (rbehind != NULL) {
Respect the caller's hints when performing swap readahead. The pager getpages interface allows the caller to bound the number of readahead and readbehind pages, and vm_fault_hold() makes use of this feature. These bounds were ignored after r305056, causing the swap pager to potentially page in more than the specified number of pages. Reported and reviewed by: alc X-MFC with: r305056
2016-09-04 00:25:49 +00:00
*rbehind = imin(*rbehind, maxbehind);
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
pindex = ma[0]->pindex;
mpred = TAILQ_PREV(ma[0], pglist, listq);
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
if (mpred != NULL && pindex - mpred->pindex - 1 < *rbehind)
*rbehind = pindex - mpred->pindex - 1;
}
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
bm = ma[0];
for (i = 0; i < count; i++)
ma[i]->oflags |= VPO_SWAPINPROG;
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
/*
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
* Allocate readahead and readbehind pages.
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
*/
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
if (rbehind != NULL) {
for (i = 1; i <= *rbehind; i++) {
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
p = vm_page_alloc(object, ma[0]->pindex - i,
Remove most of the code for implementing PG_CACHED pages. (This change does not remove user-space visible fields from vm_cnt or all of the references to cached pages from comments. Those changes will come later.) Reviewed by: kib, markj Tested by: pho Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D8497
2016-11-15 18:22:50 +00:00
VM_ALLOC_NORMAL);
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
if (p == NULL)
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
break;
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
p->oflags |= VPO_SWAPINPROG;
bm = p;
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
}
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
*rbehind = i - 1;
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
}
if (rahead != NULL) {
for (i = 0; i < *rahead; i++) {
p = vm_page_alloc(object,
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
ma[reqcount - 1]->pindex + i + 1, VM_ALLOC_NORMAL);
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
if (p == NULL)
break;
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
p->oflags |= VPO_SWAPINPROG;
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
}
*rahead = i;
}
if (rbehind != NULL)
count += *rbehind;
if (rahead != NULL)
count += *rahead;
vm_object_pip_add(object, count);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
pindex = bm->pindex;
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
blk = swp_pager_meta_lookup(object, pindex);
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
KASSERT(blk != SWAPBLK_NONE,
("no swap blocking containing %p(%jx)", object, (uintmax_t)pindex));
VM_OBJECT_WUNLOCK(object);
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
bp = uma_zalloc(swrbuf_zone, M_WAITOK);
Handle the race between fork/vm_object_split() and faults. If fault started before vmspace_fork() locked the map, and then during fork, vm_map_copy_entry()->vm_object_split() is executed, it is possible that the fault instantiate the page into the original object when the page was already copied into the new object (see vm_map_split() for the orig/new objects terminology). This can happen if split found a busy page (e.g. from the fault) and slept dropping the objects lock, which allows the swap pager to instantiate read-behind pages for the fault. Then the restart of the scan can see a page in the scanned range, where it was already copied to the upper object. Fix it by instantiating the read-ahead pages before swap_pager_getpages() method drops the lock to allocate pbuf. The object scan would see the whole range prefilled with the busy pages and not proceed the range. Note that vm_fault rechecks the map generation count after the object unlock, so that it restarts the handling if raced with split, and re-lookups the right page from the upper object. In collaboration with: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2018-06-14 19:41:02 +00:00
/* Pages cannot leave the object while busy. */
for (i = 0, p = bm; i < count; i++, p = TAILQ_NEXT(p, listq)) {
MPASS(p->pindex == bm->pindex + i);
bp->b_pages[i] = p;
}
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
bp->b_flags |= B_PAGING;
Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new field in struct buf: b_iocmd. The b_iocmd is enforced to have exactly one bit set. B_WRITE was bogusly defined as zero giving rise to obvious coding mistakes. Also eliminate the redundant struct buf flag B_CALL, it can just as efficiently be done by comparing b_iodone to NULL. Should you get a panic or drop into the debugger, complaining about "b_iocmd", don't continue. It is likely to write on your disk where it should have been reading. This change is a step in the direction towards a stackable BIO capability. A lot of this patch were machine generated (Thanks to style(9) compliance!) Vinum users: Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00
bp->b_iocmd = BIO_READ;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
bp->b_iodone = swp_pager_async_iodone;
Use thread0.td_ucred instead of proc0.p_ucred. This change is cosmetic and isn't strictly required. However, it lowers the number of false positives found when grep'ing the kernel sources for p_ucred to ensure proper locking.
2002-02-27 19:18:10 +00:00
bp->b_rcred = crhold(thread0.td_ucred);
bp->b_wcred = crhold(thread0.td_ucred);
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
bp->b_blkno = blk;
bp->b_bcount = PAGE_SIZE * count;
bp->b_bufsize = PAGE_SIZE * count;
bp->b_npages = count;
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
bp->b_pgbefore = rbehind != NULL ? *rbehind : 0;
bp->b_pgafter = rahead != NULL ? *rahead : 0;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
- Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter in place. To do per-cpu stats, convert all fields that previously were maintained in the vmmeters that sit in pcpus to counter(9). - Since some vmmeter stats may be touched at very early stages of boot, before we have set up UMA and we can do counter_u64_alloc(), provide an early counter mechanism: o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter. o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter, so that at early stages of boot, before counters are allocated we already point to a counter that can be safely written to. o For sparc64 that required a whole dummy pcpu[MAXCPU] array. Further related changes: - Don't include vmmeter.h into pcpu.h. - vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit, to match kernel representation. - struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion. This is based on benno@'s 4-year old patch: https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html Reviewed by: kib, gallatin, marius, lidl Differential Revision: https://reviews.freebsd.org/D10156
2017-04-17 17:34:47 +00:00
VM_CNT_INC(v_swapin);
VM_CNT_ADD(v_swappgsin, count);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* perform the I/O. NOTE!!! bp cannot be considered valid after
* this point because we automatically release it on completion.
* Instead, we look at the one page we are interested in which we
* still hold a lock on even through the I/O completion.
*
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
* The other pages in our ma[] array are also released on completion,
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* so we cannot assume they are valid anymore either.
*
Rip out the totally bogos vnode swapdev_vp with extreeme prejudice. Don't mark buffers with B_KEEPGIANT, we don't drop giant in strategy at this point in time.
2003-08-06 06:53:31 +00:00
* NOTE: b_blkno is destroyed by the call to swapdev_strategy
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Kirk missed a required BUF_KERNPROC(). Even though this is a non-async transfer, the b_iodone hook causes biodone() to release it from interrupt context.
1999-06-27 22:08:38 +00:00
BUF_KERNPROC(bp);
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
swp_pager_strategy(bp);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
* Wait for the pages we want to complete. VPO_SWAPINPROG is always
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* cleared on completion. If an I/O error occurs, SWAPBLK_NONE
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
* is set in the metadata for each page in the request.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WLOCK(object);
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
while ((ma[0]->oflags & VPO_SWAPINPROG) != 0) {
ma[0]->oflags |= VPO_SWAPSLEEP;
- Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter in place. To do per-cpu stats, convert all fields that previously were maintained in the vmmeters that sit in pcpus to counter(9). - Since some vmmeter stats may be touched at very early stages of boot, before we have set up UMA and we can do counter_u64_alloc(), provide an early counter mechanism: o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter. o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter, so that at early stages of boot, before counters are allocated we already point to a counter that can be safely written to. o For sparc64 that required a whole dummy pcpu[MAXCPU] array. Further related changes: - Don't include vmmeter.h into pcpu.h. - vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit, to match kernel representation. - struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion. This is based on benno@'s 4-year old patch: https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html Reviewed by: kib, gallatin, marius, lidl Differential Revision: https://reviews.freebsd.org/D10156
2017-04-17 17:34:47 +00:00
VM_CNT_INC(v_intrans);
Use an atomic reference count for paging in progress so that callers do not require the object lock. Reviewed by: markj Tested by: pho (as part of a larger branch) Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D21311
2019-08-19 23:09:38 +00:00
if (VM_OBJECT_SLEEP(object, &object->handle, PSWP,
The soft and hard busy mechanism rely on the vm object lock to work. Unify the 2 concept into a real, minimal, sxlock where the shared acquisition represent the soft busy and the exclusive acquisition represent the hard busy. The old VPO_WANTED mechanism becames the hard-path for this new lock and it becomes per-page rather than per-object. The vm_object lock becames an interlock for this functionality: it can be held in both read or write mode. However, if the vm_object lock is held in read mode while acquiring or releasing the busy state, the thread owner cannot make any assumption on the busy state unless it is also busying it. Also: - Add a new flag to directly shared busy pages while vm_page_alloc and vm_page_grab are being executed. This will be very helpful once these functions happen under a read object lock. - Move the swapping sleep into its own per-object flag The KPI is heavilly changed this is why the version is bumped. It is very likely that some VM ports users will need to change their own code. Sponsored by: EMC / Isilon storage division Discussed with: alc Reviewed by: jeff, kib Tested by: gavin, bapt (older version) Tested by: pho, scottl
2013-08-09 11:11:11 +00:00
"swread", hz * 20)) {
Properly brucify a string by outdenting it.
2004-07-06 02:27:30 +00:00
printf(
Remove buf->b_dev field.
2004-11-04 07:59:57 +00:00
"swap_pager: indefinite wait buffer: bufobj: %p, blkno: %jd, size: %ld\n",
bp->b_bufobj, (intmax_t)bp->b_blkno, bp->b_bcount);
Mostly superficial code improvements, add a diagnostic. The code improvements include significant simplification of the reservation of the swap pager control blocks for reads. Add a panic for an inconsistent swap pager control block count.
1996-06-10 04:58:48 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
/*
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
* If we had an unrecoverable read error pages will not be valid.
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
*/
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
for (i = 0; i < reqcount; i++)
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
if (ma[i]->valid != VM_PAGE_BITS_ALL)
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
return (VM_PAGER_ERROR);
return (VM_PAGER_OK);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* A final note: in a low swap situation, we cannot deallocate swap
* and mark a page dirty here because the caller is likely to mark
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* the page clean when we return, causing the page to possibly revert
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* to all-zero's later.
*/
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Merge from projects/sendfile: o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc.
2014-11-23 12:01:52 +00:00
/*
* swap_pager_getpages_async():
*
* Right now this is emulation of asynchronous operation on top of
* swap_pager_getpages().
*/
static int
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
swap_pager_getpages_async(vm_object_t object, vm_page_t *ma, int count,
A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). o With new KPI consumers can request contiguous ranges of pages, and unlike before, all pages will be kept busied on return, like it was done before with the 'reqpage' only. Now the reqpage goes away. With new interface it is easier to implement code protected from race conditions. Such arrayed requests for now should be preceeded by a call to vm_pager_haspage() to make sure that request is possible. This could be improved later, making vm_pager_haspage() obsolete. Strenghtening the promises on the business of the array of pages allows us to remove such hacks as swp_pager_free_nrpage() and vm_pager_free_nonreq(). o New KPI accepts two integer pointers that may optionally point at values for read ahead and read behind, that a pager may do, if it can. These pages are completely owned by pager, and not controlled by the caller. This shifts the UFS-specific readahead logic from vm_fault.c, which should be file system agnostic, into vnode_pager.c. It also removes one VOP_BMAP() request per hard fault. Discussed with: kib, alc, jeff, scottl Sponsored by: Nginx, Inc. Sponsored by: Netflix
2015-12-16 21:30:45 +00:00
int *rbehind, int *rahead, pgo_getpages_iodone_t iodone, void *arg)
Merge from projects/sendfile: o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc.
2014-11-23 12:01:52 +00:00
{
int r, error;
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
r = swap_pager_getpages(object, ma, count, rbehind, rahead);
Merge from projects/sendfile: o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc.
2014-11-23 12:01:52 +00:00
VM_OBJECT_WUNLOCK(object);
switch (r) {
case VM_PAGER_OK:
error = 0;
break;
case VM_PAGER_ERROR:
error = EIO;
break;
case VM_PAGER_FAIL:
error = EINVAL;
break;
default:
\n at end of panicstr is redundant. Submitted by: alc
2014-11-23 18:32:21 +00:00
panic("unhandled swap_pager_getpages() error %d", r);
Merge from projects/sendfile: o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc.
2014-11-23 12:01:52 +00:00
}
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
(iodone)(arg, ma, count, error);
Merge from projects/sendfile: o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but doesn't sleep. It returns immediately, and will execute the I/O done handler function that must be supplied as argument. o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager. o Extend pagertab to support pgo_getpages_async method, and implement this method for vnode_pager. Reviewed by: kib Tested by: pho Sponsored by: Netflix Sponsored by: Nginx, Inc.
2014-11-23 12:01:52 +00:00
VM_OBJECT_WLOCK(object);
return (r);
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* swap_pager_putpages:
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
* Assign swap (if necessary) and initiate I/O on the specified pages.
*
* We support both OBJT_DEFAULT and OBJT_SWAP objects. DEFAULT objects
* are automatically converted to SWAP objects.
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* In a low memory situation we may block in VOP_STRATEGY(), but the new
* vm_page reservation system coupled with properly written VFS devices
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* should ensure that no low-memory deadlock occurs. This is an area
* which needs work.
*
* The parent has N vm_object_pip_add() references prior to
* calling us and will remove references for rtvals[] that are
* not set to VM_PAGER_PEND. We need to remove the rest on I/O
* completion.
*
* The parent has soft-busy'd the pages it passes us and will unbusy
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
* those whose rtvals[] entry is not set to VM_PAGER_PEND on return.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* We need to unbusy the rest on I/O completion.
*/
Mark swap_pager_putpages static at its definition. It was already static at its declaration. Remove needless swapdev_strategy forward declaration. MFC After: 3 days
2015-10-05 21:29:17 +00:00
static void
Use the conventional name for an array of pages. No functional change intended. Discussed with: kib MFC after: 3 days
2018-02-16 15:38:22 +00:00
swap_pager_putpages(vm_object_t object, vm_page_t *ma, int count,
Fix mis-spelling of bits and types names in the default_pager_putpages() and swap_pager_putpages(). It is the same fix as was done for vnode_pager_putpages() in r271586. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 1 week
2014-11-04 19:56:04 +00:00
int flags, int *rtvals)
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
{
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
struct buf *bp;
daddr_t addr, blk, n_free, s_free;
vm_page_t mreq;
int i, j, n;
bool async;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
KASSERT(count == 0 || ma[0]->object == object,
("%s: object mismatch %p/%p",
__func__, object, ma[0]->object));
- Add some of the required vm object locking, including assertions where the vm object lock is required and already held.
2003-10-25 23:42:17 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Step 1
*
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
* Turn object into OBJT_SWAP. Force sync if not a pageout process.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
if (object->type != OBJT_SWAP) {
addr = swp_pager_meta_build(object, 0, SWAPBLK_NONE);
KASSERT(addr == SWAPBLK_NONE,
("unexpected object swap block"));
}
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WUNLOCK(object);
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
async = curproc == pageproc && (flags & VM_PAGER_PUT_SYNC) == 0;
swp_pager_init_freerange(&s_free, &n_free);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Step 2
*
* Assign swap blocks and issue I/O. We reallocate swap on the fly.
* The page is left dirty until the pageout operation completes
* successfully.
*/
for (i = 0; i < count; i += n) {
Change blist_next_leaf_alloc so that it can examine more than one leaf after the one where the possible block allocation begins, and allocate a larger number of blocks than the current limit. This does not affect the limit on minimum allocation size, which still cannot exceed BLIST_MAX_ALLOC. Use this change to modify swp_pager_getswapspace and its callers, so that they can allocate more than BLIST_MAX_ALLOC blocks if they are available. Tested by: pho Approved by: markj (mentor) Differential Revision: https://reviews.freebsd.org/D20579
2019-07-06 06:15:03 +00:00
/* Maximum I/O size is limited by maximum swap block size. */
n = min(count - i, nsw_cluster_max);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Callers of swp_pager_getswapspace get either as many blocks as they requested, or none, and in the latter case it is up to them to pick a smaller request to make - which they always do by halving the failed request. This change to swp_pager_getswapspace leaves the task of downsizing the request to the function and not its caller. It still does so by halving the original request. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20228
2019-05-11 10:16:43 +00:00
/* Get a block of swap of size up to size n. */
blk = swp_pager_getswapspace(&n, 4);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (blk == SWAPBLK_NONE) {
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
for (j = 0; j < n; ++j)
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
rtvals[i + j] = VM_PAGER_FAIL;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
continue;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
* All I/O parameters have been satisfied. Build the I/O
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* request and assign the swap space.
*/
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
if (async) {
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
mtx_lock(&swbuf_mtx);
while (nsw_wcount_async == 0)
msleep(&nsw_wcount_async, &swbuf_mtx, PVM,
"swbufa", 0);
nsw_wcount_async--;
mtx_unlock(&swbuf_mtx);
Limit number of simultanious asynchronous swap pager I/Os that can be in progress at any given moment. Add two swap tuneables to sysctl: vm.swap_async_max: 4 vm.swap_cluster_max: 16 Recommended values are a cluster size of 8 or 16 pages. async_max is about right for 1-4 swap devices. Reduce to 2 if swap is eating too much bandwidth, or even 1 if swap is both eating too much bandwidth and sitting on a slow network (10BaseT). The defaults work well across a broad range of configurations and should normally be left alone.
1999-02-18 19:57:33 +00:00
}
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
bp = uma_zalloc(swwbuf_zone, M_WAITOK);
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
if (async)
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
bp->b_flags = B_ASYNC;
Explicitly set B_PAGING
2003-08-06 09:22:47 +00:00
bp->b_flags |= B_PAGING;
Fix one place which knew that B_WRITE was zero. Fix a stylistic mistake of mine while here. Found by: Stephen Hocking <shocking@prth.pgs.com>
2000-03-22 08:40:13 +00:00
bp->b_iocmd = BIO_WRITE;
This fix should help the panic problems in -current. There were some errors in "interval" management. Due to the clustering mechanism, the code is necessarily complex and error prone.
1998-02-03 00:50:36 +00:00
Use thread0.td_ucred instead of proc0.p_ucred. This change is cosmetic and isn't strictly required. However, it lowers the number of false positives found when grep'ing the kernel sources for p_ucred to ensure proper locking.
2002-02-27 19:18:10 +00:00
bp->b_rcred = crhold(thread0.td_ucred);
bp->b_wcred = crhold(thread0.td_ucred);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
bp->b_bcount = PAGE_SIZE * n;
bp->b_bufsize = PAGE_SIZE * n;
bp->b_blkno = blk;
This fix should help the panic problems in -current. There were some errors in "interval" management. Due to the clustering mechanism, the code is necessarily complex and error prone.
1998-02-03 00:50:36 +00:00
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WLOCK(object);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
for (j = 0; j < n; ++j) {
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
mreq = ma[i + j];
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
vm_page_aflag_clear(mreq, PGA_SWAP_FREE);
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
addr = swp_pager_meta_build(mreq->object, mreq->pindex,
blk + j);
if (addr != SWAPBLK_NONE)
swp_pager_update_freerange(&s_free, &n_free,
addr);
Pages that are passed to swap_pager_putpages() should already be fully dirty. Assert that they are fully dirty rather than redundantly calling vm_page_dirty() on them. Reviewed by: kib, markj MFC after: 1 week X-MFC after: r319932
2017-06-17 03:05:25 +00:00
MPASS(mreq->dirty == VM_PAGE_BITS_ALL);
Introduce a field to struct vm_page for storing flags that are synchronized by the lock on the object containing the page. Transition PG_WANTED and PG_SWAPINPROG to use the new field, eliminating the need for holding the page queues lock when setting or clearing these flags. Rename PG_WANTED and PG_SWAPINPROG to VPO_WANTED and VPO_SWAPINPROG, respectively. Eliminate the assertion that the page queues lock is held in vm_page_io_finish(). Eliminate the acquisition and release of the page queues lock around calls to vm_page_io_finish() in kern_sendfile() and vfs_unbusy_pages().
2006-08-09 17:43:27 +00:00
mreq->oflags |= VPO_SWAPINPROG;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
bp->b_pages[j] = mreq;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WUNLOCK(object);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
bp->b_npages = n;
Submitted by: Matt Dillon <dillon@freebsd.org> The old VN device broke in -4.x when the definition of B_PAGING changed. This patch fixes this plus implements additional capabilities. The new VN device can be backed by a file ( as per normal ), or it can be directly backed by swap. Due to dependencies in VM include files (on opt_xxx options) the new vn device cannot be a module yet. This will be fixed in a later commit. This commit delimitted by tags {PRE,POST}_MATT_VNDEV
1999-03-14 09:20:01 +00:00
/*
* Must set dirty range for NFS to work.
*/
bp->b_dirtyoff = 0;
bp->b_dirtyend = bp->b_bcount;
Patches from John Dyson to improve swap code efficiency. Religiously add back pmap_clear_modify() in vnode_pager_input until we figure out why system performance isn't what we expect. Submitted by: John Dyson (swap_pager) & David Greenman (vnode_pager)
1994-08-29 06:23:19 +00:00
- Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter in place. To do per-cpu stats, convert all fields that previously were maintained in the vmmeters that sit in pcpus to counter(9). - Since some vmmeter stats may be touched at very early stages of boot, before we have set up UMA and we can do counter_u64_alloc(), provide an early counter mechanism: o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter. o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter, so that at early stages of boot, before counters are allocated we already point to a counter that can be safely written to. o For sparc64 that required a whole dummy pcpu[MAXCPU] array. Further related changes: - Don't include vmmeter.h into pcpu.h. - vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit, to match kernel representation. - struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion. This is based on benno@'s 4-year old patch: https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html Reviewed by: kib, gallatin, marius, lidl Differential Revision: https://reviews.freebsd.org/D10156
2017-04-17 17:34:47 +00:00
VM_CNT_INC(v_swapout);
VM_CNT_ADD(v_swappgsout, bp->b_npages);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Eliminate pointless assignments to rtvals[] in swap_pager_putpages(). Reviewed by: kib Sponsored by: EMC / Isilon Storage Division
2015-08-21 17:00:39 +00:00
/*
* We unconditionally set rtvals[] to VM_PAGER_PEND so that we
* can call the async completion routine at the end of a
* synchronous I/O operation. Otherwise, our caller would
* perform duplicate unbusy and wakeup operations on the page
* and object, respectively.
*/
for (j = 0; j < n; j++)
rtvals[i + j] = VM_PAGER_PEND;
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* asynchronous
*
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
* NOTE: b_blkno is destroyed by the call to swapdev_strategy.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
if (async) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
bp->b_iodone = swp_pager_async_iodone;
Convert buffer locking from using the B_BUSY and B_WANTED flags to using lockmgr locks. This commit should be functionally equivalent to the old semantics. That is, all buffer locking is done with LK_EXCLUSIVE requests. Changes to take advantage of LK_SHARED and LK_RECURSIVE will be done in future commits.
1999-06-26 02:47:16 +00:00
BUF_KERNPROC(bp);
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
swp_pager_strategy(bp);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
continue;
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* synchronous
*
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
* NOTE: b_blkno is destroyed by the call to swapdev_strategy.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
- Substitute bdone() and bwait() from vfs_bio.c for swap_pager_putpages()'s buffer completion code. Note: the only difference between swp_pager_sync_iodone() and bdone(), aside from the locking in the latter, was the unnecessary clearing of B_ASYNC. - Remove an unnecessary pmap_page_protect() from swp_pager_async_iodone(). Reviewed by: tegge
2004-02-23 03:15:13 +00:00
bp->b_iodone = bdone;
Make the strategy function a method of the individual swapdev.
2003-08-30 09:42:00 +00:00
swp_pager_strategy(bp);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
Eliminate pointless assignments to rtvals[] in swap_pager_putpages(). Reviewed by: kib Sponsored by: EMC / Isilon Storage Division
2015-08-21 17:00:39 +00:00
* Wait for the sync I/O to complete.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
- Substitute bdone() and bwait() from vfs_bio.c for swap_pager_putpages()'s buffer completion code. Note: the only difference between swp_pager_sync_iodone() and bdone(), aside from the locking in the latter, was the unnecessary clearing of B_ASYNC. - Remove an unnecessary pmap_page_protect() from swp_pager_async_iodone(). Reviewed by: tegge
2004-02-23 03:15:13 +00:00
bwait(bp, PVM, "swwrt");
Eliminate pointless assignments to rtvals[] in swap_pager_putpages(). Reviewed by: kib Sponsored by: EMC / Isilon Storage Division
2015-08-21 17:00:39 +00:00
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* Now that we are through with the bp, we can call the
* normal async completion, which frees everything up.
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
swp_pager_async_iodone(bp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_freeswapspace(s_free, n_free);
In swap_pager_putpages, move the initialization of a free-blocks counter, and the final freeing of freed swap blocks, outside the region where an object lock is held. Correct some style(9) and spelling errors. Change a panic() to a KASSERT(). Change a boolean_t to a bool. Suggested by: alc Reviewed by: alc Approved by: kib, markj (mentors) Differential Revision: https://reviews.freebsd.org/D21093
2019-07-28 19:32:23 +00:00
VM_OBJECT_WLOCK(object);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
/*
* swp_pager_async_iodone:
*
* Completion routine for asynchronous reads and writes from/to swap.
* Also called manually by synchronous code to finish up a bp.
*
Update some comments in swap_pager.c. Reviewed and most wording by: alc MFC after: 1 week Approved by: re (bz)
2011-08-22 20:44:18 +00:00
* This routine may not sleep.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
static void
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swp_pager_async_iodone(struct buf *bp)
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
{
int i;
vm_object_t object = NULL;
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
/*
Improve error reporting when the swap pager runs out of memory. Reviewed by: kib MFC after: 2 weeks Sponsored by: Klara Inc. Differential Revision: https://reviews.freebsd.org/D19699
2019-03-26 19:11:15 +00:00
* Report error - unless we ran out of memory, in which case
* we've already logged it in swapgeom_strategy().
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
*/
Improve error reporting when the swap pager runs out of memory. Reviewed by: kib MFC after: 2 weeks Sponsored by: Klara Inc. Differential Revision: https://reviews.freebsd.org/D19699
2019-03-26 19:11:15 +00:00
if (bp->b_ioflags & BIO_ERROR && bp->b_error != ENOMEM) {
Fixed printf format errors.
1998-07-11 07:46:16 +00:00
printf(
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
"swap_pager: I/O error - %s failed; blkno %ld,"
"size %ld, error %d\n",
Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new field in struct buf: b_iocmd. The b_iocmd is enforced to have exactly one bit set. B_WRITE was bogusly defined as zero giving rise to obvious coding mistakes. Also eliminate the redundant struct buf flag B_CALL, it can just as efficiently be done by comparing b_iodone to NULL. Should you get a panic or drop into the debugger, complaining about "b_iocmd", don't continue. It is likely to write on your disk where it should have been reading. This change is a step in the direction towards a stackable BIO capability. A lot of this patch were machine generated (Thanks to style(9) compliance!) Vinum users: Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00
((bp->b_iocmd == BIO_READ) ? "pagein" : "pageout"),
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
(long)bp->b_blkno,
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
(long)bp->b_bcount,
bp->b_error
);
Improved I/O error reporting.
1994-10-25 07:06:20 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
* remove the mapping for kernel virtual
*/
Refactor unmapped buffer address handling. - Use pointer assignment rather than a combination of pointers and flags to switch buffers between unmapped and mapped. This eliminates multiple flags and generally simplifies the logic. - Eliminate b_saveaddr since it is only used with pager bufs which have their b_data re-initialized on each allocation. - Gather up some convenience routines in the buffer cache for manipulating buf space and buf malloc space. - Add an inline, buf_mapped(), to standardize checks around unmapped buffers. In collaboration with: mlaier Reviewed by: kib Tested by: pho (many small revisions ago) Sponsored by: EMC / Isilon Storage Division
2015-07-23 19:13:41 +00:00
if (buf_mapped(bp))
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
pmap_qremove((vm_offset_t)bp->b_data, bp->b_npages);
Refactor unmapped buffer address handling. - Use pointer assignment rather than a combination of pointers and flags to switch buffers between unmapped and mapped. This eliminates multiple flags and generally simplifies the logic. - Eliminate b_saveaddr since it is only used with pager bufs which have their b_data re-initialized on each allocation. - Gather up some convenience routines in the buffer cache for manipulating buf space and buf malloc space. - Add an inline, buf_mapped(), to standardize checks around unmapped buffers. In collaboration with: mlaier Reviewed by: kib Tested by: pho (many small revisions ago) Sponsored by: EMC / Isilon Storage Division
2015-07-23 19:13:41 +00:00
else
bp->b_data = bp->b_kvabase;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Extend the scope of the vm object lock in swp_pager_async_iodone() to cover a vm_page_free().
2003-06-13 06:17:42 +00:00
if (bp->b_npages) {
object = bp->b_pages[0]->object;
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WLOCK(object);
Extend the scope of the vm object lock in swp_pager_async_iodone() to cover a vm_page_free().
2003-06-13 06:17:42 +00:00
}
On Alan's advice, rather than do a wholesale conversion on a single architecture from page queue lock to a hashed array of page locks (based on a patch by Jeff Roberson), I've implemented page lock support in the MI code and have only moved vm_page's hold_count out from under page queue mutex to page lock. This changes pmap_extract_and_hold on all pmaps. Supported by: Bitgravity Inc. Discussed with: alc, jeffr, and kib
2010-04-30 00:46:43 +00:00
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* cleanup pages. If an error occurs writing to swap, we are in
* very serious trouble. If it happens to be a disk error, though,
* we may be able to recover by reassigning the swap later on. So
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* in this case we remove the m->swapblk assignment for the page
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* but do not free it in the rlist. The errornous block(s) are thus
* never reallocated as swap. Redirty the page and continue.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
for (i = 0; i < bp->b_npages; ++i) {
vm_page_t m = bp->b_pages[i];
Introduce a field to struct vm_page for storing flags that are synchronized by the lock on the object containing the page. Transition PG_WANTED and PG_SWAPINPROG to use the new field, eliminating the need for holding the page queues lock when setting or clearing these flags. Rename PG_WANTED and PG_SWAPINPROG to VPO_WANTED and VPO_SWAPINPROG, respectively. Eliminate the assertion that the page queues lock is held in vm_page_io_finish(). Eliminate the acquisition and release of the page queues lock around calls to vm_page_io_finish() in kern_sendfile() and vfs_unbusy_pages().
2006-08-09 17:43:27 +00:00
m->oflags &= ~VPO_SWAPINPROG;
The soft and hard busy mechanism rely on the vm object lock to work. Unify the 2 concept into a real, minimal, sxlock where the shared acquisition represent the soft busy and the exclusive acquisition represent the hard busy. The old VPO_WANTED mechanism becames the hard-path for this new lock and it becomes per-page rather than per-object. The vm_object lock becames an interlock for this functionality: it can be held in both read or write mode. However, if the vm_object lock is held in read mode while acquiring or releasing the busy state, the thread owner cannot make any assumption on the busy state unless it is also busying it. Also: - Add a new flag to directly shared busy pages while vm_page_alloc and vm_page_grab are being executed. This will be very helpful once these functions happen under a read object lock. - Move the swapping sleep into its own per-object flag The KPI is heavilly changed this is why the version is bumped. It is very likely that some VM ports users will need to change their own code. Sponsored by: EMC / Isilon storage division Discussed with: alc Reviewed by: jeff, kib Tested by: gavin, bapt (older version) Tested by: pho, scottl
2013-08-09 11:11:11 +00:00
if (m->oflags & VPO_SWAPSLEEP) {
m->oflags &= ~VPO_SWAPSLEEP;
Use an atomic reference count for paging in progress so that callers do not require the object lock. Reviewed by: markj Tested by: pho (as part of a larger branch) Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D21311
2019-08-19 23:09:38 +00:00
wakeup(&object->handle);
The soft and hard busy mechanism rely on the vm object lock to work. Unify the 2 concept into a real, minimal, sxlock where the shared acquisition represent the soft busy and the exclusive acquisition represent the hard busy. The old VPO_WANTED mechanism becames the hard-path for this new lock and it becomes per-page rather than per-object. The vm_object lock becames an interlock for this functionality: it can be held in both read or write mode. However, if the vm_object lock is held in read mode while acquiring or releasing the busy state, the thread owner cannot make any assumption on the busy state unless it is also busying it. Also: - Add a new flag to directly shared busy pages while vm_page_alloc and vm_page_grab are being executed. This will be very helpful once these functions happen under a read object lock. - Move the swapping sleep into its own per-object flag The KPI is heavilly changed this is why the version is bumped. It is very likely that some VM ports users will need to change their own code. Sponsored by: EMC / Isilon storage division Discussed with: alc Reviewed by: jeff, kib Tested by: gavin, bapt (older version) Tested by: pho, scottl
2013-08-09 11:11:11 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
/* We always have space after I/O, successful or not. */
vm_page_aflag_set(m, PGA_SWAP_SPACE);
Move B_ERROR flag to b_ioflags and call it BIO_ERROR. (Much of this done by script) Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED. Move b_pblkno and b_iodone_chain to struct bio while we transition, they will be obsoleted once bio structs chain/stack. Add bio_queue field for struct bio aware disksort. Address a lot of stylistic issues brought up by bde.
2000-04-02 15:24:56 +00:00
if (bp->b_ioflags & BIO_ERROR) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* If an error occurs I'd love to throw the swapblk
* away without freeing it back to swapspace, so it
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* can never be used again. But I can't from an
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* interrupt.
*/
Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new field in struct buf: b_iocmd. The b_iocmd is enforced to have exactly one bit set. B_WRITE was bogusly defined as zero giving rise to obvious coding mistakes. Also eliminate the redundant struct buf flag B_CALL, it can just as efficiently be done by comparing b_iodone to NULL. Should you get a panic or drop into the debugger, complaining about "b_iocmd", don't continue. It is likely to write on your disk where it should have been reading. This change is a step in the direction towards a stackable BIO capability. A lot of this patch were machine generated (Thanks to style(9) compliance!) Vinum users: Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00
if (bp->b_iocmd == BIO_READ) {
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* NOTE: for reads, m->dirty will probably
Spelling
2000-03-26 15:20:23 +00:00
* be overridden by the original caller of
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* getpages so don't play cute tricks here.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
(4/6) Protect page valid with the busy lock. Atomics are used for page busy and valid state when the shared busy is held. The details of the locking protocol and valid and dirty synchronization are in the updated vm_page.h comments. Reviewed by: kib, markj Tested by: pho Sponsored by: Netflix, Intel Differential Revision: https://reviews.freebsd.org/D21594
2019-10-15 03:45:41 +00:00
vm_page_invalid(m);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
} else {
/*
* If a write error occurs, reactivate page
* so it doesn't clog the inactive list,
* then finish the I/O.
*/
When an I/O error occurs on page out, there is no need to dirty the page, because it is already dirty. Instead, assert that the page is dirty. Reviewed by: kib, markj MFC after: 1 week
2017-10-01 17:04:26 +00:00
MPASS(m->dirty == VM_PAGE_BITS_ALL);
Remove page locking for queue operations. With the previous reviews, the page lock is no longer required in order to perform queue operations on a page. It is also no longer needed in the page queue scans. This change effectively eliminates remaining uses of the page lock and also the false sharing caused by multiple pages sharing a page lock. Reviewed by: jeff Tested by: pho Sponsored by: Netflix, Intel Differential Revision: https://reviews.freebsd.org/D22885
2019-12-28 19:04:00 +00:00
Add a deferred free mechanism for freeing swap space that does not require an exclusive object lock. Previously swap space was freed on a best effort basis when a page that had valid swap was dirtied, thus invalidating the swap copy. This may be done inconsistently and requires the object lock which is not always convenient. Instead, track when swap space is present. The first dirty is responsible for deleting space or setting PGA_SWAP_FREE which will trigger background scans to free the swap space. Simplify the locking in vm_fault_dirty() now that we can reliably identify the first dirty. Discussed with: alc, kib, markj Differential Revision: https://reviews.freebsd.org/D22654
2019-12-15 03:15:06 +00:00
/* PQ_UNSWAPPABLE? */
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
vm_page_activate(m);
The soft and hard busy mechanism rely on the vm object lock to work. Unify the 2 concept into a real, minimal, sxlock where the shared acquisition represent the soft busy and the exclusive acquisition represent the hard busy. The old VPO_WANTED mechanism becames the hard-path for this new lock and it becomes per-page rather than per-object. The vm_object lock becames an interlock for this functionality: it can be held in both read or write mode. However, if the vm_object lock is held in read mode while acquiring or releasing the busy state, the thread owner cannot make any assumption on the busy state unless it is also busying it. Also: - Add a new flag to directly shared busy pages while vm_page_alloc and vm_page_grab are being executed. This will be very helpful once these functions happen under a read object lock. - Move the swapping sleep into its own per-object flag The KPI is heavilly changed this is why the version is bumped. It is very likely that some VM ports users will need to change their own code. Sponsored by: EMC / Isilon storage division Discussed with: alc Reviewed by: jeff, kib Tested by: gavin, bapt (older version) Tested by: pho, scottl
2013-08-09 11:11:11 +00:00
vm_page_sunbusy(m);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new field in struct buf: b_iocmd. The b_iocmd is enforced to have exactly one bit set. B_WRITE was bogusly defined as zero giving rise to obvious coding mistakes. Also eliminate the redundant struct buf flag B_CALL, it can just as efficiently be done by comparing b_iodone to NULL. Should you get a panic or drop into the debugger, complaining about "b_iocmd", don't continue. It is likely to write on your disk where it should have been reading. This change is a step in the direction towards a stackable BIO capability. A lot of this patch were machine generated (Thanks to style(9) compliance!) Vinum users: Greg has not had time to test this yet, be careful.
2000-03-20 10:44:49 +00:00
} else if (bp->b_iocmd == BIO_READ) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* NOTE: for reads, m->dirty will probably be
Spelling
2000-03-26 15:20:23 +00:00
* overridden by the original caller of getpages so
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* we cannot set them in order to free the underlying
* swap in a low-swap situation. I don't think we'd
* want to do that anyway, but it was an optimization
* that existed in the old swapper for a time before
* it got ripped out due to precisely this problem.
*/
Eliminate unnecessary calls to pmap_clear_modify(). Specifically, calling pmap_clear_modify() on a page is pointless if that page is not mapped or it is only mapped for read access. Instead, assert that the page is not mapped or not mapped for write access as appropriate. Eliminate unnecessary clearing of a page's dirty mask. Instead, assert that the page's dirty mask is clear.
2009-04-25 02:59:06 +00:00
KASSERT(!pmap_page_is_mapped(m),
("swp_pager_async_iodone: page %p is mapped", m));
KASSERT(m->dirty == 0,
("swp_pager_async_iodone: page %p is dirty", m));
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
(4/6) Protect page valid with the busy lock. Atomics are used for page busy and valid state when the shared busy is held. The details of the locking protocol and valid and dirty synchronization are in the updated vm_page.h comments. Reviewed by: kib, markj Tested by: pho Sponsored by: Netflix, Intel Differential Revision: https://reviews.freebsd.org/D21594
2019-10-15 03:45:41 +00:00
vm_page_valid(m);
Restore swap pager readahead after r292373. The removal of vm_fault_additional_pages() meant that a hard fault on a swap-backed page would result in only that page being read in. This change implements readahead and readbehind for the swap pager in swap_pager_getpages(). swap_pager_haspage() is modified to return the largest contiguous non-resident range of pages containing the requested range. Reviewed by: alc, kib Tested by: pho MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7677
2016-08-30 05:56:21 +00:00
if (i < bp->b_pgbefore ||
i >= bp->b_npages - bp->b_pgafter)
vm_page_readahead_finish(m);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
} else {
/*
Eliminate unnecessary calls to pmap_clear_modify(). Specifically, calling pmap_clear_modify() on a page is pointless if that page is not mapped or it is only mapped for read access. Instead, assert that the page is not mapped or not mapped for write access as appropriate. Eliminate unnecessary clearing of a page's dirty mask. Instead, assert that the page's dirty mask is clear.
2009-04-25 02:59:06 +00:00
* For write success, clear the dirty
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* status, then finish the I/O ( which decrements the
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* busy count and possibly wakes waiter's up ).
Introduce a new page queue, PQ_LAUNDRY, for storing unreferenced, dirty pages, specificially, dirty pages that have passed once through the inactive queue. A new, dedicated thread is responsible for both deciding when to launder pages and actually laundering them. The new policy uses the relative sizes of the inactive and laundry queues to determine whether to launder pages at a given point in time. In general, this leads to more intelligent swapping behavior, since the laundry thread will avoid pageouts when the marginal benefit of doing so is low. Previously, without a dedicated queue for dirty pages, the page daemon didn't have the information to determine whether pageout provides any benefit to the system. Thus, the previous policy often resulted in small but steadily increasing amounts of swap usage when the system is under memory pressure, even when the inactive queue consisted mostly of clean pages. This change addresses that issue, and also paves the way for some future virtual memory system improvements by removing the last source of object-cached clean pages, i.e., PG_CACHE pages. The new laundry thread sleeps while waiting for a request from the page daemon thread(s). A request is raised by setting the variable vm_laundry_request and waking the laundry thread. We request launderings for two reasons: to try and balance the inactive and laundry queue sizes ("background laundering"), and to quickly make up for a shortage of free pages and clean inactive pages ("shortfall laundering"). When background laundering is requested, the laundry thread computes the number of page daemon wakeups that have taken place since the last laundering. If this number is large enough relative to the ratio of the laundry and (global) inactive queue sizes, we will launder vm_background_launder_target pages at vm_background_launder_rate KB/s. Otherwise, the laundry thread goes back to sleep without doing any work. When scanning the laundry queue during background laundering, reactivated pages are counted towards the laundry thread's target. In contrast, shortfall laundering is requested when an inactive queue scan fails to meet its target. In this case, the laundry thread attempts to launder enough pages to meet v_free_target within 0.5s, which is the inactive queue scan period. A laundry request can be latched while another is currently being serviced. In particular, a shortfall request will immediately preempt a background laundering. This change also redefines the meaning of vm_cnt.v_reactivated and removes the functions vm_page_cache() and vm_page_try_to_cache(). The new meaning of vm_cnt.v_reactivated now better reflects its name. It represents the number of inactive or laundry pages that are returned to the active queue on account of a reference. In collaboration with: markj Reviewed by: kib Tested by: pho Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D8302
2016-11-09 18:48:37 +00:00
* A page is only written to swap after a period of
* inactivity. Therefore, we do not expect it to be
* reused.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
The page flag PGA_WRITEABLE is set and cleared exclusively by the pmap layer, but it is read directly by the MI VM layer. This change introduces pmap_page_is_write_mapped() in order to completely encapsulate all direct access to PGA_WRITEABLE in the pmap layer. Aesthetics aside, I am making this change because amd64 will likely begin using an alternative method to track write mappings, and having pmap_page_is_write_mapped() in place allows me to make such a change without further modification to the MI VM layer. As an added bonus, tidy up some nearby comments concerning page flags. Reviewed by: kib MFC after: 6 weeks
2012-06-16 18:56:19 +00:00
KASSERT(!pmap_page_is_write_mapped(m),
Eliminate unnecessary calls to pmap_clear_modify(). Specifically, calling pmap_clear_modify() on a page is pointless if that page is not mapped or it is only mapped for read access. Instead, assert that the page is not mapped or not mapped for write access as appropriate. Eliminate unnecessary clearing of a page's dirty mask. Instead, assert that the page's dirty mask is clear.
2009-04-25 02:59:06 +00:00
("swp_pager_async_iodone: page %p is not write"
" protected", m));
Correct an accidental omission of one "vm_page_undirty" replacement from the previous commit.
1999-08-17 05:56:00 +00:00
vm_page_undirty(m);
Introduce a new page queue, PQ_LAUNDRY, for storing unreferenced, dirty pages, specificially, dirty pages that have passed once through the inactive queue. A new, dedicated thread is responsible for both deciding when to launder pages and actually laundering them. The new policy uses the relative sizes of the inactive and laundry queues to determine whether to launder pages at a given point in time. In general, this leads to more intelligent swapping behavior, since the laundry thread will avoid pageouts when the marginal benefit of doing so is low. Previously, without a dedicated queue for dirty pages, the page daemon didn't have the information to determine whether pageout provides any benefit to the system. Thus, the previous policy often resulted in small but steadily increasing amounts of swap usage when the system is under memory pressure, even when the inactive queue consisted mostly of clean pages. This change addresses that issue, and also paves the way for some future virtual memory system improvements by removing the last source of object-cached clean pages, i.e., PG_CACHE pages. The new laundry thread sleeps while waiting for a request from the page daemon thread(s). A request is raised by setting the variable vm_laundry_request and waking the laundry thread. We request launderings for two reasons: to try and balance the inactive and laundry queue sizes ("background laundering"), and to quickly make up for a shortage of free pages and clean inactive pages ("shortfall laundering"). When background laundering is requested, the laundry thread computes the number of page daemon wakeups that have taken place since the last laundering. If this number is large enough relative to the ratio of the laundry and (global) inactive queue sizes, we will launder vm_background_launder_target pages at vm_background_launder_rate KB/s. Otherwise, the laundry thread goes back to sleep without doing any work. When scanning the laundry queue during background laundering, reactivated pages are counted towards the laundry thread's target. In contrast, shortfall laundering is requested when an inactive queue scan fails to meet its target. In this case, the laundry thread attempts to launder enough pages to meet v_free_target within 0.5s, which is the inactive queue scan period. A laundry request can be latched while another is currently being serviced. In particular, a shortfall request will immediately preempt a background laundering. This change also redefines the meaning of vm_cnt.v_reactivated and removes the functions vm_page_cache() and vm_page_try_to_cache(). The new meaning of vm_cnt.v_reactivated now better reflects its name. It represents the number of inactive or laundry pages that are returned to the active queue on account of a reference. In collaboration with: markj Reviewed by: kib Tested by: pho Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D8302
2016-11-09 18:48:37 +00:00
vm_page_deactivate_noreuse(m);
The soft and hard busy mechanism rely on the vm object lock to work. Unify the 2 concept into a real, minimal, sxlock where the shared acquisition represent the soft busy and the exclusive acquisition represent the hard busy. The old VPO_WANTED mechanism becames the hard-path for this new lock and it becomes per-page rather than per-object. The vm_object lock becames an interlock for this functionality: it can be held in both read or write mode. However, if the vm_object lock is held in read mode while acquiring or releasing the busy state, the thread owner cannot make any assumption on the busy state unless it is also busying it. Also: - Add a new flag to directly shared busy pages while vm_page_alloc and vm_page_grab are being executed. This will be very helpful once these functions happen under a read object lock. - Move the swapping sleep into its own per-object flag The KPI is heavilly changed this is why the version is bumped. It is very likely that some VM ports users will need to change their own code. Sponsored by: EMC / Isilon storage division Discussed with: alc Reviewed by: jeff, kib Tested by: gavin, bapt (older version) Tested by: pho, scottl
2013-08-09 11:11:11 +00:00
vm_page_sunbusy(m);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* adjust pip. NOTE: the original parent may still have its own
* pip refs on the object.
*/
- Lock the vm_object when performing vm_object_pip_wakeupn(). - Assert that the vm_object lock is held in vm_object_pip_wakeupn(). - Add a new macro VM_OBJECT_LOCK_ASSERT().
2003-04-19 21:15:44 +00:00
if (object != NULL) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
vm_object_pip_wakeupn(object, bp->b_npages);
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WUNLOCK(object);
- Lock the vm_object when performing vm_object_pip_wakeupn(). - Assert that the vm_object lock is held in vm_object_pip_wakeupn(). - Add a new macro VM_OBJECT_LOCK_ASSERT().
2003-04-19 21:15:44 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
/*
* swapdev_strategy() manually sets b_vp and b_bufobj before calling
Make sure b_vp and b_bufobj are NULL before calling relpbuf(), as it asserts they are. They should be NULL at this point, except if we're coming from swapdev_strategy(). It should only affect the case where we're swapping directly on a file over NFS.
2006-01-27 21:11:50 +00:00
* bstrategy(). Set them back to NULL now we're done with it, or we'll
* trigger a KASSERT in relpbuf().
*/
if (bp->b_vp) {
bp->b_vp = NULL;
bp->b_bufobj = NULL;
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* release the physical I/O buffer
*/
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
if (bp->b_flags & B_ASYNC) {
mtx_lock(&swbuf_mtx);
if (++nsw_wcount_async == 1)
wakeup(&nsw_wcount_async);
mtx_unlock(&swbuf_mtx);
}
uma_zfree((bp->b_iocmd == BIO_READ) ? swrbuf_zone : swwbuf_zone, bp);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
Add a page queue for holding dirty anonymous unswappable pages. On systems without a configured swap device, an attempt to launder pages from a swap object will always fail and result in the page being reactivated. This means that the page daemon will continuously scan pages that can never be evicted. With this change, anonymous pages are instead moved to PQ_UNSWAPPABLE after a failed laundering attempt when no swap devices are configured. PQ_UNSWAPPABLE is not scanned unless a swap device is configured, so unreferenced unswappable pages are excluded from the page daemon's workload. Reviewed by: alc
2017-01-03 00:05:44 +00:00
int
swap_pager_nswapdev(void)
{
return (nswapdev);
}
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
static void
swp_pager_force_dirty(vm_page_t m)
{
vm_page_dirty(m);
Revert r352406, which contained changes I didn't intend to commit.
2019-09-16 15:04:45 +00:00
#ifdef INVARIANTS
Introduce vm_page_astate. This is a 32-bit structure embedded in each vm_page, consisting mostly of page queue state. The use of a structure makes it easy to store a snapshot of a page's queue state in a stack variable and use cmpset loops to update that state without requiring the page lock. This change merely adds the structure and updates references to atomic state fields. No functional change intended. Reviewed by: alc, jeff, kib Sponsored by: Netflix, Intel Differential Revision: https://reviews.freebsd.org/D22650
2019-12-10 18:14:50 +00:00
if (!vm_page_wired(m) && m->a.queue == PQ_NONE)
Revert r352406, which contained changes I didn't intend to commit.
2019-09-16 15:04:45 +00:00
panic("page %p is neither wired nor queued", m);
#endif
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
vm_page_xunbusy(m);
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
swap_pager_unswapped(m);
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
}
static void
swp_pager_force_launder(vm_page_t m)
{
vm_page_dirty(m);
vm_page_launder(m);
vm_page_xunbusy(m);
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
swap_pager_unswapped(m);
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
}
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
/*
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
* SWP_PAGER_FORCE_PAGEIN() - force swap blocks to be paged in
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
*
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
* This routine dissociates pages starting at the given index within an
* object from their backing store, paging them in if they do not reside
* in memory. Pages that are paged in are marked dirty and placed in the
* laundry queue. Pages are marked dirty because they no longer have
* backing store. They are placed in the laundry queue because they have
* not been accessed recently. Otherwise, they would already reside in
* memory.
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
*/
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
static void
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
swp_pager_force_pagein(vm_object_t object, vm_pindex_t pindex, int npages)
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
{
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
vm_page_t ma[npages];
int i, j;
KASSERT(npages > 0, ("%s: No pages", __func__));
KASSERT(npages <= MAXPHYS / PAGE_SIZE,
("%s: Too many pages: %d", __func__, npages));
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
KASSERT(object->type == OBJT_SWAP,
("%s: Object not swappable", __func__));
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
vm_object_pip_add(object, npages);
vm_page_grab_pages(object, pindex, VM_ALLOC_NORMAL, ma, npages);
for (i = j = 0;; i++) {
/* Count nonresident pages, to page-in all at once. */
if (i < npages && ma[i]->valid != VM_PAGE_BITS_ALL)
continue;
if (j < i) {
/* Page-in nonresident pages. Mark for laundering. */
if (swap_pager_getpages(object, &ma[j], i - j, NULL,
NULL) != VM_PAGER_OK)
panic("%s: read from swap failed", __func__);
do {
swp_pager_force_launder(ma[j]);
} while (++j < i);
}
if (i == npages)
break;
/* Mark dirty a resident page. */
swp_pager_force_dirty(ma[j++]);
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
}
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
vm_object_pip_wakeupn(object, npages);
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
}
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
/*
* swap_pager_swapoff_object:
*
* Page in all of the pages that have been paged out for an object
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
* to a swap device.
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
*/
static void
swap_pager_swapoff_object(struct swdevt *sp, vm_object_t object)
{
struct swblk *sb;
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
vm_pindex_t pi, s_pindex;
daddr_t blk, n_blks, s_blk;
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
int i;
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
KASSERT(object->type == OBJT_SWAP,
("%s: Object not swappable", __func__));
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
n_blks = 0;
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
for (pi = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(
&object->un_pager.swp.swp_blks, pi)) != NULL; ) {
for (i = 0; i < SWAP_META_PAGES; i++) {
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
blk = sb->d[i];
if (!swp_pager_isondev(blk, sp))
blk = SWAPBLK_NONE;
/*
* If there are no blocks/pages accumulated, start a new
* accumulation here.
*/
if (n_blks == 0) {
if (blk != SWAPBLK_NONE) {
s_blk = blk;
s_pindex = sb->p + i;
n_blks = 1;
}
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
continue;
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
}
/*
* If the accumulation can be extended without breaking
* the sequence of consecutive blocks and pages that
* swp_pager_force_pagein() depends on, do so.
*/
if (n_blks < MAXPHYS / PAGE_SIZE &&
s_blk + n_blks == blk &&
s_pindex + n_blks == sb->p + i) {
++n_blks;
continue;
}
/*
* The sequence of consecutive blocks and pages cannot
* be extended, so page them all in here. Then,
* because doing so involves releasing and reacquiring
* a lock that protects the swap block pctrie, do not
* rely on the current swap block. Break this loop and
* re-fetch the same pindex from the pctrie again.
*/
swp_pager_force_pagein(object, s_pindex, n_blks);
n_blks = 0;
break;
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
}
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
if (i == SWAP_META_PAGES)
pi = sb->p + SWAP_META_PAGES;
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
}
Based on work posted at https://reviews.freebsd.org/D13484, change swap_pager_swapoff_object and swp_pager_force_pagein so that they can page in multiple pages at a time to a swap device, rather than doing one I/O operation for each page. Tested by: pho Submitted by: ota_j.email.ne.jp (Yoshihiro Ota) Reviewed by: alc, markj, kib Approved by: kib, markj (mentors) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20635
2019-07-05 16:49:34 +00:00
if (n_blks > 0)
swp_pager_force_pagein(object, s_pindex, n_blks);
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
}
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
/*
* swap_pager_swapoff:
*
* Page in all of the pages that have been paged out to the
* given device. The corresponding blocks in the bitmap must be
* marked as allocated and the device must be flagged SW_CLOSING.
* There may be no processes swapped out to the device.
*
* This routine may block.
*/
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
static void
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
swap_pager_swapoff(struct swdevt *sp)
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
{
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
vm_object_t object;
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
int retries;
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_assert(&swdev_syscall_lock, SA_XLOCKED);
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
Fix the last known race in swapoff(), which could lead to a spurious panic: swapoff: failed to locate %d swap blocks The race occurred because putpages() can block between the time it allocates swap space and the time it updates the swap metadata to associate that space with a vm_object, so swapoff() would complain about the temporary inconsistency. I hoped to fix this by making swp_pager_getswapspace() and swp_pager_meta_build() a single atomic operation, but that proved to be inconvenient. With this change, swapoff() simply doesn't attempt to be so clever about detecting when all the pageout activity to the target device should have drained.
2004-11-06 07:17:50 +00:00
retries = 0;
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
full_rescan:
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
mtx_lock(&vm_object_list_mtx);
TAILQ_FOREACH(object, &vm_object_list, object_list) {
if (object->type != OBJT_SWAP)
continue;
mtx_unlock(&vm_object_list_mtx);
/* Depends on type-stability. */
VM_OBJECT_WLOCK(object);
/*
* Dead objects are eventually terminated on their own.
*/
if ((object->flags & OBJ_DEAD) != 0)
goto next_obj;
/*
* Sync with fences placed after pctrie
* initialization. We must not access pctrie below
* unless we checked that our object is swap and not
* dead.
*/
atomic_thread_fence_acq();
if (object->type != OBJT_SWAP)
goto next_obj;
Simple code refactoring originally in D13484. Extract swp_pager_force_dirty() and swp_pager_force_launder() out of swp_pager_force_pagein(). Extract swap_pager_swapoff_object() out of swap_pager_swapoff(). Submitted by: ota_j.email.ne.jp Reviewed by: alc, dougm Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20545
2019-06-08 17:49:17 +00:00
swap_pager_swapoff_object(sp, object);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
next_obj:
VM_OBJECT_WUNLOCK(object);
mtx_lock(&vm_object_list_mtx);
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
mtx_unlock(&vm_object_list_mtx);
Fix the last known race in swapoff(), which could lead to a spurious panic: swapoff: failed to locate %d swap blocks The race occurred because putpages() can block between the time it allocates swap space and the time it updates the swap metadata to associate that space with a vm_object, so swapoff() would complain about the temporary inconsistency. I hoped to fix this by making swp_pager_getswapspace() and swp_pager_meta_build() a single atomic operation, but that proved to be inconvenient. With this change, swapoff() simply doesn't attempt to be so clever about detecting when all the pageout activity to the target device should have drained.
2004-11-06 07:17:50 +00:00
if (sp->sw_used) {
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
/*
Fix the last known race in swapoff(), which could lead to a spurious panic: swapoff: failed to locate %d swap blocks The race occurred because putpages() can block between the time it allocates swap space and the time it updates the swap metadata to associate that space with a vm_object, so swapoff() would complain about the temporary inconsistency. I hoped to fix this by making swp_pager_getswapspace() and swp_pager_meta_build() a single atomic operation, but that proved to be inconvenient. With this change, swapoff() simply doesn't attempt to be so clever about detecting when all the pageout activity to the target device should have drained.
2004-11-06 07:17:50 +00:00
* Objects may be locked or paging to the device being
* removed, so we will miss their pages and need to
* make another pass. We have marked this device as
* SW_CLOSING, so the activity should finish soon.
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
*/
Fix the last known race in swapoff(), which could lead to a spurious panic: swapoff: failed to locate %d swap blocks The race occurred because putpages() can block between the time it allocates swap space and the time it updates the swap metadata to associate that space with a vm_object, so swapoff() would complain about the temporary inconsistency. I hoped to fix this by making swp_pager_getswapspace() and swp_pager_meta_build() a single atomic operation, but that proved to be inconvenient. With this change, swapoff() simply doesn't attempt to be so clever about detecting when all the pageout activity to the target device should have drained.
2004-11-06 07:17:50 +00:00
retries++;
if (retries > 100) {
panic("swapoff: failed to locate %d swap blocks",
sp->sw_used);
}
Use pause() rather than tsleep() on stack variables and function pointers.
2007-02-27 17:23:29 +00:00
pause("swpoff", hz / 20);
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
goto full_rescan;
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
}
Add a page queue for holding dirty anonymous unswappable pages. On systems without a configured swap device, an attempt to launder pages from a swap object will always fail and result in the page being reactivated. This means that the page daemon will continuously scan pages that can never be evicted. With this change, anonymous pages are instead moved to PQ_UNSWAPPABLE after a failed laundering attempt when no swap devices are configured. PQ_UNSWAPPABLE is not scanned unless a swap device is configured, so unreferenced unswappable pages are excluded from the page daemon's workload. Reviewed by: alc
2017-01-03 00:05:44 +00:00
EVENTHANDLER_INVOKE(swapoff, sp);
This is David Schultz's swapoff code which I am finally able to commit. This should be considered highly experimental for the moment. Submitted by: David Schultz <dschultz@uclink.Berkeley.EDU> MFC after: 3 weeks
2002-12-15 19:17:57 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/************************************************************************
* SWAP META DATA *
************************************************************************
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* These routines manipulate the swap metadata stored in the
Reap old SPL comments. Reviewed by: alc
2011-04-26 22:18:53 +00:00
* OBJT_SWAP object.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
* Swap metadata is implemented with a global hash and not directly
* linked into the object. Instead the object simply contains
* appropriate tracking counters.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
/*
* SWP_PAGER_SWBLK_EMPTY() - is a range of blocks free?
*/
static bool
swp_pager_swblk_empty(struct swblk *sb, int start, int limit)
{
int i;
MPASS(0 <= start && start <= limit && limit <= SWAP_META_PAGES);
for (i = start; i < limit; i++) {
if (sb->d[i] != SWAPBLK_NONE)
return (false);
}
return (true);
}
Add a helper function for testing a swap block and freeing it if empty. Submitted by: ota_j.email.ne.jp Approved by: alc, kib, dougm Differential Revision: https://reviews.freebsd.org/D22402
2019-11-17 18:38:37 +00:00
/*
* SWP_PAGER_FREE_EMPTY_SWBLK() - frees if a block is free
*
* Nothing is done if the block is still in use.
*/
static void
swp_pager_free_empty_swblk(vm_object_t object, struct swblk *sb)
{
if (swp_pager_swblk_empty(sb, 0, SWAP_META_PAGES)) {
SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, sb->p);
uma_zfree(swblk_zone, sb);
}
}
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* SWP_PAGER_META_BUILD() - add swap block to swap meta data for object
*
* We first convert the object to a swap object if it is a default
* object.
*
* The specified swapblk is added to the object's swap metadata. If
* the swapblk is not valid, it is freed instead. Any previously
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
* assigned swapblk is returned.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*/
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
static daddr_t
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
swp_pager_meta_build(vm_object_t object, vm_pindex_t pindex, daddr_t swapblk)
{
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
static volatile int swblk_zone_exhausted, swpctrie_zone_exhausted;
In swp_pager_meta_build(), handle a race with other thread allocating swapblk for our index while we dropped the object lock. Noted by: jeff Reviewed by: alc, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2017-09-06 16:16:11 +00:00
struct swblk *sb, *sb1;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
vm_pindex_t modpi, rdpi;
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
daddr_t prev_swapblk;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
int error, i;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Hide the details for the assertion for VM_OBJECT_LOCK operations. Rename current VM_OBJECT_LOCK_ASSERT(foo, RA_WLOCKED) into VM_OBJECT_ASSERT_WLOCKED(foo) Sponsored by: EMC / Isilon storage division Requested by: alc
2013-02-21 21:54:53 +00:00
VM_OBJECT_ASSERT_WLOCKED(object);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* Convert default object to swap object if necessary
*/
if (object->type != OBJT_SWAP) {
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
pctrie_init(&object->un_pager.swp.swp_blks);
/*
* Ensure that swap_pager_swapoff()'s iteration over
* object_list does not see a garbage pctrie.
*/
atomic_thread_fence_rel();
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
object->type = OBJT_SWAP;
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
object->un_pager.swp.writemappings = 0;
Store the bottom of the shadow chain in OBJ_ANON object->handle member. The handle value is stable for all shadow objects in the inheritance chain. This allows to avoid descending the shadow chain to get to the bottom of it in vm_map_entry_set_vnode_text(), and eliminate corresponding object relocking which appeared to be contending. Change vm_object_allocate_anon() and vm_object_shadow() to handle more of the cred/charge initialization for the new shadow object, in addition to set up the handle. Reported by: jeff Reviewed by: alc (previous version), jeff (previous version) Tested by: pho Sponsored by: The FreeBSD Foundation Differrential revision: https://reviews.freebsd.org/D22541
2019-12-01 20:43:04 +00:00
KASSERT((object->flags & OBJ_ANON) != 0 ||
object->handle == NULL,
("default pager %p with handle %p",
object, object->handle));
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
rdpi = rounddown(pindex, SWAP_META_PAGES);
sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks, rdpi);
if (sb == NULL) {
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (swapblk == SWAPBLK_NONE)
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
return (SWAPBLK_NONE);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
for (;;) {
sb = uma_zalloc(swblk_zone, M_NOWAIT | (curproc ==
pageproc ? M_USE_RESERVE : 0));
if (sb != NULL) {
sb->p = rdpi;
for (i = 0; i < SWAP_META_PAGES; i++)
sb->d[i] = SWAPBLK_NONE;
if (atomic_cmpset_int(&swblk_zone_exhausted,
1, 0))
printf("swblk zone ok\n");
break;
}
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WUNLOCK(object);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (uma_zone_exhausted(swblk_zone)) {
if (atomic_cmpset_int(&swblk_zone_exhausted,
0, 1))
printf("swap blk zone exhausted, "
- When running out of swzone, instead of spewing an error message every tick until the situation is resolved (if ever), just print a single message when running out and another when space becomes available. - When adding more swap, warn if the total amount exceeds half the theoretical maximum we can handle.
2012-08-16 08:29:49 +00:00
"increase kern.maxswzone\n");
Move the code for doing out-of-memory grass from vm_pageout_scan() into the separate function vm_pageout_oom(). Supply a parameter for vm_pageout_oom() describing a reason for the call. Call vm_pageout_oom() from the swp_pager_meta_build() when swap zone is exhausted. Reviewed by: alc Tested by: pho, jhb MFC after: 2 weeks
2008-09-29 19:45:12 +00:00
vm_pageout_oom(VM_OOM_SWAPZ);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
pause("swzonxb", 10);
} else
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
uma_zwait(swblk_zone);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
VM_OBJECT_WLOCK(object);
In swp_pager_meta_build(), handle a race with other thread allocating swapblk for our index while we dropped the object lock. Noted by: jeff Reviewed by: alc, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2017-09-06 16:16:11 +00:00
sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks,
rdpi);
if (sb != NULL)
/*
* Somebody swapped out a nearby page,
* allocating swblk at the rdpi index,
* while we dropped the object lock.
*/
goto allocated;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
}
for (;;) {
error = SWAP_PCTRIE_INSERT(
&object->un_pager.swp.swp_blks, sb);
if (error == 0) {
if (atomic_cmpset_int(&swpctrie_zone_exhausted,
1, 0))
printf("swpctrie zone ok\n");
break;
}
VM_OBJECT_WUNLOCK(object);
if (uma_zone_exhausted(swpctrie_zone)) {
if (atomic_cmpset_int(&swpctrie_zone_exhausted,
0, 1))
printf("swap pctrie zone exhausted, "
"increase kern.maxswzone\n");
vm_pageout_oom(VM_OOM_SWAPZ);
pause("swzonxp", 10);
Move the code for doing out-of-memory grass from vm_pageout_scan() into the separate function vm_pageout_oom(). Supply a parameter for vm_pageout_oom() describing a reason for the call. Call vm_pageout_oom() from the swp_pager_meta_build() when swap zone is exhausted. Reviewed by: alc Tested by: pho, jhb MFC after: 2 weeks
2008-09-29 19:45:12 +00:00
} else
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
uma_zwait(swpctrie_zone);
Rename VM_OBJECT_LOCK(), VM_OBJECT_UNLOCK() and VM_OBJECT_TRYLOCK() to their "write" versions. Sponsored by: EMC / Isilon storage division
2013-02-20 12:03:20 +00:00
VM_OBJECT_WLOCK(object);
In swp_pager_meta_build(), handle a race with other thread allocating swapblk for our index while we dropped the object lock. Noted by: jeff Reviewed by: alc, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2017-09-06 16:16:11 +00:00
sb1 = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks,
rdpi);
if (sb1 != NULL) {
uma_zfree(swblk_zone, sb);
sb = sb1;
goto allocated;
}
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
In swp_pager_meta_build(), handle a race with other thread allocating swapblk for our index while we dropped the object lock. Noted by: jeff Reviewed by: alc, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2017-09-06 16:16:11 +00:00
allocated:
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
MPASS(sb->p == rdpi);
modpi = pindex % SWAP_META_PAGES;
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
/* Return prior contents of metadata. */
prev_swapblk = sb->d[modpi];
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
/* Enter block into metadata. */
sb->d[modpi] = swapblk;
Do not leak empty swblk. In swp_pager_meta_build(), if the requested operation results in freeing the last swap pointer in the swblk, free the trie node. Other swap pager code does not expect to find completely empty swblk. Reviewed by: alc, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2017-09-06 16:18:53 +00:00
/*
* Free the swblk if we end up with the empty page run.
*/
Add a helper function for testing a swap block and freeing it if empty. Submitted by: ota_j.email.ne.jp Approved by: alc, kib, dougm Differential Revision: https://reviews.freebsd.org/D22402
2019-11-17 18:38:37 +00:00
if (swapblk == SWAPBLK_NONE)
swp_pager_free_empty_swblk(object, sb);
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
return (prev_swapblk);
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
/*
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
* SWP_PAGER_META_TRANSFER() - free a range of blocks in the srcobject's swap
* metadata, or transfer it into dstobject.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* This routine will free swap metadata structures as they are cleaned
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
* out.
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
*/
staticize.
1995-11-14 20:53:20 +00:00
static void
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
swp_pager_meta_transfer(vm_object_t srcobject, vm_object_t dstobject,
vm_pindex_t pindex, vm_pindex_t count)
BSD 4.4 Lite Kernel Sources
1994-05-24 10:09:53 +00:00
{
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
struct swblk *sb;
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
daddr_t n_free, s_free;
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
vm_pindex_t offset, last;
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
int i, limit, start;
- Synchronize access to the swdevt's sw_flags with sw_dev_mtx. - Remove several instances of GIANT_REQUIRED.
2003-10-31 05:18:45 +00:00
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
VM_OBJECT_ASSERT_WLOCKED(srcobject);
if (srcobject->type != OBJT_SWAP || count == 0)
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
return;
1) Use a more consistent page wait methodology. 2) Do not unnecessarily force page blocking when paging pages out. 3) Further improve swap pager performance and correctness, including fixing the paging in progress deadlock (except in severe I/O error conditions.) 4) Enable vfs_ioopt=1 as a default. 5) Fix and enable the page prezeroing in SMP mode. All in all, SMP systems especially should show a significant improvement in "snappyness."
1998-03-01 04:18:54 +00:00
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_init_freerange(&s_free, &n_free);
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
offset = pindex;
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
last = pindex + count;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
for (;;) {
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
sb = SWAP_PCTRIE_LOOKUP_GE(&srcobject->un_pager.swp.swp_blks,
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
rounddown(pindex, SWAP_META_PAGES));
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
if (sb == NULL || sb->p >= last)
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
break;
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
start = pindex > sb->p ? pindex - sb->p : 0;
limit = last - sb->p < SWAP_META_PAGES ? last - sb->p :
SWAP_META_PAGES;
for (i = start; i < limit; i++) {
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (sb->d[i] == SWAPBLK_NONE)
Fix argument type and microoptimize swp_pager_meta_free(). The count argument natural type if vm_pindex_t, but due to the loop organization, it has to be signed type to detect the termination condition. Replace this logic by using distinguished counter for the processed pages, and terminate loop when the counter exceeds the argument. Completely process one swblock for all relevant indexes instead of doing relookup in hash when incrementing page index on the loop step. Do not drop hash mutex around iterations. Noted and reviewed by: alc Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-24 09:57:31 +00:00
continue;
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
if (dstobject == NULL ||
!swp_pager_xfer_source(srcobject, dstobject,
sb->p + i - offset, sb->d[i])) {
swp_pager_update_freerange(&s_free, &n_free,
sb->d[i]);
}
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
sb->d[i] = SWAPBLK_NONE;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
}
Fix a use-after-free in swp_pager_meta_free(). This was introduced in r326329 and explains the crashes mentioned in the commit log message for r339934. In particular, on INVARIANTS kernels, UMA trashing causes the loop to exit early, leaving swap blocks behind when they should have been freed. After r336984 this became more problematic since new anonymous mappings were more likely to reuse swapped-out subranges of existing VM objects, so faults would trigger pageins of freed memory rather than returning zeroed pages. Reviewed by: kib MFC after: 3 days Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17897
2018-11-07 23:28:11 +00:00
pindex = sb->p + SWAP_META_PAGES;
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
if (swp_pager_swblk_empty(sb, 0, start) &&
swp_pager_swblk_empty(sb, limit, SWAP_META_PAGES)) {
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
SWAP_PCTRIE_REMOVE(&srcobject->un_pager.swp.swp_blks,
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
sb->p);
uma_zfree(swblk_zone, sb);
1) Use a more consistent page wait methodology. 2) Do not unnecessarily force page blocking when paging pages out. 3) Further improve swap pager performance and correctness, including fixing the paging in progress deadlock (except in severe I/O error conditions.) 4) Enable vfs_ioopt=1 as a default. 5) Fix and enable the page prezeroing in SMP mode. All in all, SMP systems especially should show a significant improvement in "snappyness."
1998-03-01 04:18:54 +00:00
}
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_freeswapspace(s_free, n_free);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
These changes embody the support of the fully coherent merged VM buffer cache, much higher filesystem I/O performance, and much better paging performance. It represents the culmination of over 6 months of R&D. The majority of the merged VM/cache work is by John Dyson. The following highlights the most significant changes. Additionally, there are (mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to support the new VM/buffer scheme. vfs_bio.c: Significant rewrite of most of vfs_bio to support the merged VM buffer cache scheme. The scheme is almost fully compatible with the old filesystem interface. Significant improvement in the number of opportunities for write clustering. vfs_cluster.c, vfs_subr.c Upgrade and performance enhancements in vfs layer code to support merged VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff. vm_object.c: Yet more improvements in the collapse code. Elimination of some windows that can cause list corruption. vm_pageout.c: Fixed it, it really works better now. Somehow in 2.0, some "enhancements" broke the code. This code has been reworked from the ground-up. vm_fault.c, vm_page.c, pmap.c, vm_object.c Support for small-block filesystems with merged VM/buffer cache scheme. pmap.c vm_map.c Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of kernel PTs. vm_glue.c Much simpler and more effective swapping code. No more gratuitous swapping. proc.h Fixed the problem that the p_lock flag was not being cleared on a fork. swap_pager.c, vnode_pager.c Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the code doesn't need it anymore. machdep.c Changes to better support the parameter values for the merged VM/buffer cache scheme. machdep.c, kern_exec.c, vm_glue.c Implemented a seperate submap for temporary exec string space and another one to contain process upages. This eliminates all map fragmentation problems that previously existed. ffs_inode.c, ufs_inode.c, ufs_readwrite.c Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on busy buffers. Submitted by: John Dyson and David Greenman
1995-01-09 16:06:02 +00:00
swap_pager_meta_free() frees allocated blocks in a way that exploits the sparsity of allocated blocks in a range, without issuing an "are you there?" query for every block in the range. swap_pager_copy() is not so smart. Modify the implementation of swap_pager_meta_free() slightly so that swap_pager_copy() can use that smarter implementation too. Based on an observation of: Yoshihiro Ota (ota_j.email.ne.jp) Reviewed by: kib,alc Tested by: pho Differential Revision: https://reviews.freebsd.org/D22280
2019-11-11 16:59:49 +00:00
/*
* SWP_PAGER_META_FREE() - free a range of blocks in the object's swap metadata
*
* The requested range of blocks is freed, with any associated swap
* returned to the swap bitmap.
*
* This routine will free swap metadata structures as they are cleaned
* out. This routine does *NOT* operate on swap metadata associated
* with resident pages.
*/
static void
swp_pager_meta_free(vm_object_t object, vm_pindex_t pindex, vm_pindex_t count)
{
swp_pager_meta_transfer(object, NULL, pindex, count);
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
* SWP_PAGER_META_FREE_ALL() - destroy all swap metadata associated with object
*
* This routine locates and destroys all swap metadata associated with
* an object.
*/
static void
swp_pager_meta_free_all(vm_object_t object)
{
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
struct swblk *sb;
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
daddr_t n_free, s_free;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
vm_pindex_t pindex;
In swp_pager_meta_free_all(), fix type of the index variable. Style. Noted and reviewed by: alc (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 week
2016-12-16 23:33:37 +00:00
int i;
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
Hide the details for the assertion for VM_OBJECT_LOCK operations. Rename current VM_OBJECT_LOCK_ASSERT(foo, RA_WLOCKED) into VM_OBJECT_ASSERT_WLOCKED(foo) Sponsored by: EMC / Isilon storage division Requested by: alc
2013-02-21 21:54:53 +00:00
VM_OBJECT_ASSERT_WLOCKED(object);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
if (object->type != OBJT_SWAP)
return;
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_init_freerange(&s_free, &n_free);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
for (pindex = 0; (sb = SWAP_PCTRIE_LOOKUP_GE(
&object->un_pager.swp.swp_blks, pindex)) != NULL;) {
pindex = sb->p + SWAP_META_PAGES;
for (i = 0; i < SWAP_META_PAGES; i++) {
When the swap pager allocates space on disk, it requests contiguous blocks in a single call to blist_alloc(). However, when it frees that space, it previously called blist_free() on each block, one at a time. With this change, the swap pager identifies ranges of contiguous blocks to be freed, and calls blist_free() once per range. In one extreme case, that is described in the review, the time to perform an munmap(2) was reduced by 55%. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D12397
2017-11-28 17:46:03 +00:00
if (sb->d[i] == SWAPBLK_NONE)
continue;
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_update_freerange(&s_free, &n_free, sb->d[i]);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, sb->p);
uma_zfree(swblk_zone, sb);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
Defer and aggregate swap_pager_meta_build frees. Before swp_pager_meta_build replaces an old swapblk with an new one, it frees the old one. To allow such freeing of blocks to be aggregated, have swp_pager_meta_build return the old swap block, and make the caller responsible for freeing it. Define a pair of short static functions, swp_pager_init_freerange and swp_pager_update_freerange, to do the initialization and updating of blk addresses and counters used in aggregating blocks to be freed. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib, markj (an earlier version) Tested by: pho MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13707
2018-08-08 02:30:34 +00:00
swp_pager_freeswapspace(s_free, n_free);
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
}
/*
Previously, swap_pager_copy() freed swap blocks one at at time, via swp_pager_meta_ctl(), with no opportunity to recognize freeing of consecutive blocks and free fewer block ranges. To open that opportunity, this change removes the SWM_FREE option from swp_pager_meta_ctl(), and compels the caller to do the freeing when a valid block address is returned. In swap_pager_copy(), these frees are aggregated, so that a sequence of them can be done at one time. The only other caller to swp_pager_meta_ctl() that passed SWM_FREE, swp_pager_unswapped(), is also modified to handle its single free explicitly. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib (an earlier version) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13290
2017-12-31 04:01:47 +00:00
* SWP_PAGER_METACTL() - misc control of swap meta data.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
Previously, swap_pager_copy() freed swap blocks one at at time, via swp_pager_meta_ctl(), with no opportunity to recognize freeing of consecutive blocks and free fewer block ranges. To open that opportunity, this change removes the SWM_FREE option from swp_pager_meta_ctl(), and compels the caller to do the freeing when a valid block address is returned. In swap_pager_copy(), these frees are aggregated, so that a sequence of them can be done at one time. The only other caller to swp_pager_meta_ctl() that passed SWM_FREE, swp_pager_unswapped(), is also modified to handle its single free explicitly. Submitted by: Doug Moore <dougm@rice.edu> Reviewed by: kib (an earlier version) MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D13290
2017-12-31 04:01:47 +00:00
* This routine is capable of looking up, or removing swapblk
* assignments in the swap meta data. It returns the swapblk being
* looked-up, popped, or SWAPBLK_NONE if the block was invalid.
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
*
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
* When acting on a busy resident page and paging is in progress, we
* have to wait until paging is complete but otherwise can act on the
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* busy page.
*/
static daddr_t
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
swp_pager_meta_lookup(vm_object_t object, vm_pindex_t pindex)
Consistent use modern function definitions
2003-08-30 08:32:42 +00:00
{
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
struct swblk *sb;
Fix a number of spl bugs related to reserving and freeing swap space. Swap space can be freed from an interrupt and so swap reservation and freeing must occur at splvm. Add swap_pager_reserve() code to support a new swap pre-reservation capability for the VN device. Generally cleanup the swap code by simplifying the swp_pager_meta_build() static function and consolidating the SWAPBLK_NONE test from a bit test to an absolute compare. The bit test was left over from a rejected swap allocation scheme that was not ultimately committed. A few other minor cleanups were also made. Reorganize the swap strategy code, again for VN support, to not reallocate swap when writing as this messes up pre-reservation and can fragment I/O unnecessarily as VN-baesd disk is messed around with. Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
1999-09-17 05:09:24 +00:00
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
VM_OBJECT_ASSERT_LOCKED(object);
Update a couple vm_object lock assertions in the swap pager to reflect the new use of the vm_object's lock to synchronize updates to a radix trie mapping per-vm object page indices to on-disk swap blocks. Fix a typo in a nearby comment. Reviewed by: kib, markj X-MFC with: r322913 Differential Revision: https://reviews.freebsd.org/D12134
2017-08-28 17:02:25 +00:00
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
/*
Update a couple vm_object lock assertions in the swap pager to reflect the new use of the vm_object's lock to synchronize updates to a radix trie mapping per-vm object page indices to on-disk swap blocks. Fix a typo in a nearby comment. Reviewed by: kib, markj X-MFC with: r322913 Differential Revision: https://reviews.freebsd.org/D12134
2017-08-28 17:02:25 +00:00
* The meta data only exists if the object is OBJT_SWAP
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
* and even then might not be allocated yet.
*/
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
KASSERT(object->type == OBJT_SWAP,
("Lookup object not swappable"));
Significantly improve the efficiency of the swap pager, which appears to have declined due to code-rot over time. The swap pager rundown code has been clean-up, and unneeded wakeups removed. Lots of splbio's are changed to splvm's. Also, set the dynamic tunables for the pageout daemon to be more sane for larger systems (thereby decreasing the daemon overheadla.)
1998-02-23 08:22:48 +00:00
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
sb = SWAP_PCTRIE_LOOKUP(&object->un_pager.swp.swp_blks,
rounddown(pindex, SWAP_META_PAGES));
if (sb == NULL)
return (SWAPBLK_NONE);
Drop the extra argument from swp_pager_meta_ctl and have it do lookup only. Rename it swp_pager_meta_lookup. Stop checking for obj->type == swap there and assert it instead. Make the caller responsible for the obj->type check. Move the meta_ctl 'pop' functionality to swap_pager_unswapped, the only place that uses it, and assume obj->type == swap there too. Assisted by: ota_j.email.ne.jp Reviewed by: kib Tested by: pho Differential Revision: https://reviews.freebsd.org/D22437
2019-11-19 08:06:31 +00:00
return (sb->d[pindex % SWAP_META_PAGES]);
The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch. Reviewed by: Rodney W. Grimes Submitted by: John Dyson and David Greenman
1994-05-25 09:21:21 +00:00
}
This is a rather large commit that encompasses the new swapper, changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
1999-01-21 08:29:12 +00:00
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
/*
* Returns the least page index which is greater than or equal to the
* parameter pindex and for which there is a swap block allocated.
* Returns object's size if the object's type is not swap or if there
* are no allocated swap blocks for the object after the requested
* pindex.
*/
vm_pindex_t
swap_pager_find_least(vm_object_t object, vm_pindex_t pindex)
{
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
struct swblk *sb;
int i;
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
VM_OBJECT_ASSERT_LOCKED(object);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (object->type != OBJT_SWAP)
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
return (object->size);
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks,
rounddown(pindex, SWAP_META_PAGES));
if (sb == NULL)
return (object->size);
if (sb->p < pindex) {
for (i = pindex % SWAP_META_PAGES; i < SWAP_META_PAGES; i++) {
if (sb->d[i] != SWAPBLK_NONE)
return (sb->p + i);
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
sb = SWAP_PCTRIE_LOOKUP_GE(&object->un_pager.swp.swp_blks,
roundup(pindex, SWAP_META_PAGES));
if (sb == NULL)
return (object->size);
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
for (i = 0; i < SWAP_META_PAGES; i++) {
if (sb->d[i] != SWAPBLK_NONE)
return (sb->p + i);
}
/*
* We get here if a swblk is present in the trie but it
* doesn't map any blocks.
*/
MPASS(0);
return (object->size);
Improve vm_object_scan_all_shadowed() to also check swap backing objects. As noted in the removed comment, it is possible and not prohibitively costly to look up the swap blocks for the given page index. Implement a swap_pager_find_least() function to do that, and use it to iterate simultaneously over both backing object page queue and swap allocations when looking for shadowed pages. Testing shows that number of new succesful scans, enabled by this addition, is small but non-zero. When worked out, the change both further reduces the depth of the shadow object chain, and frees unused but allocated swap and memory. Suggested and reviewed by: alc Tested by: pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-12-18 20:56:14 +00:00
}
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* System call swapon(name) enables swapping on device name,
* which must be in the swdevsw. Return EBUSY
* if already swapping on this device.
*/
#ifndef _SYS_SYSPROTO_H_
struct swapon_args {
char *name;
};
#endif
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
/*
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
* MPSAFE
*/
/* ARGSUSED */
int
In order to maximize the re-usability of kernel code in user space this patch modifies makesyscalls.sh to prefix all of the non-compatibility calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel entry points and all places in the code that use them. It also fixes an additional name space collision between the kernel function psignal and the libc function of the same name by renaming the kernel psignal kern_psignal(). By introducing this change now we will ease future MFCs that change syscalls. Reviewed by: rwatson Approved by: re (bz)
2011-09-16 13:58:51 +00:00
sys_swapon(struct thread *td, struct swapon_args *uap)
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
{
struct vattr attr;
struct vnode *vp;
struct nameidata nd;
int error;
Sweep kernel replacing suser(9) calls with priv(9) calls, assigning specific privilege names to a broad range of privileges. These may require some future tweaking. Sponsored by: nCircle Network Security, Inc. Obtained from: TrustedBSD Project Discussed on: arch@ Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri, Alex Lyashkov <umka at sevcity dot net>, Skip Ford <skip dot ford at verizon dot net>, Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
error = priv_check(td, PRIV_SWAPON);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
if (error)
Sweep kernel replacing suser(9) calls with priv(9) calls, assigning specific privilege names to a broad range of privileges. These may require some future tweaking. Sponsored by: nCircle Network Security, Inc. Obtained from: TrustedBSD Project Discussed on: arch@ Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri, Alex Lyashkov <umka at sevcity dot net>, Skip Ford <skip dot ford at verizon dot net>, Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
return (error);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_xlock(&swdev_syscall_lock);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* Swap metadata may not fit in the KVM if we have physical
* memory of >1GB.
*/
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if (swblk_zone == NULL) {
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
error = ENOMEM;
goto done;
}
Audit pathnames looked up in swapon(2) and swapoff(2). MFC after: 2 weeks Obtained from: TrustedBSD Project
2007-04-23 14:41:34 +00:00
NDINIT(&nd, LOOKUP, ISOPEN | FOLLOW | AUDITVNODE1, UIO_USERSPACE,
uap->name, td);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
error = namei(&nd);
if (error)
goto done;
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
if (vn_isdisk(vp, &error)) {
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
error = swapongeom(vp);
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
} else if (vp->v_type == VREG &&
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
(vp->v_mount->mnt_vfc->vfc_flags & VFCF_NETWORK) != 0 &&
Decontextualize the couplet VOP_GETATTR / VOP_SETATTR as the passed thread was always curthread and totally unuseful. Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
2008-08-28 15:23:18 +00:00
(error = VOP_GETATTR(vp, &attr, td->td_ucred)) == 0) {
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* Allow direct swapping to NFS regular files in the same
* way that nfs_mountroot() sets up diskless swapping.
*/
Continue the objectification of the swapdev backends: Remove the vnode and dev_t fields and replace them with a void *. Introduce separate strategy functions for devices and regular (NFS) vnodes. For devices we don't need the vnode v_numoutput stuff. Add a generic swaponsomething() function to add a swapdevice and split the remainder of swaponvp() into swaponvp() and swapondev() which calls this backend.
2003-08-30 11:33:25 +00:00
error = swaponvp(td, vp, attr.va_size / DEV_BSIZE);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
}
if (error)
vrele(vp);
done:
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_xunlock(&swdev_syscall_lock);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
return (error);
}
- When running out of swzone, instead of spewing an error message every tick until the situation is resolved (if ever), just print a single message when running out and another when space becomes available. - When adding more swap, warn if the total amount exceeds half the theoretical maximum we can handle.
2012-08-16 08:29:49 +00:00
/*
* Check that the total amount of swap currently configured does not
* exceed half the theoretical maximum. If it does, print a warning
Adjust interface of swapon_check_swzone() to its actual usage. The function return value is not used. Its argument is always swap_total/PAGE_SIZE, so make it not take any arguments. Submitted by: ota@j.email.ne.jp PR: 221356 MFC after: 1 week
2017-08-30 10:17:00 +00:00
* message.
- When running out of swzone, instead of spewing an error message every tick until the situation is resolved (if ever), just print a single message when running out and another when space becomes available. - When adding more swap, warn if the total amount exceeds half the theoretical maximum we can handle.
2012-08-16 08:29:49 +00:00
*/
Adjust interface of swapon_check_swzone() to its actual usage. The function return value is not used. Its argument is always swap_total/PAGE_SIZE, so make it not take any arguments. Submitted by: ota@j.email.ne.jp PR: 221356 MFC after: 1 week
2017-08-30 10:17:00 +00:00
static void
swapon_check_swzone(void)
- When running out of swzone, instead of spewing an error message every tick until the situation is resolved (if ever), just print a single message when running out and another when space becomes available. - When adding more swap, warn if the total amount exceeds half the theoretical maximum we can handle.
2012-08-16 08:29:49 +00:00
{
/* recommend using no more than half that amount */
swapon_check_swzone(): use already calculated static variables. Submitted by: ota@j.email.ne.jp MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22065
2019-10-17 13:49:47 +00:00
if (swap_total > swap_maxpages / 2) {
- When running out of swzone, instead of spewing an error message every tick until the situation is resolved (if ever), just print a single message when running out and another when space becomes available. - When adding more swap, warn if the total amount exceeds half the theoretical maximum we can handle.
2012-08-16 08:29:49 +00:00
printf("warning: total configured swap (%lu pages) "
"exceeds maximum recommended amount (%lu pages).\n",
swapon_check_swzone(): use already calculated static variables. Submitted by: ota@j.email.ne.jp MFC after: 1 week Differential revision: https://reviews.freebsd.org/D22065
2019-10-17 13:49:47 +00:00
swap_total, swap_maxpages / 2);
- When running out of swzone, instead of spewing an error message every tick until the situation is resolved (if ever), just print a single message when running out and another when space becomes available. - When adding more swap, warn if the total amount exceeds half the theoretical maximum we can handle.
2012-08-16 08:29:49 +00:00
printf("warning: increase kern.maxswzone "
"or reduce amount of swap.\n");
}
}
Continue the objectification of the swapdev backends: Remove the vnode and dev_t fields and replace them with a void *. Introduce separate strategy functions for devices and regular (NFS) vnodes. For devices we don't need the vnode v_numoutput stuff. Add a generic swaponsomething() function to add a swapdevice and split the remainder of swaponvp() into swaponvp() and swapondev() which calls this backend.
2003-08-30 11:33:25 +00:00
static void
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
swaponsomething(struct vnode *vp, void *id, u_long nblks,
sw_strategy_t *strategy, sw_close_t *close, dev_t dev, int flags)
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
{
- Avoid a race in swaponsomething(): Calculate the new swdevt's first and end swblk and insert this new swdevt into the list of swap devices in the same critical section.
2003-10-29 05:42:28 +00:00
struct swdevt *sp, *tsp;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
swblk_t dvbase;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
u_long mblocks;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* nblks is in DEV_BSIZE'd chunks, convert to PAGE_SIZE'd chunks.
* First chop nblks off to page-align it, then convert.
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
*
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
* sw->sw_nblks is in page-sized chunks now too.
*/
nblks &= ~(ctodb(1) - 1);
nblks = dbtoc(nblks);
Apply the limit to avoid the overflows in the radix tree subr_blist.c after the conversion of the swap device size to the page size units, not before. That lifts the limit on the usable swap partition size from 32GB to 256GB, that is less depressing for the modern systems. Submitted by: Alexander V. Chernikov <melifaro ipfw ru> Reviewed by: alc Approved by: re (bz) MFC after: 2 weeks
2011-08-22 11:18:47 +00:00
/*
* If we go beyond this, we get overflows in the radix
* tree bitmap code.
*/
mblocks = 0x40000000 / BLIST_META_RADIX;
if (nblks > mblocks) {
printf(
"WARNING: reducing swap size to maximum of %luMB per unit\n",
mblocks / 1024 / 1024 * PAGE_SIZE);
nblks = mblocks;
}
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
sp = malloc(sizeof *sp, M_VMPGDATA, M_WAITOK | M_ZERO);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
sp->sw_vp = vp;
sp->sw_id = id;
Second half of the dev_t cleanup. The big lines are: NODEV -> NULL NOUDEV -> NODEV udev_t -> dev_t udev2dev() -> findcdev() Various minor adjustments including handling of userland access to kernel space struct cdev etc.
2004-06-17 17:16:53 +00:00
sp->sw_dev = dev;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
sp->sw_nblks = nblks;
sp->sw_used = 0;
Continue the objectification of the swapdev backends: Remove the vnode and dev_t fields and replace them with a void *. Introduce separate strategy functions for devices and regular (NFS) vnodes. For devices we don't need the vnode v_numoutput stuff. Add a generic swaponsomething() function to add a swapdevice and split the remainder of swaponvp() into swaponvp() and swapondev() which calls this backend.
2003-08-30 11:33:25 +00:00
sp->sw_strategy = strategy;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
sp->sw_close = close;
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
sp->sw_flags = flags;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
add malloc flag to blist so that it can be used in ithread context Reviewed by: alc, bsdimp
2008-05-05 19:48:54 +00:00
sp->sw_blist = blist_create(nblks, M_WAITOK);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
swap_pager.c reserves 2 blocks for a bsd label. Change that 2 to the expression howmany(BBSIZE, PAGE_SIZE), where BBSIZE is the size of the boot block area. That can be less than 2 if PAGE_SIZE is big. swapon(8) has an option to trim (delete) all the blocks of a device at startup. However, if the first of those blocks is a bsd label, then trimming those blocks is destructive. Change swapon to leave the first BBSIZE bytes untrimmed. Update manual pages to reflect changes in how swapon and how it may be used, espeically in association with savecore. Reviewed by: alc Approved by: markj (mentor) MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D21191
2019-08-15 02:30:44 +00:00
* Do not free the first blocks in order to avoid overwriting
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
* any bsd label at the front of the partition
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
*/
swap_pager.c reserves 2 blocks for a bsd label. Change that 2 to the expression howmany(BBSIZE, PAGE_SIZE), where BBSIZE is the size of the boot block area. That can be less than 2 if PAGE_SIZE is big. swapon(8) has an option to trim (delete) all the blocks of a device at startup. However, if the first of those blocks is a bsd label, then trimming those blocks is destructive. Change swapon to leave the first BBSIZE bytes untrimmed. Update manual pages to reflect changes in how swapon and how it may be used, espeically in association with savecore. Reviewed by: alc Approved by: markj (mentor) MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D21191
2019-08-15 02:30:44 +00:00
blist_free(sp->sw_blist, howmany(BBSIZE, PAGE_SIZE),
nblks - howmany(BBSIZE, PAGE_SIZE));
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
- Avoid a race in swaponsomething(): Calculate the new swdevt's first and end swblk and insert this new swdevt into the list of swap devices in the same critical section.
2003-10-29 05:42:28 +00:00
dvbase = 0;
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
- Avoid a race in swaponsomething(): Calculate the new swdevt's first and end swblk and insert this new swdevt into the list of swap devices in the same critical section.
2003-10-29 05:42:28 +00:00
TAILQ_FOREACH(tsp, &swtailq, sw_list) {
if (tsp->sw_end >= dvbase) {
/*
* We put one uncovered page between the devices
* in order to definitively prevent any cross-device
* I/O requests
*/
dvbase = tsp->sw_end + 1;
}
}
sp->sw_first = dvbase;
sp->sw_end = dvbase + nblks;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
TAILQ_INSERT_TAIL(&swtailq, sp, sw_list);
nswapdev++;
swap_pager.c reserves 2 blocks for a bsd label. Change that 2 to the expression howmany(BBSIZE, PAGE_SIZE), where BBSIZE is the size of the boot block area. That can be less than 2 if PAGE_SIZE is big. swapon(8) has an option to trim (delete) all the blocks of a device at startup. However, if the first of those blocks is a bsd label, then trimming those blocks is destructive. Change swapon to leave the first BBSIZE bytes untrimmed. Update manual pages to reflect changes in how swapon and how it may be used, espeically in association with savecore. Reviewed by: alc Approved by: markj (mentor) MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D21191
2019-08-15 02:30:44 +00:00
swap_pager_avail += nblks - howmany(BBSIZE, PAGE_SIZE);
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
swap_total += nblks;
Adjust interface of swapon_check_swzone() to its actual usage. The function return value is not used. Its argument is always swap_total/PAGE_SIZE, so make it not take any arguments. Submitted by: ota@j.email.ne.jp PR: 221356 MFC after: 1 week
2017-08-30 10:17:00 +00:00
swapon_check_swzone();
- Synchronize access to swdevhd using sw_dev_mtx. - Use swp_sizecheck() rather than assignment to swap_pager_full in swaponsomething().
2003-10-30 07:11:06 +00:00
swp_sizecheck();
mtx_unlock(&sw_dev_mtx);
Add a page queue for holding dirty anonymous unswappable pages. On systems without a configured swap device, an attempt to launder pages from a swap object will always fail and result in the page being reactivated. This means that the page daemon will continuously scan pages that can never be evicted. With this change, anonymous pages are instead moved to PQ_UNSWAPPABLE after a failed laundering attempt when no swap devices are configured. PQ_UNSWAPPABLE is not scanned unless a swap device is configured, so unreferenced unswappable pages are excluded from the page daemon's workload. Reviewed by: alc
2017-01-03 00:05:44 +00:00
EVENTHANDLER_INVOKE(swapon, sp);
Continue the objectification of the swapdev backends: Remove the vnode and dev_t fields and replace them with a void *. Introduce separate strategy functions for devices and regular (NFS) vnodes. For devices we don't need the vnode v_numoutput stuff. Add a generic swaponsomething() function to add a swapdevice and split the remainder of swaponvp() into swaponvp() and swapondev() which calls this backend.
2003-08-30 11:33:25 +00:00
}
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* SYSCALL: swapoff(devname)
*
* Disable swapping on the given device.
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
*
* XXX: Badly designed system call: it should use a device index
* rather than filename as specification. We keep sw_vp around
* only to make this work.
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
*/
#ifndef _SYS_SYSPROTO_H_
struct swapoff_args {
char *name;
};
#endif
/*
* MPSAFE
*/
/* ARGSUSED */
int
In order to maximize the re-usability of kernel code in user space this patch modifies makesyscalls.sh to prefix all of the non-compatibility calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel entry points and all places in the code that use them. It also fixes an additional name space collision between the kernel function psignal and the libc function of the same name by renaming the kernel psignal kern_psignal(). By introducing this change now we will ease future MFCs that change syscalls. Reviewed by: rwatson Approved by: re (bz)
2011-09-16 13:58:51 +00:00
sys_swapoff(struct thread *td, struct swapoff_args *uap)
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
{
struct vnode *vp;
struct nameidata nd;
struct swdevt *sp;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
int error;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
Sweep kernel replacing suser(9) calls with priv(9) calls, assigning specific privilege names to a broad range of privileges. These may require some future tweaking. Sponsored by: nCircle Network Security, Inc. Obtained from: TrustedBSD Project Discussed on: arch@ Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri, Alex Lyashkov <umka at sevcity dot net>, Skip Ford <skip dot ford at verizon dot net>, Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
error = priv_check(td, PRIV_SWAPOFF);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
if (error)
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
return (error);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_xlock(&swdev_syscall_lock);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
Audit pathnames looked up in swapon(2) and swapoff(2). MFC after: 2 weeks Obtained from: TrustedBSD Project
2007-04-23 14:41:34 +00:00
NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, UIO_USERSPACE, uap->name,
td);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
error = namei(&nd);
if (error)
goto done;
NDFREE(&nd, NDF_ONLY_PNBUF);
vp = nd.ni_vp;
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
TAILQ_FOREACH(sp, &swtailq, sw_list) {
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
if (sp->sw_vp == vp)
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
break;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
}
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_unlock(&sw_dev_mtx);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
if (sp == NULL) {
error = EINVAL;
goto done;
}
When MAC is enabled in the kernel, fix a panic triggered by a locking assertion hit in swapoff_one() when we un-mount a swap partition. We should be using curthread where we used thread0 before. This change also replaces the thread argument with a credential argument, as the MAC framework only requires the cred. It should be noted that this allows the machine to be rebooted without panicing with "cannot differ from curthread or NULL" when MAC is enabled. Submitted by: rwatson Reviewed by: attilio MFC after: 2 weeks
2008-01-08 14:58:41 +00:00
error = swapoff_one(sp, td->td_ucred);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
done:
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_xunlock(&swdev_syscall_lock);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
return (error);
}
static int
When MAC is enabled in the kernel, fix a panic triggered by a locking assertion hit in swapoff_one() when we un-mount a swap partition. We should be using curthread where we used thread0 before. This change also replaces the thread argument with a credential argument, as the MAC framework only requires the cred. It should be noted that this allows the machine to be rebooted without panicing with "cannot differ from curthread or NULL" when MAC is enabled. Submitted by: rwatson Reviewed by: attilio MFC after: 2 weeks
2008-01-08 14:58:41 +00:00
swapoff_one(struct swdevt *sp, struct ucred *cred)
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
{
When the function blist_fill() was added to the kernel in r107913, the swap pager used a different scheme for striping the allocation of swap space across multiple devices. And, although blist_fill() was intended to support fill operations with large counts, the old striping scheme never performed a fill larger than the stripe size. Consequently, the misplacement of a sanity check in blst_meta_fill() went undetected. Now, moving forward in time to r118390, a new scheme for striping was introduced that maintained a blist allocator per device, but as noted in r318995, swapoff_one() was not fully and correctly converted to the new scheme. This change completes what was started in r318995 by fixing the underlying bug in blst_meta_fill() that stops swapoff_one() from simply performing a single blist_fill() operation. Reviewed by: kib MFC after: 5 days Differential Revision: https://reviews.freebsd.org/D11043
2017-06-06 03:32:17 +00:00
u_long nblks;
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
#ifdef MAC
int error;
#endif
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_assert(&swdev_syscall_lock, SA_XLOCKED);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#ifdef MAC
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
(void) vn_lock(sp->sw_vp, LK_EXCLUSIVE | LK_RETRY);
When MAC is enabled in the kernel, fix a panic triggered by a locking assertion hit in swapoff_one() when we un-mount a swap partition. We should be using curthread where we used thread0 before. This change also replaces the thread argument with a credential argument, as the MAC framework only requires the cred. It should be noted that this allows the machine to be rebooted without panicing with "cannot differ from curthread or NULL" when MAC is enabled. Submitted by: rwatson Reviewed by: attilio MFC after: 2 weeks
2008-01-08 14:58:41 +00:00
error = mac_system_check_swapoff(cred, sp->sw_vp);
vfs: drop the mostly unused flags argument from VOP_UNLOCK Filesystems which want to use it in limited capacity can employ the VOP_UNLOCK_FLAGS macro. Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D21427
2020-01-03 22:29:58 +00:00
(void) VOP_UNLOCK(sp->sw_vp);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
if (error != 0)
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
return (error);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
#endif
nblks = sp->sw_nblks;
/*
* We can turn off this swap device safely only if the
* available virtual memory in the system will fit the amount
* of data we will have to page back in, plus an epsilon so
* the system doesn't become critically low on swap space.
*/
Use per-domain locks for vm page queue free. Move paging control from global to per-domain state. Protect reservations with the free lock from the domain that they belong to. Refactor to make vm domains more of a first class object. Reviewed by: markj, kib, gallatin Tested by: pho Sponsored by: Netflix, Dell/EMC Isilon Differential Revision: https://reviews.freebsd.org/D14000
2018-02-06 22:10:07 +00:00
if (vm_free_count() + swap_pager_avail < nblks + nswap_lowat)
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
return (ENOMEM);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* Prevent further allocations on this device.
*/
- Synchronize access to the swdevt's sw_flags with sw_dev_mtx. - Remove several instances of GIANT_REQUIRED.
2003-10-31 05:18:45 +00:00
mtx_lock(&sw_dev_mtx);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
sp->sw_flags |= SW_CLOSING;
When the function blist_fill() was added to the kernel in r107913, the swap pager used a different scheme for striping the allocation of swap space across multiple devices. And, although blist_fill() was intended to support fill operations with large counts, the old striping scheme never performed a fill larger than the stripe size. Consequently, the misplacement of a sanity check in blst_meta_fill() went undetected. Now, moving forward in time to r118390, a new scheme for striping was introduced that maintained a blist allocator per device, but as noted in r318995, swapoff_one() was not fully and correctly converted to the new scheme. This change completes what was started in r318995 by fixing the underlying bug in blst_meta_fill() that stops swapoff_one() from simply performing a single blist_fill() operation. Reviewed by: kib MFC after: 5 days Differential Revision: https://reviews.freebsd.org/D11043
2017-06-06 03:32:17 +00:00
swap_pager_avail -= blist_fill(sp->sw_blist, 0, nblks);
eliminate locking surrounding ui_vmsize and swap reserve by using atomics Change swap_reserve and swap_total to be in units of pages so that swap reservations can be done using only atomics instead of using a single global mutex for swap_reserve and a single mutex for all processes running under the same uid for uid accounting. Results in mmap speed up and a 70% increase in brk calls / second. Reviewed by: alc@, markj@, kib@ Approved by: re (delphij@) Differential Revision: https://reviews.freebsd.org/D16273
2018-10-05 05:50:56 +00:00
swap_total -= nblks;
- Synchronize access to the swdevt's sw_flags with sw_dev_mtx. - Remove several instances of GIANT_REQUIRED.
2003-10-31 05:18:45 +00:00
mtx_unlock(&sw_dev_mtx);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
/*
* Page in the contents of the device and close it.
*/
Close a race in swapoff(). Here are the gory details: In order to avoid livelock, swapoff() skips over objects with a nonzero pip count and makes another pass if necessary. Since it is impossible to know which objects we care about, it would choose an arbitrary object with a nonzero pip count and wait for it before making another pass, the theory being that this object would finish paging about as quickly as the ones we care about. Unfortunately, we may have slept since we acquired a reference to this object. Hack around this problem by tsleep()ing on the pointer anyway, but timeout after a fixed interval. More elegant solutions are possible, but the ones I considered unnecessarily complicate this rare case. Also, kill some nits that seem to have crept into the swapoff() code in the last 75 revisions or so: - Don't pass both sp and sp->sw_used to swap_pager_swapoff(), since the latter can be derived from the former. - Replace swp_pager_find_dev() with something simpler. There's no need to iterate over the entire list of swap devices just to determine if a given block is assigned to the one we're interested in. - Expand the scope of the swhash_mtx in a couple of places so that it isn't released and reacquired once for every hash bucket. - Don't drop the swhash_mtx while holding a reference to an object. We need to lock the object first. Unfortunately, doing so would violate the established lock order, so use VM_OBJECT_TRYLOCK() and try again on a subsequent pass if the object is already locked. - Refactor swp_pager_force_pagein() and swap_pager_swapoff() a bit.
2004-11-05 05:36:56 +00:00
swap_pager_swapoff(sp);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
When MAC is enabled in the kernel, fix a panic triggered by a locking assertion hit in swapoff_one() when we un-mount a swap partition. We should be using curthread where we used thread0 before. This change also replaces the thread argument with a credential argument, as the MAC framework only requires the cred. It should be noted that this allows the machine to be rebooted without panicing with "cannot differ from curthread or NULL" when MAC is enabled. Submitted by: rwatson Reviewed by: attilio MFC after: 2 weeks
2008-01-08 14:58:41 +00:00
sp->sw_close(curthread, sp);
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
sp->sw_id = NULL;
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
TAILQ_REMOVE(&swtailq, sp, sw_list);
- Synchronize updates to nswapdev using sw_dev_mtx.
2003-10-29 07:51:41 +00:00
nswapdev--;
1. Statically initialize swap_pager_full and swap_pager_almost_full to the full state. (When swap is added their state will change appropriately.) 2. Set swap_pager_full and swap_pager_almost_full to the full state when the last swap device is removed. Combined these changes eliminate nonsense messages from the kernel on swap- less machines. Item 2 submitted by: Divacky Roman <xdivac02@stud.fit.vutbr.cz> Prodding by: phk
2004-01-24 21:31:06 +00:00
if (nswapdev == 0) {
swap_pager_full = 2;
swap_pager_almost_full = 1;
}
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
if (swdevhd == sp)
swdevhd = NULL;
- Synchronize access to swdevhd using sw_dev_mtx. - Use swp_sizecheck() rather than assignment to swap_pager_full in swaponsomething().
2003-10-30 07:11:06 +00:00
mtx_unlock(&sw_dev_mtx);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
blist_destroy(sp->sw_blist);
free(sp, M_VMPGDATA);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
return (0);
}
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
void
swapoff_all(void)
{
struct swdevt *sp, *spt;
const char *devname;
int error;
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_xlock(&swdev_syscall_lock);
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH_SAFE(sp, &swtailq, sw_list, spt) {
mtx_unlock(&sw_dev_mtx);
if (vn_isdisk(sp->sw_vp, NULL))
Remove direct access to si_name. Code should just use the devtoname() function to obtain the name of a character device. Also add const keywords to pieces of code that need it to build properly. MFC after: 2 weeks
2012-02-10 12:35:57 +00:00
devname = devtoname(sp->sw_vp->v_rdev);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
else
devname = "[file]";
When MAC is enabled in the kernel, fix a panic triggered by a locking assertion hit in swapoff_one() when we un-mount a swap partition. We should be using curthread where we used thread0 before. This change also replaces the thread argument with a credential argument, as the MAC framework only requires the cred. It should be noted that this allows the machine to be rebooted without panicing with "cannot differ from curthread or NULL" when MAC is enabled. Submitted by: rwatson Reviewed by: attilio MFC after: 2 weeks
2008-01-08 14:58:41 +00:00
error = swapoff_one(sp, thread0.td_ucred);
On shutdown try to turn off all swap devices. This way GEOM providers are properly closed on shutdown. Requested by: ru Reviewed by: alc MFC after: 2 weeks
2006-04-10 10:03:41 +00:00
if (error != 0) {
printf("Cannot remove swap device %s (error=%d), "
"skipping.\n", devname, error);
} else if (bootverbose) {
printf("Swap device %s removed.\n", devname);
}
mtx_lock(&sw_dev_mtx);
}
mtx_unlock(&sw_dev_mtx);
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
Replace hand-made exclusive lock, protecting against parallel swapon/swapoff invocations, with sx. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:25:01 +00:00
sx_xunlock(&swdev_syscall_lock);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
}
Add a new function swap_pager_status() which reports the total size of the paging space and how much of it is in use (in pages). Use this interface from the Linuxolator instead of groping around in the internals of the swap_pager.
2003-07-18 10:26:09 +00:00
void
swap_pager_status(int *total, int *used)
{
struct swdevt *sp;
*total = 0;
*used = 0;
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
TAILQ_FOREACH(sp, &swtailq, sw_list) {
Add a new function swap_pager_status() which reports the total size of the paging space and how much of it is in use (in pages). Use this interface from the Linuxolator instead of groping around in the internals of the swap_pager.
2003-07-18 10:26:09 +00:00
*total += sp->sw_nblks;
*used += sp->sw_used;
}
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_unlock(&sw_dev_mtx);
Add a new function swap_pager_status() which reports the total size of the paging space and how much of it is in use (in pages). Use this interface from the Linuxolator instead of groping around in the internals of the swap_pager.
2003-07-18 10:26:09 +00:00
}
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
int
swap_dev_info(int name, struct xswdev *xs, char *devname, size_t len)
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
{
struct swdevt *sp;
Remove direct access to si_name. Code should just use the devtoname() function to obtain the name of a character device. Also add const keywords to pieces of code that need it to build properly. MFC after: 2 weeks
2012-02-10 12:35:57 +00:00
const char *tmp_devname;
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
int error, n;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
n = 0;
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
error = ENOENT;
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_lock(&sw_dev_mtx);
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
TAILQ_FOREACH(sp, &swtailq, sw_list) {
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
if (n != name) {
n++;
continue;
}
xs->xsw_version = XSWDEV_VERSION;
xs->xsw_dev = sp->sw_dev;
xs->xsw_flags = sp->sw_flags;
xs->xsw_nblks = sp->sw_nblks;
xs->xsw_used = sp->sw_used;
if (devname != NULL) {
if (vn_isdisk(sp->sw_vp, NULL))
Remove direct access to si_name. Code should just use the devtoname() function to obtain the name of a character device. Also add const keywords to pieces of code that need it to build properly. MFC after: 2 weeks
2012-02-10 12:35:57 +00:00
tmp_devname = devtoname(sp->sw_vp->v_rdev);
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
else
tmp_devname = "[file]";
strncpy(devname, tmp_devname, len);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
}
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
error = 0;
break;
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
}
Protect the swapdevice tailq with a mutex. Store the udev_t we will report to userland in the swdevt.
2003-08-30 16:10:28 +00:00
mtx_unlock(&sw_dev_mtx);
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
return (error);
}
Commit the 64-bit inode project. Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify struct dirent layout to add d_off, increase the size of d_fileno to 64-bits, increase the size of d_namlen to 16-bits, and change the required alignment. Increase struct statfs f_mntfromname[] and f_mntonname[] array length MNAMELEN to 1024. ABI breakage is mitigated by providing compatibility using versioned symbols, ingenious use of the existing padding in structures, and by employing other tricks. Unfortunately, not everything can be fixed, especially outside the base system. For instance, third-party APIs which pass struct stat around are broken in backward and forward incompatible ways. Kinfo sysctl MIBs ABI is changed in backward-compatible way, but there is no general mechanism to handle other sysctl MIBS which return structures where the layout has changed. It was considered that the breakage is either in the management interfaces, where we usually allow ABI slip, or is not important. Struct xvnode changed layout, no compat shims are provided. For struct xtty, dev_t tty device member was reduced to uint32_t. It was decided that keeping ABI compat in this case is more useful than reporting 64-bit dev_t, for the sake of pstat. Update note: strictly follow the instructions in UPDATING. Build and install the new kernel with COMPAT_FREEBSD11 option enabled, then reboot, and only then install new world. Credits: The 64-bit inode project, also known as ino64, started life many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick (mckusick) then picked up and updated the patch, and acted as a flag-waver. Feedback, suggestions, and discussions were carried by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles), and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial ports investigation followed by an exp-run by Antoine Brodin (antoine). Essential and all-embracing testing was done by Peter Holm (pho). The heavy lifting of coordinating all these efforts and bringing the project to completion were done by Konstantin Belousov (kib). Sponsored by: The FreeBSD Foundation (emaste, kib) Differential revision: https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
#if defined(COMPAT_FREEBSD11)
#define XSWDEV_VERSION_11 1
struct xswdev11 {
u_int xsw_version;
uint32_t xsw_dev;
int xsw_flags;
int xsw_nblks;
int xsw_used;
};
#endif
struct xswdev on amd64 requires compat32 shims after ino64. i386 is the only architecture where uint64_t does not specify 8-bytes alignment, which makes struct xswdev layout not compatible between 64bit and i386. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2019-02-10 19:01:05 +00:00
#if defined(__amd64__) && defined(COMPAT_FREEBSD32)
struct xswdev32 {
u_int xsw_version;
u_int xsw_dev1, xsw_dev2;
int xsw_flags;
int xsw_nblks;
int xsw_used;
};
#endif
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
static int
sysctl_vm_swap_info(SYSCTL_HANDLER_ARGS)
{
struct xswdev xs;
struct xswdev on amd64 requires compat32 shims after ino64. i386 is the only architecture where uint64_t does not specify 8-bytes alignment, which makes struct xswdev layout not compatible between 64bit and i386. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2019-02-10 19:01:05 +00:00
#if defined(__amd64__) && defined(COMPAT_FREEBSD32)
struct xswdev32 xs32;
#endif
Commit the 64-bit inode project. Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify struct dirent layout to add d_off, increase the size of d_fileno to 64-bits, increase the size of d_namlen to 16-bits, and change the required alignment. Increase struct statfs f_mntfromname[] and f_mntonname[] array length MNAMELEN to 1024. ABI breakage is mitigated by providing compatibility using versioned symbols, ingenious use of the existing padding in structures, and by employing other tricks. Unfortunately, not everything can be fixed, especially outside the base system. For instance, third-party APIs which pass struct stat around are broken in backward and forward incompatible ways. Kinfo sysctl MIBs ABI is changed in backward-compatible way, but there is no general mechanism to handle other sysctl MIBS which return structures where the layout has changed. It was considered that the breakage is either in the management interfaces, where we usually allow ABI slip, or is not important. Struct xvnode changed layout, no compat shims are provided. For struct xtty, dev_t tty device member was reduced to uint32_t. It was decided that keeping ABI compat in this case is more useful than reporting 64-bit dev_t, for the sake of pstat. Update note: strictly follow the instructions in UPDATING. Build and install the new kernel with COMPAT_FREEBSD11 option enabled, then reboot, and only then install new world. Credits: The 64-bit inode project, also known as ino64, started life many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick (mckusick) then picked up and updated the patch, and acted as a flag-waver. Feedback, suggestions, and discussions were carried by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles), and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial ports investigation followed by an exp-run by Antoine Brodin (antoine). Essential and all-embracing testing was done by Peter Holm (pho). The heavy lifting of coordinating all these efforts and bringing the project to completion were done by Konstantin Belousov (kib). Sponsored by: The FreeBSD Foundation (emaste, kib) Differential revision: https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
#if defined(COMPAT_FREEBSD11)
struct xswdev11 xs11;
#endif
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
int error;
if (arg2 != 1) /* name length */
return (EINVAL);
error = swap_dev_info(*(int *)arg1, &xs, NULL, 0);
if (error != 0)
return (error);
struct xswdev on amd64 requires compat32 shims after ino64. i386 is the only architecture where uint64_t does not specify 8-bytes alignment, which makes struct xswdev layout not compatible between 64bit and i386. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2019-02-10 19:01:05 +00:00
#if defined(__amd64__) && defined(COMPAT_FREEBSD32)
if (req->oldlen == sizeof(xs32)) {
xs32.xsw_version = XSWDEV_VERSION;
xs32.xsw_dev1 = xs.xsw_dev;
xs32.xsw_dev2 = xs.xsw_dev >> 32;
xs32.xsw_flags = xs.xsw_flags;
xs32.xsw_nblks = xs.xsw_nblks;
xs32.xsw_used = xs.xsw_used;
error = SYSCTL_OUT(req, &xs32, sizeof(xs32));
return (error);
}
#endif
Commit the 64-bit inode project. Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify struct dirent layout to add d_off, increase the size of d_fileno to 64-bits, increase the size of d_namlen to 16-bits, and change the required alignment. Increase struct statfs f_mntfromname[] and f_mntonname[] array length MNAMELEN to 1024. ABI breakage is mitigated by providing compatibility using versioned symbols, ingenious use of the existing padding in structures, and by employing other tricks. Unfortunately, not everything can be fixed, especially outside the base system. For instance, third-party APIs which pass struct stat around are broken in backward and forward incompatible ways. Kinfo sysctl MIBs ABI is changed in backward-compatible way, but there is no general mechanism to handle other sysctl MIBS which return structures where the layout has changed. It was considered that the breakage is either in the management interfaces, where we usually allow ABI slip, or is not important. Struct xvnode changed layout, no compat shims are provided. For struct xtty, dev_t tty device member was reduced to uint32_t. It was decided that keeping ABI compat in this case is more useful than reporting 64-bit dev_t, for the sake of pstat. Update note: strictly follow the instructions in UPDATING. Build and install the new kernel with COMPAT_FREEBSD11 option enabled, then reboot, and only then install new world. Credits: The 64-bit inode project, also known as ino64, started life many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick (mckusick) then picked up and updated the patch, and acted as a flag-waver. Feedback, suggestions, and discussions were carried by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles), and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial ports investigation followed by an exp-run by Antoine Brodin (antoine). Essential and all-embracing testing was done by Peter Holm (pho). The heavy lifting of coordinating all these efforts and bringing the project to completion were done by Konstantin Belousov (kib). Sponsored by: The FreeBSD Foundation (emaste, kib) Differential revision: https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
#if defined(COMPAT_FREEBSD11)
if (req->oldlen == sizeof(xs11)) {
xs11.xsw_version = XSWDEV_VERSION_11;
xs11.xsw_dev = xs.xsw_dev; /* truncation */
xs11.xsw_flags = xs.xsw_flags;
xs11.xsw_nblks = xs.xsw_nblks;
xs11.xsw_used = xs.xsw_used;
error = SYSCTL_OUT(req, &xs11, sizeof(xs11));
struct xswdev on amd64 requires compat32 shims after ino64. i386 is the only architecture where uint64_t does not specify 8-bytes alignment, which makes struct xswdev layout not compatible between 64bit and i386. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2019-02-10 19:01:05 +00:00
return (error);
}
Commit the 64-bit inode project. Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify struct dirent layout to add d_off, increase the size of d_fileno to 64-bits, increase the size of d_namlen to 16-bits, and change the required alignment. Increase struct statfs f_mntfromname[] and f_mntonname[] array length MNAMELEN to 1024. ABI breakage is mitigated by providing compatibility using versioned symbols, ingenious use of the existing padding in structures, and by employing other tricks. Unfortunately, not everything can be fixed, especially outside the base system. For instance, third-party APIs which pass struct stat around are broken in backward and forward incompatible ways. Kinfo sysctl MIBs ABI is changed in backward-compatible way, but there is no general mechanism to handle other sysctl MIBS which return structures where the layout has changed. It was considered that the breakage is either in the management interfaces, where we usually allow ABI slip, or is not important. Struct xvnode changed layout, no compat shims are provided. For struct xtty, dev_t tty device member was reduced to uint32_t. It was decided that keeping ABI compat in this case is more useful than reporting 64-bit dev_t, for the sake of pstat. Update note: strictly follow the instructions in UPDATING. Build and install the new kernel with COMPAT_FREEBSD11 option enabled, then reboot, and only then install new world. Credits: The 64-bit inode project, also known as ino64, started life many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick (mckusick) then picked up and updated the patch, and acted as a flag-waver. Feedback, suggestions, and discussions were carried by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles), and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial ports investigation followed by an exp-run by Antoine Brodin (antoine). Essential and all-embracing testing was done by Peter Holm (pho). The heavy lifting of coordinating all these efforts and bringing the project to completion were done by Konstantin Belousov (kib). Sponsored by: The FreeBSD Foundation (emaste, kib) Differential revision: https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
#endif
struct xswdev on amd64 requires compat32 shims after ino64. i386 is the only architecture where uint64_t does not specify 8-bytes alignment, which makes struct xswdev layout not compatible between 64bit and i386. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week
2019-02-10 19:01:05 +00:00
error = SYSCTL_OUT(req, &xs, sizeof(xs));
Implement the linprocfs swaps file, providing information about the configured swap devices in the Linux-compatible format. Based on the submission by: Robert Millan <rmh debian org> PR: kern/159281 Reviewed by: bde Approved by: re (kensmith) MFC after: 2 weeks
2011-08-01 19:12:15 +00:00
return (error);
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
}
Change the layout policy of the swap_pager from a hardcoded width striping to a per device round-robin algorithm. Because of the policy of not attempting to retain previous swap allocation on page-out, this means that a newly added swap device almost instantly takes its 1/N share of the I/O load but it takes somewhat longer for it to assume it's 1/N share of the pages if there is plenty of space on the other devices. Change the 8G total swapspace limitation to 8G per device instead by using a per device blist rather than one global blist. This reduces the memory footprint by 75% (typically a couple hundred kilobytes) for the common case with one swapdevice but NSWAPDEV=4. Remove the compile time constant limit of number of swap devices, there is no limit now. Instead of a fixed size array, store the per swapdev structure in a TAILQ. Total swap space is still addressed by a 32 bit page number and therefore the upper limit is now 2^42 bytes = 16TB (for i386). We still do not allocate the first page of each device in order to give some amount of protection to any bsdlabel at the start of the device. A new device is appended after the existing devices in the swap space, no attempt is made to fill in holes left behind by swapoff (this can trivially be changed should it ever become a problem). The sysctl vm.nswapdev now reflects the number of currently configured swap devices. Rename vm_swap_size to swap_pager_avail for consistency with other exported names. Change argument type for vm_proc_swapin_all() and swap_pager_isswapped() to be a struct swdevt pointer rather than an index. Not changed: we are still using blists to manage the free space, but since the swapspace is no longer fragmented by the striping different resource managers might fare better.
2003-08-03 13:35:31 +00:00
SYSCTL_INT(_vm, OID_AUTO, nswapdev, CTLFLAG_RD, &nswapdev, 0,
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
"Number of swap devices");
Mark swap-related proc sysctls as not requiring Giant. Reviewed by: alc (as part of larger patch) Sponsored by: The FreeBSD Foundation
2016-05-22 23:28:23 +00:00
SYSCTL_NODE(_vm, OID_AUTO, swap_info, CTLFLAG_RD | CTLFLAG_MPSAFE,
sysctl_vm_swap_info,
Merge swap_pager.c and vm_swap.c into swap_pager.c, the separation is not natural and needlessly exposes a lot of dirty laundry. Move private interfaces between the two from swap_pager.h to swap_pager.c and staticize as much as possible. No functional change.
2003-07-18 10:02:44 +00:00
"Swap statistics by device");
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
/*
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
* Count the approximate swap usage in pages for a vmspace. The
* shadowed or not yet copied on write swap blocks are not accounted.
* The map must be locked.
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
*/
Change the return type of vmspace_swap_count to a long to match the other vmspace_*_count functions. MFC after: 3 days
2011-03-01 11:04:30 +00:00
long
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
vmspace_swap_count(struct vmspace *vmspace)
{
Calculate and return the count in vmspace_swap_count as a vm_offset_t instead of an int to avoid overflow. While here, clean up some style(9) issues. PR: kern/152200 Reviewed by: kib MFC after: 2 weeks
2011-02-23 10:28:37 +00:00
vm_map_t map;
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
vm_map_entry_t cur;
Calculate and return the count in vmspace_swap_count as a vm_offset_t instead of an int to avoid overflow. While here, clean up some style(9) issues. PR: kern/152200 Reviewed by: kib MFC after: 2 weeks
2011-02-23 10:28:37 +00:00
vm_object_t object;
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
struct swblk *sb;
vm_pindex_t e, pi;
long count;
int i;
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
Calculate and return the count in vmspace_swap_count as a vm_offset_t instead of an int to avoid overflow. While here, clean up some style(9) issues. PR: kern/152200 Reviewed by: kib MFC after: 2 weeks
2011-02-23 10:28:37 +00:00
map = &vmspace->vm_map;
count = 0;
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
Define macro VM_MAP_ENTRY_FOREACH for enumerating the entries in a vm_map. In case the implementation ever changes from using a chain of next pointers, then changing the macro definition will be necessary, but changing all the files that iterate over vm_map entries will not. Drop a counter in vm_object.c that would have an effect only if the vm_map entry count was wrong. Discussed with: alc Reviewed by: markj Tested by: pho (earlier version) Differential Revision: https://reviews.freebsd.org/D21882
2019-10-08 07:14:21 +00:00
VM_MAP_ENTRY_FOREACH(cur, map) {
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
if ((cur->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
continue;
object = cur->object.vm_object;
if (object == NULL || object->type != OBJT_SWAP)
continue;
VM_OBJECT_RLOCK(object);
if (object->type != OBJT_SWAP)
goto unlock;
pi = OFF_TO_IDX(cur->offset);
e = pi + OFF_TO_IDX(cur->end - cur->start);
for (;; pi = sb->p + SWAP_META_PAGES) {
sb = SWAP_PCTRIE_LOOKUP_GE(
&object->un_pager.swp.swp_blks, pi);
if (sb == NULL || sb->p >= e)
break;
for (i = 0; i < SWAP_META_PAGES; i++) {
if (sb->p + i < e &&
sb->d[i] != SWAPBLK_NONE)
count++;
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
}
}
Replace global swhash in swap pager with per-object trie to track swap blocks assigned to the object pages. - The global swhash_mtx is removed, trie is synchronized by the corresponding object lock. - The swp_pager_meta_free_all() function used during object termination is optimized by only looking at the trie instead of having to search whole hash for the swap blocks owned by the object. - On swap_pager_swapoff(), instead of iterating over the swhash, global object list have to be inspected. There, we have to ensure that we do see valid trie content if we see that the object type is swap. Sizing of the swblk zone is same as for swblock zone, each swblk maps SWAP_META_PAGES pages. Proposed by: alc Reviewed by: alc, markj (previous version) Tested by: alc, pho (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D11435
2017-08-25 23:13:21 +00:00
unlock:
VM_OBJECT_RUNLOCK(object);
Move the implementation of the vmspace_swap_count() (used only in the "toss the largest process" emergency handling) from vm_map.c to swap_pager.c. The quantity calculated depends strongly on the internals of the swap_pager and by moving it, we no longer need to expose the internal metrics of the swap_pager to the world.
2003-07-18 10:47:58 +00:00
}
return (count);
}
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
/*
* GEOM backend
*
* Swapping onto disk devices.
*
*/
Tag all geom classes in the tree with a version number.
2004-08-08 07:57:53 +00:00
static g_orphan_t swapgeom_orphan;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
static struct g_class g_swap_class = {
.name = "SWAP",
Tag all geom classes in the tree with a version number.
2004-08-08 07:57:53 +00:00
.version = G_VERSION,
.orphan = swapgeom_orphan,
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
};
DECLARE_GEOM_CLASS(g_swap_class, g_class);
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
static void
swapgeom_close_ev(void *arg, int flags)
{
struct g_consumer *cp;
cp = arg;
g_access(cp, -1, -1, 0);
g_detach(cp);
g_destroy_consumer(cp);
}
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
/*
* Add a reference to the g_consumer for an inflight transaction.
*/
static void
swapgeom_acquire(struct g_consumer *cp)
{
mtx_assert(&sw_dev_mtx, MA_OWNED);
cp->index++;
}
/*
Explain why swapgeom_close_ev() is delegated. Sponsored by: The FreeBSD Foundation MFC after: 1 week
2016-08-03 07:11:19 +00:00
* Remove a reference from the g_consumer. Post a close event if all
* references go away, since the function might be called from the
* biodone context.
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
*/
static void
swapgeom_release(struct g_consumer *cp, struct swdevt *sp)
{
mtx_assert(&sw_dev_mtx, MA_OWNED);
cp->index--;
if (cp->index == 0) {
if (g_post_event(swapgeom_close_ev, cp, M_NOWAIT, NULL) == 0)
sp->sw_id = NULL;
}
}
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
static void
swapgeom_done(struct bio *bp2)
{
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
struct swdevt *sp;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
struct buf *bp;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
struct g_consumer *cp;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bp = bp2->bio_caller2;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
cp = bp2->bio_from;
De-couple our I/O bio request from the embedded bio in buf by explicitly copying the fields.
2004-11-04 08:38:07 +00:00
bp->b_ioflags = bp2->bio_flags;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
if (bp2->bio_error)
bp->b_ioflags |= BIO_ERROR;
De-couple our I/O bio request from the embedded bio in buf by explicitly copying the fields.
2004-11-04 08:38:07 +00:00
bp->b_resid = bp->b_bcount - bp2->bio_completed;
bp->b_error = bp2->bio_error;
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
bp->b_caller1 = NULL;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bufdone(bp);
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
sp = bp2->bio_caller1;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
mtx_lock(&sw_dev_mtx);
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
swapgeom_release(cp, sp);
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
mtx_unlock(&sw_dev_mtx);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
g_destroy_bio(bp2);
}
static void
swapgeom_strategy(struct buf *bp, struct swdevt *sp)
{
struct bio *bio;
struct g_consumer *cp;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
mtx_lock(&sw_dev_mtx);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
cp = sp->sw_id;
if (cp == NULL) {
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
mtx_unlock(&sw_dev_mtx);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bp->b_error = ENXIO;
bp->b_ioflags |= BIO_ERROR;
bufdone(bp);
return;
}
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
swapgeom_acquire(cp);
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
mtx_unlock(&sw_dev_mtx);
Use the VM_ALLOC_INTERRUPT for the page requests when allocating memory for the bio for swapout write. It allows the page allocator to drain free page list deeper. As result, a deadlock where pageout deamon sleeps waiting for bio to be allocated for swapout is no more reproducable in practice. Alan said that M_USE_RESERVE shall be ressurrected and used there, but until this is implemented, M_NOWAIT does exactly what is needed. Tested by: pho, kris Reviewed by: alc No objections from: phk MFC after: 2 weeks (RELENG_7 only)
2008-07-11 11:27:42 +00:00
if (bp->b_iocmd == BIO_WRITE)
bio = g_new_bio();
else
bio = g_alloc_bio();
Check error return from g_clone_bio(). (netchild@) Add XXX comment about why this is still not optimal. (phk@) Submitted by: netchild@
2004-02-02 13:08:03 +00:00
if (bio == NULL) {
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
mtx_lock(&sw_dev_mtx);
swapgeom_release(cp, sp);
mtx_unlock(&sw_dev_mtx);
Check error return from g_clone_bio(). (netchild@) Add XXX comment about why this is still not optimal. (phk@) Submitted by: netchild@
2004-02-02 13:08:03 +00:00
bp->b_error = ENOMEM;
bp->b_ioflags |= BIO_ERROR;
Improve error reporting when the swap pager runs out of memory. Reviewed by: kib MFC after: 2 weeks Sponsored by: Klara Inc. Differential Revision: https://reviews.freebsd.org/D19699
2019-03-26 19:11:15 +00:00
printf("swap_pager: cannot allocate bio\n");
Check error return from g_clone_bio(). (netchild@) Add XXX comment about why this is still not optimal. (phk@) Submitted by: netchild@
2004-02-02 13:08:03 +00:00
bufdone(bp);
return;
}
Use the VM_ALLOC_INTERRUPT for the page requests when allocating memory for the bio for swapout write. It allows the page allocator to drain free page list deeper. As result, a deadlock where pageout deamon sleeps waiting for bio to be allocated for swapout is no more reproducable in practice. Alan said that M_USE_RESERVE shall be ressurrected and used there, but until this is implemented, M_NOWAIT does exactly what is needed. Tested by: pho, kris Reviewed by: alc No objections from: phk MFC after: 2 weeks (RELENG_7 only)
2008-07-11 11:27:42 +00:00
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
bp->b_caller1 = bio;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
bio->bio_caller1 = sp;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bio->bio_caller2 = bp;
De-couple our I/O bio request from the embedded bio in buf by explicitly copying the fields.
2004-11-04 08:38:07 +00:00
bio->bio_cmd = bp->b_iocmd;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bio->bio_offset = (bp->b_blkno - sp->sw_first) * PAGE_SIZE;
bio->bio_length = bp->b_bcount;
bio->bio_done = swapgeom_done;
Refactor unmapped buffer address handling. - Use pointer assignment rather than a combination of pointers and flags to switch buffers between unmapped and mapped. This eliminates multiple flags and generally simplifies the logic. - Eliminate b_saveaddr since it is only used with pager bufs which have their b_data re-initialized on each allocation. - Gather up some convenience routines in the buffer cache for manipulating buf space and buf malloc space. - Add an inline, buf_mapped(), to standardize checks around unmapped buffers. In collaboration with: mlaier Reviewed by: kib Tested by: pho (many small revisions ago) Sponsored by: EMC / Isilon Storage Division
2015-07-23 19:13:41 +00:00
if (!buf_mapped(bp)) {
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
bio->bio_ma = bp->b_pages;
bio->bio_data = unmapped_buf;
bio->bio_ma_offset = (vm_offset_t)bp->b_offset & PAGE_MASK;
bio->bio_ma_n = bp->b_npages;
bio->bio_flags |= BIO_UNMAPPED;
} else {
bio->bio_data = bp->b_data;
bio->bio_ma = NULL;
}
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
g_io_request(bio, cp);
return;
}
static void
swapgeom_orphan(struct g_consumer *cp)
{
struct swdevt *sp;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
int destroy;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
mtx_lock(&sw_dev_mtx);
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (sp->sw_id == cp) {
Fix NULL dereference panic on attempt to turn off (on system shutdown) disconnected swap device. This is quick and imperfect solution, as swap device will still be opened and GEOM will not be able to destroy it. Proper solution would be to automatically turn off and close disconnected swap device, but with existing code it will cause panic if there is at least one page on device, even if it is unimportant page of the user-level process. It needs some work. Reviewed by: kib@ MFC after: 1 week
2012-02-01 20:12:44 +00:00
sp->sw_flags |= SW_CLOSING;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
break;
}
}
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
/*
* Drop reference we were created with. Do directly since we're in a
* special context where we don't have to queue the call to
* swapgeom_close_ev().
*/
cp->index--;
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
destroy = ((sp != NULL) && (cp->index == 0));
if (destroy)
sp->sw_id = NULL;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
mtx_unlock(&sw_dev_mtx);
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
if (destroy)
swapgeom_close_ev(cp, 0);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
}
static void
swapgeom_close(struct thread *td, struct swdevt *sw)
{
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
struct g_consumer *cp;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
mtx_lock(&sw_dev_mtx);
cp = sw->sw_id;
sw->sw_id = NULL;
mtx_unlock(&sw_dev_mtx);
Explain why swapgeom_close_ev() is delegated. Sponsored by: The FreeBSD Foundation MFC after: 1 week
2016-08-03 07:11:19 +00:00
/*
* swapgeom_close() may be called from the biodone context,
* where we cannot perform topology changes. Delegate the
* work to the events thread.
*/
Make swapper release orphaned (lost) GEOM provider. Swap device is still reported as enabled, and system still may crash later if some swapped-out kernel pages were lost with the device, but at least GEOM and CAM can now release the lost disk, allowing it to be reconnected. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2015-03-26 17:21:12 +00:00
if (cp != NULL)
g_waitfor_event(swapgeom_close_ev, cp, M_WAITOK, NULL);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
}
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
static int
swapongeom_locked(struct cdev *dev, struct vnode *vp)
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
{
struct g_provider *pp;
struct g_consumer *cp;
static struct g_geom *gp;
struct swdevt *sp;
u_long nblks;
int error;
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
pp = g_dev_getprovider(dev);
if (pp == NULL)
return (ENODEV);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
cp = sp->sw_id;
if (cp != NULL && cp->provider == pp) {
mtx_unlock(&sw_dev_mtx);
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
return (EBUSY);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
}
}
mtx_unlock(&sw_dev_mtx);
Tag all geom classes in the tree with a version number.
2004-08-08 07:57:53 +00:00
if (gp == NULL)
- Don't pass geom and provider names as format strings. - Add __printflike() attributes. - Remove an extra argument for the g_new_geomf() call in swapongeom_ev(). Reviewed by: pjd
2012-11-20 12:32:18 +00:00
gp = g_new_geomf(&g_swap_class, "swap");
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
cp = g_new_consumer(gp);
Fix style and typo. Sponsored by: The FreeBSD Foundation MFC after: 1 week
2016-07-28 15:49:51 +00:00
cp->index = 1; /* Number of active I/Os, plus one for being active. */
The swap pager is compatible with direct dispatch. It does its own locking and doesn't sleep. Flag the consumer we create as such. In addition, decrement the in flight index when we have an out of memory error after having incremented it previously. This would have prevented swapoff from working if the swap pager ever hit a resource shortage trying to swap out something (the swap in path always waits for a bio, so won't have this issue). Simplify the close logic by abandoning the use of private and initializing the index to 1 and dropping that reference when we previously set private. Also, set sw_id only while sw_dev_mtx is held. This should only affect swapping to a vnode, as opposed to a geom whose close always sets it to NULL with sw_dev_mtx held. Differential Review: https://reviews.freebsd.org/D3547
2015-09-08 17:47:56 +00:00
cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
g_attach(cp, pp);
Don't open with exclusive bit, swapon(8) wants to trash our swapdev. Add XXX comment with a rating of this concept.
2003-09-02 05:53:44 +00:00
/*
sys/vm: minor spelling fixes in comments. No functional change.
2016-05-02 20:16:29 +00:00
* XXX: Every time you think you can improve the margin for
Don't open with exclusive bit, swapon(8) wants to trash our swapdev. Add XXX comment with a rating of this concept.
2003-09-02 05:53:44 +00:00
* footshooting, somebody depends on the ability to do so:
* savecore(8) wants to write to our swapdev so we cannot
* set an exclusive count :-(
*/
Remove the absolute count g_access_abs() function since experience has shown that it is not useful. Rename the relative count g_access_rel() function to g_access(), only the name has changed. Change all g_access_rel() calls in our CVS tree to call g_access() instead. Add an #ifndef BURN_BRIDGES #define of g_access_rel() for source code compatibility.
2004-02-12 22:42:11 +00:00
error = g_access(cp, 1, 1, 0);
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
if (error != 0) {
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
g_detach(cp);
g_destroy_consumer(cp);
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
return (error);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
}
nblks = pp->mediasize / DEV_BSIZE;
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
swaponsomething(vp, cp, nblks, swapgeom_strategy,
swapgeom_close, dev2udev(dev),
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
(pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 ? SW_UNMAPPED : 0);
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
return (0);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
}
static int
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
swapongeom(struct vnode *vp)
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
{
int error;
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
vfs: introduce v_irflag and make v_type smaller The current vnode layout is not smp-friendly by having frequently read data avoidably sharing cachelines with very frequently modified fields. In particular v_iflag inspected for VI_DOOMED can be found in the same line with v_usecount. Instead make it available in the same cacheline as the v_op, v_data and v_type which all get read all the time. v_type is avoidably 4 bytes while the necessary data will easily fit in 1. Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new flag field with a new value: VIRF_DOOMED. Reviewed by: kib, jeff Differential Revision: https://reviews.freebsd.org/D22715
2019-12-08 21:30:04 +00:00
if (vp->v_type != VCHR || VN_IS_DOOMED(vp)) {
Do not delegate a work to geom event thread which can be done inline. In particular, swapongeom_ev() needed event thread context when swap pager configuration was performed under Giant and geom asserted that Giant is not owned. Now both of the reason went away. On the other hand, note that swpageom_release() is called from the bio_done context, and possible close cannot be performed inline. Also fix some minor issues. The swapgeom() function does not use the td argument, remove it. Recheck that the vnode passed is still VCHR and not reclaimed after the lock. Reviewed by: mav Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
2016-07-28 15:57:01 +00:00
error = ENOENT;
} else {
g_topology_lock();
error = swapongeom_locked(vp->v_rdev, vp);
g_topology_unlock();
}
vfs: drop the mostly unused flags argument from VOP_UNLOCK Filesystems which want to use it in limited capacity can employ the VOP_UNLOCK_FLAGS macro. Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D21427
2020-01-03 22:29:58 +00:00
VOP_UNLOCK(vp);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
return (error);
}
/*
* VNODE backend
*
* This is used mainly for network filesystem (read: probably only tested
* with NFS) swapfiles.
*
*/
static void
swapdev_strategy(struct buf *bp, struct swdevt *sp)
{
Add b_bufobj to struct buf which eventually will eliminate the need for b_vp. Initialize b_bufobj for all buffers. Make incore() and gbincore() take a bufobj instead of a vnode. Make inmem() local to vfs_bio.c Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj) also VI_MTX() to BO_MTX(), Make buf_vlist_add() take a bufobj instead of a vnode. Eliminate other uses of bp->b_vp where bp->b_bufobj will do. Various minor polishing: remove "register", turn panic into KASSERT, use new function declarations, TAILQ_FOREACH_SAFE() etc.
2004-10-22 08:47:20 +00:00
struct vnode *vp2;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bp->b_blkno = ctodb(bp->b_blkno - sp->sw_first);
vp2 = sp->sw_id;
vhold(vp2);
if (bp->b_iocmd == BIO_WRITE) {
Make sure we have a bufobj before calling bstrategy(). I'm not sure this is the right thing to do, but at least I don't panic anymore when swapping on a NFS file without using md(4). X-MFC after: proper review
2005-09-21 15:01:09 +00:00
if (bp->b_bufobj)
Add b_bufobj to struct buf which eventually will eliminate the need for b_vp. Initialize b_bufobj for all buffers. Make incore() and gbincore() take a bufobj instead of a vnode. Make inmem() local to vfs_bio.c Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj) also VI_MTX() to BO_MTX(), Make buf_vlist_add() take a bufobj instead of a vnode. Eliminate other uses of bp->b_vp where bp->b_bufobj will do. Various minor polishing: remove "register", turn panic into KASSERT, use new function declarations, TAILQ_FOREACH_SAFE() etc.
2004-10-22 08:47:20 +00:00
bufobj_wdrop(bp->b_bufobj);
Move the VI_BWAIT flag into no bo_flag element of bufobj and call it BO_WWAIT Add bufobj_wref(), bufobj_wdrop() and bufobj_wwait() to handle the write count on a bufobj. Bufobj_wdrop() replaces vwakeup(). Use these functions all relevant places except in ffs_softdep.c where the use if interlocked_sleep() makes this impossible. Rename b_vnbufs to b_bobufs now that we touch all the relevant files anyway.
2004-10-21 15:53:54 +00:00
bufobj_wref(&vp2->v_bufobj);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
}
Make sure we have a bufobj before calling bstrategy(). I'm not sure this is the right thing to do, but at least I don't panic anymore when swapping on a NFS file without using md(4). X-MFC after: proper review
2005-09-21 15:01:09 +00:00
if (bp->b_bufobj != &vp2->v_bufobj)
bp->b_bufobj = &vp2->v_bufobj;
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
bp->b_vp = vp2;
DuH! bp->b_iooffset (the spot on the disk), not bp->b_offset (the offset in the file)
2003-10-18 14:10:28 +00:00
bp->b_iooffset = dbtob(bp->b_blkno);
Move the buffer method vector (buf->b_op) to the bufobj. Extend it with a strategy method. Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY song and dance. Rename ibwrite to bufwrite(). Move the two NFS buf_ops to more sensible places, add bufstrategy to them. Add inlines for bwrite() and bstrategy() which calls through buf->b_bufobj->b_ops->b_{write,strategy}(). Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().
2004-10-24 20:03:41 +00:00
bstrategy(bp);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
return;
}
static void
swapdev_close(struct thread *td, struct swdevt *sp)
{
VOP_CLOSE(sp->sw_vp, FREAD | FWRITE, td->td_ucred, td);
vrele(sp->sw_vp);
}
static int
swaponvp(struct thread *td, struct vnode *vp, u_long nblks)
{
struct swdevt *sp;
int error;
if (nblks == 0)
return (ENXIO);
mtx_lock(&sw_dev_mtx);
TAILQ_FOREACH(sp, &swtailq, sw_list) {
if (sp->sw_id == vp) {
mtx_unlock(&sw_dev_mtx);
return (EBUSY);
}
}
mtx_unlock(&sw_dev_mtx);
Whitespace cleanup.
2012-09-05 12:24:50 +00:00
vn_lock() is currently only used with the 'curthread' passed as argument. Remove this argument and pass curthread directly to underlying VOP_LOCK1() VFS method. This modify makes the code cleaner and in particular remove an annoying dependence helping next lockmgr() cleanup. KPI results, obviously, changed. Manpage and FreeBSD_version will be updated through further commits. As a side note, would be valuable to say that next commits will address a similar cleanup about VFS methods, in particular vop_lock1 and vop_unlock. Tested by: Diego Sardina <siarodx at gmail dot com>, Andrea Di Pasquale <whyx dot it at gmail dot com>
2008-01-10 01:10:58 +00:00
(void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
#ifdef MAC
Merge first in a series of TrustedBSD MAC Framework KPI changes from Mac OS X Leopard--rationalize naming for entry points to the following general forms: mac_<object>_<method/action> mac_<object>_check_<method/action> The previous naming scheme was inconsistent and mostly reversed from the new scheme. Also, make object types more consistent and remove spaces from object types that contain multiple parts ("posix_sem" -> "posixsem") to make mechanical parsing easier. Introduce a new "netinet" object type for certain IPv4/IPv6-related methods. Also simplify, slightly, some entry point names. All MAC policy modules will need to be recompiled, and modules not updates as part of this commit will need to be modified to conform to the new KPI. Sponsored by: SPARTA (original patches against Mac OS X) Obtained from: TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
error = mac_system_check_swapon(td->td_ucred, vp);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
if (error == 0)
#endif
Revert UF_OPENING workaround for CURRENT. Change the VOP_OPEN(), vn_open() vnode operation and d_fdopen() cdev operation argument from being file descriptor index into the pointer to struct file. Proposed and reviewed by: jhb Reviewed by: daichi (unionfs) Approved by: re (kensmith)
2007-05-31 11:51:53 +00:00
error = VOP_OPEN(vp, FREAD | FWRITE, td->td_ucred, td, NULL);
vfs: drop the mostly unused flags argument from VOP_UNLOCK Filesystems which want to use it in limited capacity can employ the VOP_UNLOCK_FLAGS macro. Reviewed by: kib (previous version) Differential Revision: https://reviews.freebsd.org/D21427
2020-01-03 22:29:58 +00:00
(void) VOP_UNLOCK(vp);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
if (error)
return (error);
swaponsomething(vp, vp, nblks, swapdev_strategy, swapdev_close,
Do not map the swap i/o pbufs if the geom provider for the swap partition accepts unmapped requests. Sponsored by: The FreeBSD Foundation Tested by: pho
2013-03-19 14:39:27 +00:00
NODEV, 0);
Add a close() method to a swapdev. Add a GEOM based backend. Remove the device/VOP_SPECSTRATEGY() based backend.
2003-08-30 16:44:26 +00:00
return (0);
}
Instead of reading, validating and adjusting value of the vm.swap_async_max in the main swapper work cycle, do it in the sysctl handler. This removes extra mutex acquisition from the main cycle and makes the sysctl knob return error on an invalid value, instead of accepting and fixing it. Reviewed by: kib Sponsored by: Netflix Sponsored by: Nginx, Inc.
2015-05-02 20:27:37 +00:00
static int
sysctl_swap_async_max(SYSCTL_HANDLER_ARGS)
{
int error, new, n;
new = nsw_wcount_async_max;
error = sysctl_handle_int(oidp, &new, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (new > nswbuf / 2 || new < 1)
return (EINVAL);
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
mtx_lock(&swbuf_mtx);
Instead of reading, validating and adjusting value of the vm.swap_async_max in the main swapper work cycle, do it in the sysctl handler. This removes extra mutex acquisition from the main cycle and makes the sysctl knob return error on an invalid value, instead of accepting and fixing it. Reviewed by: kib Sponsored by: Netflix Sponsored by: Nginx, Inc.
2015-05-02 20:27:37 +00:00
while (nsw_wcount_async_max != new) {
/*
* Adjust difference. If the current async count is too low,
* we will need to sqeeze our update slowly in. Sleep with a
* higher priority than getpbuf() to finish faster.
*/
n = new - nsw_wcount_async_max;
if (nsw_wcount_async + n >= 0) {
nsw_wcount_async += n;
nsw_wcount_async_max += n;
wakeup(&nsw_wcount_async);
} else {
nsw_wcount_async_max -= nsw_wcount_async;
nsw_wcount_async = 0;
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
msleep(&nsw_wcount_async, &swbuf_mtx, PSWP,
Instead of reading, validating and adjusting value of the vm.swap_async_max in the main swapper work cycle, do it in the sysctl handler. This removes extra mutex acquisition from the main cycle and makes the sysctl knob return error on an invalid value, instead of accepting and fixing it. Reviewed by: kib Sponsored by: Netflix Sponsored by: Nginx, Inc.
2015-05-02 20:27:37 +00:00
"swpsysctl", 0);
}
}
Allocate pager bufs from UMA instead of 80-ish mutex protected linked list. o In vm_pager_bufferinit() create pbuf_zone and start accounting on how many pbufs are we going to have set. In various subsystems that are going to utilize pbufs create private zones via call to pbuf_zsecond_create(). The latter calls uma_zsecond_create(), and sets a limit on created zone. After startup preallocate pbufs according to requirements of all pbuf zones. Subsystems that used to have a private limit with old allocator now have private pbuf zones: md(4), fusefs, NFS client, smbfs, VFS cluster, FFS, swap, vnode pager. The following subsystems use shared pbuf zone: cam(4), nvme(4), physio(9), aio(4). They should have their private limits, but changing that is out of scope of this commit. o Fetch tunable value of kern.nswbuf from init_param2() and while here move NSWBUF_MIN to opt_param.h and eliminate opt_swap.h, that was holding only this option. Default values aren't touched by this commit, but they probably should be reviewed wrt to modern hardware. This change removes a tight bottleneck from sendfile(2) operation, that uses pbufs in vnode pager. Other pagers also would benefit from faster allocation. Together with: gallatin Tested by: pho
2019-01-15 01:02:16 +00:00
mtx_unlock(&swbuf_mtx);
Instead of reading, validating and adjusting value of the vm.swap_async_max in the main swapper work cycle, do it in the sysctl handler. This removes extra mutex acquisition from the main cycle and makes the sysctl knob return error on an invalid value, instead of accepting and fixing it. Reviewed by: kib Sponsored by: Netflix Sponsored by: Nginx, Inc.
2015-05-02 20:27:37 +00:00
return (0);
}
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
static void
swap_pager_update_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
VM_OBJECT_WLOCK(object);
Simplify anonymous memory handling with an OBJ_ANON flag. This eliminates reudundant complicated checks and additional locking required only for anonymous memory. Introduce vm_object_allocate_anon() to create these objects. DEFAULT and SWAP objects now have the correct settings for non-anonymous consumers and so individual consumers need not modify the default flags to create super-pages and avoid ONEMAPPING/NOSPLIT. Reviewed by: alc, dougm, kib, markj Tested by: pho Differential Revision: https://reviews.freebsd.org/D22119
2019-11-19 23:19:43 +00:00
KASSERT((object->flags & OBJ_ANON) == 0,
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
("Splittable object with writecount"));
object->un_pager.swp.writemappings += (vm_ooffset_t)end - start;
VM_OBJECT_WUNLOCK(object);
}
static void
swap_pager_release_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
VM_OBJECT_WLOCK(object);
Simplify anonymous memory handling with an OBJ_ANON flag. This eliminates reudundant complicated checks and additional locking required only for anonymous memory. Introduce vm_object_allocate_anon() to create these objects. DEFAULT and SWAP objects now have the correct settings for non-anonymous consumers and so individual consumers need not modify the default flags to create super-pages and avoid ONEMAPPING/NOSPLIT. Reviewed by: alc, dougm, kib, markj Tested by: pho Differential Revision: https://reviews.freebsd.org/D22119
2019-11-19 23:19:43 +00:00
KASSERT((object->flags & OBJ_ANON) == 0,
vm pager: writemapping accounting for OBJT_SWAP Currently writemapping accounting is only done for vnode_pager which does some accounting on the underlying vnode. Extend this to allow accounting to be possible for any of the pager types. New pageops are added to update/release writecount that need to be implemented for any pager wishing to do said accounting, and we implement these methods now for both vnode_pager (unchanged) and swap_pager. The primary motivation for this is to allow other systems with OBJT_SWAP objects to check if their objects have any write mappings and reject operations with EBUSY if so. posixshm will be the first to do so in order to reject adding write seals to the shmfd if any writable mappings exist. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D21456
2019-09-03 20:31:48 +00:00
("Splittable object with writecount"));
object->un_pager.swp.writemappings -= (vm_ooffset_t)end - start;
VM_OBJECT_WUNLOCK(object);
}
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