d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
db0ac6ded6
freebsd-nq/sys/vm/uma_core.c
Mark Johnston 7585c5db25 uma: Fix handling of reserves in zone_import() 
Kegs with no items reserved have uk_reserve = 0.  So the check
keg->uk_reserve >= dom->ud_free_items will be true once all slabs are
depleted.  Then, rather than go and allocate a fresh slab, we return to
the cache layer.

The intent was to do this only when the keg actually has a reserve, so
modify the check to verify this first.  Another approach would be to
make uk_reserve signed and set it to -1 until uma_zone_reserve() is
called, but this requires a few casts elsewhere.

Fixes:	1b2dcc8c54 ("uma: Avoid depleting keg reserves when filling a bucket")
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32516
2021-11-01 09:51:43 -04:00

5871 lines
150 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2002-2019 Jeffrey Roberson <jeff@FreeBSD.org>
* Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
* Copyright (c) 2004-2006 Robert N. M. Watson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* uma_core.c Implementation of the Universal Memory allocator
*
* This allocator is intended to replace the multitude of similar object caches
* in the standard FreeBSD kernel. The intent is to be flexible as well as
* efficient. A primary design goal is to return unused memory to the rest of
* the system. This will make the system as a whole more flexible due to the
* ability to move memory to subsystems which most need it instead of leaving
* pools of reserved memory unused.
*
* The basic ideas stem from similar slab/zone based allocators whose algorithms
* are well known.
*
*/
/*
* TODO:
* - Improve memory usage for large allocations
* - Investigate cache size adjustments
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_param.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/asan.h>
#include <sys/bitset.h>
#include <sys/domainset.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/limits.h>
#include <sys/queue.h>
#include <sys/malloc.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/msan.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/sleepqueue.h>
#include <sys/smp.h>
#include <sys/smr.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_domainset.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_phys.h>
#include <vm/vm_pagequeue.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vm_dumpset.h>
#include <vm/uma.h>
#include <vm/uma_int.h>
#include <vm/uma_dbg.h>
#include <ddb/ddb.h>
#ifdef DEBUG_MEMGUARD
#include <vm/memguard.h>
#endif
#include <machine/md_var.h>
#ifdef INVARIANTS
#define UMA_ALWAYS_CTORDTOR 1
#else
#define UMA_ALWAYS_CTORDTOR 0
#endif
/*
* This is the zone and keg from which all zones are spawned.
*/
static uma_zone_t kegs;
static uma_zone_t zones;
/*
* On INVARIANTS builds, the slab contains a second bitset of the same size,
* "dbg_bits", which is laid out immediately after us_free.
*/
#ifdef INVARIANTS
#define SLAB_BITSETS 2
#else
#define SLAB_BITSETS 1
#endif
/*
* These are the two zones from which all offpage uma_slab_ts are allocated.
*
* One zone is for slab headers that can represent a larger number of items,
* making the slabs themselves more efficient, and the other zone is for
* headers that are smaller and represent fewer items, making the headers more
* efficient.
*/
#define SLABZONE_SIZE(setsize) \
(sizeof(struct uma_hash_slab) + BITSET_SIZE(setsize) * SLAB_BITSETS)
#define SLABZONE0_SETSIZE (PAGE_SIZE / 16)
#define SLABZONE1_SETSIZE SLAB_MAX_SETSIZE
#define SLABZONE0_SIZE SLABZONE_SIZE(SLABZONE0_SETSIZE)
#define SLABZONE1_SIZE SLABZONE_SIZE(SLABZONE1_SETSIZE)
static uma_zone_t slabzones[2];
/*
* The initial hash tables come out of this zone so they can be allocated
* prior to malloc coming up.
*/
static uma_zone_t hashzone;
/* The boot-time adjusted value for cache line alignment. */
int uma_align_cache = 64 - 1;
static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
static MALLOC_DEFINE(M_UMA, "UMA", "UMA Misc");
/*
* Are we allowed to allocate buckets?
*/
static int bucketdisable = 1;
/* Linked list of all kegs in the system */
static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
/* Linked list of all cache-only zones in the system */
static LIST_HEAD(,uma_zone) uma_cachezones =
LIST_HEAD_INITIALIZER(uma_cachezones);
/*
* Mutex for global lists: uma_kegs, uma_cachezones, and the per-keg list of
* zones.
*/
static struct rwlock_padalign __exclusive_cache_line uma_rwlock;
static struct sx uma_reclaim_lock;
/*
* First available virual address for boot time allocations.
*/
static vm_offset_t bootstart;
static vm_offset_t bootmem;
/*
* kmem soft limit, initialized by uma_set_limit(). Ensure that early
* allocations don't trigger a wakeup of the reclaim thread.
*/
unsigned long uma_kmem_limit = LONG_MAX;
SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_limit, CTLFLAG_RD, &uma_kmem_limit, 0,
"UMA kernel memory soft limit");
unsigned long uma_kmem_total;
SYSCTL_ULONG(_vm, OID_AUTO, uma_kmem_total, CTLFLAG_RD, &uma_kmem_total, 0,
"UMA kernel memory usage");
/* Is the VM done starting up? */
static enum {
BOOT_COLD,
BOOT_KVA,
BOOT_PCPU,
BOOT_RUNNING,
BOOT_SHUTDOWN,
} booted = BOOT_COLD;
/*
* This is the handle used to schedule events that need to happen
* outside of the allocation fast path.
*/
static struct callout uma_callout;
#define UMA_TIMEOUT 20 /* Seconds for callout interval. */
/*
* This structure is passed as the zone ctor arg so that I don't have to create
* a special allocation function just for zones.
*/
struct uma_zctor_args {
const char *name;
size_t size;
uma_ctor ctor;
uma_dtor dtor;
uma_init uminit;
uma_fini fini;
uma_import import;
uma_release release;
void *arg;
uma_keg_t keg;
int align;
uint32_t flags;
};
struct uma_kctor_args {
uma_zone_t zone;
size_t size;
uma_init uminit;
uma_fini fini;
int align;
uint32_t flags;
};
struct uma_bucket_zone {
uma_zone_t ubz_zone;
const char *ubz_name;
int ubz_entries; /* Number of items it can hold. */
int ubz_maxsize; /* Maximum allocation size per-item. */
};
/*
* Compute the actual number of bucket entries to pack them in power
* of two sizes for more efficient space utilization.
*/
#define BUCKET_SIZE(n) \
(((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
#define BUCKET_MAX BUCKET_SIZE(256)
struct uma_bucket_zone bucket_zones[] = {
/* Literal bucket sizes. */
{ NULL, "2 Bucket", 2, 4096 },
{ NULL, "4 Bucket", 4, 3072 },
{ NULL, "8 Bucket", 8, 2048 },
{ NULL, "16 Bucket", 16, 1024 },
/* Rounded down power of 2 sizes for efficiency. */
{ NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
{ NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
{ NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
{ NULL, "256 Bucket", BUCKET_SIZE(256), 64 },
{ NULL, NULL, 0}
};
/*
* Flags and enumerations to be passed to internal functions.
*/
enum zfreeskip {
SKIP_NONE = 0,
SKIP_CNT = 0x00000001,
SKIP_DTOR = 0x00010000,
SKIP_FINI = 0x00020000,
};
/* Prototypes.. */
void uma_startup1(vm_offset_t);
void uma_startup2(void);
static void *noobj_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
static void *page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
static void *pcpu_page_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
static void *startup_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
static void *contig_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
static void page_free(void *, vm_size_t, uint8_t);
static void pcpu_page_free(void *, vm_size_t, uint8_t);
static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int, int, int);
static void cache_drain(uma_zone_t);
static void bucket_drain(uma_zone_t, uma_bucket_t);
static void bucket_cache_reclaim(uma_zone_t zone, bool, int);
static bool bucket_cache_reclaim_domain(uma_zone_t, bool, bool, int);
static int keg_ctor(void *, int, void *, int);
static void keg_dtor(void *, int, void *);
static void keg_drain(uma_keg_t keg, int domain);
static int zone_ctor(void *, int, void *, int);
static void zone_dtor(void *, int, void *);
static inline void item_dtor(uma_zone_t zone, void *item, int size,
void *udata, enum zfreeskip skip);
static int zero_init(void *, int, int);
static void zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
int itemdomain, bool ws);
static void zone_foreach(void (*zfunc)(uma_zone_t, void *), void *);
static void zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *), void *);
static void zone_timeout(uma_zone_t zone, void *);
static int hash_alloc(struct uma_hash *, u_int);
static int hash_expand(struct uma_hash *, struct uma_hash *);
static void hash_free(struct uma_hash *hash);
static void uma_timeout(void *);
static void uma_shutdown(void);
static void *zone_alloc_item(uma_zone_t, void *, int, int);
static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
static int zone_alloc_limit(uma_zone_t zone, int count, int flags);
static void zone_free_limit(uma_zone_t zone, int count);
static void bucket_enable(void);
static void bucket_init(void);
static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
static void bucket_zone_drain(int domain);
static uma_bucket_t zone_alloc_bucket(uma_zone_t, void *, int, int);
static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
static void slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item);
static size_t slab_sizeof(int nitems);
static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
uma_fini fini, int align, uint32_t flags);
static int zone_import(void *, void **, int, int, int);
static void zone_release(void *, void **, int);
static bool cache_alloc(uma_zone_t, uma_cache_t, void *, int);
static bool cache_free(uma_zone_t, uma_cache_t, void *, void *, int);
static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS);
static int sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS);
static uint64_t uma_zone_get_allocs(uma_zone_t zone);
static SYSCTL_NODE(_vm, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"Memory allocation debugging");
#ifdef INVARIANTS
static uint64_t uma_keg_get_allocs(uma_keg_t zone);
static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg);
static bool uma_dbg_kskip(uma_keg_t keg, void *mem);
static bool uma_dbg_zskip(uma_zone_t zone, void *mem);
static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item);
static void uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item);
static u_int dbg_divisor = 1;
SYSCTL_UINT(_vm_debug, OID_AUTO, divisor,
CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &dbg_divisor, 0,
"Debug & thrash every this item in memory allocator");
static counter_u64_t uma_dbg_cnt = EARLY_COUNTER;
static counter_u64_t uma_skip_cnt = EARLY_COUNTER;
SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, trashed, CTLFLAG_RD,
&uma_dbg_cnt, "memory items debugged");
SYSCTL_COUNTER_U64(_vm_debug, OID_AUTO, skipped, CTLFLAG_RD,
&uma_skip_cnt, "memory items skipped, not debugged");
#endif
SYSCTL_NODE(_vm, OID_AUTO, uma, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Universal Memory Allocator");
SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_INT,
0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLFLAG_MPSAFE|CTLTYPE_STRUCT,
0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
static int zone_warnings = 1;
SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RWTUN, &zone_warnings, 0,
"Warn when UMA zones becomes full");
static int multipage_slabs = 1;
TUNABLE_INT("vm.debug.uma_multipage_slabs", &multipage_slabs);
SYSCTL_INT(_vm_debug, OID_AUTO, uma_multipage_slabs,
CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &multipage_slabs, 0,
"UMA may choose larger slab sizes for better efficiency");
/*
* Select the slab zone for an offpage slab with the given maximum item count.
*/
static inline uma_zone_t
slabzone(int ipers)
{
return (slabzones[ipers > SLABZONE0_SETSIZE]);
}
/*
* This routine checks to see whether or not it's safe to enable buckets.
*/
static void
bucket_enable(void)
{
KASSERT(booted >= BOOT_KVA, ("Bucket enable before init"));
bucketdisable = vm_page_count_min();
}
/*
* Initialize bucket_zones, the array of zones of buckets of various sizes.
*
* For each zone, calculate the memory required for each bucket, consisting
* of the header and an array of pointers.
*/
static void
bucket_init(void)
{
struct uma_bucket_zone *ubz;
int size;
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
size = roundup(sizeof(struct uma_bucket), sizeof(void *));
size += sizeof(void *) * ubz->ubz_entries;
ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET |
UMA_ZONE_FIRSTTOUCH);
}
}
/*
* Given a desired number of entries for a bucket, return the zone from which
* to allocate the bucket.
*/
static struct uma_bucket_zone *
bucket_zone_lookup(int entries)
{
struct uma_bucket_zone *ubz;
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
if (ubz->ubz_entries >= entries)
return (ubz);
ubz--;
return (ubz);
}
static int
bucket_select(int size)
{
struct uma_bucket_zone *ubz;
ubz = &bucket_zones[0];
if (size > ubz->ubz_maxsize)
return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
for (; ubz->ubz_entries != 0; ubz++)
if (ubz->ubz_maxsize < size)
break;
ubz--;
return (ubz->ubz_entries);
}
static uma_bucket_t
bucket_alloc(uma_zone_t zone, void *udata, int flags)
{
struct uma_bucket_zone *ubz;
uma_bucket_t bucket;
/*
* Don't allocate buckets early in boot.
*/
if (__predict_false(booted < BOOT_KVA))
return (NULL);
/*
* To limit bucket recursion we store the original zone flags
* in a cookie passed via zalloc_arg/zfree_arg. This allows the
* NOVM flag to persist even through deep recursions. We also
* store ZFLAG_BUCKET once we have recursed attempting to allocate
* a bucket for a bucket zone so we do not allow infinite bucket
* recursion. This cookie will even persist to frees of unused
* buckets via the allocation path or bucket allocations in the
* free path.
*/
if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
udata = (void *)(uintptr_t)zone->uz_flags;
else {
if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
return (NULL);
udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
}
if (((uintptr_t)udata & UMA_ZONE_VM) != 0)
flags |= M_NOVM;
ubz = bucket_zone_lookup(atomic_load_16(&zone->uz_bucket_size));
if (ubz->ubz_zone == zone && (ubz + 1)->ubz_entries != 0)
ubz++;
bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
if (bucket) {
#ifdef INVARIANTS
bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
#endif
bucket->ub_cnt = 0;
bucket->ub_entries = min(ubz->ubz_entries,
zone->uz_bucket_size_max);
bucket->ub_seq = SMR_SEQ_INVALID;
CTR3(KTR_UMA, "bucket_alloc: zone %s(%p) allocated bucket %p",
zone->uz_name, zone, bucket);
}
return (bucket);
}
static void
bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
{
struct uma_bucket_zone *ubz;
if (bucket->ub_cnt != 0)
bucket_drain(zone, bucket);
KASSERT(bucket->ub_cnt == 0,
("bucket_free: Freeing a non free bucket."));
KASSERT(bucket->ub_seq == SMR_SEQ_INVALID,
("bucket_free: Freeing an SMR bucket."));
if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
udata = (void *)(uintptr_t)zone->uz_flags;
ubz = bucket_zone_lookup(bucket->ub_entries);
uma_zfree_arg(ubz->ubz_zone, bucket, udata);
}
static void
bucket_zone_drain(int domain)
{
struct uma_bucket_zone *ubz;
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
uma_zone_reclaim_domain(ubz->ubz_zone, UMA_RECLAIM_DRAIN,
domain);
}
#ifdef KASAN
_Static_assert(UMA_SMALLEST_UNIT % KASAN_SHADOW_SCALE == 0,
"Base UMA allocation size not a multiple of the KASAN scale factor");
static void
kasan_mark_item_valid(uma_zone_t zone, void *item)
{
void *pcpu_item;
size_t sz, rsz;
int i;
if ((zone->uz_flags & UMA_ZONE_NOKASAN) != 0)
return;
sz = zone->uz_size;
rsz = roundup2(sz, KASAN_SHADOW_SCALE);
if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
kasan_mark(item, sz, rsz, KASAN_GENERIC_REDZONE);
} else {
pcpu_item = zpcpu_base_to_offset(item);
for (i = 0; i <= mp_maxid; i++)
kasan_mark(zpcpu_get_cpu(pcpu_item, i), sz, rsz,
KASAN_GENERIC_REDZONE);
}
}
static void
kasan_mark_item_invalid(uma_zone_t zone, void *item)
{
void *pcpu_item;
size_t sz;
int i;
if ((zone->uz_flags & UMA_ZONE_NOKASAN) != 0)
return;
sz = roundup2(zone->uz_size, KASAN_SHADOW_SCALE);
if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
kasan_mark(item, 0, sz, KASAN_UMA_FREED);
} else {
pcpu_item = zpcpu_base_to_offset(item);
for (i = 0; i <= mp_maxid; i++)
kasan_mark(zpcpu_get_cpu(pcpu_item, i), 0, sz,
KASAN_UMA_FREED);
}
}
static void
kasan_mark_slab_valid(uma_keg_t keg, void *mem)
{
size_t sz;
if ((keg->uk_flags & UMA_ZONE_NOKASAN) == 0) {
sz = keg->uk_ppera * PAGE_SIZE;
kasan_mark(mem, sz, sz, 0);
}
}
static void
kasan_mark_slab_invalid(uma_keg_t keg, void *mem)
{
size_t sz;
if ((keg->uk_flags & UMA_ZONE_NOKASAN) == 0) {
if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
sz = keg->uk_ppera * PAGE_SIZE;
else
sz = keg->uk_pgoff;
kasan_mark(mem, 0, sz, KASAN_UMA_FREED);
}
}
#else /* !KASAN */
static void
kasan_mark_item_valid(uma_zone_t zone __unused, void *item __unused)
{
}
static void
kasan_mark_item_invalid(uma_zone_t zone __unused, void *item __unused)
{
}
static void
kasan_mark_slab_valid(uma_keg_t keg __unused, void *mem __unused)
{
}
static void
kasan_mark_slab_invalid(uma_keg_t keg __unused, void *mem __unused)
{
}
#endif /* KASAN */
#ifdef KMSAN
static inline void
kmsan_mark_item_uninitialized(uma_zone_t zone, void *item)
{
void *pcpu_item;
size_t sz;
int i;
if ((zone->uz_flags &
(UMA_ZFLAG_CACHE | UMA_ZONE_SECONDARY | UMA_ZONE_MALLOC)) != 0) {
/*
* Cache zones should not be instrumented by default, as UMA
* does not have enough information to do so correctly.
* Consumers can mark items themselves if it makes sense to do
* so.
*
* Items from secondary zones are initialized by the parent
* zone and thus cannot safely be marked by UMA.
*
* malloc zones are handled directly by malloc(9) and friends,
* since they can provide more precise origin tracking.
*/
return;
}
if (zone->uz_keg->uk_init != NULL) {
/*
* By definition, initialized items cannot be marked. The
* best we can do is mark items from these zones after they
* are freed to the keg.
*/
return;
}
sz = zone->uz_size;
if ((zone->uz_flags & UMA_ZONE_PCPU) == 0) {
kmsan_orig(item, sz, KMSAN_TYPE_UMA, KMSAN_RET_ADDR);
kmsan_mark(item, sz, KMSAN_STATE_UNINIT);
} else {
pcpu_item = zpcpu_base_to_offset(item);
for (i = 0; i <= mp_maxid; i++) {
kmsan_orig(zpcpu_get_cpu(pcpu_item, i), sz,
KMSAN_TYPE_UMA, KMSAN_RET_ADDR);
kmsan_mark(zpcpu_get_cpu(pcpu_item, i), sz,
KMSAN_STATE_INITED);
}
}
}
#else /* !KMSAN */
static inline void
kmsan_mark_item_uninitialized(uma_zone_t zone __unused, void *item __unused)
{
}
#endif /* KMSAN */
/*
* Acquire the domain lock and record contention.
*/
static uma_zone_domain_t
zone_domain_lock(uma_zone_t zone, int domain)
{
uma_zone_domain_t zdom;
bool lockfail;
zdom = ZDOM_GET(zone, domain);
lockfail = false;
if (ZDOM_OWNED(zdom))
lockfail = true;
ZDOM_LOCK(zdom);
/* This is unsynchronized. The counter does not need to be precise. */
if (lockfail && zone->uz_bucket_size < zone->uz_bucket_size_max)
zone->uz_bucket_size++;
return (zdom);
}
/*
* Search for the domain with the least cached items and return it if it
* is out of balance with the preferred domain.
*/
static __noinline int
zone_domain_lowest(uma_zone_t zone, int pref)
{
long least, nitems, prefitems;
int domain;
int i;
prefitems = least = LONG_MAX;
domain = 0;
for (i = 0; i < vm_ndomains; i++) {
nitems = ZDOM_GET(zone, i)->uzd_nitems;
if (nitems < least) {
domain = i;
least = nitems;
}
if (domain == pref)
prefitems = nitems;
}
if (prefitems < least * 2)
return (pref);
return (domain);
}
/*
* Search for the domain with the most cached items and return it or the
* preferred domain if it has enough to proceed.
*/
static __noinline int
zone_domain_highest(uma_zone_t zone, int pref)
{
long most, nitems;
int domain;
int i;
if (ZDOM_GET(zone, pref)->uzd_nitems > BUCKET_MAX)
return (pref);
most = 0;
domain = 0;
for (i = 0; i < vm_ndomains; i++) {
nitems = ZDOM_GET(zone, i)->uzd_nitems;
if (nitems > most) {
domain = i;
most = nitems;
}
}
return (domain);
}
/*
* Set the maximum imax value.
*/
static void
zone_domain_imax_set(uma_zone_domain_t zdom, int nitems)
{
long old;
old = zdom->uzd_imax;
do {
if (old >= nitems)
return;
} while (atomic_fcmpset_long(&zdom->uzd_imax, &old, nitems) == 0);
/*
* We are at new maximum, so do the last WSS update for the old
* bimin and prepare to measure next allocation batch.
*/
if (zdom->uzd_wss < old - zdom->uzd_bimin)
zdom->uzd_wss = old - zdom->uzd_bimin;
zdom->uzd_bimin = nitems;
}
/*
* Attempt to satisfy an allocation by retrieving a full bucket from one of the
* zone's caches. If a bucket is found the zone is not locked on return.
*/
static uma_bucket_t
zone_fetch_bucket(uma_zone_t zone, uma_zone_domain_t zdom, bool reclaim)
{
uma_bucket_t bucket;
long cnt;
int i;
bool dtor = false;
ZDOM_LOCK_ASSERT(zdom);
if ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) == NULL)
return (NULL);
/* SMR Buckets can not be re-used until readers expire. */
if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
bucket->ub_seq != SMR_SEQ_INVALID) {
if (!smr_poll(zone->uz_smr, bucket->ub_seq, false))
return (NULL);
bucket->ub_seq = SMR_SEQ_INVALID;
dtor = (zone->uz_dtor != NULL) || UMA_ALWAYS_CTORDTOR;
if (STAILQ_NEXT(bucket, ub_link) != NULL)
zdom->uzd_seq = STAILQ_NEXT(bucket, ub_link)->ub_seq;
}
STAILQ_REMOVE_HEAD(&zdom->uzd_buckets, ub_link);
KASSERT(zdom->uzd_nitems >= bucket->ub_cnt,
("%s: item count underflow (%ld, %d)",
__func__, zdom->uzd_nitems, bucket->ub_cnt));
KASSERT(bucket->ub_cnt > 0,
("%s: empty bucket in bucket cache", __func__));
zdom->uzd_nitems -= bucket->ub_cnt;
if (reclaim) {
/*
* Shift the bounds of the current WSS interval to avoid
* perturbing the estimates.
*/
cnt = lmin(zdom->uzd_bimin, bucket->ub_cnt);
atomic_subtract_long(&zdom->uzd_imax, cnt);
zdom->uzd_bimin -= cnt;
zdom->uzd_imin -= lmin(zdom->uzd_imin, bucket->ub_cnt);
if (zdom->uzd_limin >= bucket->ub_cnt) {
zdom->uzd_limin -= bucket->ub_cnt;
} else {
zdom->uzd_limin = 0;
zdom->uzd_timin = 0;
}
} else if (zdom->uzd_bimin > zdom->uzd_nitems) {
zdom->uzd_bimin = zdom->uzd_nitems;
if (zdom->uzd_imin > zdom->uzd_nitems)
zdom->uzd_imin = zdom->uzd_nitems;
}
ZDOM_UNLOCK(zdom);
if (dtor)
for (i = 0; i < bucket->ub_cnt; i++)
item_dtor(zone, bucket->ub_bucket[i], zone->uz_size,
NULL, SKIP_NONE);
return (bucket);
}
/*
* Insert a full bucket into the specified cache. The "ws" parameter indicates
* whether the bucket's contents should be counted as part of the zone's working
* set. The bucket may be freed if it exceeds the bucket limit.
*/
static void
zone_put_bucket(uma_zone_t zone, int domain, uma_bucket_t bucket, void *udata,
const bool ws)
{
uma_zone_domain_t zdom;
/* We don't cache empty buckets. This can happen after a reclaim. */
if (bucket->ub_cnt == 0)
goto out;
zdom = zone_domain_lock(zone, domain);
/*
* Conditionally set the maximum number of items.
*/
zdom->uzd_nitems += bucket->ub_cnt;
if (__predict_true(zdom->uzd_nitems < zone->uz_bucket_max)) {
if (ws) {
zone_domain_imax_set(zdom, zdom->uzd_nitems);
} else {
/*
* Shift the bounds of the current WSS interval to
* avoid perturbing the estimates.
*/
atomic_add_long(&zdom->uzd_imax, bucket->ub_cnt);
zdom->uzd_imin += bucket->ub_cnt;
zdom->uzd_bimin += bucket->ub_cnt;
zdom->uzd_limin += bucket->ub_cnt;
}
if (STAILQ_EMPTY(&zdom->uzd_buckets))
zdom->uzd_seq = bucket->ub_seq;
/*
* Try to promote reuse of recently used items. For items
* protected by SMR, try to defer reuse to minimize polling.
*/
if (bucket->ub_seq == SMR_SEQ_INVALID)
STAILQ_INSERT_HEAD(&zdom->uzd_buckets, bucket, ub_link);
else
STAILQ_INSERT_TAIL(&zdom->uzd_buckets, bucket, ub_link);
ZDOM_UNLOCK(zdom);
return;
}
zdom->uzd_nitems -= bucket->ub_cnt;
ZDOM_UNLOCK(zdom);
out:
bucket_free(zone, bucket, udata);
}
/* Pops an item out of a per-cpu cache bucket. */
static inline void *
cache_bucket_pop(uma_cache_t cache, uma_cache_bucket_t bucket)
{
void *item;
CRITICAL_ASSERT(curthread);
bucket->ucb_cnt--;
item = bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt];
#ifdef INVARIANTS
bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = NULL;
KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
#endif
cache->uc_allocs++;
return (item);
}
/* Pushes an item into a per-cpu cache bucket. */
static inline void
cache_bucket_push(uma_cache_t cache, uma_cache_bucket_t bucket, void *item)
{
CRITICAL_ASSERT(curthread);
KASSERT(bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] == NULL,
("uma_zfree: Freeing to non free bucket index."));
bucket->ucb_bucket->ub_bucket[bucket->ucb_cnt] = item;
bucket->ucb_cnt++;
cache->uc_frees++;
}
/*
* Unload a UMA bucket from a per-cpu cache.
*/
static inline uma_bucket_t
cache_bucket_unload(uma_cache_bucket_t bucket)
{
uma_bucket_t b;
b = bucket->ucb_bucket;
if (b != NULL) {
MPASS(b->ub_entries == bucket->ucb_entries);
b->ub_cnt = bucket->ucb_cnt;
bucket->ucb_bucket = NULL;
bucket->ucb_entries = bucket->ucb_cnt = 0;
}
return (b);
}
static inline uma_bucket_t
cache_bucket_unload_alloc(uma_cache_t cache)
{
return (cache_bucket_unload(&cache->uc_allocbucket));
}
static inline uma_bucket_t
cache_bucket_unload_free(uma_cache_t cache)
{
return (cache_bucket_unload(&cache->uc_freebucket));
}
static inline uma_bucket_t
cache_bucket_unload_cross(uma_cache_t cache)
{
return (cache_bucket_unload(&cache->uc_crossbucket));
}
/*
* Load a bucket into a per-cpu cache bucket.
*/
static inline void
cache_bucket_load(uma_cache_bucket_t bucket, uma_bucket_t b)
{
CRITICAL_ASSERT(curthread);
MPASS(bucket->ucb_bucket == NULL);
MPASS(b->ub_seq == SMR_SEQ_INVALID);
bucket->ucb_bucket = b;
bucket->ucb_cnt = b->ub_cnt;
bucket->ucb_entries = b->ub_entries;
}
static inline void
cache_bucket_load_alloc(uma_cache_t cache, uma_bucket_t b)
{
cache_bucket_load(&cache->uc_allocbucket, b);
}
static inline void
cache_bucket_load_free(uma_cache_t cache, uma_bucket_t b)
{
cache_bucket_load(&cache->uc_freebucket, b);
}
#ifdef NUMA
static inline void
cache_bucket_load_cross(uma_cache_t cache, uma_bucket_t b)
{
cache_bucket_load(&cache->uc_crossbucket, b);
}
#endif
/*
* Copy and preserve ucb_spare.
*/
static inline void
cache_bucket_copy(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
{
b1->ucb_bucket = b2->ucb_bucket;
b1->ucb_entries = b2->ucb_entries;
b1->ucb_cnt = b2->ucb_cnt;
}
/*
* Swap two cache buckets.
*/
static inline void
cache_bucket_swap(uma_cache_bucket_t b1, uma_cache_bucket_t b2)
{
struct uma_cache_bucket b3;
CRITICAL_ASSERT(curthread);
cache_bucket_copy(&b3, b1);
cache_bucket_copy(b1, b2);
cache_bucket_copy(b2, &b3);
}
/*
* Attempt to fetch a bucket from a zone on behalf of the current cpu cache.
*/
static uma_bucket_t
cache_fetch_bucket(uma_zone_t zone, uma_cache_t cache, int domain)
{
uma_zone_domain_t zdom;
uma_bucket_t bucket;
/*
* Avoid the lock if possible.
*/
zdom = ZDOM_GET(zone, domain);
if (zdom->uzd_nitems == 0)
return (NULL);
if ((cache_uz_flags(cache) & UMA_ZONE_SMR) != 0 &&
!smr_poll(zone->uz_smr, zdom->uzd_seq, false))
return (NULL);
/*
* Check the zone's cache of buckets.
*/
zdom = zone_domain_lock(zone, domain);
if ((bucket = zone_fetch_bucket(zone, zdom, false)) != NULL)
return (bucket);
ZDOM_UNLOCK(zdom);
return (NULL);
}
static void
zone_log_warning(uma_zone_t zone)
{
static const struct timeval warninterval = { 300, 0 };
if (!zone_warnings || zone->uz_warning == NULL)
return;
if (ratecheck(&zone->uz_ratecheck, &warninterval))
printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
}
static inline void
zone_maxaction(uma_zone_t zone)
{
if (zone->uz_maxaction.ta_func != NULL)
taskqueue_enqueue(taskqueue_thread, &zone->uz_maxaction);
}
/*
* Routine called by timeout which is used to fire off some time interval
* based calculations. (stats, hash size, etc.)
*
* Arguments:
* arg Unused
*
* Returns:
* Nothing
*/
static void
uma_timeout(void *unused)
{
bucket_enable();
zone_foreach(zone_timeout, NULL);
/* Reschedule this event */
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
}
/*
* Update the working set size estimates for the zone's bucket cache.
* The constants chosen here are somewhat arbitrary.
*/
static void
zone_domain_update_wss(uma_zone_domain_t zdom)
{
long m;
ZDOM_LOCK_ASSERT(zdom);
MPASS(zdom->uzd_imax >= zdom->uzd_nitems);
MPASS(zdom->uzd_nitems >= zdom->uzd_bimin);
MPASS(zdom->uzd_bimin >= zdom->uzd_imin);
/*
* Estimate WSS as modified moving average of biggest allocation
* batches for each period over few minutes (UMA_TIMEOUT of 20s).
*/
zdom->uzd_wss = lmax(zdom->uzd_wss * 3 / 4,
zdom->uzd_imax - zdom->uzd_bimin);
/*
* Estimate longtime minimum item count as a combination of recent
* minimum item count, adjusted by WSS for safety, and the modified
* moving average over the last several hours (UMA_TIMEOUT of 20s).
* timin measures time since limin tried to go negative, that means
* we were dangerously close to or got out of cache.
*/
m = zdom->uzd_imin - zdom->uzd_wss;
if (m >= 0) {
if (zdom->uzd_limin >= m)
zdom->uzd_limin = m;
else
zdom->uzd_limin = (m + zdom->uzd_limin * 255) / 256;
zdom->uzd_timin++;
} else {
zdom->uzd_limin = 0;
zdom->uzd_timin = 0;
}
/* To reduce period edge effects on WSS keep half of the imax. */
atomic_subtract_long(&zdom->uzd_imax,
(zdom->uzd_imax - zdom->uzd_nitems + 1) / 2);
zdom->uzd_imin = zdom->uzd_bimin = zdom->uzd_nitems;
}
/*
* Routine to perform timeout driven calculations. This expands the
* hashes and does per cpu statistics aggregation.
*
* Returns nothing.
*/
static void
zone_timeout(uma_zone_t zone, void *unused)
{
uma_keg_t keg;
u_int slabs, pages;
if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
goto trim;
keg = zone->uz_keg;
/*
* Hash zones are non-numa by definition so the first domain
* is the only one present.
*/
KEG_LOCK(keg, 0);
pages = keg->uk_domain[0].ud_pages;
/*
* Expand the keg hash table.
*
* This is done if the number of slabs is larger than the hash size.
* What I'm trying to do here is completely reduce collisions. This
* may be a little aggressive. Should I allow for two collisions max?
*/
if ((slabs = pages / keg->uk_ppera) > keg->uk_hash.uh_hashsize) {
struct uma_hash newhash;
struct uma_hash oldhash;
int ret;
/*
* This is so involved because allocating and freeing
* while the keg lock is held will lead to deadlock.
* I have to do everything in stages and check for
* races.
*/
KEG_UNLOCK(keg, 0);
ret = hash_alloc(&newhash, 1 << fls(slabs));
KEG_LOCK(keg, 0);
if (ret) {
if (hash_expand(&keg->uk_hash, &newhash)) {
oldhash = keg->uk_hash;
keg->uk_hash = newhash;
} else
oldhash = newhash;
KEG_UNLOCK(keg, 0);
hash_free(&oldhash);
goto trim;
}
}
KEG_UNLOCK(keg, 0);
trim:
/* Trim caches not used for a long time. */
for (int i = 0; i < vm_ndomains; i++) {
if (bucket_cache_reclaim_domain(zone, false, false, i) &&
(zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
keg_drain(zone->uz_keg, i);
}
}
/*
* Allocate and zero fill the next sized hash table from the appropriate
* backing store.
*
* Arguments:
* hash A new hash structure with the old hash size in uh_hashsize
*
* Returns:
* 1 on success and 0 on failure.
*/
static int
hash_alloc(struct uma_hash *hash, u_int size)
{
size_t alloc;
KASSERT(powerof2(size), ("hash size must be power of 2"));
if (size > UMA_HASH_SIZE_INIT) {
hash->uh_hashsize = size;
alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
hash->uh_slab_hash = malloc(alloc, M_UMAHASH, M_NOWAIT);
} else {
alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
UMA_ANYDOMAIN, M_WAITOK);
hash->uh_hashsize = UMA_HASH_SIZE_INIT;
}
if (hash->uh_slab_hash) {
bzero(hash->uh_slab_hash, alloc);
hash->uh_hashmask = hash->uh_hashsize - 1;
return (1);
}
return (0);
}
/*
* Expands the hash table for HASH zones. This is done from zone_timeout
* to reduce collisions. This must not be done in the regular allocation
* path, otherwise, we can recurse on the vm while allocating pages.
*
* Arguments:
* oldhash The hash you want to expand
* newhash The hash structure for the new table
*
* Returns:
* Nothing
*
* Discussion:
*/
static int
hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
{
uma_hash_slab_t slab;
u_int hval;
u_int idx;
if (!newhash->uh_slab_hash)
return (0);
if (oldhash->uh_hashsize >= newhash->uh_hashsize)
return (0);
/*
* I need to investigate hash algorithms for resizing without a
* full rehash.
*/
for (idx = 0; idx < oldhash->uh_hashsize; idx++)
while (!LIST_EMPTY(&oldhash->uh_slab_hash[idx])) {
slab = LIST_FIRST(&oldhash->uh_slab_hash[idx]);
LIST_REMOVE(slab, uhs_hlink);
hval = UMA_HASH(newhash, slab->uhs_data);
LIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
slab, uhs_hlink);
}
return (1);
}
/*
* Free the hash bucket to the appropriate backing store.
*
* Arguments:
* slab_hash The hash bucket we're freeing
* hashsize The number of entries in that hash bucket
*
* Returns:
* Nothing
*/
static void
hash_free(struct uma_hash *hash)
{
if (hash->uh_slab_hash == NULL)
return;
if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
else
free(hash->uh_slab_hash, M_UMAHASH);
}
/*
* Frees all outstanding items in a bucket
*
* Arguments:
* zone The zone to free to, must be unlocked.
* bucket The free/alloc bucket with items.
*
* Returns:
* Nothing
*/
static void
bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
{
int i;
if (bucket->ub_cnt == 0)
return;
if ((zone->uz_flags & UMA_ZONE_SMR) != 0 &&
bucket->ub_seq != SMR_SEQ_INVALID) {
smr_wait(zone->uz_smr, bucket->ub_seq);
bucket->ub_seq = SMR_SEQ_INVALID;
for (i = 0; i < bucket->ub_cnt; i++)
item_dtor(zone, bucket->ub_bucket[i],
zone->uz_size, NULL, SKIP_NONE);
}
if (zone->uz_fini)
for (i = 0; i < bucket->ub_cnt; i++) {
kasan_mark_item_valid(zone, bucket->ub_bucket[i]);
zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
kasan_mark_item_invalid(zone, bucket->ub_bucket[i]);
}
zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
if (zone->uz_max_items > 0)
zone_free_limit(zone, bucket->ub_cnt);
#ifdef INVARIANTS
bzero(bucket->ub_bucket, sizeof(void *) * bucket->ub_cnt);
#endif
bucket->ub_cnt = 0;
}
/*
* Drains the per cpu caches for a zone.
*
* NOTE: This may only be called while the zone is being torn down, and not
* during normal operation. This is necessary in order that we do not have
* to migrate CPUs to drain the per-CPU caches.
*
* Arguments:
* zone The zone to drain, must be unlocked.
*
* Returns:
* Nothing
*/
static void
cache_drain(uma_zone_t zone)
{
uma_cache_t cache;
uma_bucket_t bucket;
smr_seq_t seq;
int cpu;
/*
* XXX: It is safe to not lock the per-CPU caches, because we're
* tearing down the zone anyway. I.e., there will be no further use
* of the caches at this point.
*
* XXX: It would good to be able to assert that the zone is being
* torn down to prevent improper use of cache_drain().
*/
seq = SMR_SEQ_INVALID;
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
seq = smr_advance(zone->uz_smr);
CPU_FOREACH(cpu) {
cache = &zone->uz_cpu[cpu];
bucket = cache_bucket_unload_alloc(cache);
if (bucket != NULL)
bucket_free(zone, bucket, NULL);
bucket = cache_bucket_unload_free(cache);
if (bucket != NULL) {
bucket->ub_seq = seq;
bucket_free(zone, bucket, NULL);
}
bucket = cache_bucket_unload_cross(cache);
if (bucket != NULL) {
bucket->ub_seq = seq;
bucket_free(zone, bucket, NULL);
}
}
bucket_cache_reclaim(zone, true, UMA_ANYDOMAIN);
}
static void
cache_shrink(uma_zone_t zone, void *unused)
{
if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
return;
ZONE_LOCK(zone);
zone->uz_bucket_size =
(zone->uz_bucket_size_min + zone->uz_bucket_size) / 2;
ZONE_UNLOCK(zone);
}
static void
cache_drain_safe_cpu(uma_zone_t zone, void *unused)
{
uma_cache_t cache;
uma_bucket_t b1, b2, b3;
int domain;
if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
return;
b1 = b2 = b3 = NULL;
critical_enter();
cache = &zone->uz_cpu[curcpu];
domain = PCPU_GET(domain);
b1 = cache_bucket_unload_alloc(cache);
/*
* Don't flush SMR zone buckets. This leaves the zone without a
* bucket and forces every free to synchronize().
*/
if ((zone->uz_flags & UMA_ZONE_SMR) == 0) {
b2 = cache_bucket_unload_free(cache);
b3 = cache_bucket_unload_cross(cache);
}
critical_exit();
if (b1 != NULL)
zone_free_bucket(zone, b1, NULL, domain, false);
if (b2 != NULL)
zone_free_bucket(zone, b2, NULL, domain, false);
if (b3 != NULL) {
/* Adjust the domain so it goes to zone_free_cross. */
domain = (domain + 1) % vm_ndomains;
zone_free_bucket(zone, b3, NULL, domain, false);
}
}
/*
* Safely drain per-CPU caches of a zone(s) to alloc bucket.
* This is an expensive call because it needs to bind to all CPUs
* one by one and enter a critical section on each of them in order
* to safely access their cache buckets.
* Zone lock must not be held on call this function.
*/
static void
pcpu_cache_drain_safe(uma_zone_t zone)
{
int cpu;
/*
* Polite bucket sizes shrinking was not enough, shrink aggressively.
*/
if (zone)
cache_shrink(zone, NULL);
else
zone_foreach(cache_shrink, NULL);
CPU_FOREACH(cpu) {
thread_lock(curthread);
sched_bind(curthread, cpu);
thread_unlock(curthread);
if (zone)
cache_drain_safe_cpu(zone, NULL);
else
zone_foreach(cache_drain_safe_cpu, NULL);
}
thread_lock(curthread);
sched_unbind(curthread);
thread_unlock(curthread);
}
/*
* Reclaim cached buckets from a zone. All buckets are reclaimed if the caller
* requested a drain, otherwise the per-domain caches are trimmed to either
* estimated working set size.
*/
static bool
bucket_cache_reclaim_domain(uma_zone_t zone, bool drain, bool trim, int domain)
{
uma_zone_domain_t zdom;
uma_bucket_t bucket;
long target;
bool done = false;
/*
* The cross bucket is partially filled and not part of
* the item count. Reclaim it individually here.
*/
zdom = ZDOM_GET(zone, domain);
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 || drain) {
ZONE_CROSS_LOCK(zone);
bucket = zdom->uzd_cross;
zdom->uzd_cross = NULL;
ZONE_CROSS_UNLOCK(zone);
if (bucket != NULL)
bucket_free(zone, bucket, NULL);
}
/*
* If we were asked to drain the zone, we are done only once
* this bucket cache is empty. If trim, we reclaim items in
* excess of the zone's estimated working set size. Multiple
* consecutive calls will shrink the WSS and so reclaim more.
* If neither drain nor trim, then voluntarily reclaim 1/4
* (to reduce first spike) of items not used for a long time.
*/
ZDOM_LOCK(zdom);
zone_domain_update_wss(zdom);
if (drain)
target = 0;
else if (trim)
target = zdom->uzd_wss;
else if (zdom->uzd_timin > 900 / UMA_TIMEOUT)
target = zdom->uzd_nitems - zdom->uzd_limin / 4;
else {
ZDOM_UNLOCK(zdom);
return (done);
}
while ((bucket = STAILQ_FIRST(&zdom->uzd_buckets)) != NULL &&
zdom->uzd_nitems >= target + bucket->ub_cnt) {
bucket = zone_fetch_bucket(zone, zdom, true);
if (bucket == NULL)
break;
bucket_free(zone, bucket, NULL);
done = true;
ZDOM_LOCK(zdom);
}
ZDOM_UNLOCK(zdom);
return (done);
}
static void
bucket_cache_reclaim(uma_zone_t zone, bool drain, int domain)
{
int i;
/*
* Shrink the zone bucket size to ensure that the per-CPU caches
* don't grow too large.
*/
if (zone->uz_bucket_size > zone->uz_bucket_size_min)
zone->uz_bucket_size--;
if (domain != UMA_ANYDOMAIN &&
(zone->uz_flags & UMA_ZONE_ROUNDROBIN) == 0) {
bucket_cache_reclaim_domain(zone, drain, true, domain);
} else {
for (i = 0; i < vm_ndomains; i++)
bucket_cache_reclaim_domain(zone, drain, true, i);
}
}
static void
keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
{
uint8_t *mem;
size_t size;
int i;
uint8_t flags;
CTR4(KTR_UMA, "keg_free_slab keg %s(%p) slab %p, returning %d bytes",
keg->uk_name, keg, slab, PAGE_SIZE * keg->uk_ppera);
mem = slab_data(slab, keg);
size = PAGE_SIZE * keg->uk_ppera;
kasan_mark_slab_valid(keg, mem);
if (keg->uk_fini != NULL) {
for (i = start - 1; i > -1; i--)
#ifdef INVARIANTS
/*
* trash_fini implies that dtor was trash_dtor. trash_fini
* would check that memory hasn't been modified since free,
* which executed trash_dtor.
* That's why we need to run uma_dbg_kskip() check here,
* albeit we don't make skip check for other init/fini
* invocations.
*/
if (!uma_dbg_kskip(keg, slab_item(slab, keg, i)) ||
keg->uk_fini != trash_fini)
#endif
keg->uk_fini(slab_item(slab, keg, i), keg->uk_size);
}
flags = slab->us_flags;
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
zone_free_item(slabzone(keg->uk_ipers), slab_tohashslab(slab),
NULL, SKIP_NONE);
}
keg->uk_freef(mem, size, flags);
uma_total_dec(size);
}
static void
keg_drain_domain(uma_keg_t keg, int domain)
{
struct slabhead freeslabs;
uma_domain_t dom;
uma_slab_t slab, tmp;
uint32_t i, stofree, stokeep, partial;
dom = &keg->uk_domain[domain];
LIST_INIT(&freeslabs);
CTR4(KTR_UMA, "keg_drain %s(%p) domain %d free items: %u",
keg->uk_name, keg, domain, dom->ud_free_items);
KEG_LOCK(keg, domain);
/*
* Are the free items in partially allocated slabs sufficient to meet
* the reserve? If not, compute the number of fully free slabs that must
* be kept.
*/
partial = dom->ud_free_items - dom->ud_free_slabs * keg->uk_ipers;
if (partial < keg->uk_reserve) {
stokeep = min(dom->ud_free_slabs,
howmany(keg->uk_reserve - partial, keg->uk_ipers));
} else {
stokeep = 0;
}
stofree = dom->ud_free_slabs - stokeep;
/*
* Partition the free slabs into two sets: those that must be kept in
* order to maintain the reserve, and those that may be released back to
* the system. Since one set may be much larger than the other,
* populate the smaller of the two sets and swap them if necessary.
*/
for (i = min(stofree, stokeep); i > 0; i--) {
slab = LIST_FIRST(&dom->ud_free_slab);
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&freeslabs, slab, us_link);
}
if (stofree > stokeep)
LIST_SWAP(&freeslabs, &dom->ud_free_slab, uma_slab, us_link);
if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0) {
LIST_FOREACH(slab, &freeslabs, us_link)
UMA_HASH_REMOVE(&keg->uk_hash, slab);
}
dom->ud_free_items -= stofree * keg->uk_ipers;
dom->ud_free_slabs -= stofree;
dom->ud_pages -= stofree * keg->uk_ppera;
KEG_UNLOCK(keg, domain);
LIST_FOREACH_SAFE(slab, &freeslabs, us_link, tmp)
keg_free_slab(keg, slab, keg->uk_ipers);
}
/*
* Frees pages from a keg back to the system. This is done on demand from
* the pageout daemon.
*
* Returns nothing.
*/
static void
keg_drain(uma_keg_t keg, int domain)
{
int i;
if ((keg->uk_flags & UMA_ZONE_NOFREE) != 0)
return;
if (domain != UMA_ANYDOMAIN) {
keg_drain_domain(keg, domain);
} else {
for (i = 0; i < vm_ndomains; i++)
keg_drain_domain(keg, i);
}
}
static void
zone_reclaim(uma_zone_t zone, int domain, int waitok, bool drain)
{
/*
* Count active reclaim operations in order to interlock with
* zone_dtor(), which removes the zone from global lists before
* attempting to reclaim items itself.
*
* The zone may be destroyed while sleeping, so only zone_dtor() should
* specify M_WAITOK.
*/
ZONE_LOCK(zone);
if (waitok == M_WAITOK) {
while (zone->uz_reclaimers > 0)
msleep(zone, ZONE_LOCKPTR(zone), PVM, "zonedrain", 1);
}
zone->uz_reclaimers++;
ZONE_UNLOCK(zone);
bucket_cache_reclaim(zone, drain, domain);
if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0)
keg_drain(zone->uz_keg, domain);
ZONE_LOCK(zone);
zone->uz_reclaimers--;
if (zone->uz_reclaimers == 0)
wakeup(zone);
ZONE_UNLOCK(zone);
}
static void
zone_drain(uma_zone_t zone, void *arg)
{
int domain;
domain = (int)(uintptr_t)arg;
zone_reclaim(zone, domain, M_NOWAIT, true);
}
static void
zone_trim(uma_zone_t zone, void *arg)
{
int domain;
domain = (int)(uintptr_t)arg;
zone_reclaim(zone, domain, M_NOWAIT, false);
}
/*
* Allocate a new slab for a keg and inserts it into the partial slab list.
* The keg should be unlocked on entry. If the allocation succeeds it will
* be locked on return.
*
* Arguments:
* flags Wait flags for the item initialization routine
* aflags Wait flags for the slab allocation
*
* Returns:
* The slab that was allocated or NULL if there is no memory and the
* caller specified M_NOWAIT.
*/
static uma_slab_t
keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int domain, int flags,
int aflags)
{
uma_domain_t dom;
uma_slab_t slab;
unsigned long size;
uint8_t *mem;
uint8_t sflags;
int i;
KASSERT(domain >= 0 && domain < vm_ndomains,
("keg_alloc_slab: domain %d out of range", domain));
slab = NULL;
mem = NULL;
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE) {
uma_hash_slab_t hslab;
hslab = zone_alloc_item(slabzone(keg->uk_ipers), NULL,
domain, aflags);
if (hslab == NULL)
goto fail;
slab = &hslab->uhs_slab;
}
/*
* This reproduces the old vm_zone behavior of zero filling pages the
* first time they are added to a zone.
*
* Malloced items are zeroed in uma_zalloc.
*/
if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
aflags |= M_ZERO;
else
aflags &= ~M_ZERO;
if (keg->uk_flags & UMA_ZONE_NODUMP)
aflags |= M_NODUMP;
/* zone is passed for legacy reasons. */
size = keg->uk_ppera * PAGE_SIZE;
mem = keg->uk_allocf(zone, size, domain, &sflags, aflags);
if (mem == NULL) {
if (keg->uk_flags & UMA_ZFLAG_OFFPAGE)
zone_free_item(slabzone(keg->uk_ipers),
slab_tohashslab(slab), NULL, SKIP_NONE);
goto fail;
}
uma_total_inc(size);
/* For HASH zones all pages go to the same uma_domain. */
if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
domain = 0;
/* Point the slab into the allocated memory */
if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE))
slab = (uma_slab_t)(mem + keg->uk_pgoff);
else
slab_tohashslab(slab)->uhs_data = mem;
if (keg->uk_flags & UMA_ZFLAG_VTOSLAB)
for (i = 0; i < keg->uk_ppera; i++)
vsetzoneslab((vm_offset_t)mem + (i * PAGE_SIZE),
zone, slab);
slab->us_freecount = keg->uk_ipers;
slab->us_flags = sflags;
slab->us_domain = domain;
BIT_FILL(keg->uk_ipers, &slab->us_free);
#ifdef INVARIANTS
BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg));
#endif
if (keg->uk_init != NULL) {
for (i = 0; i < keg->uk_ipers; i++)
if (keg->uk_init(slab_item(slab, keg, i),
keg->uk_size, flags) != 0)
break;
if (i != keg->uk_ipers) {
keg_free_slab(keg, slab, i);
goto fail;
}
}
kasan_mark_slab_invalid(keg, mem);
KEG_LOCK(keg, domain);
CTR3(KTR_UMA, "keg_alloc_slab: allocated slab %p for %s(%p)",
slab, keg->uk_name, keg);
if (keg->uk_flags & UMA_ZFLAG_HASH)
UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
/*
* If we got a slab here it's safe to mark it partially used
* and return. We assume that the caller is going to remove
* at least one item.
*/
dom = &keg->uk_domain[domain];
LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
dom->ud_pages += keg->uk_ppera;
dom->ud_free_items += keg->uk_ipers;
return (slab);
fail:
return (NULL);
}
/*
* This function is intended to be used early on in place of page_alloc(). It
* performs contiguous physical memory allocations and uses a bump allocator for
* KVA, so is usable before the kernel map is initialized.
*/
static void *
startup_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
vm_paddr_t pa;
vm_page_t m;
int i, pages;
pages = howmany(bytes, PAGE_SIZE);
KASSERT(pages > 0, ("%s can't reserve 0 pages", __func__));
*pflag = UMA_SLAB_BOOT;
m = vm_page_alloc_noobj_contig_domain(domain, malloc2vm_flags(wait) |
VM_ALLOC_WIRED, pages, (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0,
VM_MEMATTR_DEFAULT);
if (m == NULL)
return (NULL);
pa = VM_PAGE_TO_PHYS(m);
for (i = 0; i < pages; i++, pa += PAGE_SIZE) {
#if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
defined(__riscv) || defined(__powerpc64__)
if ((wait & M_NODUMP) == 0)
dump_add_page(pa);
#endif
}
/* Allocate KVA and indirectly advance bootmem. */
return ((void *)pmap_map(&bootmem, m->phys_addr,
m->phys_addr + (pages * PAGE_SIZE), VM_PROT_READ | VM_PROT_WRITE));
}
static void
startup_free(void *mem, vm_size_t bytes)
{
vm_offset_t va;
vm_page_t m;
va = (vm_offset_t)mem;
m = PHYS_TO_VM_PAGE(pmap_kextract(va));
/*
* startup_alloc() returns direct-mapped slabs on some platforms. Avoid
* unmapping ranges of the direct map.
*/
if (va >= bootstart && va + bytes <= bootmem)
pmap_remove(kernel_pmap, va, va + bytes);
for (; bytes != 0; bytes -= PAGE_SIZE, m++) {
#if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
defined(__riscv) || defined(__powerpc64__)
dump_drop_page(VM_PAGE_TO_PHYS(m));
#endif
vm_page_unwire_noq(m);
vm_page_free(m);
}
}
/*
* Allocates a number of pages from the system
*
* Arguments:
* bytes The number of bytes requested
* wait Shall we wait?
*
* Returns:
* A pointer to the alloced memory or possibly
* NULL if M_NOWAIT is set.
*/
static void *
page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
void *p; /* Returned page */
*pflag = UMA_SLAB_KERNEL;
p = (void *)kmem_malloc_domainset(DOMAINSET_FIXED(domain), bytes, wait);
return (p);
}
static void *
pcpu_page_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
struct pglist alloctail;
vm_offset_t addr, zkva;
int cpu, flags;
vm_page_t p, p_next;
#ifdef NUMA
struct pcpu *pc;
#endif
MPASS(bytes == (mp_maxid + 1) * PAGE_SIZE);
TAILQ_INIT(&alloctail);
flags = VM_ALLOC_SYSTEM | VM_ALLOC_WIRED | malloc2vm_flags(wait);
*pflag = UMA_SLAB_KERNEL;
for (cpu = 0; cpu <= mp_maxid; cpu++) {
if (CPU_ABSENT(cpu)) {
p = vm_page_alloc_noobj(flags);
} else {
#ifndef NUMA
p = vm_page_alloc_noobj(flags);
#else
pc = pcpu_find(cpu);
if (__predict_false(VM_DOMAIN_EMPTY(pc->pc_domain)))
p = NULL;
else
p = vm_page_alloc_noobj_domain(pc->pc_domain,
flags);
if (__predict_false(p == NULL))
p = vm_page_alloc_noobj(flags);
#endif
}
if (__predict_false(p == NULL))
goto fail;
TAILQ_INSERT_TAIL(&alloctail, p, listq);
}
if ((addr = kva_alloc(bytes)) == 0)
goto fail;
zkva = addr;
TAILQ_FOREACH(p, &alloctail, listq) {
pmap_qenter(zkva, &p, 1);
zkva += PAGE_SIZE;
}
return ((void*)addr);
fail:
TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
vm_page_unwire_noq(p);
vm_page_free(p);
}
return (NULL);
}
/*
* Allocates a number of pages not belonging to a VM object
*
* Arguments:
* bytes The number of bytes requested
* wait Shall we wait?
*
* Returns:
* A pointer to the alloced memory or possibly
* NULL if M_NOWAIT is set.
*/
static void *
noobj_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
int wait)
{
TAILQ_HEAD(, vm_page) alloctail;
u_long npages;
vm_offset_t retkva, zkva;
vm_page_t p, p_next;
uma_keg_t keg;
int req;
TAILQ_INIT(&alloctail);
keg = zone->uz_keg;
req = VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED;
if ((wait & M_WAITOK) != 0)
req |= VM_ALLOC_WAITOK;
npages = howmany(bytes, PAGE_SIZE);
while (npages > 0) {
p = vm_page_alloc_noobj_domain(domain, req);
if (p != NULL) {
/*
* Since the page does not belong to an object, its
* listq is unused.
*/
TAILQ_INSERT_TAIL(&alloctail, p, listq);
npages--;
continue;
}
/*
* Page allocation failed, free intermediate pages and
* exit.
*/
TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
vm_page_unwire_noq(p);
vm_page_free(p);
}
return (NULL);
}
*flags = UMA_SLAB_PRIV;
zkva = keg->uk_kva +
atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
retkva = zkva;
TAILQ_FOREACH(p, &alloctail, listq) {
pmap_qenter(zkva, &p, 1);
zkva += PAGE_SIZE;
}
return ((void *)retkva);
}
/*
* Allocate physically contiguous pages.
*/
static void *
contig_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
*pflag = UMA_SLAB_KERNEL;
return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
bytes, wait, 0, ~(vm_paddr_t)0, 1, 0, VM_MEMATTR_DEFAULT));
}
/*
* Frees a number of pages to the system
*
* Arguments:
* mem A pointer to the memory to be freed
* size The size of the memory being freed
* flags The original p->us_flags field
*
* Returns:
* Nothing
*/
static void
page_free(void *mem, vm_size_t size, uint8_t flags)
{
if ((flags & UMA_SLAB_BOOT) != 0) {
startup_free(mem, size);
return;
}
KASSERT((flags & UMA_SLAB_KERNEL) != 0,
("UMA: page_free used with invalid flags %x", flags));
kmem_free((vm_offset_t)mem, size);
}
/*
* Frees pcpu zone allocations
*
* Arguments:
* mem A pointer to the memory to be freed
* size The size of the memory being freed
* flags The original p->us_flags field
*
* Returns:
* Nothing
*/
static void
pcpu_page_free(void *mem, vm_size_t size, uint8_t flags)
{
vm_offset_t sva, curva;
vm_paddr_t paddr;
vm_page_t m;
MPASS(size == (mp_maxid+1)*PAGE_SIZE);
if ((flags & UMA_SLAB_BOOT) != 0) {
startup_free(mem, size);
return;
}
sva = (vm_offset_t)mem;
for (curva = sva; curva < sva + size; curva += PAGE_SIZE) {
paddr = pmap_kextract(curva);
m = PHYS_TO_VM_PAGE(paddr);
vm_page_unwire_noq(m);
vm_page_free(m);
}
pmap_qremove(sva, size >> PAGE_SHIFT);
kva_free(sva, size);
}
/*
* Zero fill initializer
*
* Arguments/Returns follow uma_init specifications
*/
static int
zero_init(void *mem, int size, int flags)
{
bzero(mem, size);
return (0);
}
#ifdef INVARIANTS
static struct noslabbits *
slab_dbg_bits(uma_slab_t slab, uma_keg_t keg)
{
return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers)));
}
#endif
/*
* Actual size of embedded struct slab (!OFFPAGE).
*/
static size_t
slab_sizeof(int nitems)
{
size_t s;
s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS;
return (roundup(s, UMA_ALIGN_PTR + 1));
}
#define UMA_FIXPT_SHIFT 31
#define UMA_FRAC_FIXPT(n, d) \
((uint32_t)(((uint64_t)(n) << UMA_FIXPT_SHIFT) / (d)))
#define UMA_FIXPT_PCT(f) \
((u_int)(((uint64_t)100 * (f)) >> UMA_FIXPT_SHIFT))
#define UMA_PCT_FIXPT(pct) UMA_FRAC_FIXPT((pct), 100)
#define UMA_MIN_EFF UMA_PCT_FIXPT(100 - UMA_MAX_WASTE)
/*
* Compute the number of items that will fit in a slab. If hdr is true, the
* item count may be limited to provide space in the slab for an inline slab
* header. Otherwise, all slab space will be provided for item storage.
*/
static u_int
slab_ipers_hdr(u_int size, u_int rsize, u_int slabsize, bool hdr)
{
u_int ipers;
u_int padpi;
/* The padding between items is not needed after the last item. */
padpi = rsize - size;
if (hdr) {
/*
* Start with the maximum item count and remove items until
* the slab header first alongside the allocatable memory.
*/
for (ipers = MIN(SLAB_MAX_SETSIZE,
(slabsize + padpi - slab_sizeof(1)) / rsize);
ipers > 0 &&
ipers * rsize - padpi + slab_sizeof(ipers) > slabsize;
ipers--)
continue;
} else {
ipers = MIN((slabsize + padpi) / rsize, SLAB_MAX_SETSIZE);
}
return (ipers);
}
struct keg_layout_result {
u_int format;
u_int slabsize;
u_int ipers;
u_int eff;
};
static void
keg_layout_one(uma_keg_t keg, u_int rsize, u_int slabsize, u_int fmt,
struct keg_layout_result *kl)
{
u_int total;
kl->format = fmt;
kl->slabsize = slabsize;
/* Handle INTERNAL as inline with an extra page. */
if ((fmt & UMA_ZFLAG_INTERNAL) != 0) {
kl->format &= ~UMA_ZFLAG_INTERNAL;
kl->slabsize += PAGE_SIZE;
}
kl->ipers = slab_ipers_hdr(keg->uk_size, rsize, kl->slabsize,
(fmt & UMA_ZFLAG_OFFPAGE) == 0);
/* Account for memory used by an offpage slab header. */
total = kl->slabsize;
if ((fmt & UMA_ZFLAG_OFFPAGE) != 0)
total += slabzone(kl->ipers)->uz_keg->uk_rsize;
kl->eff = UMA_FRAC_FIXPT(kl->ipers * rsize, total);
}
/*
* Determine the format of a uma keg. This determines where the slab header
* will be placed (inline or offpage) and calculates ipers, rsize, and ppera.
*
* Arguments
* keg The zone we should initialize
*
* Returns
* Nothing
*/
static void
keg_layout(uma_keg_t keg)
{
struct keg_layout_result kl = {}, kl_tmp;
u_int fmts[2];
u_int alignsize;
u_int nfmt;
u_int pages;
u_int rsize;
u_int slabsize;
u_int i, j;
KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
(keg->uk_size <= UMA_PCPU_ALLOC_SIZE &&
(keg->uk_flags & UMA_ZONE_CACHESPREAD) == 0),
("%s: cannot configure for PCPU: keg=%s, size=%u, flags=0x%b",
__func__, keg->uk_name, keg->uk_size, keg->uk_flags,
PRINT_UMA_ZFLAGS));
KASSERT((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) == 0 ||
(keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0,
("%s: incompatible flags 0x%b", __func__, keg->uk_flags,
PRINT_UMA_ZFLAGS));
alignsize = keg->uk_align + 1;
#ifdef KASAN
/*
* ASAN requires that each allocation be aligned to the shadow map
* scale factor.
*/
if (alignsize < KASAN_SHADOW_SCALE)
alignsize = KASAN_SHADOW_SCALE;
#endif
/*
* Calculate the size of each allocation (rsize) according to
* alignment. If the requested size is smaller than we have
* allocation bits for we round it up.
*/
rsize = MAX(keg->uk_size, UMA_SMALLEST_UNIT);
rsize = roundup2(rsize, alignsize);
if ((keg->uk_flags & UMA_ZONE_CACHESPREAD) != 0) {
/*
* We want one item to start on every align boundary in a page.
* To do this we will span pages. We will also extend the item
* by the size of align if it is an even multiple of align.
* Otherwise, it would fall on the same boundary every time.
*/
if ((rsize & alignsize) == 0)
rsize += alignsize;
slabsize = rsize * (PAGE_SIZE / alignsize);
slabsize = MIN(slabsize, rsize * SLAB_MAX_SETSIZE);
slabsize = MIN(slabsize, UMA_CACHESPREAD_MAX_SIZE);
slabsize = round_page(slabsize);
} else {
/*
* Start with a slab size of as many pages as it takes to
* represent a single item. We will try to fit as many
* additional items into the slab as possible.
*/
slabsize = round_page(keg->uk_size);
}
/* Build a list of all of the available formats for this keg. */
nfmt = 0;
/* Evaluate an inline slab layout. */
if ((keg->uk_flags & (UMA_ZONE_NOTOUCH | UMA_ZONE_PCPU)) == 0)
fmts[nfmt++] = 0;
/* TODO: vm_page-embedded slab. */
/*
* We can't do OFFPAGE if we're internal or if we've been
* asked to not go to the VM for buckets. If we do this we
* may end up going to the VM for slabs which we do not want
* to do if we're UMA_ZONE_VM, which clearly forbids it.
* In those cases, evaluate a pseudo-format called INTERNAL
* which has an inline slab header and one extra page to
* guarantee that it fits.
*
* Otherwise, see if using an OFFPAGE slab will improve our
* efficiency.
*/
if ((keg->uk_flags & (UMA_ZFLAG_INTERNAL | UMA_ZONE_VM)) != 0)
fmts[nfmt++] = UMA_ZFLAG_INTERNAL;
else
fmts[nfmt++] = UMA_ZFLAG_OFFPAGE;
/*
* Choose a slab size and format which satisfy the minimum efficiency.
* Prefer the smallest slab size that meets the constraints.
*
* Start with a minimum slab size, to accommodate CACHESPREAD. Then,
* for small items (up to PAGE_SIZE), the iteration increment is one
* page; and for large items, the increment is one item.
*/
i = (slabsize + rsize - keg->uk_size) / MAX(PAGE_SIZE, rsize);
KASSERT(i >= 1, ("keg %s(%p) flags=0x%b slabsize=%u, rsize=%u, i=%u",
keg->uk_name, keg, keg->uk_flags, PRINT_UMA_ZFLAGS, slabsize,
rsize, i));
for ( ; ; i++) {
slabsize = (rsize <= PAGE_SIZE) ? ptoa(i) :
round_page(rsize * (i - 1) + keg->uk_size);
for (j = 0; j < nfmt; j++) {
/* Only if we have no viable format yet. */
if ((fmts[j] & UMA_ZFLAG_INTERNAL) != 0 &&
kl.ipers > 0)
continue;
keg_layout_one(keg, rsize, slabsize, fmts[j], &kl_tmp);
if (kl_tmp.eff <= kl.eff)
continue;
kl = kl_tmp;
CTR6(KTR_UMA, "keg %s layout: format %#x "
"(ipers %u * rsize %u) / slabsize %#x = %u%% eff",
keg->uk_name, kl.format, kl.ipers, rsize,
kl.slabsize, UMA_FIXPT_PCT(kl.eff));
/* Stop when we reach the minimum efficiency. */
if (kl.eff >= UMA_MIN_EFF)
break;
}
if (kl.eff >= UMA_MIN_EFF || !multipage_slabs ||
slabsize >= SLAB_MAX_SETSIZE * rsize ||
(keg->uk_flags & (UMA_ZONE_PCPU | UMA_ZONE_CONTIG)) != 0)
break;
}
pages = atop(kl.slabsize);
if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
pages *= mp_maxid + 1;
keg->uk_rsize = rsize;
keg->uk_ipers = kl.ipers;
keg->uk_ppera = pages;
keg->uk_flags |= kl.format;
/*
* How do we find the slab header if it is offpage or if not all item
* start addresses are in the same page? We could solve the latter
* case with vaddr alignment, but we don't.
*/
if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0 ||
(keg->uk_ipers - 1) * rsize >= PAGE_SIZE) {
if ((keg->uk_flags & UMA_ZONE_NOTPAGE) != 0)
keg->uk_flags |= UMA_ZFLAG_HASH;
else
keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
}
CTR6(KTR_UMA, "%s: keg=%s, flags=%#x, rsize=%u, ipers=%u, ppera=%u",
__func__, keg->uk_name, keg->uk_flags, rsize, keg->uk_ipers,
pages);
KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_MAX_SETSIZE,
("%s: keg=%s, flags=0x%b, rsize=%u, ipers=%u, ppera=%u", __func__,
keg->uk_name, keg->uk_flags, PRINT_UMA_ZFLAGS, rsize,
keg->uk_ipers, pages));
}
/*
* Keg header ctor. This initializes all fields, locks, etc. And inserts
* the keg onto the global keg list.
*
* Arguments/Returns follow uma_ctor specifications
* udata Actually uma_kctor_args
*/
static int
keg_ctor(void *mem, int size, void *udata, int flags)
{
struct uma_kctor_args *arg = udata;
uma_keg_t keg = mem;
uma_zone_t zone;
int i;
bzero(keg, size);
keg->uk_size = arg->size;
keg->uk_init = arg->uminit;
keg->uk_fini = arg->fini;
keg->uk_align = arg->align;
keg->uk_reserve = 0;
keg->uk_flags = arg->flags;
/*
* We use a global round-robin policy by default. Zones with
* UMA_ZONE_FIRSTTOUCH set will use first-touch instead, in which
* case the iterator is never run.
*/
keg->uk_dr.dr_policy = DOMAINSET_RR();
keg->uk_dr.dr_iter = 0;
/*
* The primary zone is passed to us at keg-creation time.
*/
zone = arg->zone;
keg->uk_name = zone->uz_name;
if (arg->flags & UMA_ZONE_ZINIT)
keg->uk_init = zero_init;
if (arg->flags & UMA_ZONE_MALLOC)
keg->uk_flags |= UMA_ZFLAG_VTOSLAB;
#ifndef SMP
keg->uk_flags &= ~UMA_ZONE_PCPU;
#endif
keg_layout(keg);
/*
* Use a first-touch NUMA policy for kegs that pmap_extract() will
* work on. Use round-robin for everything else.
*
* Zones may override the default by specifying either.
*/
#ifdef NUMA
if ((keg->uk_flags &
(UMA_ZONE_ROUNDROBIN | UMA_ZFLAG_CACHE | UMA_ZONE_NOTPAGE)) == 0)
keg->uk_flags |= UMA_ZONE_FIRSTTOUCH;
else if ((keg->uk_flags & UMA_ZONE_FIRSTTOUCH) == 0)
keg->uk_flags |= UMA_ZONE_ROUNDROBIN;
#endif
/*
* If we haven't booted yet we need allocations to go through the
* startup cache until the vm is ready.
*/
#ifdef UMA_MD_SMALL_ALLOC
if (keg->uk_ppera == 1)
keg->uk_allocf = uma_small_alloc;
else
#endif
if (booted < BOOT_KVA)
keg->uk_allocf = startup_alloc;
else if (keg->uk_flags & UMA_ZONE_PCPU)
keg->uk_allocf = pcpu_page_alloc;
else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 && keg->uk_ppera > 1)
keg->uk_allocf = contig_alloc;
else
keg->uk_allocf = page_alloc;
#ifdef UMA_MD_SMALL_ALLOC
if (keg->uk_ppera == 1)
keg->uk_freef = uma_small_free;
else
#endif
if (keg->uk_flags & UMA_ZONE_PCPU)
keg->uk_freef = pcpu_page_free;
else
keg->uk_freef = page_free;
/*
* Initialize keg's locks.
*/
for (i = 0; i < vm_ndomains; i++)
KEG_LOCK_INIT(keg, i, (arg->flags & UMA_ZONE_MTXCLASS));
/*
* If we're putting the slab header in the actual page we need to
* figure out where in each page it goes. See slab_sizeof
* definition.
*/
if (!(keg->uk_flags & UMA_ZFLAG_OFFPAGE)) {
size_t shsize;
shsize = slab_sizeof(keg->uk_ipers);
keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - shsize;
/*
* The only way the following is possible is if with our
* UMA_ALIGN_PTR adjustments we are now bigger than
* UMA_SLAB_SIZE. I haven't checked whether this is
* mathematically possible for all cases, so we make
* sure here anyway.
*/
KASSERT(keg->uk_pgoff + shsize <= PAGE_SIZE * keg->uk_ppera,
("zone %s ipers %d rsize %d size %d slab won't fit",
zone->uz_name, keg->uk_ipers, keg->uk_rsize, keg->uk_size));
}
if (keg->uk_flags & UMA_ZFLAG_HASH)
hash_alloc(&keg->uk_hash, 0);
CTR3(KTR_UMA, "keg_ctor %p zone %s(%p)", keg, zone->uz_name, zone);
LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
rw_wlock(&uma_rwlock);
LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
rw_wunlock(&uma_rwlock);
return (0);
}
static void
zone_kva_available(uma_zone_t zone, void *unused)
{
uma_keg_t keg;
if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
return;
KEG_GET(zone, keg);
if (keg->uk_allocf == startup_alloc) {
/* Switch to the real allocator. */
if (keg->uk_flags & UMA_ZONE_PCPU)
keg->uk_allocf = pcpu_page_alloc;
else if ((keg->uk_flags & UMA_ZONE_CONTIG) != 0 &&
keg->uk_ppera > 1)
keg->uk_allocf = contig_alloc;
else
keg->uk_allocf = page_alloc;
}
}
static void
zone_alloc_counters(uma_zone_t zone, void *unused)
{
zone->uz_allocs = counter_u64_alloc(M_WAITOK);
zone->uz_frees = counter_u64_alloc(M_WAITOK);
zone->uz_fails = counter_u64_alloc(M_WAITOK);
zone->uz_xdomain = counter_u64_alloc(M_WAITOK);
}
static void
zone_alloc_sysctl(uma_zone_t zone, void *unused)
{
uma_zone_domain_t zdom;
uma_domain_t dom;
uma_keg_t keg;
struct sysctl_oid *oid, *domainoid;
int domains, i, cnt;
static const char *nokeg = "cache zone";
char *c;
/*
* Make a sysctl safe copy of the zone name by removing
* any special characters and handling dups by appending
* an index.
*/
if (zone->uz_namecnt != 0) {
/* Count the number of decimal digits and '_' separator. */
for (i = 1, cnt = zone->uz_namecnt; cnt != 0; i++)
cnt /= 10;
zone->uz_ctlname = malloc(strlen(zone->uz_name) + i + 1,
M_UMA, M_WAITOK);
sprintf(zone->uz_ctlname, "%s_%d", zone->uz_name,
zone->uz_namecnt);
} else
zone->uz_ctlname = strdup(zone->uz_name, M_UMA);
for (c = zone->uz_ctlname; *c != '\0'; c++)
if (strchr("./\\ -", *c) != NULL)
*c = '_';
/*
* Basic parameters at the root.
*/
zone->uz_oid = SYSCTL_ADD_NODE(NULL, SYSCTL_STATIC_CHILDREN(_vm_uma),
OID_AUTO, zone->uz_ctlname, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
oid = zone->uz_oid;
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"size", CTLFLAG_RD, &zone->uz_size, 0, "Allocation size");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"flags", CTLFLAG_RD | CTLTYPE_STRING | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_flags, "A",
"Allocator configuration flags");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_size", CTLFLAG_RD, &zone->uz_bucket_size, 0,
"Desired per-cpu cache size");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_size_max", CTLFLAG_RD, &zone->uz_bucket_size_max, 0,
"Maximum allowed per-cpu cache size");
/*
* keg if present.
*/
if ((zone->uz_flags & UMA_ZFLAG_HASH) == 0)
domains = vm_ndomains;
else
domains = 1;
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
"keg", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
keg = zone->uz_keg;
if ((zone->uz_flags & UMA_ZFLAG_CACHE) == 0) {
SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"name", CTLFLAG_RD, keg->uk_name, "Keg name");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"rsize", CTLFLAG_RD, &keg->uk_rsize, 0,
"Real object size with alignment");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"ppera", CTLFLAG_RD, &keg->uk_ppera, 0,
"pages per-slab allocation");
SYSCTL_ADD_U16(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"ipers", CTLFLAG_RD, &keg->uk_ipers, 0,
"items available per-slab");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"align", CTLFLAG_RD, &keg->uk_align, 0,
"item alignment mask");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"reserve", CTLFLAG_RD, &keg->uk_reserve, 0,
"number of reserved items");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"efficiency", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
keg, 0, sysctl_handle_uma_slab_efficiency, "I",
"Slab utilization (100 - internal fragmentation %)");
domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(oid),
OID_AUTO, "domain", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
for (i = 0; i < domains; i++) {
dom = &keg->uk_domain[i];
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
OID_AUTO, VM_DOMAIN(i)->vmd_name,
CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"pages", CTLFLAG_RD, &dom->ud_pages, 0,
"Total pages currently allocated from VM");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"free_items", CTLFLAG_RD, &dom->ud_free_items, 0,
"Items free in the slab layer");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"free_slabs", CTLFLAG_RD, &dom->ud_free_slabs, 0,
"Unused slabs");
}
} else
SYSCTL_ADD_CONST_STRING(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"name", CTLFLAG_RD, nokeg, "Keg name");
/*
* Information about zone limits.
*/
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
"limit", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"items", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_items, "QU",
"Current number of allocated items if limit is set");
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"max_items", CTLFLAG_RD, &zone->uz_max_items, 0,
"Maximum number of allocated and cached items");
SYSCTL_ADD_U32(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"sleepers", CTLFLAG_RD, &zone->uz_sleepers, 0,
"Number of threads sleeping at limit");
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"sleeps", CTLFLAG_RD, &zone->uz_sleeps, 0,
"Total zone limit sleeps");
SYSCTL_ADD_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bucket_max", CTLFLAG_RD, &zone->uz_bucket_max, 0,
"Maximum number of items in each domain's bucket cache");
/*
* Per-domain zone information.
*/
domainoid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid),
OID_AUTO, "domain", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
for (i = 0; i < domains; i++) {
zdom = ZDOM_GET(zone, i);
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(domainoid),
OID_AUTO, VM_DOMAIN(i)->vmd_name,
CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"nitems", CTLFLAG_RD, &zdom->uzd_nitems,
"number of items in this domain");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"imax", CTLFLAG_RD, &zdom->uzd_imax,
"maximum item count in this period");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"imin", CTLFLAG_RD, &zdom->uzd_imin,
"minimum item count in this period");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"bimin", CTLFLAG_RD, &zdom->uzd_bimin,
"Minimum item count in this batch");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"wss", CTLFLAG_RD, &zdom->uzd_wss,
"Working set size");
SYSCTL_ADD_LONG(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"limin", CTLFLAG_RD, &zdom->uzd_limin,
"Long time minimum item count");
SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"timin", CTLFLAG_RD, &zdom->uzd_timin, 0,
"Time since zero long time minimum item count");
}
/*
* General statistics.
*/
oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(zone->uz_oid), OID_AUTO,
"stats", CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"current", CTLFLAG_RD | CTLTYPE_INT | CTLFLAG_MPSAFE,
zone, 1, sysctl_handle_uma_zone_cur, "I",
"Current number of allocated items");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"allocs", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_allocs, "QU",
"Total allocation calls");
SYSCTL_ADD_PROC(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"frees", CTLFLAG_RD | CTLTYPE_U64 | CTLFLAG_MPSAFE,
zone, 0, sysctl_handle_uma_zone_frees, "QU",
"Total free calls");
SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"fails", CTLFLAG_RD, &zone->uz_fails,
"Number of allocation failures");
SYSCTL_ADD_COUNTER_U64(NULL, SYSCTL_CHILDREN(oid), OID_AUTO,
"xdomain", CTLFLAG_RD, &zone->uz_xdomain,
"Free calls from the wrong domain");
}
struct uma_zone_count {
const char *name;
int count;
};
static void
zone_count(uma_zone_t zone, void *arg)
{
struct uma_zone_count *cnt;
cnt = arg;
/*
* Some zones are rapidly created with identical names and
* destroyed out of order. This can lead to gaps in the count.
* Use one greater than the maximum observed for this name.
*/
if (strcmp(zone->uz_name, cnt->name) == 0)
cnt->count = MAX(cnt->count,
zone->uz_namecnt + 1);
}
static void
zone_update_caches(uma_zone_t zone)
{
int i;
for (i = 0; i <= mp_maxid; i++) {
cache_set_uz_size(&zone->uz_cpu[i], zone->uz_size);
cache_set_uz_flags(&zone->uz_cpu[i], zone->uz_flags);
}
}
/*
* Zone header ctor. This initializes all fields, locks, etc.
*
* Arguments/Returns follow uma_ctor specifications
* udata Actually uma_zctor_args
*/
static int
zone_ctor(void *mem, int size, void *udata, int flags)
{
struct uma_zone_count cnt;
struct uma_zctor_args *arg = udata;
uma_zone_domain_t zdom;
uma_zone_t zone = mem;
uma_zone_t z;
uma_keg_t keg;
int i;
bzero(zone, size);
zone->uz_name = arg->name;
zone->uz_ctor = arg->ctor;
zone->uz_dtor = arg->dtor;
zone->uz_init = NULL;
zone->uz_fini = NULL;
zone->uz_sleeps = 0;
zone->uz_bucket_size = 0;
zone->uz_bucket_size_min = 0;
zone->uz_bucket_size_max = BUCKET_MAX;
zone->uz_flags = (arg->flags & UMA_ZONE_SMR);
zone->uz_warning = NULL;
/* The domain structures follow the cpu structures. */
zone->uz_bucket_max = ULONG_MAX;
timevalclear(&zone->uz_ratecheck);
/* Count the number of duplicate names. */
cnt.name = arg->name;
cnt.count = 0;
zone_foreach(zone_count, &cnt);
zone->uz_namecnt = cnt.count;
ZONE_CROSS_LOCK_INIT(zone);
for (i = 0; i < vm_ndomains; i++) {
zdom = ZDOM_GET(zone, i);
ZDOM_LOCK_INIT(zone, zdom, (arg->flags & UMA_ZONE_MTXCLASS));
STAILQ_INIT(&zdom->uzd_buckets);
}
#if defined(INVARIANTS) && !defined(KASAN) && !defined(KMSAN)
if (arg->uminit == trash_init && arg->fini == trash_fini)
zone->uz_flags |= UMA_ZFLAG_TRASH | UMA_ZFLAG_CTORDTOR;
#elif defined(KASAN)
if ((arg->flags & (UMA_ZONE_NOFREE | UMA_ZFLAG_CACHE)) != 0)
arg->flags |= UMA_ZONE_NOKASAN;
#endif
/*
* This is a pure cache zone, no kegs.
*/
if (arg->import) {
KASSERT((arg->flags & UMA_ZFLAG_CACHE) != 0,
("zone_ctor: Import specified for non-cache zone."));
zone->uz_flags = arg->flags;
zone->uz_size = arg->size;
zone->uz_import = arg->import;
zone->uz_release = arg->release;
zone->uz_arg = arg->arg;
#ifdef NUMA
/*
* Cache zones are round-robin unless a policy is
* specified because they may have incompatible
* constraints.
*/
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) == 0)
zone->uz_flags |= UMA_ZONE_ROUNDROBIN;
#endif
rw_wlock(&uma_rwlock);
LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
rw_wunlock(&uma_rwlock);
goto out;
}
/*
* Use the regular zone/keg/slab allocator.
*/
zone->uz_import = zone_import;
zone->uz_release = zone_release;
zone->uz_arg = zone;
keg = arg->keg;
if (arg->flags & UMA_ZONE_SECONDARY) {
KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
("Secondary zone requested UMA_ZFLAG_INTERNAL"));
KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
zone->uz_init = arg->uminit;
zone->uz_fini = arg->fini;
zone->uz_flags |= UMA_ZONE_SECONDARY;
rw_wlock(&uma_rwlock);
ZONE_LOCK(zone);
LIST_FOREACH(z, &keg->uk_zones, uz_link) {
if (LIST_NEXT(z, uz_link) == NULL) {
LIST_INSERT_AFTER(z, zone, uz_link);
break;
}
}
ZONE_UNLOCK(zone);
rw_wunlock(&uma_rwlock);
} else if (keg == NULL) {
if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
arg->align, arg->flags)) == NULL)
return (ENOMEM);
} else {
struct uma_kctor_args karg;
int error;
/* We should only be here from uma_startup() */
karg.size = arg->size;
karg.uminit = arg->uminit;
karg.fini = arg->fini;
karg.align = arg->align;
karg.flags = (arg->flags & ~UMA_ZONE_SMR);
karg.zone = zone;
error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
flags);
if (error)
return (error);
}
/* Inherit properties from the keg. */
zone->uz_keg = keg;
zone->uz_size = keg->uk_size;
zone->uz_flags |= (keg->uk_flags &
(UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
out:
if (booted >= BOOT_PCPU) {
zone_alloc_counters(zone, NULL);
if (booted >= BOOT_RUNNING)
zone_alloc_sysctl(zone, NULL);
} else {
zone->uz_allocs = EARLY_COUNTER;
zone->uz_frees = EARLY_COUNTER;
zone->uz_fails = EARLY_COUNTER;
}
/* Caller requests a private SMR context. */
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
zone->uz_smr = smr_create(zone->uz_name, 0, 0);
KASSERT((arg->flags & (UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET)) !=
(UMA_ZONE_MAXBUCKET | UMA_ZONE_NOBUCKET),
("Invalid zone flag combination"));
if (arg->flags & UMA_ZFLAG_INTERNAL)
zone->uz_bucket_size_max = zone->uz_bucket_size = 0;
if ((arg->flags & UMA_ZONE_MAXBUCKET) != 0)
zone->uz_bucket_size = BUCKET_MAX;
else if ((arg->flags & UMA_ZONE_NOBUCKET) != 0)
zone->uz_bucket_size = 0;
else
zone->uz_bucket_size = bucket_select(zone->uz_size);
zone->uz_bucket_size_min = zone->uz_bucket_size;
if (zone->uz_dtor != NULL || zone->uz_ctor != NULL)
zone->uz_flags |= UMA_ZFLAG_CTORDTOR;
zone_update_caches(zone);
return (0);
}
/*
* Keg header dtor. This frees all data, destroys locks, frees the hash
* table and removes the keg from the global list.
*
* Arguments/Returns follow uma_dtor specifications
* udata unused
*/
static void
keg_dtor(void *arg, int size, void *udata)
{
uma_keg_t keg;
uint32_t free, pages;
int i;
keg = (uma_keg_t)arg;
free = pages = 0;
for (i = 0; i < vm_ndomains; i++) {
free += keg->uk_domain[i].ud_free_items;
pages += keg->uk_domain[i].ud_pages;
KEG_LOCK_FINI(keg, i);
}
if (pages != 0)
printf("Freed UMA keg (%s) was not empty (%u items). "
" Lost %u pages of memory.\n",
keg->uk_name ? keg->uk_name : "",
pages / keg->uk_ppera * keg->uk_ipers - free, pages);
hash_free(&keg->uk_hash);
}
/*
* Zone header dtor.
*
* Arguments/Returns follow uma_dtor specifications
* udata unused
*/
static void
zone_dtor(void *arg, int size, void *udata)
{
uma_zone_t zone;
uma_keg_t keg;
int i;
zone = (uma_zone_t)arg;
sysctl_remove_oid(zone->uz_oid, 1, 1);
if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
cache_drain(zone);
rw_wlock(&uma_rwlock);
LIST_REMOVE(zone, uz_link);
rw_wunlock(&uma_rwlock);
if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
keg = zone->uz_keg;
keg->uk_reserve = 0;
}
zone_reclaim(zone, UMA_ANYDOMAIN, M_WAITOK, true);
/*
* We only destroy kegs from non secondary/non cache zones.
*/
if ((zone->uz_flags & (UMA_ZONE_SECONDARY | UMA_ZFLAG_CACHE)) == 0) {
keg = zone->uz_keg;
rw_wlock(&uma_rwlock);
LIST_REMOVE(keg, uk_link);
rw_wunlock(&uma_rwlock);
zone_free_item(kegs, keg, NULL, SKIP_NONE);
}
counter_u64_free(zone->uz_allocs);
counter_u64_free(zone->uz_frees);
counter_u64_free(zone->uz_fails);
counter_u64_free(zone->uz_xdomain);
free(zone->uz_ctlname, M_UMA);
for (i = 0; i < vm_ndomains; i++)
ZDOM_LOCK_FINI(ZDOM_GET(zone, i));
ZONE_CROSS_LOCK_FINI(zone);
}
static void
zone_foreach_unlocked(void (*zfunc)(uma_zone_t, void *arg), void *arg)
{
uma_keg_t keg;
uma_zone_t zone;
LIST_FOREACH(keg, &uma_kegs, uk_link) {
LIST_FOREACH(zone, &keg->uk_zones, uz_link)
zfunc(zone, arg);
}
LIST_FOREACH(zone, &uma_cachezones, uz_link)
zfunc(zone, arg);
}
/*
* Traverses every zone in the system and calls a callback
*
* Arguments:
* zfunc A pointer to a function which accepts a zone
* as an argument.
*
* Returns:
* Nothing
*/
static void
zone_foreach(void (*zfunc)(uma_zone_t, void *arg), void *arg)
{
rw_rlock(&uma_rwlock);
zone_foreach_unlocked(zfunc, arg);
rw_runlock(&uma_rwlock);
}
/*
* Initialize the kernel memory allocator. This is done after pages can be
* allocated but before general KVA is available.
*/
void
uma_startup1(vm_offset_t virtual_avail)
{
struct uma_zctor_args args;
size_t ksize, zsize, size;
uma_keg_t primarykeg;
uintptr_t m;
int domain;
uint8_t pflag;
bootstart = bootmem = virtual_avail;
rw_init(&uma_rwlock, "UMA lock");
sx_init(&uma_reclaim_lock, "umareclaim");
ksize = sizeof(struct uma_keg) +
(sizeof(struct uma_domain) * vm_ndomains);
ksize = roundup(ksize, UMA_SUPER_ALIGN);
zsize = sizeof(struct uma_zone) +
(sizeof(struct uma_cache) * (mp_maxid + 1)) +
(sizeof(struct uma_zone_domain) * vm_ndomains);
zsize = roundup(zsize, UMA_SUPER_ALIGN);
/* Allocate the zone of zones, zone of kegs, and zone of zones keg. */
size = (zsize * 2) + ksize;
for (domain = 0; domain < vm_ndomains; domain++) {
m = (uintptr_t)startup_alloc(NULL, size, domain, &pflag,
M_NOWAIT | M_ZERO);
if (m != 0)
break;
}
zones = (uma_zone_t)m;
m += zsize;
kegs = (uma_zone_t)m;
m += zsize;
primarykeg = (uma_keg_t)m;
/* "manually" create the initial zone */
memset(&args, 0, sizeof(args));
args.name = "UMA Kegs";
args.size = ksize;
args.ctor = keg_ctor;
args.dtor = keg_dtor;
args.uminit = zero_init;
args.fini = NULL;
args.keg = primarykeg;
args.align = UMA_SUPER_ALIGN - 1;
args.flags = UMA_ZFLAG_INTERNAL;
zone_ctor(kegs, zsize, &args, M_WAITOK);
args.name = "UMA Zones";
args.size = zsize;
args.ctor = zone_ctor;
args.dtor = zone_dtor;
args.uminit = zero_init;
args.fini = NULL;
args.keg = NULL;
args.align = UMA_SUPER_ALIGN - 1;
args.flags = UMA_ZFLAG_INTERNAL;
zone_ctor(zones, zsize, &args, M_WAITOK);
/* Now make zones for slab headers */
slabzones[0] = uma_zcreate("UMA Slabs 0", SLABZONE0_SIZE,
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
slabzones[1] = uma_zcreate("UMA Slabs 1", SLABZONE1_SIZE,
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
hashzone = uma_zcreate("UMA Hash",
sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
bucket_init();
smr_init();
}
#ifndef UMA_MD_SMALL_ALLOC
extern void vm_radix_reserve_kva(void);
#endif
/*
* Advertise the availability of normal kva allocations and switch to
* the default back-end allocator. Marks the KVA we consumed on startup
* as used in the map.
*/
void
uma_startup2(void)
{
if (bootstart != bootmem) {
vm_map_lock(kernel_map);
(void)vm_map_insert(kernel_map, NULL, 0, bootstart, bootmem,
VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
vm_map_unlock(kernel_map);
}
#ifndef UMA_MD_SMALL_ALLOC
/* Set up radix zone to use noobj_alloc. */
vm_radix_reserve_kva();
#endif
booted = BOOT_KVA;
zone_foreach_unlocked(zone_kva_available, NULL);
bucket_enable();
}
/*
* Allocate counters as early as possible so that boot-time allocations are
* accounted more precisely.
*/
static void
uma_startup_pcpu(void *arg __unused)
{
zone_foreach_unlocked(zone_alloc_counters, NULL);
booted = BOOT_PCPU;
}
SYSINIT(uma_startup_pcpu, SI_SUB_COUNTER, SI_ORDER_ANY, uma_startup_pcpu, NULL);
/*
* Finish our initialization steps.
*/
static void
uma_startup3(void *arg __unused)
{
#ifdef INVARIANTS
TUNABLE_INT_FETCH("vm.debug.divisor", &dbg_divisor);
uma_dbg_cnt = counter_u64_alloc(M_WAITOK);
uma_skip_cnt = counter_u64_alloc(M_WAITOK);
#endif
zone_foreach_unlocked(zone_alloc_sysctl, NULL);
callout_init(&uma_callout, 1);
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
booted = BOOT_RUNNING;
EVENTHANDLER_REGISTER(shutdown_post_sync, uma_shutdown, NULL,
EVENTHANDLER_PRI_FIRST);
}
SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
static void
uma_shutdown(void)
{
booted = BOOT_SHUTDOWN;
}
static uma_keg_t
uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
int align, uint32_t flags)
{
struct uma_kctor_args args;
args.size = size;
args.uminit = uminit;
args.fini = fini;
args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
args.flags = flags;
args.zone = zone;
return (zone_alloc_item(kegs, &args, UMA_ANYDOMAIN, M_WAITOK));
}
/* Public functions */
/* See uma.h */
void
uma_set_align(int align)
{
if (align != UMA_ALIGN_CACHE)
uma_align_cache = align;
}
/* See uma.h */
uma_zone_t
uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
uma_init uminit, uma_fini fini, int align, uint32_t flags)
{
struct uma_zctor_args args;
uma_zone_t res;
KASSERT(powerof2(align + 1), ("invalid zone alignment %d for \"%s\"",
align, name));
/* This stuff is essential for the zone ctor */
memset(&args, 0, sizeof(args));
args.name = name;
args.size = size;
args.ctor = ctor;
args.dtor = dtor;
args.uminit = uminit;
args.fini = fini;
#if defined(INVARIANTS) && !defined(KASAN) && !defined(KMSAN)
/*
* Inject procedures which check for memory use after free if we are
* allowed to scramble the memory while it is not allocated. This
* requires that: UMA is actually able to access the memory, no init
* or fini procedures, no dependency on the initial value of the
* memory, and no (legitimate) use of the memory after free. Note,
* the ctor and dtor do not need to be empty.
*/
if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOTOUCH |
UMA_ZONE_NOFREE))) && uminit == NULL && fini == NULL) {
args.uminit = trash_init;
args.fini = trash_fini;
}
#endif
args.align = align;
args.flags = flags;
args.keg = NULL;
sx_xlock(&uma_reclaim_lock);
res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
sx_xunlock(&uma_reclaim_lock);
return (res);
}
/* See uma.h */
uma_zone_t
uma_zsecond_create(const char *name, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_zone_t primary)
{
struct uma_zctor_args args;
uma_keg_t keg;
uma_zone_t res;
keg = primary->uz_keg;
memset(&args, 0, sizeof(args));
args.name = name;
args.size = keg->uk_size;
args.ctor = ctor;
args.dtor = dtor;
args.uminit = zinit;
args.fini = zfini;
args.align = keg->uk_align;
args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
args.keg = keg;
sx_xlock(&uma_reclaim_lock);
res = zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK);
sx_xunlock(&uma_reclaim_lock);
return (res);
}
/* See uma.h */
uma_zone_t
uma_zcache_create(const char *name, int size, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_import zimport, uma_release zrelease,
void *arg, int flags)
{
struct uma_zctor_args args;
memset(&args, 0, sizeof(args));
args.name = name;
args.size = size;
args.ctor = ctor;
args.dtor = dtor;
args.uminit = zinit;
args.fini = zfini;
args.import = zimport;
args.release = zrelease;
args.arg = arg;
args.align = 0;
args.flags = flags | UMA_ZFLAG_CACHE;
return (zone_alloc_item(zones, &args, UMA_ANYDOMAIN, M_WAITOK));
}
/* See uma.h */
void
uma_zdestroy(uma_zone_t zone)
{
/*
* Large slabs are expensive to reclaim, so don't bother doing
* unnecessary work if we're shutting down.
*/
if (booted == BOOT_SHUTDOWN &&
zone->uz_fini == NULL && zone->uz_release == zone_release)
return;
sx_xlock(&uma_reclaim_lock);
zone_free_item(zones, zone, NULL, SKIP_NONE);
sx_xunlock(&uma_reclaim_lock);
}
void
uma_zwait(uma_zone_t zone)
{
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
uma_zfree_smr(zone, uma_zalloc_smr(zone, M_WAITOK));
else if ((zone->uz_flags & UMA_ZONE_PCPU) != 0)
uma_zfree_pcpu(zone, uma_zalloc_pcpu(zone, M_WAITOK));
else
uma_zfree(zone, uma_zalloc(zone, M_WAITOK));
}
void *
uma_zalloc_pcpu_arg(uma_zone_t zone, void *udata, int flags)
{
void *item, *pcpu_item;
#ifdef SMP
int i;
MPASS(zone->uz_flags & UMA_ZONE_PCPU);
#endif
item = uma_zalloc_arg(zone, udata, flags & ~M_ZERO);
if (item == NULL)
return (NULL);
pcpu_item = zpcpu_base_to_offset(item);
if (flags & M_ZERO) {
#ifdef SMP
for (i = 0; i <= mp_maxid; i++)
bzero(zpcpu_get_cpu(pcpu_item, i), zone->uz_size);
#else
bzero(item, zone->uz_size);
#endif
}
return (pcpu_item);
}
/*
* A stub while both regular and pcpu cases are identical.
*/
void
uma_zfree_pcpu_arg(uma_zone_t zone, void *pcpu_item, void *udata)
{
void *item;
#ifdef SMP
MPASS(zone->uz_flags & UMA_ZONE_PCPU);
#endif
/* uma_zfree_pcu_*(..., NULL) does nothing, to match free(9). */
if (pcpu_item == NULL)
return;
item = zpcpu_offset_to_base(pcpu_item);
uma_zfree_arg(zone, item, udata);
}
static inline void *
item_ctor(uma_zone_t zone, int uz_flags, int size, void *udata, int flags,
void *item)
{
#ifdef INVARIANTS
bool skipdbg;
#endif
kasan_mark_item_valid(zone, item);
kmsan_mark_item_uninitialized(zone, item);
#ifdef INVARIANTS
skipdbg = uma_dbg_zskip(zone, item);
if (!skipdbg && (uz_flags & UMA_ZFLAG_TRASH) != 0 &&
zone->uz_ctor != trash_ctor)
trash_ctor(item, size, udata, flags);
#endif
/* Check flags before loading ctor pointer. */
if (__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0) &&
__predict_false(zone->uz_ctor != NULL) &&
zone->uz_ctor(item, size, udata, flags) != 0) {
counter_u64_add(zone->uz_fails, 1);
zone_free_item(zone, item, udata, SKIP_DTOR | SKIP_CNT);
return (NULL);
}
#ifdef INVARIANTS
if (!skipdbg)
uma_dbg_alloc(zone, NULL, item);
#endif
if (__predict_false(flags & M_ZERO))
return (memset(item, 0, size));
return (item);
}
static inline void
item_dtor(uma_zone_t zone, void *item, int size, void *udata,
enum zfreeskip skip)
{
#ifdef INVARIANTS
bool skipdbg;
skipdbg = uma_dbg_zskip(zone, item);
if (skip == SKIP_NONE && !skipdbg) {
if ((zone->uz_flags & UMA_ZONE_MALLOC) != 0)
uma_dbg_free(zone, udata, item);
else
uma_dbg_free(zone, NULL, item);
}
#endif
if (__predict_true(skip < SKIP_DTOR)) {
if (zone->uz_dtor != NULL)
zone->uz_dtor(item, size, udata);
#ifdef INVARIANTS
if (!skipdbg && (zone->uz_flags & UMA_ZFLAG_TRASH) != 0 &&
zone->uz_dtor != trash_dtor)
trash_dtor(item, size, udata);
#endif
}
kasan_mark_item_invalid(zone, item);
}
#ifdef NUMA
static int
item_domain(void *item)
{
int domain;
domain = vm_phys_domain(vtophys(item));
KASSERT(domain >= 0 && domain < vm_ndomains,
("%s: unknown domain for item %p", __func__, item));
return (domain);
}
#endif
#if defined(INVARIANTS) || defined(DEBUG_MEMGUARD) || defined(WITNESS)
#define UMA_ZALLOC_DEBUG
static int
uma_zalloc_debug(uma_zone_t zone, void **itemp, void *udata, int flags)
{
int error;
error = 0;
#ifdef WITNESS
if (flags & M_WAITOK) {
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"uma_zalloc_debug: zone \"%s\"", zone->uz_name);
}
#endif
#ifdef INVARIANTS
KASSERT((flags & M_EXEC) == 0,
("uma_zalloc_debug: called with M_EXEC"));
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zalloc_debug: called within spinlock or critical section"));
KASSERT((zone->uz_flags & UMA_ZONE_PCPU) == 0 || (flags & M_ZERO) == 0,
("uma_zalloc_debug: allocating from a pcpu zone with M_ZERO"));
#endif
#ifdef DEBUG_MEMGUARD
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && memguard_cmp_zone(zone)) {
void *item;
item = memguard_alloc(zone->uz_size, flags);
if (item != NULL) {
error = EJUSTRETURN;
if (zone->uz_init != NULL &&
zone->uz_init(item, zone->uz_size, flags) != 0) {
*itemp = NULL;
return (error);
}
if (zone->uz_ctor != NULL &&
zone->uz_ctor(item, zone->uz_size, udata,
flags) != 0) {
counter_u64_add(zone->uz_fails, 1);
zone->uz_fini(item, zone->uz_size);
*itemp = NULL;
return (error);
}
*itemp = item;
return (error);
}
/* This is unfortunate but should not be fatal. */
}
#endif
return (error);
}
static int
uma_zfree_debug(uma_zone_t zone, void *item, void *udata)
{
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zfree_debug: called with spinlock or critical section held"));
#ifdef DEBUG_MEMGUARD
if ((zone->uz_flags & UMA_ZONE_SMR) == 0 && is_memguard_addr(item)) {
if (zone->uz_dtor != NULL)
zone->uz_dtor(item, zone->uz_size, udata);
if (zone->uz_fini != NULL)
zone->uz_fini(item, zone->uz_size);
memguard_free(item);
return (EJUSTRETURN);
}
#endif
return (0);
}
#endif
static inline void *
cache_alloc_item(uma_zone_t zone, uma_cache_t cache, uma_cache_bucket_t bucket,
void *udata, int flags)
{
void *item;
int size, uz_flags;
item = cache_bucket_pop(cache, bucket);
size = cache_uz_size(cache);
uz_flags = cache_uz_flags(cache);
critical_exit();
return (item_ctor(zone, uz_flags, size, udata, flags, item));
}
static __noinline void *
cache_alloc_retry(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
{
uma_cache_bucket_t bucket;
int domain;
while (cache_alloc(zone, cache, udata, flags)) {
cache = &zone->uz_cpu[curcpu];
bucket = &cache->uc_allocbucket;
if (__predict_false(bucket->ucb_cnt == 0))
continue;
return (cache_alloc_item(zone, cache, bucket, udata, flags));
}
critical_exit();
/*
* We can not get a bucket so try to return a single item.
*/
if (zone->uz_flags & UMA_ZONE_FIRSTTOUCH)
domain = PCPU_GET(domain);
else
domain = UMA_ANYDOMAIN;
return (zone_alloc_item(zone, udata, domain, flags));
}
/* See uma.h */
void *
uma_zalloc_smr(uma_zone_t zone, int flags)
{
uma_cache_bucket_t bucket;
uma_cache_t cache;
#ifdef UMA_ZALLOC_DEBUG
void *item;
KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
("uma_zalloc_arg: called with non-SMR zone."));
if (uma_zalloc_debug(zone, &item, NULL, flags) == EJUSTRETURN)
return (item);
#endif
critical_enter();
cache = &zone->uz_cpu[curcpu];
bucket = &cache->uc_allocbucket;
if (__predict_false(bucket->ucb_cnt == 0))
return (cache_alloc_retry(zone, cache, NULL, flags));
return (cache_alloc_item(zone, cache, bucket, NULL, flags));
}
/* See uma.h */
void *
uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
{
uma_cache_bucket_t bucket;
uma_cache_t cache;
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
/* This is the fast path allocation */
CTR3(KTR_UMA, "uma_zalloc_arg zone %s(%p) flags %d", zone->uz_name,
zone, flags);
#ifdef UMA_ZALLOC_DEBUG
void *item;
KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("uma_zalloc_arg: called with SMR zone."));
if (uma_zalloc_debug(zone, &item, udata, flags) == EJUSTRETURN)
return (item);
#endif
/*
* If possible, allocate from the per-CPU cache. There are two
* requirements for safe access to the per-CPU cache: (1) the thread
* accessing the cache must not be preempted or yield during access,
* and (2) the thread must not migrate CPUs without switching which
* cache it accesses. We rely on a critical section to prevent
* preemption and migration. We release the critical section in
* order to acquire the zone mutex if we are unable to allocate from
* the current cache; when we re-acquire the critical section, we
* must detect and handle migration if it has occurred.
*/
critical_enter();
cache = &zone->uz_cpu[curcpu];
bucket = &cache->uc_allocbucket;
if (__predict_false(bucket->ucb_cnt == 0))
return (cache_alloc_retry(zone, cache, udata, flags));
return (cache_alloc_item(zone, cache, bucket, udata, flags));
}
/*
* Replenish an alloc bucket and possibly restore an old one. Called in
* a critical section. Returns in a critical section.
*
* A false return value indicates an allocation failure.
* A true return value indicates success and the caller should retry.
*/
static __noinline bool
cache_alloc(uma_zone_t zone, uma_cache_t cache, void *udata, int flags)
{
uma_bucket_t bucket;
int curdomain, domain;
bool new;
CRITICAL_ASSERT(curthread);
/*
* If we have run out of items in our alloc bucket see
* if we can switch with the free bucket.
*
* SMR Zones can't re-use the free bucket until the sequence has
* expired.
*/
if ((cache_uz_flags(cache) & UMA_ZONE_SMR) == 0 &&
cache->uc_freebucket.ucb_cnt != 0) {
cache_bucket_swap(&cache->uc_freebucket,
&cache->uc_allocbucket);
return (true);
}
/*
* Discard any empty allocation bucket while we hold no locks.
*/
bucket = cache_bucket_unload_alloc(cache);
critical_exit();
if (bucket != NULL) {
KASSERT(bucket->ub_cnt == 0,
("cache_alloc: Entered with non-empty alloc bucket."));
bucket_free(zone, bucket, udata);
}
/*
* Attempt to retrieve the item from the per-CPU cache has failed, so
* we must go back to the zone. This requires the zdom lock, so we
* must drop the critical section, then re-acquire it when we go back
* to the cache. Since the critical section is released, we may be
* preempted or migrate. As such, make sure not to maintain any
* thread-local state specific to the cache from prior to releasing
* the critical section.
*/
domain = PCPU_GET(domain);
if ((cache_uz_flags(cache) & UMA_ZONE_ROUNDROBIN) != 0 ||
VM_DOMAIN_EMPTY(domain))
domain = zone_domain_highest(zone, domain);
bucket = cache_fetch_bucket(zone, cache, domain);
if (bucket == NULL && zone->uz_bucket_size != 0 && !bucketdisable) {
bucket = zone_alloc_bucket(zone, udata, domain, flags);
new = true;
} else {
new = false;
}
CTR3(KTR_UMA, "uma_zalloc: zone %s(%p) bucket zone returned %p",
zone->uz_name, zone, bucket);
if (bucket == NULL) {
critical_enter();
return (false);
}
/*
* See if we lost the race or were migrated. Cache the
* initialized bucket to make this less likely or claim
* the memory directly.
*/
critical_enter();
cache = &zone->uz_cpu[curcpu];
if (cache->uc_allocbucket.ucb_bucket == NULL &&
((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) == 0 ||
(curdomain = PCPU_GET(domain)) == domain ||
VM_DOMAIN_EMPTY(curdomain))) {
if (new)
atomic_add_long(&ZDOM_GET(zone, domain)->uzd_imax,
bucket->ub_cnt);
cache_bucket_load_alloc(cache, bucket);
return (true);
}
/*
* We lost the race, release this bucket and start over.
*/
critical_exit();
zone_put_bucket(zone, domain, bucket, udata, !new);
critical_enter();
return (true);
}
void *
uma_zalloc_domain(uma_zone_t zone, void *udata, int domain, int flags)
{
#ifdef NUMA
uma_bucket_t bucket;
uma_zone_domain_t zdom;
void *item;
#endif
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
/* This is the fast path allocation */
CTR4(KTR_UMA, "uma_zalloc_domain zone %s(%p) domain %d flags %d",
zone->uz_name, zone, domain, flags);
if (flags & M_WAITOK) {
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"uma_zalloc_domain: zone \"%s\"", zone->uz_name);
}
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("uma_zalloc_domain: called with spinlock or critical section held"));
KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("uma_zalloc_domain: called with SMR zone."));
#ifdef NUMA
KASSERT((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0,
("uma_zalloc_domain: called with non-FIRSTTOUCH zone."));
if (vm_ndomains == 1)
return (uma_zalloc_arg(zone, udata, flags));
/*
* Try to allocate from the bucket cache before falling back to the keg.
* We could try harder and attempt to allocate from per-CPU caches or
* the per-domain cross-domain buckets, but the complexity is probably
* not worth it. It is more important that frees of previous
* cross-domain allocations do not blow up the cache.
*/
zdom = zone_domain_lock(zone, domain);
if ((bucket = zone_fetch_bucket(zone, zdom, false)) != NULL) {
item = bucket->ub_bucket[bucket->ub_cnt - 1];
#ifdef INVARIANTS
bucket->ub_bucket[bucket->ub_cnt - 1] = NULL;
#endif
bucket->ub_cnt--;
zone_put_bucket(zone, domain, bucket, udata, true);
item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata,
flags, item);
if (item != NULL) {
KASSERT(item_domain(item) == domain,
("%s: bucket cache item %p from wrong domain",
__func__, item));
counter_u64_add(zone->uz_allocs, 1);
}
return (item);
}
ZDOM_UNLOCK(zdom);
return (zone_alloc_item(zone, udata, domain, flags));
#else
return (uma_zalloc_arg(zone, udata, flags));
#endif
}
/*
* Find a slab with some space. Prefer slabs that are partially used over those
* that are totally full. This helps to reduce fragmentation.
*
* If 'rr' is 1, search all domains starting from 'domain'. Otherwise check
* only 'domain'.
*/
static uma_slab_t
keg_first_slab(uma_keg_t keg, int domain, bool rr)
{
uma_domain_t dom;
uma_slab_t slab;
int start;
KASSERT(domain >= 0 && domain < vm_ndomains,
("keg_first_slab: domain %d out of range", domain));
KEG_LOCK_ASSERT(keg, domain);
slab = NULL;
start = domain;
do {
dom = &keg->uk_domain[domain];
if ((slab = LIST_FIRST(&dom->ud_part_slab)) != NULL)
return (slab);
if ((slab = LIST_FIRST(&dom->ud_free_slab)) != NULL) {
LIST_REMOVE(slab, us_link);
dom->ud_free_slabs--;
LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
return (slab);
}
if (rr)
domain = (domain + 1) % vm_ndomains;
} while (domain != start);
return (NULL);
}
/*
* Fetch an existing slab from a free or partial list. Returns with the
* keg domain lock held if a slab was found or unlocked if not.
*/
static uma_slab_t
keg_fetch_free_slab(uma_keg_t keg, int domain, bool rr, int flags)
{
uma_slab_t slab;
uint32_t reserve;
/* HASH has a single free list. */
if ((keg->uk_flags & UMA_ZFLAG_HASH) != 0)
domain = 0;
KEG_LOCK(keg, domain);
reserve = (flags & M_USE_RESERVE) != 0 ? 0 : keg->uk_reserve;
if (keg->uk_domain[domain].ud_free_items <= reserve ||
(slab = keg_first_slab(keg, domain, rr)) == NULL) {
KEG_UNLOCK(keg, domain);
return (NULL);
}
return (slab);
}
static uma_slab_t
keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int rdomain, const int flags)
{
struct vm_domainset_iter di;
uma_slab_t slab;
int aflags, domain;
bool rr;
KASSERT((flags & (M_WAITOK | M_NOVM)) != (M_WAITOK | M_NOVM),
("%s: invalid flags %#x", __func__, flags));
restart:
/*
* Use the keg's policy if upper layers haven't already specified a
* domain (as happens with first-touch zones).
*
* To avoid races we run the iterator with the keg lock held, but that
* means that we cannot allow the vm_domainset layer to sleep. Thus,
* clear M_WAITOK and handle low memory conditions locally.
*/
rr = rdomain == UMA_ANYDOMAIN;
if (rr) {
aflags = (flags & ~M_WAITOK) | M_NOWAIT;
vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
&aflags);
} else {
aflags = flags;
domain = rdomain;
}
for (;;) {
slab = keg_fetch_free_slab(keg, domain, rr, flags);
if (slab != NULL)
return (slab);
/*
* M_NOVM is used to break the recursion that can otherwise
* occur if low-level memory management routines use UMA.
*/
if ((flags & M_NOVM) == 0) {
slab = keg_alloc_slab(keg, zone, domain, flags, aflags);
if (slab != NULL)
return (slab);
}
if (!rr) {
if ((flags & M_USE_RESERVE) != 0) {
/*
* Drain reserves from other domains before
* giving up or sleeping. It may be useful to
* support per-domain reserves eventually.
*/
rdomain = UMA_ANYDOMAIN;
goto restart;
}
if ((flags & M_WAITOK) == 0)
break;
vm_wait_domain(domain);
} else if (vm_domainset_iter_policy(&di, &domain) != 0) {
if ((flags & M_WAITOK) != 0) {
vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0);
goto restart;
}
break;
}
}
/*
* We might not have been able to get a slab but another cpu
* could have while we were unlocked. Check again before we
* fail.
*/
if ((slab = keg_fetch_free_slab(keg, domain, rr, flags)) != NULL)
return (slab);
return (NULL);
}
static void *
slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
{
uma_domain_t dom;
void *item;
int freei;
KEG_LOCK_ASSERT(keg, slab->us_domain);
dom = &keg->uk_domain[slab->us_domain];
freei = BIT_FFS(keg->uk_ipers, &slab->us_free) - 1;
BIT_CLR(keg->uk_ipers, freei, &slab->us_free);
item = slab_item(slab, keg, freei);
slab->us_freecount--;
dom->ud_free_items--;
/*
* Move this slab to the full list. It must be on the partial list, so
* we do not need to update the free slab count. In particular,
* keg_fetch_slab() always returns slabs on the partial list.
*/
if (slab->us_freecount == 0) {
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&dom->ud_full_slab, slab, us_link);
}
return (item);
}
static int
zone_import(void *arg, void **bucket, int max, int domain, int flags)
{
uma_domain_t dom;
uma_zone_t zone;
uma_slab_t slab;
uma_keg_t keg;
#ifdef NUMA
int stripe;
#endif
int i;
zone = arg;
slab = NULL;
keg = zone->uz_keg;
/* Try to keep the buckets totally full */
for (i = 0; i < max; ) {
if ((slab = keg_fetch_slab(keg, zone, domain, flags)) == NULL)
break;
#ifdef NUMA
stripe = howmany(max, vm_ndomains);
#endif
dom = &keg->uk_domain[slab->us_domain];
do {
bucket[i++] = slab_alloc_item(keg, slab);
if (keg->uk_reserve > 0 &&
dom->ud_free_items <= keg->uk_reserve) {
/*
* Avoid depleting the reserve after a
* successful item allocation, even if
* M_USE_RESERVE is specified.
*/
KEG_UNLOCK(keg, slab->us_domain);
goto out;
}
#ifdef NUMA
/*
* If the zone is striped we pick a new slab for every
* N allocations. Eliminating this conditional will
* instead pick a new domain for each bucket rather
* than stripe within each bucket. The current option
* produces more fragmentation and requires more cpu
* time but yields better distribution.
*/
if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0 &&
vm_ndomains > 1 && --stripe == 0)
break;
#endif
} while (slab->us_freecount != 0 && i < max);
KEG_UNLOCK(keg, slab->us_domain);
/* Don't block if we allocated any successfully. */
flags &= ~M_WAITOK;
flags |= M_NOWAIT;
}
out:
return i;
}
static int
zone_alloc_limit_hard(uma_zone_t zone, int count, int flags)
{
uint64_t old, new, total, max;
/*
* The hard case. We're going to sleep because there were existing
* sleepers or because we ran out of items. This routine enforces
* fairness by keeping fifo order.
*
* First release our ill gotten gains and make some noise.
*/
for (;;) {
zone_free_limit(zone, count);
zone_log_warning(zone);
zone_maxaction(zone);
if (flags & M_NOWAIT)
return (0);
/*
* We need to allocate an item or set ourself as a sleeper
* while the sleepq lock is held to avoid wakeup races. This
* is essentially a home rolled semaphore.
*/
sleepq_lock(&zone->uz_max_items);
old = zone->uz_items;
do {
MPASS(UZ_ITEMS_SLEEPERS(old) < UZ_ITEMS_SLEEPERS_MAX);
/* Cache the max since we will evaluate twice. */
max = zone->uz_max_items;
if (UZ_ITEMS_SLEEPERS(old) != 0 ||
UZ_ITEMS_COUNT(old) >= max)
new = old + UZ_ITEMS_SLEEPER;
else
new = old + MIN(count, max - old);
} while (atomic_fcmpset_64(&zone->uz_items, &old, new) == 0);
/* We may have successfully allocated under the sleepq lock. */
if (UZ_ITEMS_SLEEPERS(new) == 0) {
sleepq_release(&zone->uz_max_items);
return (new - old);
}
/*
* This is in a different cacheline from uz_items so that we
* don't constantly invalidate the fastpath cacheline when we
* adjust item counts. This could be limited to toggling on
* transitions.
*/
atomic_add_32(&zone->uz_sleepers, 1);
atomic_add_64(&zone->uz_sleeps, 1);
/*
* We have added ourselves as a sleeper. The sleepq lock
* protects us from wakeup races. Sleep now and then retry.
*/
sleepq_add(&zone->uz_max_items, NULL, "zonelimit", 0, 0);
sleepq_wait(&zone->uz_max_items, PVM);
/*
* After wakeup, remove ourselves as a sleeper and try
* again. We no longer have the sleepq lock for protection.
*
* Subract ourselves as a sleeper while attempting to add
* our count.
*/
atomic_subtract_32(&zone->uz_sleepers, 1);
old = atomic_fetchadd_64(&zone->uz_items,
-(UZ_ITEMS_SLEEPER - count));
/* We're no longer a sleeper. */
old -= UZ_ITEMS_SLEEPER;
/*
* If we're still at the limit, restart. Notably do not
* block on other sleepers. Cache the max value to protect
* against changes via sysctl.
*/
total = UZ_ITEMS_COUNT(old);
max = zone->uz_max_items;
if (total >= max)
continue;
/* Truncate if necessary, otherwise wake other sleepers. */
if (total + count > max) {
zone_free_limit(zone, total + count - max);
count = max - total;
} else if (total + count < max && UZ_ITEMS_SLEEPERS(old) != 0)
wakeup_one(&zone->uz_max_items);
return (count);
}
}
/*
* Allocate 'count' items from our max_items limit. Returns the number
* available. If M_NOWAIT is not specified it will sleep until at least
* one item can be allocated.
*/
static int
zone_alloc_limit(uma_zone_t zone, int count, int flags)
{
uint64_t old;
uint64_t max;
max = zone->uz_max_items;
MPASS(max > 0);
/*
* We expect normal allocations to succeed with a simple
* fetchadd.
*/
old = atomic_fetchadd_64(&zone->uz_items, count);
if (__predict_true(old + count <= max))
return (count);
/*
* If we had some items and no sleepers just return the
* truncated value. We have to release the excess space
* though because that may wake sleepers who weren't woken
* because we were temporarily over the limit.
*/
if (old < max) {
zone_free_limit(zone, (old + count) - max);
return (max - old);
}
return (zone_alloc_limit_hard(zone, count, flags));
}
/*
* Free a number of items back to the limit.
*/
static void
zone_free_limit(uma_zone_t zone, int count)
{
uint64_t old;
MPASS(count > 0);
/*
* In the common case we either have no sleepers or
* are still over the limit and can just return.
*/
old = atomic_fetchadd_64(&zone->uz_items, -count);
if (__predict_true(UZ_ITEMS_SLEEPERS(old) == 0 ||
UZ_ITEMS_COUNT(old) - count >= zone->uz_max_items))
return;
/*
* Moderate the rate of wakeups. Sleepers will continue
* to generate wakeups if necessary.
*/
wakeup_one(&zone->uz_max_items);
}
static uma_bucket_t
zone_alloc_bucket(uma_zone_t zone, void *udata, int domain, int flags)
{
uma_bucket_t bucket;
int error, maxbucket, cnt;
CTR3(KTR_UMA, "zone_alloc_bucket zone %s(%p) domain %d", zone->uz_name,
zone, domain);
/* Avoid allocs targeting empty domains. */
if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
domain = UMA_ANYDOMAIN;
else if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0)
domain = UMA_ANYDOMAIN;
if (zone->uz_max_items > 0)
maxbucket = zone_alloc_limit(zone, zone->uz_bucket_size,
M_NOWAIT);
else
maxbucket = zone->uz_bucket_size;
if (maxbucket == 0)
return (false);
/* Don't wait for buckets, preserve caller's NOVM setting. */
bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
if (bucket == NULL) {
cnt = 0;
goto out;
}
bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
MIN(maxbucket, bucket->ub_entries), domain, flags);
/*
* Initialize the memory if necessary.
*/
if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
int i;
for (i = 0; i < bucket->ub_cnt; i++) {
kasan_mark_item_valid(zone, bucket->ub_bucket[i]);
error = zone->uz_init(bucket->ub_bucket[i],
zone->uz_size, flags);
kasan_mark_item_invalid(zone, bucket->ub_bucket[i]);
if (error != 0)
break;
}
/*
* If we couldn't initialize the whole bucket, put the
* rest back onto the freelist.
*/
if (i != bucket->ub_cnt) {
zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
bucket->ub_cnt - i);
#ifdef INVARIANTS
bzero(&bucket->ub_bucket[i],
sizeof(void *) * (bucket->ub_cnt - i));
#endif
bucket->ub_cnt = i;
}
}
cnt = bucket->ub_cnt;
if (bucket->ub_cnt == 0) {
bucket_free(zone, bucket, udata);
counter_u64_add(zone->uz_fails, 1);
bucket = NULL;
}
out:
if (zone->uz_max_items > 0 && cnt < maxbucket)
zone_free_limit(zone, maxbucket - cnt);
return (bucket);
}
/*
* Allocates a single item from a zone.
*
* Arguments
* zone The zone to alloc for.
* udata The data to be passed to the constructor.
* domain The domain to allocate from or UMA_ANYDOMAIN.
* flags M_WAITOK, M_NOWAIT, M_ZERO.
*
* Returns
* NULL if there is no memory and M_NOWAIT is set
* An item if successful
*/
static void *
zone_alloc_item(uma_zone_t zone, void *udata, int domain, int flags)
{
void *item;
if (zone->uz_max_items > 0 && zone_alloc_limit(zone, 1, flags) == 0) {
counter_u64_add(zone->uz_fails, 1);
return (NULL);
}
/* Avoid allocs targeting empty domains. */
if (domain != UMA_ANYDOMAIN && VM_DOMAIN_EMPTY(domain))
domain = UMA_ANYDOMAIN;
if (zone->uz_import(zone->uz_arg, &item, 1, domain, flags) != 1)
goto fail_cnt;
/*
* We have to call both the zone's init (not the keg's init)
* and the zone's ctor. This is because the item is going from
* a keg slab directly to the user, and the user is expecting it
* to be both zone-init'd as well as zone-ctor'd.
*/
if (zone->uz_init != NULL) {
int error;
kasan_mark_item_valid(zone, item);
error = zone->uz_init(item, zone->uz_size, flags);
kasan_mark_item_invalid(zone, item);
if (error != 0) {
zone_free_item(zone, item, udata, SKIP_FINI | SKIP_CNT);
goto fail_cnt;
}
}
item = item_ctor(zone, zone->uz_flags, zone->uz_size, udata, flags,
item);
if (item == NULL)
goto fail;
counter_u64_add(zone->uz_allocs, 1);
CTR3(KTR_UMA, "zone_alloc_item item %p from %s(%p)", item,
zone->uz_name, zone);
return (item);
fail_cnt:
counter_u64_add(zone->uz_fails, 1);
fail:
if (zone->uz_max_items > 0)
zone_free_limit(zone, 1);
CTR2(KTR_UMA, "zone_alloc_item failed from %s(%p)",
zone->uz_name, zone);
return (NULL);
}
/* See uma.h */
void
uma_zfree_smr(uma_zone_t zone, void *item)
{
uma_cache_t cache;
uma_cache_bucket_t bucket;
int itemdomain, uz_flags;
#ifdef UMA_ZALLOC_DEBUG
KASSERT((zone->uz_flags & UMA_ZONE_SMR) != 0,
("uma_zfree_smr: called with non-SMR zone."));
KASSERT(item != NULL, ("uma_zfree_smr: Called with NULL pointer."));
SMR_ASSERT_NOT_ENTERED(zone->uz_smr);
if (uma_zfree_debug(zone, item, NULL) == EJUSTRETURN)
return;
#endif
cache = &zone->uz_cpu[curcpu];
uz_flags = cache_uz_flags(cache);
itemdomain = 0;
#ifdef NUMA
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
itemdomain = item_domain(item);
#endif
critical_enter();
do {
cache = &zone->uz_cpu[curcpu];
/* SMR Zones must free to the free bucket. */
bucket = &cache->uc_freebucket;
#ifdef NUMA
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
PCPU_GET(domain) != itemdomain) {
bucket = &cache->uc_crossbucket;
}
#endif
if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
cache_bucket_push(cache, bucket, item);
critical_exit();
return;
}
} while (cache_free(zone, cache, NULL, item, itemdomain));
critical_exit();
/*
* If nothing else caught this, we'll just do an internal free.
*/
zone_free_item(zone, item, NULL, SKIP_NONE);
}
/* See uma.h */
void
uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
{
uma_cache_t cache;
uma_cache_bucket_t bucket;
int itemdomain, uz_flags;
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
random_harvest_fast_uma(&zone, sizeof(zone), RANDOM_UMA);
CTR2(KTR_UMA, "uma_zfree_arg zone %s(%p)", zone->uz_name, zone);
#ifdef UMA_ZALLOC_DEBUG
KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("uma_zfree_arg: called with SMR zone."));
if (uma_zfree_debug(zone, item, udata) == EJUSTRETURN)
return;
#endif
/* uma_zfree(..., NULL) does nothing, to match free(9). */
if (item == NULL)
return;
/*
* We are accessing the per-cpu cache without a critical section to
* fetch size and flags. This is acceptable, if we are preempted we
* will simply read another cpu's line.
*/
cache = &zone->uz_cpu[curcpu];
uz_flags = cache_uz_flags(cache);
if (UMA_ALWAYS_CTORDTOR ||
__predict_false((uz_flags & UMA_ZFLAG_CTORDTOR) != 0))
item_dtor(zone, item, cache_uz_size(cache), udata, SKIP_NONE);
/*
* The race here is acceptable. If we miss it we'll just have to wait
* a little longer for the limits to be reset.
*/
if (__predict_false(uz_flags & UMA_ZFLAG_LIMIT)) {
if (atomic_load_32(&zone->uz_sleepers) > 0)
goto zfree_item;
}
/*
* If possible, free to the per-CPU cache. There are two
* requirements for safe access to the per-CPU cache: (1) the thread
* accessing the cache must not be preempted or yield during access,
* and (2) the thread must not migrate CPUs without switching which
* cache it accesses. We rely on a critical section to prevent
* preemption and migration. We release the critical section in
* order to acquire the zone mutex if we are unable to free to the
* current cache; when we re-acquire the critical section, we must
* detect and handle migration if it has occurred.
*/
itemdomain = 0;
#ifdef NUMA
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0)
itemdomain = item_domain(item);
#endif
critical_enter();
do {
cache = &zone->uz_cpu[curcpu];
/*
* Try to free into the allocbucket first to give LIFO
* ordering for cache-hot datastructures. Spill over
* into the freebucket if necessary. Alloc will swap
* them if one runs dry.
*/
bucket = &cache->uc_allocbucket;
#ifdef NUMA
if ((uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
PCPU_GET(domain) != itemdomain) {
bucket = &cache->uc_crossbucket;
} else
#endif
if (bucket->ucb_cnt == bucket->ucb_entries &&
cache->uc_freebucket.ucb_cnt <
cache->uc_freebucket.ucb_entries)
cache_bucket_swap(&cache->uc_freebucket,
&cache->uc_allocbucket);
if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) {
cache_bucket_push(cache, bucket, item);
critical_exit();
return;
}
} while (cache_free(zone, cache, udata, item, itemdomain));
critical_exit();
/*
* If nothing else caught this, we'll just do an internal free.
*/
zfree_item:
zone_free_item(zone, item, udata, SKIP_DTOR);
}
#ifdef NUMA
/*
* sort crossdomain free buckets to domain correct buckets and cache
* them.
*/
static void
zone_free_cross(uma_zone_t zone, uma_bucket_t bucket, void *udata)
{
struct uma_bucketlist emptybuckets, fullbuckets;
uma_zone_domain_t zdom;
uma_bucket_t b;
smr_seq_t seq;
void *item;
int domain;
CTR3(KTR_UMA,
"uma_zfree: zone %s(%p) draining cross bucket %p",
zone->uz_name, zone, bucket);
/*
* It is possible for buckets to arrive here out of order so we fetch
* the current smr seq rather than accepting the bucket's.
*/
seq = SMR_SEQ_INVALID;
if ((zone->uz_flags & UMA_ZONE_SMR) != 0)
seq = smr_advance(zone->uz_smr);
/*
* To avoid having ndomain * ndomain buckets for sorting we have a
* lock on the current crossfree bucket. A full matrix with
* per-domain locking could be used if necessary.
*/
STAILQ_INIT(&emptybuckets);
STAILQ_INIT(&fullbuckets);
ZONE_CROSS_LOCK(zone);
for (; bucket->ub_cnt > 0; bucket->ub_cnt--) {
item = bucket->ub_bucket[bucket->ub_cnt - 1];
domain = item_domain(item);
zdom = ZDOM_GET(zone, domain);
if (zdom->uzd_cross == NULL) {
if ((b = STAILQ_FIRST(&emptybuckets)) != NULL) {
STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
zdom->uzd_cross = b;
} else {
/*
* Avoid allocating a bucket with the cross lock
* held, since allocation can trigger a
* cross-domain free and bucket zones may
* allocate from each other.
*/
ZONE_CROSS_UNLOCK(zone);
b = bucket_alloc(zone, udata, M_NOWAIT);
if (b == NULL)
goto out;
ZONE_CROSS_LOCK(zone);
if (zdom->uzd_cross != NULL) {
STAILQ_INSERT_HEAD(&emptybuckets, b,
ub_link);
} else {
zdom->uzd_cross = b;
}
}
}
b = zdom->uzd_cross;
b->ub_bucket[b->ub_cnt++] = item;
b->ub_seq = seq;
if (b->ub_cnt == b->ub_entries) {
STAILQ_INSERT_HEAD(&fullbuckets, b, ub_link);
if ((b = STAILQ_FIRST(&emptybuckets)) != NULL)
STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
zdom->uzd_cross = b;
}
}
ZONE_CROSS_UNLOCK(zone);
out:
if (bucket->ub_cnt == 0)
bucket->ub_seq = SMR_SEQ_INVALID;
bucket_free(zone, bucket, udata);
while ((b = STAILQ_FIRST(&emptybuckets)) != NULL) {
STAILQ_REMOVE_HEAD(&emptybuckets, ub_link);
bucket_free(zone, b, udata);
}
while ((b = STAILQ_FIRST(&fullbuckets)) != NULL) {
STAILQ_REMOVE_HEAD(&fullbuckets, ub_link);
domain = item_domain(b->ub_bucket[0]);
zone_put_bucket(zone, domain, b, udata, true);
}
}
#endif
static void
zone_free_bucket(uma_zone_t zone, uma_bucket_t bucket, void *udata,
int itemdomain, bool ws)
{
#ifdef NUMA
/*
* Buckets coming from the wrong domain will be entirely for the
* only other domain on two domain systems. In this case we can
* simply cache them. Otherwise we need to sort them back to
* correct domains.
*/
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 &&
vm_ndomains > 2 && PCPU_GET(domain) != itemdomain) {
zone_free_cross(zone, bucket, udata);
return;
}
#endif
/*
* Attempt to save the bucket in the zone's domain bucket cache.
*/
CTR3(KTR_UMA,
"uma_zfree: zone %s(%p) putting bucket %p on free list",
zone->uz_name, zone, bucket);
/* ub_cnt is pointing to the last free item */
if ((zone->uz_flags & UMA_ZONE_ROUNDROBIN) != 0)
itemdomain = zone_domain_lowest(zone, itemdomain);
zone_put_bucket(zone, itemdomain, bucket, udata, ws);
}
/*
* Populate a free or cross bucket for the current cpu cache. Free any
* existing full bucket either to the zone cache or back to the slab layer.
*
* Enters and returns in a critical section. false return indicates that
* we can not satisfy this free in the cache layer. true indicates that
* the caller should retry.
*/
static __noinline bool
cache_free(uma_zone_t zone, uma_cache_t cache, void *udata, void *item,
int itemdomain)
{
uma_cache_bucket_t cbucket;
uma_bucket_t newbucket, bucket;
CRITICAL_ASSERT(curthread);
if (zone->uz_bucket_size == 0)
return false;
cache = &zone->uz_cpu[curcpu];
newbucket = NULL;
/*
* FIRSTTOUCH domains need to free to the correct zdom. When
* enabled this is the zdom of the item. The bucket is the
* cross bucket if the current domain and itemdomain do not match.
*/
cbucket = &cache->uc_freebucket;
#ifdef NUMA
if ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) != 0) {
if (PCPU_GET(domain) != itemdomain) {
cbucket = &cache->uc_crossbucket;
if (cbucket->ucb_cnt != 0)
counter_u64_add(zone->uz_xdomain,
cbucket->ucb_cnt);
}
}
#endif
bucket = cache_bucket_unload(cbucket);
KASSERT(bucket == NULL || bucket->ub_cnt == bucket->ub_entries,
("cache_free: Entered with non-full free bucket."));
/* We are no longer associated with this CPU. */
critical_exit();
/*
* Don't let SMR zones operate without a free bucket. Force
* a synchronize and re-use this one. We will only degrade
* to a synchronize every bucket_size items rather than every
* item if we fail to allocate a bucket.
*/
if ((zone->uz_flags & UMA_ZONE_SMR) != 0) {
if (bucket != NULL)
bucket->ub_seq = smr_advance(zone->uz_smr);
newbucket = bucket_alloc(zone, udata, M_NOWAIT);
if (newbucket == NULL && bucket != NULL) {
bucket_drain(zone, bucket);
newbucket = bucket;
bucket = NULL;
}
} else if (!bucketdisable)
newbucket = bucket_alloc(zone, udata, M_NOWAIT);
if (bucket != NULL)
zone_free_bucket(zone, bucket, udata, itemdomain, true);
critical_enter();
if ((bucket = newbucket) == NULL)
return (false);
cache = &zone->uz_cpu[curcpu];
#ifdef NUMA
/*
* Check to see if we should be populating the cross bucket. If it
* is already populated we will fall through and attempt to populate
* the free bucket.
*/
if ((cache_uz_flags(cache) & UMA_ZONE_FIRSTTOUCH) != 0) {
if (PCPU_GET(domain) != itemdomain &&
cache->uc_crossbucket.ucb_bucket == NULL) {
cache_bucket_load_cross(cache, bucket);
return (true);
}
}
#endif
/*
* We may have lost the race to fill the bucket or switched CPUs.
*/
if (cache->uc_freebucket.ucb_bucket != NULL) {
critical_exit();
bucket_free(zone, bucket, udata);
critical_enter();
} else
cache_bucket_load_free(cache, bucket);
return (true);
}
static void
slab_free_item(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
uma_domain_t dom;
int freei;
keg = zone->uz_keg;
KEG_LOCK_ASSERT(keg, slab->us_domain);
/* Do we need to remove from any lists? */
dom = &keg->uk_domain[slab->us_domain];
if (slab->us_freecount + 1 == keg->uk_ipers) {
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&dom->ud_free_slab, slab, us_link);
dom->ud_free_slabs++;
} else if (slab->us_freecount == 0) {
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&dom->ud_part_slab, slab, us_link);
}
/* Slab management. */
freei = slab_item_index(slab, keg, item);
BIT_SET(keg->uk_ipers, freei, &slab->us_free);
slab->us_freecount++;
/* Keg statistics. */
dom->ud_free_items++;
}
static void
zone_release(void *arg, void **bucket, int cnt)
{
struct mtx *lock;
uma_zone_t zone;
uma_slab_t slab;
uma_keg_t keg;
uint8_t *mem;
void *item;
int i;
zone = arg;
keg = zone->uz_keg;
lock = NULL;
if (__predict_false((zone->uz_flags & UMA_ZFLAG_HASH) != 0))
lock = KEG_LOCK(keg, 0);
for (i = 0; i < cnt; i++) {
item = bucket[i];
if (__predict_true((zone->uz_flags & UMA_ZFLAG_VTOSLAB) != 0)) {
slab = vtoslab((vm_offset_t)item);
} else {
mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
if ((zone->uz_flags & UMA_ZFLAG_HASH) != 0)
slab = hash_sfind(&keg->uk_hash, mem);
else
slab = (uma_slab_t)(mem + keg->uk_pgoff);
}
if (lock != KEG_LOCKPTR(keg, slab->us_domain)) {
if (lock != NULL)
mtx_unlock(lock);
lock = KEG_LOCK(keg, slab->us_domain);
}
slab_free_item(zone, slab, item);
}
if (lock != NULL)
mtx_unlock(lock);
}
/*
* Frees a single item to any zone.
*
* Arguments:
* zone The zone to free to
* item The item we're freeing
* udata User supplied data for the dtor
* skip Skip dtors and finis
*/
static __noinline void
zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
{
/*
* If a free is sent directly to an SMR zone we have to
* synchronize immediately because the item can instantly
* be reallocated. This should only happen in degenerate
* cases when no memory is available for per-cpu caches.
*/
if ((zone->uz_flags & UMA_ZONE_SMR) != 0 && skip == SKIP_NONE)
smr_synchronize(zone->uz_smr);
item_dtor(zone, item, zone->uz_size, udata, skip);
if (skip < SKIP_FINI && zone->uz_fini) {
kasan_mark_item_valid(zone, item);
zone->uz_fini(item, zone->uz_size);
kasan_mark_item_invalid(zone, item);
}
zone->uz_release(zone->uz_arg, &item, 1);
if (skip & SKIP_CNT)
return;
counter_u64_add(zone->uz_frees, 1);
if (zone->uz_max_items > 0)
zone_free_limit(zone, 1);
}
/* See uma.h */
int
uma_zone_set_max(uma_zone_t zone, int nitems)
{
/*
* If the limit is small, we may need to constrain the maximum per-CPU
* cache size, or disable caching entirely.
*/
uma_zone_set_maxcache(zone, nitems);
/*
* XXX This can misbehave if the zone has any allocations with
* no limit and a limit is imposed. There is currently no
* way to clear a limit.
*/
ZONE_LOCK(zone);
zone->uz_max_items = nitems;
zone->uz_flags |= UMA_ZFLAG_LIMIT;
zone_update_caches(zone);
/* We may need to wake waiters. */
wakeup(&zone->uz_max_items);
ZONE_UNLOCK(zone);
return (nitems);
}
/* See uma.h */
void
uma_zone_set_maxcache(uma_zone_t zone, int nitems)
{
int bpcpu, bpdom, bsize, nb;
ZONE_LOCK(zone);
/*
* Compute a lower bound on the number of items that may be cached in
* the zone. Each CPU gets at least two buckets, and for cross-domain
* frees we use an additional bucket per CPU and per domain. Select the
* largest bucket size that does not exceed half of the requested limit,
* with the left over space given to the full bucket cache.
*/
bpdom = 0;
bpcpu = 2;
#ifdef NUMA
if ((zone->uz_flags & UMA_ZONE_FIRSTTOUCH) != 0 && vm_ndomains > 1) {
bpcpu++;
bpdom++;
}
#endif
nb = bpcpu * mp_ncpus + bpdom * vm_ndomains;
bsize = nitems / nb / 2;
if (bsize > BUCKET_MAX)
bsize = BUCKET_MAX;
else if (bsize == 0 && nitems / nb > 0)
bsize = 1;
zone->uz_bucket_size_max = zone->uz_bucket_size = bsize;
if (zone->uz_bucket_size_min > zone->uz_bucket_size_max)
zone->uz_bucket_size_min = zone->uz_bucket_size_max;
zone->uz_bucket_max = nitems - nb * bsize;
ZONE_UNLOCK(zone);
}
/* See uma.h */
int
uma_zone_get_max(uma_zone_t zone)
{
int nitems;
nitems = atomic_load_64(&zone->uz_max_items);
return (nitems);
}
/* See uma.h */
void
uma_zone_set_warning(uma_zone_t zone, const char *warning)
{
ZONE_ASSERT_COLD(zone);
zone->uz_warning = warning;
}
/* See uma.h */
void
uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t maxaction)
{
ZONE_ASSERT_COLD(zone);
TASK_INIT(&zone->uz_maxaction, 0, (task_fn_t *)maxaction, zone);
}
/* See uma.h */
int
uma_zone_get_cur(uma_zone_t zone)
{
int64_t nitems;
u_int i;
nitems = 0;
if (zone->uz_allocs != EARLY_COUNTER && zone->uz_frees != EARLY_COUNTER)
nitems = counter_u64_fetch(zone->uz_allocs) -
counter_u64_fetch(zone->uz_frees);
CPU_FOREACH(i)
nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs) -
atomic_load_64(&zone->uz_cpu[i].uc_frees);
return (nitems < 0 ? 0 : nitems);
}
static uint64_t
uma_zone_get_allocs(uma_zone_t zone)
{
uint64_t nitems;
u_int i;
nitems = 0;
if (zone->uz_allocs != EARLY_COUNTER)
nitems = counter_u64_fetch(zone->uz_allocs);
CPU_FOREACH(i)
nitems += atomic_load_64(&zone->uz_cpu[i].uc_allocs);
return (nitems);
}
static uint64_t
uma_zone_get_frees(uma_zone_t zone)
{
uint64_t nitems;
u_int i;
nitems = 0;
if (zone->uz_frees != EARLY_COUNTER)
nitems = counter_u64_fetch(zone->uz_frees);
CPU_FOREACH(i)
nitems += atomic_load_64(&zone->uz_cpu[i].uc_frees);
return (nitems);
}
#ifdef INVARIANTS
/* Used only for KEG_ASSERT_COLD(). */
static uint64_t
uma_keg_get_allocs(uma_keg_t keg)
{
uma_zone_t z;
uint64_t nitems;
nitems = 0;
LIST_FOREACH(z, &keg->uk_zones, uz_link)
nitems += uma_zone_get_allocs(z);
return (nitems);
}
#endif
/* See uma.h */
void
uma_zone_set_init(uma_zone_t zone, uma_init uminit)
{
uma_keg_t keg;
KEG_GET(zone, keg);
KEG_ASSERT_COLD(keg);
keg->uk_init = uminit;
}
/* See uma.h */
void
uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
{
uma_keg_t keg;
KEG_GET(zone, keg);
KEG_ASSERT_COLD(keg);
keg->uk_fini = fini;
}
/* See uma.h */
void
uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
{
ZONE_ASSERT_COLD(zone);
zone->uz_init = zinit;
}
/* See uma.h */
void
uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
{
ZONE_ASSERT_COLD(zone);
zone->uz_fini = zfini;
}
/* See uma.h */
void
uma_zone_set_freef(uma_zone_t zone, uma_free freef)
{
uma_keg_t keg;
KEG_GET(zone, keg);
KEG_ASSERT_COLD(keg);
keg->uk_freef = freef;
}
/* See uma.h */
void
uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
{
uma_keg_t keg;
KEG_GET(zone, keg);
KEG_ASSERT_COLD(keg);
keg->uk_allocf = allocf;
}
/* See uma.h */
void
uma_zone_set_smr(uma_zone_t zone, smr_t smr)
{
ZONE_ASSERT_COLD(zone);
KASSERT(smr != NULL, ("Got NULL smr"));
KASSERT((zone->uz_flags & UMA_ZONE_SMR) == 0,
("zone %p (%s) already uses SMR", zone, zone->uz_name));
zone->uz_flags |= UMA_ZONE_SMR;
zone->uz_smr = smr;
zone_update_caches(zone);
}
smr_t
uma_zone_get_smr(uma_zone_t zone)
{
return (zone->uz_smr);
}
/* See uma.h */
void
uma_zone_reserve(uma_zone_t zone, int items)
{
uma_keg_t keg;
KEG_GET(zone, keg);
KEG_ASSERT_COLD(keg);
keg->uk_reserve = items;
}
/* See uma.h */
int
uma_zone_reserve_kva(uma_zone_t zone, int count)
{
uma_keg_t keg;
vm_offset_t kva;
u_int pages;
KEG_GET(zone, keg);
KEG_ASSERT_COLD(keg);
ZONE_ASSERT_COLD(zone);
pages = howmany(count, keg->uk_ipers) * keg->uk_ppera;
#ifdef UMA_MD_SMALL_ALLOC
if (keg->uk_ppera > 1) {
#else
if (1) {
#endif
kva = kva_alloc((vm_size_t)pages * PAGE_SIZE);
if (kva == 0)
return (0);
} else
kva = 0;
MPASS(keg->uk_kva == 0);
keg->uk_kva = kva;
keg->uk_offset = 0;
zone->uz_max_items = pages * keg->uk_ipers;
#ifdef UMA_MD_SMALL_ALLOC
keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
#else
keg->uk_allocf = noobj_alloc;
#endif
keg->uk_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
zone->uz_flags |= UMA_ZFLAG_LIMIT | UMA_ZONE_NOFREE;
zone_update_caches(zone);
return (1);
}
/* See uma.h */
void
uma_prealloc(uma_zone_t zone, int items)
{
struct vm_domainset_iter di;
uma_domain_t dom;
uma_slab_t slab;
uma_keg_t keg;
int aflags, domain, slabs;
KEG_GET(zone, keg);
slabs = howmany(items, keg->uk_ipers);
while (slabs-- > 0) {
aflags = M_NOWAIT;
vm_domainset_iter_policy_ref_init(&di, &keg->uk_dr, &domain,
&aflags);
for (;;) {
slab = keg_alloc_slab(keg, zone, domain, M_WAITOK,
aflags);
if (slab != NULL) {
dom = &keg->uk_domain[slab->us_domain];
/*
* keg_alloc_slab() always returns a slab on the
* partial list.
*/
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&dom->ud_free_slab, slab,
us_link);
dom->ud_free_slabs++;
KEG_UNLOCK(keg, slab->us_domain);
break;
}
if (vm_domainset_iter_policy(&di, &domain) != 0)
vm_wait_doms(&keg->uk_dr.dr_policy->ds_mask, 0);
}
}
}
/*
* Returns a snapshot of memory consumption in bytes.
*/
size_t
uma_zone_memory(uma_zone_t zone)
{
size_t sz;
int i;
sz = 0;
if (zone->uz_flags & UMA_ZFLAG_CACHE) {
for (i = 0; i < vm_ndomains; i++)
sz += ZDOM_GET(zone, i)->uzd_nitems;
return (sz * zone->uz_size);
}
for (i = 0; i < vm_ndomains; i++)
sz += zone->uz_keg->uk_domain[i].ud_pages;
return (sz * PAGE_SIZE);
}
/* See uma.h */
void
uma_reclaim(int req)
{
uma_reclaim_domain(req, UMA_ANYDOMAIN);
}
void
uma_reclaim_domain(int req, int domain)
{
void *arg;
bucket_enable();
arg = (void *)(uintptr_t)domain;
sx_slock(&uma_reclaim_lock);
switch (req) {
case UMA_RECLAIM_TRIM:
zone_foreach(zone_trim, arg);
break;
case UMA_RECLAIM_DRAIN:
zone_foreach(zone_drain, arg);
break;
case UMA_RECLAIM_DRAIN_CPU:
zone_foreach(zone_drain, arg);
pcpu_cache_drain_safe(NULL);
zone_foreach(zone_drain, arg);
break;
default:
panic("unhandled reclamation request %d", req);
}
/*
* Some slabs may have been freed but this zone will be visited early
* we visit again so that we can free pages that are empty once other
* zones are drained. We have to do the same for buckets.
*/
zone_drain(slabzones[0], arg);
zone_drain(slabzones[1], arg);
bucket_zone_drain(domain);
sx_sunlock(&uma_reclaim_lock);
}
static volatile int uma_reclaim_needed;
void
uma_reclaim_wakeup(void)
{
if (atomic_fetchadd_int(&uma_reclaim_needed, 1) == 0)
wakeup(uma_reclaim);
}
void
uma_reclaim_worker(void *arg __unused)
{
for (;;) {
sx_xlock(&uma_reclaim_lock);
while (atomic_load_int(&uma_reclaim_needed) == 0)
sx_sleep(uma_reclaim, &uma_reclaim_lock, PVM, "umarcl",
hz);
sx_xunlock(&uma_reclaim_lock);
EVENTHANDLER_INVOKE(vm_lowmem, VM_LOW_KMEM);
uma_reclaim(UMA_RECLAIM_DRAIN_CPU);
atomic_store_int(&uma_reclaim_needed, 0);
/* Don't fire more than once per-second. */
pause("umarclslp", hz);
}
}
/* See uma.h */
void
uma_zone_reclaim(uma_zone_t zone, int req)
{
uma_zone_reclaim_domain(zone, req, UMA_ANYDOMAIN);
}
void
uma_zone_reclaim_domain(uma_zone_t zone, int req, int domain)
{
void *arg;
arg = (void *)(uintptr_t)domain;
switch (req) {
case UMA_RECLAIM_TRIM:
zone_trim(zone, arg);
break;
case UMA_RECLAIM_DRAIN:
zone_drain(zone, arg);
break;
case UMA_RECLAIM_DRAIN_CPU:
pcpu_cache_drain_safe(zone);
zone_drain(zone, arg);
break;
default:
panic("unhandled reclamation request %d", req);
}
}
/* See uma.h */
int
uma_zone_exhausted(uma_zone_t zone)
{
return (atomic_load_32(&zone->uz_sleepers) > 0);
}
unsigned long
uma_limit(void)
{
return (uma_kmem_limit);
}
void
uma_set_limit(unsigned long limit)
{
uma_kmem_limit = limit;
}
unsigned long
uma_size(void)
{
return (atomic_load_long(&uma_kmem_total));
}
long
uma_avail(void)
{
return (uma_kmem_limit - uma_size());
}
#ifdef DDB
/*
* Generate statistics across both the zone and its per-cpu cache's. Return
* desired statistics if the pointer is non-NULL for that statistic.
*
* Note: does not update the zone statistics, as it can't safely clear the
* per-CPU cache statistic.
*
*/
static void
uma_zone_sumstat(uma_zone_t z, long *cachefreep, uint64_t *allocsp,
uint64_t *freesp, uint64_t *sleepsp, uint64_t *xdomainp)
{
uma_cache_t cache;
uint64_t allocs, frees, sleeps, xdomain;
int cachefree, cpu;
allocs = frees = sleeps = xdomain = 0;
cachefree = 0;
CPU_FOREACH(cpu) {
cache = &z->uz_cpu[cpu];
cachefree += cache->uc_allocbucket.ucb_cnt;
cachefree += cache->uc_freebucket.ucb_cnt;
xdomain += cache->uc_crossbucket.ucb_cnt;
cachefree += cache->uc_crossbucket.ucb_cnt;
allocs += cache->uc_allocs;
frees += cache->uc_frees;
}
allocs += counter_u64_fetch(z->uz_allocs);
frees += counter_u64_fetch(z->uz_frees);
xdomain += counter_u64_fetch(z->uz_xdomain);
sleeps += z->uz_sleeps;
if (cachefreep != NULL)
*cachefreep = cachefree;
if (allocsp != NULL)
*allocsp = allocs;
if (freesp != NULL)
*freesp = frees;
if (sleepsp != NULL)
*sleepsp = sleeps;
if (xdomainp != NULL)
*xdomainp = xdomain;
}
#endif /* DDB */
static int
sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
{
uma_keg_t kz;
uma_zone_t z;
int count;
count = 0;
rw_rlock(&uma_rwlock);
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
count++;
}
LIST_FOREACH(z, &uma_cachezones, uz_link)
count++;
rw_runlock(&uma_rwlock);
return (sysctl_handle_int(oidp, &count, 0, req));
}
static void
uma_vm_zone_stats(struct uma_type_header *uth, uma_zone_t z, struct sbuf *sbuf,
struct uma_percpu_stat *ups, bool internal)
{
uma_zone_domain_t zdom;
uma_cache_t cache;
int i;
for (i = 0; i < vm_ndomains; i++) {
zdom = ZDOM_GET(z, i);
uth->uth_zone_free += zdom->uzd_nitems;
}
uth->uth_allocs = counter_u64_fetch(z->uz_allocs);
uth->uth_frees = counter_u64_fetch(z->uz_frees);
uth->uth_fails = counter_u64_fetch(z->uz_fails);
uth->uth_xdomain = counter_u64_fetch(z->uz_xdomain);
uth->uth_sleeps = z->uz_sleeps;
for (i = 0; i < mp_maxid + 1; i++) {
bzero(&ups[i], sizeof(*ups));
if (internal || CPU_ABSENT(i))
continue;
cache = &z->uz_cpu[i];
ups[i].ups_cache_free += cache->uc_allocbucket.ucb_cnt;
ups[i].ups_cache_free += cache->uc_freebucket.ucb_cnt;
ups[i].ups_cache_free += cache->uc_crossbucket.ucb_cnt;
ups[i].ups_allocs = cache->uc_allocs;
ups[i].ups_frees = cache->uc_frees;
}
}
static int
sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
{
struct uma_stream_header ush;
struct uma_type_header uth;
struct uma_percpu_stat *ups;
struct sbuf sbuf;
uma_keg_t kz;
uma_zone_t z;
uint64_t items;
uint32_t kfree, pages;
int count, error, i;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
ups = malloc((mp_maxid + 1) * sizeof(*ups), M_TEMP, M_WAITOK);
count = 0;
rw_rlock(&uma_rwlock);
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
count++;
}
LIST_FOREACH(z, &uma_cachezones, uz_link)
count++;
/*
* Insert stream header.
*/
bzero(&ush, sizeof(ush));
ush.ush_version = UMA_STREAM_VERSION;
ush.ush_maxcpus = (mp_maxid + 1);
ush.ush_count = count;
(void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
LIST_FOREACH(kz, &uma_kegs, uk_link) {
kfree = pages = 0;
for (i = 0; i < vm_ndomains; i++) {
kfree += kz->uk_domain[i].ud_free_items;
pages += kz->uk_domain[i].ud_pages;
}
LIST_FOREACH(z, &kz->uk_zones, uz_link) {
bzero(&uth, sizeof(uth));
strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
uth.uth_align = kz->uk_align;
uth.uth_size = kz->uk_size;
uth.uth_rsize = kz->uk_rsize;
if (z->uz_max_items > 0) {
items = UZ_ITEMS_COUNT(z->uz_items);
uth.uth_pages = (items / kz->uk_ipers) *
kz->uk_ppera;
} else
uth.uth_pages = pages;
uth.uth_maxpages = (z->uz_max_items / kz->uk_ipers) *
kz->uk_ppera;
uth.uth_limit = z->uz_max_items;
uth.uth_keg_free = kfree;
/*
* A zone is secondary is it is not the first entry
* on the keg's zone list.
*/
if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
(LIST_FIRST(&kz->uk_zones) != z))
uth.uth_zone_flags = UTH_ZONE_SECONDARY;
uma_vm_zone_stats(&uth, z, &sbuf, ups,
kz->uk_flags & UMA_ZFLAG_INTERNAL);
(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
for (i = 0; i < mp_maxid + 1; i++)
(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
}
}
LIST_FOREACH(z, &uma_cachezones, uz_link) {
bzero(&uth, sizeof(uth));
strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
uth.uth_size = z->uz_size;
uma_vm_zone_stats(&uth, z, &sbuf, ups, false);
(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
for (i = 0; i < mp_maxid + 1; i++)
(void)sbuf_bcat(&sbuf, &ups[i], sizeof(ups[i]));
}
rw_runlock(&uma_rwlock);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
free(ups, M_TEMP);
return (error);
}
int
sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = *(uma_zone_t *)arg1;
int error, max;
max = uma_zone_get_max(zone);
error = sysctl_handle_int(oidp, &max, 0, req);
if (error || !req->newptr)
return (error);
uma_zone_set_max(zone, max);
return (0);
}
int
sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone;
int cur;
/*
* Some callers want to add sysctls for global zones that
* may not yet exist so they pass a pointer to a pointer.
*/
if (arg2 == 0)
zone = *(uma_zone_t *)arg1;
else
zone = arg1;
cur = uma_zone_get_cur(zone);
return (sysctl_handle_int(oidp, &cur, 0, req));
}
static int
sysctl_handle_uma_zone_allocs(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = arg1;
uint64_t cur;
cur = uma_zone_get_allocs(zone);
return (sysctl_handle_64(oidp, &cur, 0, req));
}
static int
sysctl_handle_uma_zone_frees(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = arg1;
uint64_t cur;
cur = uma_zone_get_frees(zone);
return (sysctl_handle_64(oidp, &cur, 0, req));
}
static int
sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
uma_zone_t zone = arg1;
int error;
sbuf_new_for_sysctl(&sbuf, NULL, 0, req);
if (zone->uz_flags != 0)
sbuf_printf(&sbuf, "0x%b", zone->uz_flags, PRINT_UMA_ZFLAGS);
else
sbuf_printf(&sbuf, "0");
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
static int
sysctl_handle_uma_slab_efficiency(SYSCTL_HANDLER_ARGS)
{
uma_keg_t keg = arg1;
int avail, effpct, total;
total = keg->uk_ppera * PAGE_SIZE;
if ((keg->uk_flags & UMA_ZFLAG_OFFPAGE) != 0)
total += slabzone(keg->uk_ipers)->uz_keg->uk_rsize;
/*
* We consider the client's requested size and alignment here, not the
* real size determination uk_rsize, because we also adjust the real
* size for internal implementation reasons (max bitset size).
*/
avail = keg->uk_ipers * roundup2(keg->uk_size, keg->uk_align + 1);
if ((keg->uk_flags & UMA_ZONE_PCPU) != 0)
avail *= mp_maxid + 1;
effpct = 100 * avail / total;
return (sysctl_handle_int(oidp, &effpct, 0, req));
}
static int
sysctl_handle_uma_zone_items(SYSCTL_HANDLER_ARGS)
{
uma_zone_t zone = arg1;
uint64_t cur;
cur = UZ_ITEMS_COUNT(atomic_load_64(&zone->uz_items));
return (sysctl_handle_64(oidp, &cur, 0, req));
}
#ifdef INVARIANTS
static uma_slab_t
uma_dbg_getslab(uma_zone_t zone, void *item)
{
uma_slab_t slab;
uma_keg_t keg;
uint8_t *mem;
/*
* It is safe to return the slab here even though the
* zone is unlocked because the item's allocation state
* essentially holds a reference.
*/
mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
return (NULL);
if (zone->uz_flags & UMA_ZFLAG_VTOSLAB)
return (vtoslab((vm_offset_t)mem));
keg = zone->uz_keg;
if ((keg->uk_flags & UMA_ZFLAG_HASH) == 0)
return ((uma_slab_t)(mem + keg->uk_pgoff));
KEG_LOCK(keg, 0);
slab = hash_sfind(&keg->uk_hash, mem);
KEG_UNLOCK(keg, 0);
return (slab);
}
static bool
uma_dbg_zskip(uma_zone_t zone, void *mem)
{
if ((zone->uz_flags & UMA_ZFLAG_CACHE) != 0)
return (true);
return (uma_dbg_kskip(zone->uz_keg, mem));
}
static bool
uma_dbg_kskip(uma_keg_t keg, void *mem)
{
uintptr_t idx;
if (dbg_divisor == 0)
return (true);
if (dbg_divisor == 1)
return (false);
idx = (uintptr_t)mem >> PAGE_SHIFT;
if (keg->uk_ipers > 1) {
idx *= keg->uk_ipers;
idx += ((uintptr_t)mem & PAGE_MASK) / keg->uk_rsize;
}
if ((idx / dbg_divisor) * dbg_divisor != idx) {
counter_u64_add(uma_skip_cnt, 1);
return (true);
}
counter_u64_add(uma_dbg_cnt, 1);
return (false);
}
/*
* Set up the slab's freei data such that uma_dbg_free can function.
*
*/
static void
uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
int freei;
if (slab == NULL) {
slab = uma_dbg_getslab(zone, item);
if (slab == NULL)
panic("uma: item %p did not belong to zone %s",
item, zone->uz_name);
}
keg = zone->uz_keg;
freei = slab_item_index(slab, keg, item);
if (BIT_TEST_SET_ATOMIC(keg->uk_ipers, freei,
slab_dbg_bits(slab, keg)))
panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)",
item, zone, zone->uz_name, slab, freei);
}
/*
* Verifies freed addresses. Checks for alignment, valid slab membership
* and duplicate frees.
*
*/
static void
uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
int freei;
if (slab == NULL) {
slab = uma_dbg_getslab(zone, item);
if (slab == NULL)
panic("uma: Freed item %p did not belong to zone %s",
item, zone->uz_name);
}
keg = zone->uz_keg;
freei = slab_item_index(slab, keg, item);
if (freei >= keg->uk_ipers)
panic("Invalid free of %p from zone %p(%s) slab %p(%d)",
item, zone, zone->uz_name, slab, freei);
if (slab_item(slab, keg, freei) != item)
panic("Unaligned free of %p from zone %p(%s) slab %p(%d)",
item, zone, zone->uz_name, slab, freei);
if (!BIT_TEST_CLR_ATOMIC(keg->uk_ipers, freei,
slab_dbg_bits(slab, keg)))
panic("Duplicate free of %p from zone %p(%s) slab %p(%d)",
item, zone, zone->uz_name, slab, freei);
}
#endif /* INVARIANTS */
#ifdef DDB
static int64_t
get_uma_stats(uma_keg_t kz, uma_zone_t z, uint64_t *allocs, uint64_t *used,
uint64_t *sleeps, long *cachefree, uint64_t *xdomain)
{
uint64_t frees;
int i;
if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
*allocs = counter_u64_fetch(z->uz_allocs);
frees = counter_u64_fetch(z->uz_frees);
*sleeps = z->uz_sleeps;
*cachefree = 0;
*xdomain = 0;
} else
uma_zone_sumstat(z, cachefree, allocs, &frees, sleeps,
xdomain);
for (i = 0; i < vm_ndomains; i++) {
*cachefree += ZDOM_GET(z, i)->uzd_nitems;
if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
(LIST_FIRST(&kz->uk_zones) != z)))
*cachefree += kz->uk_domain[i].ud_free_items;
}
*used = *allocs - frees;
return (((int64_t)*used + *cachefree) * kz->uk_size);
}
DB_SHOW_COMMAND(uma, db_show_uma)
{
const char *fmt_hdr, *fmt_entry;
uma_keg_t kz;
uma_zone_t z;
uint64_t allocs, used, sleeps, xdomain;
long cachefree;
/* variables for sorting */
uma_keg_t cur_keg;
uma_zone_t cur_zone, last_zone;
int64_t cur_size, last_size, size;
int ties;
/* /i option produces machine-parseable CSV output */
if (modif[0] == 'i') {
fmt_hdr = "%s,%s,%s,%s,%s,%s,%s,%s,%s\n";
fmt_entry = "\"%s\",%ju,%jd,%ld,%ju,%ju,%u,%jd,%ju\n";
} else {
fmt_hdr = "%18s %6s %7s %7s %11s %7s %7s %10s %8s\n";
fmt_entry = "%18s %6ju %7jd %7ld %11ju %7ju %7u %10jd %8ju\n";
}
db_printf(fmt_hdr, "Zone", "Size", "Used", "Free", "Requests",
"Sleeps", "Bucket", "Total Mem", "XFree");
/* Sort the zones with largest size first. */
last_zone = NULL;
last_size = INT64_MAX;
for (;;) {
cur_zone = NULL;
cur_size = -1;
ties = 0;
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link) {
/*
* In the case of size ties, print out zones
* in the order they are encountered. That is,
* when we encounter the most recently output
* zone, we have already printed all preceding
* ties, and we must print all following ties.
*/
if (z == last_zone) {
ties = 1;
continue;
}
size = get_uma_stats(kz, z, &allocs, &used,
&sleeps, &cachefree, &xdomain);
if (size > cur_size && size < last_size + ties)
{
cur_size = size;
cur_zone = z;
cur_keg = kz;
}
}
}
if (cur_zone == NULL)
break;
size = get_uma_stats(cur_keg, cur_zone, &allocs, &used,
&sleeps, &cachefree, &xdomain);
db_printf(fmt_entry, cur_zone->uz_name,
(uintmax_t)cur_keg->uk_size, (intmax_t)used, cachefree,
(uintmax_t)allocs, (uintmax_t)sleeps,
(unsigned)cur_zone->uz_bucket_size, (intmax_t)size,
xdomain);
if (db_pager_quit)
return;
last_zone = cur_zone;
last_size = cur_size;
}
}
DB_SHOW_COMMAND(umacache, db_show_umacache)
{
uma_zone_t z;
uint64_t allocs, frees;
long cachefree;
int i;
db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
"Requests", "Bucket");
LIST_FOREACH(z, &uma_cachezones, uz_link) {
uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL, NULL);
for (i = 0; i < vm_ndomains; i++)
cachefree += ZDOM_GET(z, i)->uzd_nitems;
db_printf("%18s %8ju %8jd %8ld %12ju %8u\n",
z->uz_name, (uintmax_t)z->uz_size,
(intmax_t)(allocs - frees), cachefree,
(uintmax_t)allocs, z->uz_bucket_size);
if (db_pager_quit)
return;
}
}
#endif /* DDB */
Reference in New Issue View Git Blame Copy Permalink