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freebsd-dev/sys/vm/uma_core.c
Mateusz Guzik 19c591bfe2 Don't trash memory from UMA_ZONE_NOFREE zones. 
Objects obtained from such zones are supposed to retain type stability,
which was violated by aforementioned trashing.

This is a follow-up to r284861.

Discussed with:		kib
2015-09-02 23:09:01 +00:00

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/*-
* Copyright (c) 2002-2005, 2009, 2013 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
* effecient. 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("$FreeBSD$");
/* I should really use ktr.. */
/*
#define UMA_DEBUG 1
#define UMA_DEBUG_ALLOC 1
#define UMA_DEBUG_ALLOC_1 1
*/
#include "opt_ddb.h"
#include "opt_param.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bitset.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/malloc.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/sysctl.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/smp.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_param.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.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
/*
* This is the zone and keg from which all zones are spawned. The idea is that
* even the zone & keg heads are allocated from the allocator, so we use the
* bss section to bootstrap us.
*/
static struct uma_keg masterkeg;
static struct uma_zone masterzone_k;
static struct uma_zone masterzone_z;
static uma_zone_t kegs = &masterzone_k;
static uma_zone_t zones = &masterzone_z;
/* This is the zone from which all of uma_slab_t's are allocated. */
static uma_zone_t slabzone;
static uma_zone_t slabrefzone; /* With refcounters (for UMA_ZONE_REFCNT) */
/*
* 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");
/*
* 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);
/* This RW lock protects the keg list */
static struct rwlock_padalign uma_rwlock;
/* Linked list of boot time pages */
static LIST_HEAD(,uma_slab) uma_boot_pages =
LIST_HEAD_INITIALIZER(uma_boot_pages);
/* This mutex protects the boot time pages list */
static struct mtx_padalign uma_boot_pages_mtx;
static struct sx uma_drain_lock;
/* Is the VM done starting up? */
static int booted = 0;
#define UMA_STARTUP 1
#define UMA_STARTUP2 2
/*
* Only mbuf clusters use ref zones. Just provide enough references
* to support the one user. New code should not use the ref facility.
*/
static const u_int uma_max_ipers_ref = PAGE_SIZE / MCLBYTES;
/*
* 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;
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[] = {
{ NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
{ NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
{ NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
{ NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
{ NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
{ 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_DTOR, SKIP_FINI };
/* Prototypes.. */
static void *noobj_alloc(uma_zone_t, vm_size_t, uint8_t *, int);
static void *page_alloc(uma_zone_t, vm_size_t, uint8_t *, int);
static void *startup_alloc(uma_zone_t, vm_size_t, uint8_t *, int);
static void page_free(void *, vm_size_t, uint8_t);
static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int);
static void cache_drain(uma_zone_t);
static void bucket_drain(uma_zone_t, uma_bucket_t);
static void bucket_cache_drain(uma_zone_t zone);
static int keg_ctor(void *, int, void *, int);
static void keg_dtor(void *, int, void *);
static int zone_ctor(void *, int, void *, int);
static void zone_dtor(void *, int, void *);
static int zero_init(void *, int, int);
static void keg_small_init(uma_keg_t keg);
static void keg_large_init(uma_keg_t keg);
static void zone_foreach(void (*zfunc)(uma_zone_t));
static void zone_timeout(uma_zone_t zone);
static int hash_alloc(struct uma_hash *);
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_startup3(void);
static void *zone_alloc_item(uma_zone_t, void *, int);
static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
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(void);
static uma_bucket_t zone_alloc_bucket(uma_zone_t zone, void *, int flags);
static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags);
static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags);
static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
static void slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item);
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(uma_zone_t zone, void **bucket, int max, int flags);
static void zone_release(uma_zone_t zone, void **bucket, int cnt);
static void uma_zero_item(void *item, uma_zone_t zone);
void uma_print_zone(uma_zone_t);
void uma_print_stats(void);
static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|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");
/*
* This routine checks to see whether or not it's safe to enable buckets.
*/
static void
bucket_enable(void)
{
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);
}
}
/*
* 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;
/*
* This is to stop us from allocating per cpu buckets while we're
* running out of vm.boot_pages. Otherwise, we would exhaust the
* boot pages. This also prevents us from allocating buckets in
* low memory situations.
*/
if (bucketdisable)
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_ZFLAG_CACHEONLY)
flags |= M_NOVM;
ubz = bucket_zone_lookup(zone->uz_count);
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 = ubz->ubz_entries;
}
return (bucket);
}
static void
bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
{
struct uma_bucket_zone *ubz;
KASSERT(bucket->ub_cnt == 0,
("bucket_free: Freeing a non free 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(void)
{
struct uma_bucket_zone *ubz;
for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
zone_drain(ubz->ubz_zone);
}
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 void
zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
{
uma_klink_t klink;
LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
kegfn(klink->kl_keg);
}
/*
* 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);
/* Reschedule this event */
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
}
/*
* Routine to perform timeout driven calculations. This expands the
* hashes and does per cpu statistics aggregation.
*
* Returns nothing.
*/
static void
keg_timeout(uma_keg_t keg)
{
KEG_LOCK(keg);
/*
* 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 (keg->uk_flags & UMA_ZONE_HASH &&
keg->uk_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.
*/
newhash = keg->uk_hash;
KEG_UNLOCK(keg);
ret = hash_alloc(&newhash);
KEG_LOCK(keg);
if (ret) {
if (hash_expand(&keg->uk_hash, &newhash)) {
oldhash = keg->uk_hash;
keg->uk_hash = newhash;
} else
oldhash = newhash;
KEG_UNLOCK(keg);
hash_free(&oldhash);
return;
}
}
KEG_UNLOCK(keg);
}
static void
zone_timeout(uma_zone_t zone)
{
zone_foreach_keg(zone, &keg_timeout);
}
/*
* 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 sucess and 0 on failure.
*/
static int
hash_alloc(struct uma_hash *hash)
{
int oldsize;
int alloc;
oldsize = hash->uh_hashsize;
/* We're just going to go to a power of two greater */
if (oldsize) {
hash->uh_hashsize = oldsize * 2;
alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
hash->uh_slab_hash = (struct slabhead *)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,
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_slab_t slab;
int hval;
int i;
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 (i = 0; i < oldhash->uh_hashsize; i++)
while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
hval = UMA_HASH(newhash, slab->us_data);
SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
slab, us_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, cpu queue must be locked.
*
* Returns:
* Nothing
*/
static void
bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
{
int i;
if (bucket == NULL)
return;
if (zone->uz_fini)
for (i = 0; i < bucket->ub_cnt; i++)
zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
bucket->ub_cnt = 0;
}
/*
* Drains the per cpu caches for a zone.
*
* NOTE: This may only be called while the zone is being turn 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;
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().
*
* XXX: We lock the zone before passing into bucket_cache_drain() as
* it is used elsewhere. Should the tear-down path be made special
* there in some form?
*/
CPU_FOREACH(cpu) {
cache = &zone->uz_cpu[cpu];
bucket_drain(zone, cache->uc_allocbucket);
bucket_drain(zone, cache->uc_freebucket);
if (cache->uc_allocbucket != NULL)
bucket_free(zone, cache->uc_allocbucket, NULL);
if (cache->uc_freebucket != NULL)
bucket_free(zone, cache->uc_freebucket, NULL);
cache->uc_allocbucket = cache->uc_freebucket = NULL;
}
ZONE_LOCK(zone);
bucket_cache_drain(zone);
ZONE_UNLOCK(zone);
}
static void
cache_shrink(uma_zone_t zone)
{
if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
return;
ZONE_LOCK(zone);
zone->uz_count = (zone->uz_count_min + zone->uz_count) / 2;
ZONE_UNLOCK(zone);
}
static void
cache_drain_safe_cpu(uma_zone_t zone)
{
uma_cache_t cache;
uma_bucket_t b1, b2;
if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
return;
b1 = b2 = NULL;
ZONE_LOCK(zone);
critical_enter();
cache = &zone->uz_cpu[curcpu];
if (cache->uc_allocbucket) {
if (cache->uc_allocbucket->ub_cnt != 0)
LIST_INSERT_HEAD(&zone->uz_buckets,
cache->uc_allocbucket, ub_link);
else
b1 = cache->uc_allocbucket;
cache->uc_allocbucket = NULL;
}
if (cache->uc_freebucket) {
if (cache->uc_freebucket->ub_cnt != 0)
LIST_INSERT_HEAD(&zone->uz_buckets,
cache->uc_freebucket, ub_link);
else
b2 = cache->uc_freebucket;
cache->uc_freebucket = NULL;
}
critical_exit();
ZONE_UNLOCK(zone);
if (b1)
bucket_free(zone, b1, NULL);
if (b2)
bucket_free(zone, b2, NULL);
}
/*
* 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
cache_drain_safe(uma_zone_t zone)
{
int cpu;
/*
* Polite bucket sizes shrinking was not enouth, shrink aggressively.
*/
if (zone)
cache_shrink(zone);
else
zone_foreach(cache_shrink);
CPU_FOREACH(cpu) {
thread_lock(curthread);
sched_bind(curthread, cpu);
thread_unlock(curthread);
if (zone)
cache_drain_safe_cpu(zone);
else
zone_foreach(cache_drain_safe_cpu);
}
thread_lock(curthread);
sched_unbind(curthread);
thread_unlock(curthread);
}
/*
* Drain the cached buckets from a zone. Expects a locked zone on entry.
*/
static void
bucket_cache_drain(uma_zone_t zone)
{
uma_bucket_t bucket;
/*
* Drain the bucket queues and free the buckets, we just keep two per
* cpu (alloc/free).
*/
while ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
LIST_REMOVE(bucket, ub_link);
ZONE_UNLOCK(zone);
bucket_drain(zone, bucket);
bucket_free(zone, bucket, NULL);
ZONE_LOCK(zone);
}
/*
* Shrink further bucket sizes. Price of single zone lock collision
* is probably lower then price of global cache drain.
*/
if (zone->uz_count > zone->uz_count_min)
zone->uz_count--;
}
static void
keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
{
uint8_t *mem;
int i;
uint8_t flags;
mem = slab->us_data;
flags = slab->us_flags;
i = start;
if (keg->uk_fini != NULL) {
for (i--; i > -1; i--)
keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
keg->uk_size);
}
if (keg->uk_flags & UMA_ZONE_OFFPAGE)
zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
#ifdef UMA_DEBUG
printf("%s: Returning %d bytes.\n", keg->uk_name,
PAGE_SIZE * keg->uk_ppera);
#endif
keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
}
/*
* 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)
{
struct slabhead freeslabs = { 0 };
uma_slab_t slab;
uma_slab_t n;
/*
* We don't want to take pages from statically allocated kegs at this
* time
*/
if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
return;
#ifdef UMA_DEBUG
printf("%s free items: %u\n", keg->uk_name, keg->uk_free);
#endif
KEG_LOCK(keg);
if (keg->uk_free == 0)
goto finished;
slab = LIST_FIRST(&keg->uk_free_slab);
while (slab) {
n = LIST_NEXT(slab, us_link);
/* We have no where to free these to */
if (slab->us_flags & UMA_SLAB_BOOT) {
slab = n;
continue;
}
LIST_REMOVE(slab, us_link);
keg->uk_pages -= keg->uk_ppera;
keg->uk_free -= keg->uk_ipers;
if (keg->uk_flags & UMA_ZONE_HASH)
UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
slab = n;
}
finished:
KEG_UNLOCK(keg);
while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
keg_free_slab(keg, slab, keg->uk_ipers);
}
}
static void
zone_drain_wait(uma_zone_t zone, int waitok)
{
/*
* Set draining to interlock with zone_dtor() so we can release our
* locks as we go. Only dtor() should do a WAITOK call since it
* is the only call that knows the structure will still be available
* when it wakes up.
*/
ZONE_LOCK(zone);
while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
if (waitok == M_NOWAIT)
goto out;
msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
}
zone->uz_flags |= UMA_ZFLAG_DRAINING;
bucket_cache_drain(zone);
ZONE_UNLOCK(zone);
/*
* The DRAINING flag protects us from being freed while
* we're running. Normally the uma_rwlock would protect us but we
* must be able to release and acquire the right lock for each keg.
*/
zone_foreach_keg(zone, &keg_drain);
ZONE_LOCK(zone);
zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
wakeup(zone);
out:
ZONE_UNLOCK(zone);
}
void
zone_drain(uma_zone_t zone)
{
zone_drain_wait(zone, M_NOWAIT);
}
/*
* Allocate a new slab for a keg. This does not insert the slab onto a list.
*
* Arguments:
* wait Shall we wait?
*
* 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 wait)
{
uma_slabrefcnt_t slabref;
uma_alloc allocf;
uma_slab_t slab;
uint8_t *mem;
uint8_t flags;
int i;
mtx_assert(&keg->uk_lock, MA_OWNED);
slab = NULL;
mem = NULL;
#ifdef UMA_DEBUG
printf("alloc_slab: Allocating a new slab for %s\n", keg->uk_name);
#endif
allocf = keg->uk_allocf;
KEG_UNLOCK(keg);
if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
slab = zone_alloc_item(keg->uk_slabzone, NULL, wait);
if (slab == NULL)
goto out;
}
/*
* 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)
wait |= M_ZERO;
else
wait &= ~M_ZERO;
if (keg->uk_flags & UMA_ZONE_NODUMP)
wait |= M_NODUMP;
/* zone is passed for legacy reasons. */
mem = allocf(zone, keg->uk_ppera * PAGE_SIZE, &flags, wait);
if (mem == NULL) {
if (keg->uk_flags & UMA_ZONE_OFFPAGE)
zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
slab = NULL;
goto out;
}
/* Point the slab into the allocated memory */
if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
slab = (uma_slab_t )(mem + keg->uk_pgoff);
if (keg->uk_flags & UMA_ZONE_VTOSLAB)
for (i = 0; i < keg->uk_ppera; i++)
vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
slab->us_keg = keg;
slab->us_data = mem;
slab->us_freecount = keg->uk_ipers;
slab->us_flags = flags;
BIT_FILL(SLAB_SETSIZE, &slab->us_free);
#ifdef INVARIANTS
BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
#endif
if (keg->uk_flags & UMA_ZONE_REFCNT) {
slabref = (uma_slabrefcnt_t)slab;
for (i = 0; i < keg->uk_ipers; i++)
slabref->us_refcnt[i] = 0;
}
if (keg->uk_init != NULL) {
for (i = 0; i < keg->uk_ipers; i++)
if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
keg->uk_size, wait) != 0)
break;
if (i != keg->uk_ipers) {
keg_free_slab(keg, slab, i);
slab = NULL;
goto out;
}
}
out:
KEG_LOCK(keg);
if (slab != NULL) {
if (keg->uk_flags & UMA_ZONE_HASH)
UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
keg->uk_pages += keg->uk_ppera;
keg->uk_free += keg->uk_ipers;
}
return (slab);
}
/*
* This function is intended to be used early on in place of page_alloc() so
* that we may use the boot time page cache to satisfy allocations before
* the VM is ready.
*/
static void *
startup_alloc(uma_zone_t zone, vm_size_t bytes, uint8_t *pflag, int wait)
{
uma_keg_t keg;
uma_slab_t tmps;
int pages, check_pages;
keg = zone_first_keg(zone);
pages = howmany(bytes, PAGE_SIZE);
check_pages = pages - 1;
KASSERT(pages > 0, ("startup_alloc can't reserve 0 pages\n"));
/*
* Check our small startup cache to see if it has pages remaining.
*/
mtx_lock(&uma_boot_pages_mtx);
/* First check if we have enough room. */
tmps = LIST_FIRST(&uma_boot_pages);
while (tmps != NULL && check_pages-- > 0)
tmps = LIST_NEXT(tmps, us_link);
if (tmps != NULL) {
/*
* It's ok to lose tmps references. The last one will
* have tmps->us_data pointing to the start address of
* "pages" contiguous pages of memory.
*/
while (pages-- > 0) {
tmps = LIST_FIRST(&uma_boot_pages);
LIST_REMOVE(tmps, us_link);
}
mtx_unlock(&uma_boot_pages_mtx);
*pflag = tmps->us_flags;
return (tmps->us_data);
}
mtx_unlock(&uma_boot_pages_mtx);
if (booted < UMA_STARTUP2)
panic("UMA: Increase vm.boot_pages");
/*
* Now that we've booted reset these users to their real allocator.
*/
#ifdef UMA_MD_SMALL_ALLOC
keg->uk_allocf = (keg->uk_ppera > 1) ? page_alloc : uma_small_alloc;
#else
keg->uk_allocf = page_alloc;
#endif
return keg->uk_allocf(zone, bytes, pflag, wait);
}
/*
* 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, uint8_t *pflag, int wait)
{
void *p; /* Returned page */
*pflag = UMA_SLAB_KMEM;
p = (void *) kmem_malloc(kmem_arena, bytes, wait);
return (p);
}
/*
* Allocates a number of pages from within an 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, 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;
TAILQ_INIT(&alloctail);
keg = zone_first_keg(zone);
npages = howmany(bytes, PAGE_SIZE);
while (npages > 0) {
p = vm_page_alloc(NULL, 0, VM_ALLOC_INTERRUPT |
VM_ALLOC_WIRED | VM_ALLOC_NOOBJ);
if (p != NULL) {
/*
* Since the page does not belong to an object, its
* listq is unused.
*/
TAILQ_INSERT_TAIL(&alloctail, p, listq);
npages--;
continue;
}
if (wait & M_WAITOK) {
VM_WAIT;
continue;
}
/*
* Page allocation failed, free intermediate pages and
* exit.
*/
TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
vm_page_unwire(p, PQ_INACTIVE);
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);
}
/*
* 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)
{
struct vmem *vmem;
if (flags & UMA_SLAB_KMEM)
vmem = kmem_arena;
else if (flags & UMA_SLAB_KERNEL)
vmem = kernel_arena;
else
panic("UMA: page_free used with invalid flags %d", flags);
kmem_free(vmem, (vm_offset_t)mem, 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);
}
/*
* Finish creating a small uma keg. This calculates ipers, and the keg size.
*
* Arguments
* keg The zone we should initialize
*
* Returns
* Nothing
*/
static void
keg_small_init(uma_keg_t keg)
{
u_int rsize;
u_int memused;
u_int wastedspace;
u_int shsize;
if (keg->uk_flags & UMA_ZONE_PCPU) {
u_int ncpus = mp_ncpus ? mp_ncpus : MAXCPU;
keg->uk_slabsize = sizeof(struct pcpu);
keg->uk_ppera = howmany(ncpus * sizeof(struct pcpu),
PAGE_SIZE);
} else {
keg->uk_slabsize = UMA_SLAB_SIZE;
keg->uk_ppera = 1;
}
/*
* 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 = keg->uk_size;
if (rsize < keg->uk_slabsize / SLAB_SETSIZE)
rsize = keg->uk_slabsize / SLAB_SETSIZE;
if (rsize & keg->uk_align)
rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
keg->uk_rsize = rsize;
KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
keg->uk_rsize < sizeof(struct pcpu),
("%s: size %u too large", __func__, keg->uk_rsize));
if (keg->uk_flags & UMA_ZONE_REFCNT)
rsize += sizeof(uint32_t);
if (keg->uk_flags & UMA_ZONE_OFFPAGE)
shsize = 0;
else
shsize = sizeof(struct uma_slab);
keg->uk_ipers = (keg->uk_slabsize - shsize) / rsize;
KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
memused = keg->uk_ipers * rsize + shsize;
wastedspace = keg->uk_slabsize - memused;
/*
* 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_ZFLAG_CACHEONLY as a result
* of UMA_ZONE_VM, which clearly forbids it.
*/
if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
(keg->uk_flags & UMA_ZFLAG_CACHEONLY))
return;
/*
* See if using an OFFPAGE slab will limit our waste. Only do
* this if it permits more items per-slab.
*
* XXX We could try growing slabsize to limit max waste as well.
* Historically this was not done because the VM could not
* efficiently handle contiguous allocations.
*/
if ((wastedspace >= keg->uk_slabsize / UMA_MAX_WASTE) &&
(keg->uk_ipers < (keg->uk_slabsize / keg->uk_rsize))) {
keg->uk_ipers = keg->uk_slabsize / keg->uk_rsize;
KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
#ifdef UMA_DEBUG
printf("UMA decided we need offpage slab headers for "
"keg: %s, calculated wastedspace = %d, "
"maximum wasted space allowed = %d, "
"calculated ipers = %d, "
"new wasted space = %d\n", keg->uk_name, wastedspace,
keg->uk_slabsize / UMA_MAX_WASTE, keg->uk_ipers,
keg->uk_slabsize - keg->uk_ipers * keg->uk_rsize);
#endif
keg->uk_flags |= UMA_ZONE_OFFPAGE;
}
if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
(keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
keg->uk_flags |= UMA_ZONE_HASH;
}
/*
* Finish creating a large (> UMA_SLAB_SIZE) uma kegs. Just give in and do
* OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
* more complicated.
*
* Arguments
* keg The keg we should initialize
*
* Returns
* Nothing
*/
static void
keg_large_init(uma_keg_t keg)
{
u_int shsize;
KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
keg->uk_slabsize = keg->uk_ppera * PAGE_SIZE;
keg->uk_ipers = 1;
keg->uk_rsize = keg->uk_size;
/* We can't do OFFPAGE if we're internal, bail out here. */
if (keg->uk_flags & UMA_ZFLAG_INTERNAL)
return;
/* Check whether we have enough space to not do OFFPAGE. */
if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0) {
shsize = sizeof(struct uma_slab);
if (keg->uk_flags & UMA_ZONE_REFCNT)
shsize += keg->uk_ipers * sizeof(uint32_t);
if (shsize & UMA_ALIGN_PTR)
shsize = (shsize & ~UMA_ALIGN_PTR) +
(UMA_ALIGN_PTR + 1);
if ((PAGE_SIZE * keg->uk_ppera) - keg->uk_rsize < shsize)
keg->uk_flags |= UMA_ZONE_OFFPAGE;
}
if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
(keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
keg->uk_flags |= UMA_ZONE_HASH;
}
static void
keg_cachespread_init(uma_keg_t keg)
{
int alignsize;
int trailer;
int pages;
int rsize;
KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
alignsize = keg->uk_align + 1;
rsize = keg->uk_size;
/*
* 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 & keg->uk_align)
rsize = (rsize & ~keg->uk_align) + alignsize;
if ((rsize & alignsize) == 0)
rsize += alignsize;
trailer = rsize - keg->uk_size;
pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
keg->uk_rsize = rsize;
keg->uk_ppera = pages;
keg->uk_slabsize = UMA_SLAB_SIZE;
keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
KASSERT(keg->uk_ipers <= SLAB_SETSIZE,
("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
keg->uk_ipers));
}
/*
* 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;
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_free = 0;
keg->uk_reserve = 0;
keg->uk_pages = 0;
keg->uk_flags = arg->flags;
keg->uk_allocf = page_alloc;
keg->uk_freef = page_free;
keg->uk_slabzone = NULL;
/*
* The master zone is passed to us at keg-creation time.
*/
zone = arg->zone;
keg->uk_name = zone->uz_name;
if (arg->flags & UMA_ZONE_VM)
keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
if (arg->flags & UMA_ZONE_ZINIT)
keg->uk_init = zero_init;
if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC)
keg->uk_flags |= UMA_ZONE_VTOSLAB;
if (arg->flags & UMA_ZONE_PCPU)
#ifdef SMP
keg->uk_flags |= UMA_ZONE_OFFPAGE;
#else
keg->uk_flags &= ~UMA_ZONE_PCPU;
#endif
if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
keg_cachespread_init(keg);
} else if (keg->uk_flags & UMA_ZONE_REFCNT) {
if (keg->uk_size >
(UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) -
sizeof(uint32_t)))
keg_large_init(keg);
else
keg_small_init(keg);
} else {
if (keg->uk_size > (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
keg_large_init(keg);
else
keg_small_init(keg);
}
if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
if (keg->uk_flags & UMA_ZONE_REFCNT) {
if (keg->uk_ipers > uma_max_ipers_ref)
panic("Too many ref items per zone: %d > %d\n",
keg->uk_ipers, uma_max_ipers_ref);
keg->uk_slabzone = slabrefzone;
} else
keg->uk_slabzone = slabzone;
}
/*
* If we haven't booted yet we need allocations to go through the
* startup cache until the vm is ready.
*/
if (keg->uk_ppera == 1) {
#ifdef UMA_MD_SMALL_ALLOC
keg->uk_allocf = uma_small_alloc;
keg->uk_freef = uma_small_free;
if (booted < UMA_STARTUP)
keg->uk_allocf = startup_alloc;
#else
if (booted < UMA_STARTUP2)
keg->uk_allocf = startup_alloc;
#endif
} else if (booted < UMA_STARTUP2 &&
(keg->uk_flags & UMA_ZFLAG_INTERNAL))
keg->uk_allocf = startup_alloc;
/*
* Initialize keg's lock
*/
KEG_LOCK_INIT(keg, (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. This calculates a right
* justified offset into the memory on an ALIGN_PTR boundary.
*/
if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
u_int totsize;
/* Size of the slab struct and free list */
totsize = sizeof(struct uma_slab);
/* Size of the reference counts. */
if (keg->uk_flags & UMA_ZONE_REFCNT)
totsize += keg->uk_ipers * sizeof(uint32_t);
if (totsize & UMA_ALIGN_PTR)
totsize = (totsize & ~UMA_ALIGN_PTR) +
(UMA_ALIGN_PTR + 1);
keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
/*
* 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.
*/
totsize = keg->uk_pgoff + sizeof(struct uma_slab);
if (keg->uk_flags & UMA_ZONE_REFCNT)
totsize += keg->uk_ipers * sizeof(uint32_t);
if (totsize > PAGE_SIZE * keg->uk_ppera) {
printf("zone %s ipers %d rsize %d size %d\n",
zone->uz_name, keg->uk_ipers, keg->uk_rsize,
keg->uk_size);
panic("UMA slab won't fit.");
}
}
if (keg->uk_flags & UMA_ZONE_HASH)
hash_alloc(&keg->uk_hash);
#ifdef UMA_DEBUG
printf("UMA: %s(%p) size %d(%d) flags %#x ipers %d ppera %d out %d free %d\n",
zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
keg->uk_ipers, keg->uk_ppera,
(keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
#endif
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);
}
/*
* 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_zctor_args *arg = udata;
uma_zone_t zone = mem;
uma_zone_t z;
uma_keg_t keg;
bzero(zone, size);
zone->uz_name = arg->name;
zone->uz_ctor = arg->ctor;
zone->uz_dtor = arg->dtor;
zone->uz_slab = zone_fetch_slab;
zone->uz_init = NULL;
zone->uz_fini = NULL;
zone->uz_allocs = 0;
zone->uz_frees = 0;
zone->uz_fails = 0;
zone->uz_sleeps = 0;
zone->uz_count = 0;
zone->uz_count_min = 0;
zone->uz_flags = 0;
zone->uz_warning = NULL;
timevalclear(&zone->uz_ratecheck);
keg = arg->keg;
ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
/*
* This is a pure cache zone, no kegs.
*/
if (arg->import) {
if (arg->flags & UMA_ZONE_VM)
arg->flags |= UMA_ZFLAG_CACHEONLY;
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;
zone->uz_lockptr = &zone->uz_lock;
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 = (uma_import)zone_import;
zone->uz_release = (uma_release)zone_release;
zone->uz_arg = zone;
if (arg->flags & UMA_ZONE_SECONDARY) {
KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
zone->uz_init = arg->uminit;
zone->uz_fini = arg->fini;
zone->uz_lockptr = &keg->uk_lock;
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;
karg.zone = zone;
error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
flags);
if (error)
return (error);
}
/*
* Link in the first keg.
*/
zone->uz_klink.kl_keg = keg;
LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
zone->uz_lockptr = &keg->uk_lock;
zone->uz_size = keg->uk_size;
zone->uz_flags |= (keg->uk_flags &
(UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
/*
* Some internal zones don't have room allocated for the per cpu
* caches. If we're internal, bail out here.
*/
if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
("Secondary zone requested UMA_ZFLAG_INTERNAL"));
return (0);
}
out:
if ((arg->flags & UMA_ZONE_MAXBUCKET) == 0)
zone->uz_count = bucket_select(zone->uz_size);
else
zone->uz_count = BUCKET_MAX;
zone->uz_count_min = zone->uz_count;
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;
keg = (uma_keg_t)arg;
KEG_LOCK(keg);
if (keg->uk_free != 0) {
printf("Freed UMA keg (%s) was not empty (%d items). "
" Lost %d pages of memory.\n",
keg->uk_name ? keg->uk_name : "",
keg->uk_free, keg->uk_pages);
}
KEG_UNLOCK(keg);
hash_free(&keg->uk_hash);
KEG_LOCK_FINI(keg);
}
/*
* Zone header dtor.
*
* Arguments/Returns follow uma_dtor specifications
* udata unused
*/
static void
zone_dtor(void *arg, int size, void *udata)
{
uma_klink_t klink;
uma_zone_t zone;
uma_keg_t keg;
zone = (uma_zone_t)arg;
keg = zone_first_keg(zone);
if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
cache_drain(zone);
rw_wlock(&uma_rwlock);
LIST_REMOVE(zone, uz_link);
rw_wunlock(&uma_rwlock);
/*
* XXX there are some races here where
* the zone can be drained but zone lock
* released and then refilled before we
* remove it... we dont care for now
*/
zone_drain_wait(zone, M_WAITOK);
/*
* Unlink all of our kegs.
*/
while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
klink->kl_keg = NULL;
LIST_REMOVE(klink, kl_link);
if (klink == &zone->uz_klink)
continue;
free(klink, M_TEMP);
}
/*
* We only destroy kegs from non secondary zones.
*/
if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0) {
rw_wlock(&uma_rwlock);
LIST_REMOVE(keg, uk_link);
rw_wunlock(&uma_rwlock);
zone_free_item(kegs, keg, NULL, SKIP_NONE);
}
ZONE_LOCK_FINI(zone);
}
/*
* 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))
{
uma_keg_t keg;
uma_zone_t zone;
rw_rlock(&uma_rwlock);
LIST_FOREACH(keg, &uma_kegs, uk_link) {
LIST_FOREACH(zone, &keg->uk_zones, uz_link)
zfunc(zone);
}
rw_runlock(&uma_rwlock);
}
/* Public functions */
/* See uma.h */
void
uma_startup(void *bootmem, int boot_pages)
{
struct uma_zctor_args args;
uma_slab_t slab;
u_int slabsize;
int i;
#ifdef UMA_DEBUG
printf("Creating uma keg headers zone and keg.\n");
#endif
rw_init(&uma_rwlock, "UMA lock");
/* "manually" create the initial zone */
memset(&args, 0, sizeof(args));
args.name = "UMA Kegs";
args.size = sizeof(struct uma_keg);
args.ctor = keg_ctor;
args.dtor = keg_dtor;
args.uminit = zero_init;
args.fini = NULL;
args.keg = &masterkeg;
args.align = 32 - 1;
args.flags = UMA_ZFLAG_INTERNAL;
/* The initial zone has no Per cpu queues so it's smaller */
zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
#ifdef UMA_DEBUG
printf("Filling boot free list.\n");
#endif
for (i = 0; i < boot_pages; i++) {
slab = (uma_slab_t)((uint8_t *)bootmem + (i * UMA_SLAB_SIZE));
slab->us_data = (uint8_t *)slab;
slab->us_flags = UMA_SLAB_BOOT;
LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
}
mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
#ifdef UMA_DEBUG
printf("Creating uma zone headers zone and keg.\n");
#endif
args.name = "UMA Zones";
args.size = sizeof(struct uma_zone) +
(sizeof(struct uma_cache) * (mp_maxid + 1));
args.ctor = zone_ctor;
args.dtor = zone_dtor;
args.uminit = zero_init;
args.fini = NULL;
args.keg = NULL;
args.align = 32 - 1;
args.flags = UMA_ZFLAG_INTERNAL;
/* The initial zone has no Per cpu queues so it's smaller */
zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
#ifdef UMA_DEBUG
printf("Creating slab and hash zones.\n");
#endif
/* Now make a zone for slab headers */
slabzone = uma_zcreate("UMA Slabs",
sizeof(struct uma_slab),
NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
/*
* We also create a zone for the bigger slabs with reference
* counts in them, to accomodate UMA_ZONE_REFCNT zones.
*/
slabsize = sizeof(struct uma_slab_refcnt);
slabsize += uma_max_ipers_ref * sizeof(uint32_t);
slabrefzone = uma_zcreate("UMA RCntSlabs",
slabsize,
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();
booted = UMA_STARTUP;
#ifdef UMA_DEBUG
printf("UMA startup complete.\n");
#endif
}
/* see uma.h */
void
uma_startup2(void)
{
booted = UMA_STARTUP2;
bucket_enable();
sx_init(&uma_drain_lock, "umadrain");
#ifdef UMA_DEBUG
printf("UMA startup2 complete.\n");
#endif
}
/*
* Initialize our callout handle
*
*/
static void
uma_startup3(void)
{
#ifdef UMA_DEBUG
printf("Starting callout.\n");
#endif
callout_init(&uma_callout, 1);
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
#ifdef UMA_DEBUG
printf("UMA startup3 complete.\n");
#endif
}
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, M_WAITOK));
}
/* 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;
bool locked;
/* 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;
#ifdef INVARIANTS
/*
* If a zone is being created with an empty constructor and
* destructor, pass UMA constructor/destructor which checks for
* memory use after free.
*/
if ((!(flags & (UMA_ZONE_ZINIT | UMA_ZONE_NOFREE))) &&
ctor == NULL && dtor == NULL && uminit == NULL && fini == NULL) {
args.ctor = trash_ctor;
args.dtor = trash_dtor;
args.uminit = trash_init;
args.fini = trash_fini;
}
#endif
args.align = align;
args.flags = flags;
args.keg = NULL;
if (booted < UMA_STARTUP2) {
locked = false;
} else {
sx_slock(&uma_drain_lock);
locked = true;
}
res = zone_alloc_item(zones, &args, M_WAITOK);
if (locked)
sx_sunlock(&uma_drain_lock);
return (res);
}
/* See uma.h */
uma_zone_t
uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_zone_t master)
{
struct uma_zctor_args args;
uma_keg_t keg;
uma_zone_t res;
bool locked;
keg = zone_first_keg(master);
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;
if (booted < UMA_STARTUP2) {
locked = false;
} else {
sx_slock(&uma_drain_lock);
locked = true;
}
/* XXX Attaches only one keg of potentially many. */
res = zone_alloc_item(zones, &args, M_WAITOK);
if (locked)
sx_sunlock(&uma_drain_lock);
return (res);
}
/* See uma.h */
uma_zone_t
uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
uma_init zinit, uma_fini zfini, uma_import zimport,
uma_release zrelease, void *arg, int flags)
{
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;
return (zone_alloc_item(zones, &args, M_WAITOK));
}
static void
zone_lock_pair(uma_zone_t a, uma_zone_t b)
{
if (a < b) {
ZONE_LOCK(a);
mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
} else {
ZONE_LOCK(b);
mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
}
}
static void
zone_unlock_pair(uma_zone_t a, uma_zone_t b)
{
ZONE_UNLOCK(a);
ZONE_UNLOCK(b);
}
int
uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
{
uma_klink_t klink;
uma_klink_t kl;
int error;
error = 0;
klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
zone_lock_pair(zone, master);
/*
* zone must use vtoslab() to resolve objects and must already be
* a secondary.
*/
if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
!= (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
error = EINVAL;
goto out;
}
/*
* The new master must also use vtoslab().
*/
if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
error = EINVAL;
goto out;
}
/*
* Both must either be refcnt, or not be refcnt.
*/
if ((zone->uz_flags & UMA_ZONE_REFCNT) !=
(master->uz_flags & UMA_ZONE_REFCNT)) {
error = EINVAL;
goto out;
}
/*
* The underlying object must be the same size. rsize
* may be different.
*/
if (master->uz_size != zone->uz_size) {
error = E2BIG;
goto out;
}
/*
* Put it at the end of the list.
*/
klink->kl_keg = zone_first_keg(master);
LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
if (LIST_NEXT(kl, kl_link) == NULL) {
LIST_INSERT_AFTER(kl, klink, kl_link);
break;
}
}
klink = NULL;
zone->uz_flags |= UMA_ZFLAG_MULTI;
zone->uz_slab = zone_fetch_slab_multi;
out:
zone_unlock_pair(zone, master);
if (klink != NULL)
free(klink, M_TEMP);
return (error);
}
/* See uma.h */
void
uma_zdestroy(uma_zone_t zone)
{
sx_slock(&uma_drain_lock);
zone_free_item(zones, zone, NULL, SKIP_NONE);
sx_sunlock(&uma_drain_lock);
}
/* See uma.h */
void *
uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
{
void *item;
uma_cache_t cache;
uma_bucket_t bucket;
int lockfail;
int cpu;
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
/* This is the fast path allocation */
#ifdef UMA_DEBUG_ALLOC_1
printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
#endif
CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
zone->uz_name, flags);
if (flags & M_WAITOK) {
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"uma_zalloc_arg: zone \"%s\"", zone->uz_name);
}
#ifdef DEBUG_MEMGUARD
if (memguard_cmp_zone(zone)) {
item = memguard_alloc(zone->uz_size, flags);
if (item != NULL) {
/*
* Avoid conflict with the use-after-free
* protecting infrastructure from INVARIANTS.
*/
if (zone->uz_init != NULL &&
zone->uz_init != mtrash_init &&
zone->uz_init(item, zone->uz_size, flags) != 0)
return (NULL);
if (zone->uz_ctor != NULL &&
zone->uz_ctor != mtrash_ctor &&
zone->uz_ctor(item, zone->uz_size, udata,
flags) != 0) {
zone->uz_fini(item, zone->uz_size);
return (NULL);
}
return (item);
}
/* This is unfortunate but should not be fatal. */
}
#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();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
zalloc_start:
bucket = cache->uc_allocbucket;
if (bucket != NULL && bucket->ub_cnt > 0) {
bucket->ub_cnt--;
item = bucket->ub_bucket[bucket->ub_cnt];
#ifdef INVARIANTS
bucket->ub_bucket[bucket->ub_cnt] = NULL;
#endif
KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
cache->uc_allocs++;
critical_exit();
if (zone->uz_ctor != NULL &&
zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
atomic_add_long(&zone->uz_fails, 1);
zone_free_item(zone, item, udata, SKIP_DTOR);
return (NULL);
}
#ifdef INVARIANTS
uma_dbg_alloc(zone, NULL, item);
#endif
if (flags & M_ZERO)
uma_zero_item(item, zone);
return (item);
}
/*
* We have run out of items in our alloc bucket.
* See if we can switch with our free bucket.
*/
bucket = cache->uc_freebucket;
if (bucket != NULL && bucket->ub_cnt > 0) {
#ifdef UMA_DEBUG_ALLOC
printf("uma_zalloc: Swapping empty with alloc.\n");
#endif
cache->uc_freebucket = cache->uc_allocbucket;
cache->uc_allocbucket = bucket;
goto zalloc_start;
}
/*
* Discard any empty allocation bucket while we hold no locks.
*/
bucket = cache->uc_allocbucket;
cache->uc_allocbucket = NULL;
critical_exit();
if (bucket != NULL)
bucket_free(zone, bucket, udata);
/* Short-circuit for zones without buckets and low memory. */
if (zone->uz_count == 0 || bucketdisable)
goto zalloc_item;
/*
* Attempt to retrieve the item from the per-CPU cache has failed, so
* we must go back to the zone. This requires the zone lock, so we
* must drop the critical section, then re-acquire it when we go back
* to the cache. Since the critical section is released, we may be
* preempted or migrate. As such, make sure not to maintain any
* thread-local state specific to the cache from prior to releasing
* the critical section.
*/
lockfail = 0;
if (ZONE_TRYLOCK(zone) == 0) {
/* Record contention to size the buckets. */
ZONE_LOCK(zone);
lockfail = 1;
}
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
/*
* Since we have locked the zone we may as well send back our stats.
*/
atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
atomic_add_long(&zone->uz_frees, cache->uc_frees);
cache->uc_allocs = 0;
cache->uc_frees = 0;
/* See if we lost the race to fill the cache. */
if (cache->uc_allocbucket != NULL) {
ZONE_UNLOCK(zone);
goto zalloc_start;
}
/*
* Check the zone's cache of buckets.
*/
if ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
KASSERT(bucket->ub_cnt != 0,
("uma_zalloc_arg: Returning an empty bucket."));
LIST_REMOVE(bucket, ub_link);
cache->uc_allocbucket = bucket;
ZONE_UNLOCK(zone);
goto zalloc_start;
}
/* We are no longer associated with this CPU. */
critical_exit();
/*
* We bump the uz count when the cache size is insufficient to
* handle the working set.
*/
if (lockfail && zone->uz_count < BUCKET_MAX)
zone->uz_count++;
ZONE_UNLOCK(zone);
/*
* Now lets just fill a bucket and put it on the free list. If that
* works we'll restart the allocation from the begining and it
* will use the just filled bucket.
*/
bucket = zone_alloc_bucket(zone, udata, flags);
if (bucket != NULL) {
ZONE_LOCK(zone);
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
/*
* See if we lost the race or were migrated. Cache the
* initialized bucket to make this less likely or claim
* the memory directly.
*/
if (cache->uc_allocbucket == NULL)
cache->uc_allocbucket = bucket;
else
LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
ZONE_UNLOCK(zone);
goto zalloc_start;
}
/*
* We may not be able to get a bucket so return an actual item.
*/
#ifdef UMA_DEBUG
printf("uma_zalloc_arg: Bucketzone returned NULL\n");
#endif
zalloc_item:
item = zone_alloc_item(zone, udata, flags);
return (item);
}
static uma_slab_t
keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
{
uma_slab_t slab;
int reserve;
mtx_assert(&keg->uk_lock, MA_OWNED);
slab = NULL;
reserve = 0;
if ((flags & M_USE_RESERVE) == 0)
reserve = keg->uk_reserve;
for (;;) {
/*
* Find a slab with some space. Prefer slabs that are partially
* used over those that are totally full. This helps to reduce
* fragmentation.
*/
if (keg->uk_free > reserve) {
if (!LIST_EMPTY(&keg->uk_part_slab)) {
slab = LIST_FIRST(&keg->uk_part_slab);
} else {
slab = LIST_FIRST(&keg->uk_free_slab);
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
us_link);
}
MPASS(slab->us_keg == keg);
return (slab);
}
/*
* M_NOVM means don't ask at all!
*/
if (flags & M_NOVM)
break;
if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
keg->uk_flags |= UMA_ZFLAG_FULL;
/*
* If this is not a multi-zone, set the FULL bit.
* Otherwise slab_multi() takes care of it.
*/
if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
zone->uz_flags |= UMA_ZFLAG_FULL;
zone_log_warning(zone);
}
if (flags & M_NOWAIT)
break;
zone->uz_sleeps++;
msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
continue;
}
slab = keg_alloc_slab(keg, zone, flags);
/*
* 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.
*/
if (slab) {
MPASS(slab->us_keg == keg);
LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
return (slab);
}
/*
* We might not have been able to get a slab but another cpu
* could have while we were unlocked. Check again before we
* fail.
*/
flags |= M_NOVM;
}
return (slab);
}
static uma_slab_t
zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
{
uma_slab_t slab;
if (keg == NULL) {
keg = zone_first_keg(zone);
KEG_LOCK(keg);
}
for (;;) {
slab = keg_fetch_slab(keg, zone, flags);
if (slab)
return (slab);
if (flags & (M_NOWAIT | M_NOVM))
break;
}
KEG_UNLOCK(keg);
return (NULL);
}
/*
* uma_zone_fetch_slab_multi: Fetches a slab from one available keg. Returns
* with the keg locked. On NULL no lock is held.
*
* The last pointer is used to seed the search. It is not required.
*/
static uma_slab_t
zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
{
uma_klink_t klink;
uma_slab_t slab;
uma_keg_t keg;
int flags;
int empty;
int full;
/*
* Don't wait on the first pass. This will skip limit tests
* as well. We don't want to block if we can find a provider
* without blocking.
*/
flags = (rflags & ~M_WAITOK) | M_NOWAIT;
/*
* Use the last slab allocated as a hint for where to start
* the search.
*/
if (last != NULL) {
slab = keg_fetch_slab(last, zone, flags);
if (slab)
return (slab);
KEG_UNLOCK(last);
}
/*
* Loop until we have a slab incase of transient failures
* while M_WAITOK is specified. I'm not sure this is 100%
* required but we've done it for so long now.
*/
for (;;) {
empty = 0;
full = 0;
/*
* Search the available kegs for slabs. Be careful to hold the
* correct lock while calling into the keg layer.
*/
LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
keg = klink->kl_keg;
KEG_LOCK(keg);
if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
slab = keg_fetch_slab(keg, zone, flags);
if (slab)
return (slab);
}
if (keg->uk_flags & UMA_ZFLAG_FULL)
full++;
else
empty++;
KEG_UNLOCK(keg);
}
if (rflags & (M_NOWAIT | M_NOVM))
break;
flags = rflags;
/*
* All kegs are full. XXX We can't atomically check all kegs
* and sleep so just sleep for a short period and retry.
*/
if (full && !empty) {
ZONE_LOCK(zone);
zone->uz_flags |= UMA_ZFLAG_FULL;
zone->uz_sleeps++;
zone_log_warning(zone);
msleep(zone, zone->uz_lockptr, PVM,
"zonelimit", hz/100);
zone->uz_flags &= ~UMA_ZFLAG_FULL;
ZONE_UNLOCK(zone);
continue;
}
}
return (NULL);
}
static void *
slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
{
void *item;
uint8_t freei;
MPASS(keg == slab->us_keg);
mtx_assert(&keg->uk_lock, MA_OWNED);
freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
item = slab->us_data + (keg->uk_rsize * freei);
slab->us_freecount--;
keg->uk_free--;
/* Move this slab to the full list */
if (slab->us_freecount == 0) {
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
}
return (item);
}
static int
zone_import(uma_zone_t zone, void **bucket, int max, int flags)
{
uma_slab_t slab;
uma_keg_t keg;
int i;
slab = NULL;
keg = NULL;
/* Try to keep the buckets totally full */
for (i = 0; i < max; ) {
if ((slab = zone->uz_slab(zone, keg, flags)) == NULL)
break;
keg = slab->us_keg;
while (slab->us_freecount && i < max) {
bucket[i++] = slab_alloc_item(keg, slab);
if (keg->uk_free <= keg->uk_reserve)
break;
}
/* Don't grab more than one slab at a time. */
flags &= ~M_WAITOK;
flags |= M_NOWAIT;
}
if (slab != NULL)
KEG_UNLOCK(keg);
return i;
}
static uma_bucket_t
zone_alloc_bucket(uma_zone_t zone, void *udata, int flags)
{
uma_bucket_t bucket;
int max;
/* Don't wait for buckets, preserve caller's NOVM setting. */
bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
if (bucket == NULL)
return (NULL);
max = MIN(bucket->ub_entries, zone->uz_count);
bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
max, 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++)
if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
flags) != 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;
}
}
if (bucket->ub_cnt == 0) {
bucket_free(zone, bucket, udata);
atomic_add_long(&zone->uz_fails, 1);
return (NULL);
}
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.
* 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 flags)
{
void *item;
item = NULL;
#ifdef UMA_DEBUG_ALLOC
printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
#endif
if (zone->uz_import(zone->uz_arg, &item, 1, flags) != 1)
goto fail;
atomic_add_long(&zone->uz_allocs, 1);
/*
* 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) {
if (zone->uz_init(item, zone->uz_size, flags) != 0) {
zone_free_item(zone, item, udata, SKIP_FINI);
goto fail;
}
}
if (zone->uz_ctor != NULL) {
if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
zone_free_item(zone, item, udata, SKIP_DTOR);
goto fail;
}
}
#ifdef INVARIANTS
uma_dbg_alloc(zone, NULL, item);
#endif
if (flags & M_ZERO)
uma_zero_item(item, zone);
return (item);
fail:
atomic_add_long(&zone->uz_fails, 1);
return (NULL);
}
/* See uma.h */
void
uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
{
uma_cache_t cache;
uma_bucket_t bucket;
int lockfail;
int cpu;
/* Enable entropy collection for RANDOM_ENABLE_UMA kernel option */
random_harvest_fast_uma(&zone, sizeof(zone), 1, RANDOM_UMA);
#ifdef UMA_DEBUG_ALLOC_1
printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
#endif
CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
zone->uz_name);
/* uma_zfree(..., NULL) does nothing, to match free(9). */
if (item == NULL)
return;
#ifdef DEBUG_MEMGUARD
if (is_memguard_addr(item)) {
if (zone->uz_dtor != NULL && zone->uz_dtor != mtrash_dtor)
zone->uz_dtor(item, zone->uz_size, udata);
if (zone->uz_fini != NULL && zone->uz_fini != mtrash_fini)
zone->uz_fini(item, zone->uz_size);
memguard_free(item);
return;
}
#endif
#ifdef INVARIANTS
if (zone->uz_flags & UMA_ZONE_MALLOC)
uma_dbg_free(zone, udata, item);
else
uma_dbg_free(zone, NULL, item);
#endif
if (zone->uz_dtor != NULL)
zone->uz_dtor(item, zone->uz_size, udata);
/*
* 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 (zone->uz_flags & UMA_ZFLAG_FULL)
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.
*/
zfree_restart:
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
zfree_start:
/*
* 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;
if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
bucket = cache->uc_freebucket;
if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
("uma_zfree: Freeing to non free bucket index."));
bucket->ub_bucket[bucket->ub_cnt] = item;
bucket->ub_cnt++;
cache->uc_frees++;
critical_exit();
return;
}
/*
* We must go back the zone, which requires acquiring the zone lock,
* which in turn means we must release and re-acquire the critical
* section. 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.
*/
critical_exit();
if (zone->uz_count == 0 || bucketdisable)
goto zfree_item;
lockfail = 0;
if (ZONE_TRYLOCK(zone) == 0) {
/* Record contention to size the buckets. */
ZONE_LOCK(zone);
lockfail = 1;
}
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
/*
* Since we have locked the zone we may as well send back our stats.
*/
atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
atomic_add_long(&zone->uz_frees, cache->uc_frees);
cache->uc_allocs = 0;
cache->uc_frees = 0;
bucket = cache->uc_freebucket;
if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
ZONE_UNLOCK(zone);
goto zfree_start;
}
cache->uc_freebucket = NULL;
/* Can we throw this on the zone full list? */
if (bucket != NULL) {
#ifdef UMA_DEBUG_ALLOC
printf("uma_zfree: Putting old bucket on the free list.\n");
#endif
/* ub_cnt is pointing to the last free item */
KASSERT(bucket->ub_cnt != 0,
("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
}
/* We are no longer associated with this CPU. */
critical_exit();
/*
* We bump the uz count when the cache size is insufficient to
* handle the working set.
*/
if (lockfail && zone->uz_count < BUCKET_MAX)
zone->uz_count++;
ZONE_UNLOCK(zone);
#ifdef UMA_DEBUG_ALLOC
printf("uma_zfree: Allocating new free bucket.\n");
#endif
bucket = bucket_alloc(zone, udata, M_NOWAIT);
if (bucket) {
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
if (cache->uc_freebucket == NULL) {
cache->uc_freebucket = bucket;
goto zfree_start;
}
/*
* We lost the race, start over. We have to drop our
* critical section to free the bucket.
*/
critical_exit();
bucket_free(zone, bucket, udata);
goto zfree_restart;
}
/*
* If nothing else caught this, we'll just do an internal free.
*/
zfree_item:
zone_free_item(zone, item, udata, SKIP_DTOR);
return;
}
static void
slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
{
uint8_t freei;
mtx_assert(&keg->uk_lock, MA_OWNED);
MPASS(keg == slab->us_keg);
/* Do we need to remove from any lists? */
if (slab->us_freecount+1 == keg->uk_ipers) {
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
} else if (slab->us_freecount == 0) {
LIST_REMOVE(slab, us_link);
LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
}
/* Slab management. */
freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
slab->us_freecount++;
/* Keg statistics. */
keg->uk_free++;
}
static void
zone_release(uma_zone_t zone, void **bucket, int cnt)
{
void *item;
uma_slab_t slab;
uma_keg_t keg;
uint8_t *mem;
int clearfull;
int i;
clearfull = 0;
keg = zone_first_keg(zone);
KEG_LOCK(keg);
for (i = 0; i < cnt; i++) {
item = bucket[i];
if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
if (zone->uz_flags & UMA_ZONE_HASH) {
slab = hash_sfind(&keg->uk_hash, mem);
} else {
mem += keg->uk_pgoff;
slab = (uma_slab_t)mem;
}
} else {
slab = vtoslab((vm_offset_t)item);
if (slab->us_keg != keg) {
KEG_UNLOCK(keg);
keg = slab->us_keg;
KEG_LOCK(keg);
}
}
slab_free_item(keg, slab, item);
if (keg->uk_flags & UMA_ZFLAG_FULL) {
if (keg->uk_pages < keg->uk_maxpages) {
keg->uk_flags &= ~UMA_ZFLAG_FULL;
clearfull = 1;
}
/*
* We can handle one more allocation. Since we're
* clearing ZFLAG_FULL, wake up all procs blocked
* on pages. This should be uncommon, so keeping this
* simple for now (rather than adding count of blocked
* threads etc).
*/
wakeup(keg);
}
}
KEG_UNLOCK(keg);
if (clearfull) {
ZONE_LOCK(zone);
zone->uz_flags &= ~UMA_ZFLAG_FULL;
wakeup(zone);
ZONE_UNLOCK(zone);
}
}
/*
* Frees a single item to any zone.
*
* Arguments:
* zone The zone to free to
* item The item we're freeing
* udata User supplied data for the dtor
* skip Skip dtors and finis
*/
static void
zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
{
#ifdef INVARIANTS
if (skip == SKIP_NONE) {
if (zone->uz_flags & UMA_ZONE_MALLOC)
uma_dbg_free(zone, udata, item);
else
uma_dbg_free(zone, NULL, item);
}
#endif
if (skip < SKIP_DTOR && zone->uz_dtor)
zone->uz_dtor(item, zone->uz_size, udata);
if (skip < SKIP_FINI && zone->uz_fini)
zone->uz_fini(item, zone->uz_size);
atomic_add_long(&zone->uz_frees, 1);
zone->uz_release(zone->uz_arg, &item, 1);
}
/* See uma.h */
int
uma_zone_set_max(uma_zone_t zone, int nitems)
{
uma_keg_t keg;
keg = zone_first_keg(zone);
if (keg == NULL)
return (0);
KEG_LOCK(keg);
keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
if (keg->uk_maxpages * keg->uk_ipers < nitems)
keg->uk_maxpages += keg->uk_ppera;
nitems = keg->uk_maxpages * keg->uk_ipers;
KEG_UNLOCK(keg);
return (nitems);
}
/* See uma.h */
int
uma_zone_get_max(uma_zone_t zone)
{
int nitems;
uma_keg_t keg;
keg = zone_first_keg(zone);
if (keg == NULL)
return (0);
KEG_LOCK(keg);
nitems = keg->uk_maxpages * keg->uk_ipers;
KEG_UNLOCK(keg);
return (nitems);
}
/* See uma.h */
void
uma_zone_set_warning(uma_zone_t zone, const char *warning)
{
ZONE_LOCK(zone);
zone->uz_warning = warning;
ZONE_UNLOCK(zone);
}
/* See uma.h */
int
uma_zone_get_cur(uma_zone_t zone)
{
int64_t nitems;
u_int i;
ZONE_LOCK(zone);
nitems = zone->uz_allocs - zone->uz_frees;
CPU_FOREACH(i) {
/*
* See the comment in sysctl_vm_zone_stats() regarding the
* safety of accessing the per-cpu caches. With the zone lock
* held, it is safe, but can potentially result in stale data.
*/
nitems += zone->uz_cpu[i].uc_allocs -
zone->uz_cpu[i].uc_frees;
}
ZONE_UNLOCK(zone);
return (nitems < 0 ? 0 : nitems);
}
/* See uma.h */
void
uma_zone_set_init(uma_zone_t zone, uma_init uminit)
{
uma_keg_t keg;
keg = zone_first_keg(zone);
KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
KEG_LOCK(keg);
KASSERT(keg->uk_pages == 0,
("uma_zone_set_init on non-empty keg"));
keg->uk_init = uminit;
KEG_UNLOCK(keg);
}
/* See uma.h */
void
uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
{
uma_keg_t keg;
keg = zone_first_keg(zone);
KASSERT(keg != NULL, ("uma_zone_set_fini: Invalid zone type"));
KEG_LOCK(keg);
KASSERT(keg->uk_pages == 0,
("uma_zone_set_fini on non-empty keg"));
keg->uk_fini = fini;
KEG_UNLOCK(keg);
}
/* See uma.h */
void
uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
{
ZONE_LOCK(zone);
KASSERT(zone_first_keg(zone)->uk_pages == 0,
("uma_zone_set_zinit on non-empty keg"));
zone->uz_init = zinit;
ZONE_UNLOCK(zone);
}
/* See uma.h */
void
uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
{
ZONE_LOCK(zone);
KASSERT(zone_first_keg(zone)->uk_pages == 0,
("uma_zone_set_zfini on non-empty keg"));
zone->uz_fini = zfini;
ZONE_UNLOCK(zone);
}
/* See uma.h */
/* XXX uk_freef is not actually used with the zone locked */
void
uma_zone_set_freef(uma_zone_t zone, uma_free freef)
{
uma_keg_t keg;
keg = zone_first_keg(zone);
KASSERT(keg != NULL, ("uma_zone_set_freef: Invalid zone type"));
KEG_LOCK(keg);
keg->uk_freef = freef;
KEG_UNLOCK(keg);
}
/* See uma.h */
/* XXX uk_allocf is not actually used with the zone locked */
void
uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
{
uma_keg_t keg;
keg = zone_first_keg(zone);
KEG_LOCK(keg);
keg->uk_allocf = allocf;
KEG_UNLOCK(keg);
}
/* See uma.h */
void
uma_zone_reserve(uma_zone_t zone, int items)
{
uma_keg_t keg;
keg = zone_first_keg(zone);
if (keg == NULL)
return;
KEG_LOCK(keg);
keg->uk_reserve = items;
KEG_UNLOCK(keg);
return;
}
/* 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 = zone_first_keg(zone);
if (keg == NULL)
return (0);
pages = count / keg->uk_ipers;
if (pages * keg->uk_ipers < count)
pages++;
#ifdef UMA_MD_SMALL_ALLOC
if (keg->uk_ppera > 1) {
#else
if (1) {
#endif
kva = kva_alloc((vm_size_t)pages * UMA_SLAB_SIZE);
if (kva == 0)
return (0);
} else
kva = 0;
KEG_LOCK(keg);
keg->uk_kva = kva;
keg->uk_offset = 0;
keg->uk_maxpages = pages;
#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_ZONE_NOFREE;
KEG_UNLOCK(keg);
return (1);
}
/* See uma.h */
void
uma_prealloc(uma_zone_t zone, int items)
{
int slabs;
uma_slab_t slab;
uma_keg_t keg;
keg = zone_first_keg(zone);
if (keg == NULL)
return;
KEG_LOCK(keg);
slabs = items / keg->uk_ipers;
if (slabs * keg->uk_ipers < items)
slabs++;
while (slabs > 0) {
slab = keg_alloc_slab(keg, zone, M_WAITOK);
if (slab == NULL)
break;
MPASS(slab->us_keg == keg);
LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
slabs--;
}
KEG_UNLOCK(keg);
}
/* See uma.h */
uint32_t *
uma_find_refcnt(uma_zone_t zone, void *item)
{
uma_slabrefcnt_t slabref;
uma_slab_t slab;
uma_keg_t keg;
uint32_t *refcnt;
int idx;
slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
slabref = (uma_slabrefcnt_t)slab;
keg = slab->us_keg;
KASSERT(keg->uk_flags & UMA_ZONE_REFCNT,
("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
idx = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
refcnt = &slabref->us_refcnt[idx];
return refcnt;
}
/* See uma.h */
static void
uma_reclaim_locked(bool kmem_danger)
{
#ifdef UMA_DEBUG
printf("UMA: vm asked us to release pages!\n");
#endif
sx_assert(&uma_drain_lock, SA_XLOCKED);
bucket_enable();
zone_foreach(zone_drain);
if (vm_page_count_min() || kmem_danger) {
cache_drain_safe(NULL);
zone_foreach(zone_drain);
}
/*
* 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(slabzone);
zone_drain(slabrefzone);
bucket_zone_drain();
}
void
uma_reclaim(void)
{
sx_xlock(&uma_drain_lock);
uma_reclaim_locked(false);
sx_xunlock(&uma_drain_lock);
}
static int uma_reclaim_needed;
void
uma_reclaim_wakeup(void)
{
uma_reclaim_needed = 1;
wakeup(&uma_reclaim_needed);
}
void
uma_reclaim_worker(void *arg __unused)
{
sx_xlock(&uma_drain_lock);
for (;;) {
sx_sleep(&uma_reclaim_needed, &uma_drain_lock, PVM,
"umarcl", 0);
if (uma_reclaim_needed) {
uma_reclaim_needed = 0;
uma_reclaim_locked(true);
}
}
}
/* See uma.h */
int
uma_zone_exhausted(uma_zone_t zone)
{
int full;
ZONE_LOCK(zone);
full = (zone->uz_flags & UMA_ZFLAG_FULL);
ZONE_UNLOCK(zone);
return (full);
}
int
uma_zone_exhausted_nolock(uma_zone_t zone)
{
return (zone->uz_flags & UMA_ZFLAG_FULL);
}
void *
uma_large_malloc(vm_size_t size, int wait)
{
void *mem;
uma_slab_t slab;
uint8_t flags;
slab = zone_alloc_item(slabzone, NULL, wait);
if (slab == NULL)
return (NULL);
mem = page_alloc(NULL, size, &flags, wait);
if (mem) {
vsetslab((vm_offset_t)mem, slab);
slab->us_data = mem;
slab->us_flags = flags | UMA_SLAB_MALLOC;
slab->us_size = size;
} else {
zone_free_item(slabzone, slab, NULL, SKIP_NONE);
}
return (mem);
}
void
uma_large_free(uma_slab_t slab)
{
page_free(slab->us_data, slab->us_size, slab->us_flags);
zone_free_item(slabzone, slab, NULL, SKIP_NONE);
}
static void
uma_zero_item(void *item, uma_zone_t zone)
{
if (zone->uz_flags & UMA_ZONE_PCPU) {
for (int i = 0; i < mp_ncpus; i++)
bzero(zpcpu_get_cpu(item, i), zone->uz_size);
} else
bzero(item, zone->uz_size);
}
void
uma_print_stats(void)
{
zone_foreach(uma_print_zone);
}
static void
slab_print(uma_slab_t slab)
{
printf("slab: keg %p, data %p, freecount %d\n",
slab->us_keg, slab->us_data, slab->us_freecount);
}
static void
cache_print(uma_cache_t cache)
{
printf("alloc: %p(%d), free: %p(%d)\n",
cache->uc_allocbucket,
cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
cache->uc_freebucket,
cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
}
static void
uma_print_keg(uma_keg_t keg)
{
uma_slab_t slab;
printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
"out %d free %d limit %d\n",
keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
keg->uk_ipers, keg->uk_ppera,
(keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free,
(keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
printf("Part slabs:\n");
LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
slab_print(slab);
printf("Free slabs:\n");
LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
slab_print(slab);
printf("Full slabs:\n");
LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
slab_print(slab);
}
void
uma_print_zone(uma_zone_t zone)
{
uma_cache_t cache;
uma_klink_t kl;
int i;
printf("zone: %s(%p) size %d flags %#x\n",
zone->uz_name, zone, zone->uz_size, zone->uz_flags);
LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
uma_print_keg(kl->kl_keg);
CPU_FOREACH(i) {
cache = &zone->uz_cpu[i];
printf("CPU %d Cache:\n", i);
cache_print(cache);
}
}
#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.
*
* XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
* safe from off-CPU; we should modify the caches to track this information
* directly so that we don't have to.
*/
static void
uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
uint64_t *freesp, uint64_t *sleepsp)
{
uma_cache_t cache;
uint64_t allocs, frees, sleeps;
int cachefree, cpu;
allocs = frees = sleeps = 0;
cachefree = 0;
CPU_FOREACH(cpu) {
cache = &z->uz_cpu[cpu];
if (cache->uc_allocbucket != NULL)
cachefree += cache->uc_allocbucket->ub_cnt;
if (cache->uc_freebucket != NULL)
cachefree += cache->uc_freebucket->ub_cnt;
allocs += cache->uc_allocs;
frees += cache->uc_frees;
}
allocs += z->uz_allocs;
frees += z->uz_frees;
sleeps += z->uz_sleeps;
if (cachefreep != NULL)
*cachefreep = cachefree;
if (allocsp != NULL)
*allocsp = allocs;
if (freesp != NULL)
*freesp = frees;
if (sleepsp != NULL)
*sleepsp = sleeps;
}
#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++;
}
rw_runlock(&uma_rwlock);
return (sysctl_handle_int(oidp, &count, 0, req));
}
static int
sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
{
struct uma_stream_header ush;
struct uma_type_header uth;
struct uma_percpu_stat ups;
uma_bucket_t bucket;
struct sbuf sbuf;
uma_cache_t cache;
uma_klink_t kl;
uma_keg_t kz;
uma_zone_t z;
uma_keg_t k;
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);
count = 0;
rw_rlock(&uma_rwlock);
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, 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) {
LIST_FOREACH(z, &kz->uk_zones, uz_link) {
bzero(&uth, sizeof(uth));
ZONE_LOCK(z);
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;
LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
k = kl->kl_keg;
uth.uth_maxpages += k->uk_maxpages;
uth.uth_pages += k->uk_pages;
uth.uth_keg_free += k->uk_free;
uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
* k->uk_ipers;
}
/*
* 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;
LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
uth.uth_zone_free += bucket->ub_cnt;
uth.uth_allocs = z->uz_allocs;
uth.uth_frees = z->uz_frees;
uth.uth_fails = z->uz_fails;
uth.uth_sleeps = z->uz_sleeps;
(void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
/*
* While it is not normally safe to access the cache
* bucket pointers while not on the CPU that owns the
* cache, we only allow the pointers to be exchanged
* without the zone lock held, not invalidated, so
* accept the possible race associated with bucket
* exchange during monitoring.
*/
for (i = 0; i < (mp_maxid + 1); i++) {
bzero(&ups, sizeof(ups));
if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
goto skip;
if (CPU_ABSENT(i))
goto skip;
cache = &z->uz_cpu[i];
if (cache->uc_allocbucket != NULL)
ups.ups_cache_free +=
cache->uc_allocbucket->ub_cnt;
if (cache->uc_freebucket != NULL)
ups.ups_cache_free +=
cache->uc_freebucket->ub_cnt;
ups.ups_allocs = cache->uc_allocs;
ups.ups_frees = cache->uc_frees;
skip:
(void)sbuf_bcat(&sbuf, &ups, sizeof(ups));
}
ZONE_UNLOCK(z);
}
}
rw_runlock(&uma_rwlock);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
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 = *(uma_zone_t *)arg1;
int cur;
cur = uma_zone_get_cur(zone);
return (sysctl_handle_int(oidp, &cur, 0, req));
}
#ifdef DDB
DB_SHOW_COMMAND(uma, db_show_uma)
{
uint64_t allocs, frees, sleeps;
uma_bucket_t bucket;
uma_keg_t kz;
uma_zone_t z;
int cachefree;
db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
"Free", "Requests", "Sleeps", "Bucket");
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link) {
if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
allocs = z->uz_allocs;
frees = z->uz_frees;
sleeps = z->uz_sleeps;
cachefree = 0;
} else
uma_zone_sumstat(z, &cachefree, &allocs,
&frees, &sleeps);
if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
(LIST_FIRST(&kz->uk_zones) != z)))
cachefree += kz->uk_free;
LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
cachefree += bucket->ub_cnt;
db_printf("%18s %8ju %8jd %8d %12ju %8ju %8u\n",
z->uz_name, (uintmax_t)kz->uk_size,
(intmax_t)(allocs - frees), cachefree,
(uintmax_t)allocs, sleeps, z->uz_count);
if (db_pager_quit)
return;
}
}
}
DB_SHOW_COMMAND(umacache, db_show_umacache)
{
uint64_t allocs, frees;
uma_bucket_t bucket;
uma_zone_t z;
int cachefree;
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);
LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
cachefree += bucket->ub_cnt;
db_printf("%18s %8ju %8jd %8d %12ju %8u\n",
z->uz_name, (uintmax_t)z->uz_size,
(intmax_t)(allocs - frees), cachefree,
(uintmax_t)allocs, z->uz_count);
if (db_pager_quit)
return;
}
}
#endif
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