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freebsd-skq/sys/vm/uma_core.c
Robert Watson 082dc776db Skip per-cpu caches associated with absent CPUs when generating a 
memory statistics record stream via sysctl.

MFC after:	3 days
2006-02-11 19:20:56 +00:00

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/*-
* Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
* Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
* Copyright (c) 2004-2005 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 <sys/param.h>
#include <sys/systm.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/sbuf.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_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 <machine/vmparam.h>
#include <ddb/ddb.h>
/*
* 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;
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);
/* This mutex protects the keg list */
static struct mtx uma_mtx;
/* 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 uma_boot_pages_mtx;
/* Is the VM done starting up? */
static int booted = 0;
/* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
static u_int uma_max_ipers;
static u_int uma_max_ipers_ref;
/*
* 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 {
char *name;
size_t size;
uma_ctor ctor;
uma_dtor dtor;
uma_init uminit;
uma_fini fini;
uma_keg_t keg;
int align;
u_int32_t flags;
};
struct uma_kctor_args {
uma_zone_t zone;
size_t size;
uma_init uminit;
uma_fini fini;
int align;
u_int32_t flags;
};
struct uma_bucket_zone {
uma_zone_t ubz_zone;
char *ubz_name;
int ubz_entries;
};
#define BUCKET_MAX 128
struct uma_bucket_zone bucket_zones[] = {
{ NULL, "16 Bucket", 16 },
{ NULL, "32 Bucket", 32 },
{ NULL, "64 Bucket", 64 },
{ NULL, "128 Bucket", 128 },
{ NULL, NULL, 0}
};
#define BUCKET_SHIFT 4
#define BUCKET_ZONES ((BUCKET_MAX >> BUCKET_SHIFT) + 1)
/*
* bucket_size[] maps requested bucket sizes to zones that allocate a bucket
* of approximately the right size.
*/
static uint8_t bucket_size[BUCKET_ZONES];
/*
* Flags and enumerations to be passed to internal functions.
*/
enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
#define ZFREE_STATFAIL 0x00000001 /* Update zone failure statistic. */
#define ZFREE_STATFREE 0x00000002 /* Update zone free statistic. */
/* Prototypes.. */
static void *obj_alloc(uma_zone_t, int, u_int8_t *, int);
static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
static void page_free(void *, int, u_int8_t);
static uma_slab_t slab_zalloc(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 zone_small_init(uma_zone_t zone);
static void zone_large_init(uma_zone_t zone);
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 *uma_zalloc_internal(uma_zone_t, void *, int);
static void uma_zfree_internal(uma_zone_t, void *, void *, enum zfreeskip,
int);
static void bucket_enable(void);
static void bucket_init(void);
static uma_bucket_t bucket_alloc(int, int);
static void bucket_free(uma_bucket_t);
static void bucket_zone_drain(void);
static int uma_zalloc_bucket(uma_zone_t zone, int flags);
static uma_slab_t uma_zone_slab(uma_zone_t zone, int flags);
static void *uma_slab_alloc(uma_zone_t zone, uma_slab_t slab);
static void zone_drain(uma_zone_t);
static uma_zone_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
uma_fini fini, int align, u_int32_t flags);
void uma_print_zone(uma_zone_t);
void uma_print_stats(void);
static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
#ifdef WITNESS
static int nosleepwithlocks = 1;
#else
static int nosleepwithlocks = 0;
#endif
SYSCTL_INT(_debug, OID_AUTO, nosleepwithlocks, CTLFLAG_RW, &nosleepwithlocks,
0, "Convert M_WAITOK to M_NOWAIT to avoid lock-held-across-sleep paths");
SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD,
NULL, 0, sysctl_vm_zone, "A", "Zone Info");
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");
/*
* This routine checks to see whether or not it's safe to enable buckets.
*/
static void
bucket_enable(void)
{
if (cnt.v_free_count < cnt.v_free_min)
bucketdisable = 1;
else
bucketdisable = 0;
}
/*
* 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. Initialize bucket_size[] to point
* the range of appropriate bucket sizes at the zone.
*/
static void
bucket_init(void)
{
struct uma_bucket_zone *ubz;
int i;
int j;
for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
int size;
ubz = &bucket_zones[j];
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_ZFLAG_INTERNAL);
for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
bucket_size[i >> BUCKET_SHIFT] = j;
}
}
/*
* 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)
{
int idx;
idx = howmany(entries, 1 << BUCKET_SHIFT);
return (&bucket_zones[bucket_size[idx]]);
}
static uma_bucket_t
bucket_alloc(int entries, int bflags)
{
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);
ubz = bucket_zone_lookup(entries);
bucket = uma_zalloc_internal(ubz->ubz_zone, NULL, bflags);
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_bucket_t bucket)
{
struct uma_bucket_zone *ubz;
ubz = bucket_zone_lookup(bucket->ub_entries);
uma_zfree_internal(ubz->ubz_zone, bucket, NULL, SKIP_NONE,
ZFREE_STATFREE);
}
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);
}
/*
* 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.
*
* Arguments:
* zone The zone to operate on
*
* Returns:
* Nothing
*/
static void
zone_timeout(uma_zone_t zone)
{
uma_keg_t keg;
u_int64_t alloc;
keg = zone->uz_keg;
alloc = 0;
/*
* Expand the zone 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?
*/
ZONE_LOCK(zone);
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 zone lock is held will lead to deadlock.
* I have to do everything in stages and check for
* races.
*/
newhash = keg->uk_hash;
ZONE_UNLOCK(zone);
ret = hash_alloc(&newhash);
ZONE_LOCK(zone);
if (ret) {
if (hash_expand(&keg->uk_hash, &newhash)) {
oldhash = keg->uk_hash;
keg->uk_hash = newhash;
} else
oldhash = newhash;
ZONE_UNLOCK(zone);
hash_free(&oldhash);
ZONE_LOCK(zone);
}
}
ZONE_UNLOCK(zone);
}
/*
* 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 = uma_zalloc_internal(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)
uma_zfree_internal(hashzone,
hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE);
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)
{
uma_slab_t slab;
int mzone;
void *item;
if (bucket == NULL)
return;
slab = NULL;
mzone = 0;
/* We have to lookup the slab again for malloc.. */
if (zone->uz_keg->uk_flags & UMA_ZONE_MALLOC)
mzone = 1;
while (bucket->ub_cnt > 0) {
bucket->ub_cnt--;
item = bucket->ub_bucket[bucket->ub_cnt];
#ifdef INVARIANTS
bucket->ub_bucket[bucket->ub_cnt] = NULL;
KASSERT(item != NULL,
("bucket_drain: botched ptr, item is NULL"));
#endif
/*
* This is extremely inefficient. The slab pointer was passed
* to uma_zfree_arg, but we lost it because the buckets don't
* hold them. This will go away when free() gets a size passed
* to it.
*/
if (mzone)
slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
uma_zfree_internal(zone, item, slab, SKIP_DTOR, 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?
*/
for (cpu = 0; cpu <= mp_maxid; cpu++) {
if (CPU_ABSENT(cpu))
continue;
cache = &zone->uz_cpu[cpu];
bucket_drain(zone, cache->uc_allocbucket);
bucket_drain(zone, cache->uc_freebucket);
if (cache->uc_allocbucket != NULL)
bucket_free(cache->uc_allocbucket);
if (cache->uc_freebucket != NULL)
bucket_free(cache->uc_freebucket);
cache->uc_allocbucket = cache->uc_freebucket = NULL;
}
ZONE_LOCK(zone);
bucket_cache_drain(zone);
ZONE_UNLOCK(zone);
}
/*
* 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_full_bucket)) != NULL) {
LIST_REMOVE(bucket, ub_link);
ZONE_UNLOCK(zone);
bucket_drain(zone, bucket);
bucket_free(bucket);
ZONE_LOCK(zone);
}
/* Now we do the free queue.. */
while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
LIST_REMOVE(bucket, ub_link);
bucket_free(bucket);
}
}
/*
* Frees pages from a zone back to the system. This is done on demand from
* the pageout daemon.
*
* Arguments:
* zone The zone to free pages from
* all Should we drain all items?
*
* Returns:
* Nothing.
*/
static void
zone_drain(uma_zone_t zone)
{
struct slabhead freeslabs = { 0 };
uma_keg_t keg;
uma_slab_t slab;
uma_slab_t n;
u_int8_t flags;
u_int8_t *mem;
int i;
keg = zone->uz_keg;
/*
* We don't want to take pages from statically allocated zones at this
* time
*/
if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
return;
ZONE_LOCK(zone);
#ifdef UMA_DEBUG
printf("%s free items: %u\n", zone->uz_name, keg->uk_free);
#endif
bucket_cache_drain(zone);
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:
ZONE_UNLOCK(zone);
while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
if (keg->uk_fini)
for (i = 0; i < keg->uk_ipers; i++)
keg->uk_fini(
slab->us_data + (keg->uk_rsize * i),
keg->uk_size);
flags = slab->us_flags;
mem = slab->us_data;
if ((keg->uk_flags & UMA_ZONE_MALLOC) ||
(keg->uk_flags & UMA_ZONE_REFCNT)) {
vm_object_t obj;
if (flags & UMA_SLAB_KMEM)
obj = kmem_object;
else
obj = NULL;
for (i = 0; i < keg->uk_ppera; i++)
vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
obj);
}
if (keg->uk_flags & UMA_ZONE_OFFPAGE)
uma_zfree_internal(keg->uk_slabzone, slab, NULL,
SKIP_NONE, ZFREE_STATFREE);
#ifdef UMA_DEBUG
printf("%s: Returning %d bytes.\n",
zone->uz_name, UMA_SLAB_SIZE * keg->uk_ppera);
#endif
keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
}
}
/*
* Allocate a new slab for a zone. This does not insert the slab onto a list.
*
* Arguments:
* zone The zone to allocate slabs for
* 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
slab_zalloc(uma_zone_t zone, int wait)
{
uma_slabrefcnt_t slabref;
uma_slab_t slab;
uma_keg_t keg;
u_int8_t *mem;
u_int8_t flags;
int i;
slab = NULL;
keg = zone->uz_keg;
#ifdef UMA_DEBUG
printf("slab_zalloc: Allocating a new slab for %s\n", zone->uz_name);
#endif
ZONE_UNLOCK(zone);
if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
slab = uma_zalloc_internal(keg->uk_slabzone, NULL, wait);
if (slab == NULL) {
ZONE_LOCK(zone);
return NULL;
}
}
/*
* 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;
mem = keg->uk_allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE,
&flags, wait);
if (mem == NULL) {
if (keg->uk_flags & UMA_ZONE_OFFPAGE)
uma_zfree_internal(keg->uk_slabzone, slab, NULL,
SKIP_NONE, ZFREE_STATFREE);
ZONE_LOCK(zone);
return (NULL);
}
/* 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_MALLOC) ||
(keg->uk_flags & UMA_ZONE_REFCNT))
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_firstfree = 0;
slab->us_flags = flags;
if (keg->uk_flags & UMA_ZONE_REFCNT) {
slabref = (uma_slabrefcnt_t)slab;
for (i = 0; i < keg->uk_ipers; i++) {
slabref->us_freelist[i].us_refcnt = 0;
slabref->us_freelist[i].us_item = i+1;
}
} else {
for (i = 0; i < keg->uk_ipers; i++)
slab->us_freelist[i].us_item = i+1;
}
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) {
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_MALLOC) ||
(keg->uk_flags & UMA_ZONE_REFCNT)) {
vm_object_t obj;
if (flags & UMA_SLAB_KMEM)
obj = kmem_object;
else
obj = NULL;
for (i = 0; i < keg->uk_ppera; i++)
vsetobj((vm_offset_t)mem +
(i * PAGE_SIZE), obj);
}
if (keg->uk_flags & UMA_ZONE_OFFPAGE)
uma_zfree_internal(keg->uk_slabzone, slab,
NULL, SKIP_NONE, ZFREE_STATFREE);
keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
flags);
ZONE_LOCK(zone);
return (NULL);
}
}
ZONE_LOCK(zone);
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, int bytes, u_int8_t *pflag, int wait)
{
uma_keg_t keg;
uma_slab_t tmps;
keg = zone->uz_keg;
/*
* Check our small startup cache to see if it has pages remaining.
*/
mtx_lock(&uma_boot_pages_mtx);
if ((tmps = LIST_FIRST(&uma_boot_pages)) != NULL) {
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 == 0)
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 = 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:
* zone Unused
* 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, int bytes, u_int8_t *pflag, int wait)
{
void *p; /* Returned page */
*pflag = UMA_SLAB_KMEM;
p = (void *) kmem_malloc(kmem_map, bytes, wait);
return (p);
}
/*
* Allocates a number of pages from within an object
*
* Arguments:
* zone Unused
* 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 *
obj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
{
vm_object_t object;
vm_offset_t retkva, zkva;
vm_page_t p;
int pages, startpages;
object = zone->uz_keg->uk_obj;
retkva = 0;
/*
* This looks a little weird since we're getting one page at a time.
*/
VM_OBJECT_LOCK(object);
p = TAILQ_LAST(&object->memq, pglist);
pages = p != NULL ? p->pindex + 1 : 0;
startpages = pages;
zkva = zone->uz_keg->uk_kva + pages * PAGE_SIZE;
for (; bytes > 0; bytes -= PAGE_SIZE) {
p = vm_page_alloc(object, pages,
VM_ALLOC_INTERRUPT | VM_ALLOC_WIRED);
if (p == NULL) {
if (pages != startpages)
pmap_qremove(retkva, pages - startpages);
while (pages != startpages) {
pages--;
p = TAILQ_LAST(&object->memq, pglist);
vm_page_lock_queues();
vm_page_unwire(p, 0);
vm_page_free(p);
vm_page_unlock_queues();
}
retkva = 0;
goto done;
}
pmap_qenter(zkva, &p, 1);
if (retkva == 0)
retkva = zkva;
zkva += PAGE_SIZE;
pages += 1;
}
done:
VM_OBJECT_UNLOCK(object);
*flags = UMA_SLAB_PRIV;
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, int size, u_int8_t flags)
{
vm_map_t map;
if (flags & UMA_SLAB_KMEM)
map = kmem_map;
else
panic("UMA: page_free used with invalid flags %d\n", flags);
kmem_free(map, (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 zone. This calculates ipers, and the zone size.
*
* Arguments
* zone The zone we should initialize
*
* Returns
* Nothing
*/
static void
zone_small_init(uma_zone_t zone)
{
uma_keg_t keg;
u_int rsize;
u_int memused;
u_int wastedspace;
u_int shsize;
keg = zone->uz_keg;
KASSERT(keg != NULL, ("Keg is null in zone_small_init"));
rsize = keg->uk_size;
if (rsize < UMA_SMALLEST_UNIT)
rsize = UMA_SMALLEST_UNIT;
if (rsize & keg->uk_align)
rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
keg->uk_rsize = rsize;
keg->uk_ppera = 1;
if (keg->uk_flags & UMA_ZONE_REFCNT) {
rsize += UMA_FRITMREF_SZ; /* linkage & refcnt */
shsize = sizeof(struct uma_slab_refcnt);
} else {
rsize += UMA_FRITM_SZ; /* Account for linkage */
shsize = sizeof(struct uma_slab);
}
keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
KASSERT(keg->uk_ipers != 0, ("zone_small_init: ipers is 0"));
memused = keg->uk_ipers * rsize + shsize;
wastedspace = UMA_SLAB_SIZE - 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 (kmem_map) 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;
if ((wastedspace >= UMA_MAX_WASTE) &&
(keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
KASSERT(keg->uk_ipers <= 255,
("zone_small_init: keg->uk_ipers too high!"));
#ifdef UMA_DEBUG
printf("UMA decided we need offpage slab headers for "
"zone: %s, calculated wastedspace = %d, "
"maximum wasted space allowed = %d, "
"calculated ipers = %d, "
"new wasted space = %d\n", zone->uz_name, wastedspace,
UMA_MAX_WASTE, keg->uk_ipers,
UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
#endif
keg->uk_flags |= UMA_ZONE_OFFPAGE;
if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
keg->uk_flags |= UMA_ZONE_HASH;
}
}
/*
* Finish creating a large (> UMA_SLAB_SIZE) uma zone. Just give in and do
* OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
* more complicated.
*
* Arguments
* zone The zone we should initialize
*
* Returns
* Nothing
*/
static void
zone_large_init(uma_zone_t zone)
{
uma_keg_t keg;
int pages;
keg = zone->uz_keg;
KASSERT(keg != NULL, ("Keg is null in zone_large_init"));
KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
("zone_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY zone"));
pages = keg->uk_size / UMA_SLAB_SIZE;
/* Account for remainder */
if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
pages++;
keg->uk_ppera = pages;
keg->uk_ipers = 1;
keg->uk_flags |= UMA_ZONE_OFFPAGE;
if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
keg->uk_flags |= UMA_ZONE_HASH;
keg->uk_rsize = keg->uk_size;
}
/*
* 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_pages = 0;
keg->uk_flags = arg->flags;
keg->uk_allocf = page_alloc;
keg->uk_freef = page_free;
keg->uk_recurse = 0;
keg->uk_slabzone = NULL;
/*
* The master zone is passed to us at keg-creation time.
*/
zone = arg->zone;
zone->uz_keg = keg;
if (arg->flags & UMA_ZONE_VM)
keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
if (arg->flags & UMA_ZONE_ZINIT)
keg->uk_init = zero_init;
/*
* The +UMA_FRITM_SZ added to uk_size is to account for the
* linkage that is added to the size in zone_small_init(). If
* we don't account for this here then we may end up in
* zone_small_init() with a calculated 'ipers' of 0.
*/
if (keg->uk_flags & UMA_ZONE_REFCNT) {
if ((keg->uk_size+UMA_FRITMREF_SZ) >
(UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
zone_large_init(zone);
else
zone_small_init(zone);
} else {
if ((keg->uk_size+UMA_FRITM_SZ) >
(UMA_SLAB_SIZE - sizeof(struct uma_slab)))
zone_large_init(zone);
else
zone_small_init(zone);
}
if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
if (keg->uk_flags & UMA_ZONE_REFCNT)
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;
#endif
if (booted == 0)
keg->uk_allocf = startup_alloc;
}
/*
* Initialize keg's lock (shared among zones) through
* Master zone
*/
zone->uz_lock = &keg->uk_lock;
if (arg->flags & UMA_ZONE_MTXCLASS)
ZONE_LOCK_INIT(zone, 1);
else
ZONE_LOCK_INIT(zone, 0);
/*
* 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 */
if (keg->uk_flags & UMA_ZONE_REFCNT)
totsize = sizeof(struct uma_slab_refcnt) +
keg->uk_ipers * UMA_FRITMREF_SZ;
else
totsize = sizeof(struct uma_slab) +
keg->uk_ipers * UMA_FRITM_SZ;
if (totsize & UMA_ALIGN_PTR)
totsize = (totsize & ~UMA_ALIGN_PTR) +
(UMA_ALIGN_PTR + 1);
keg->uk_pgoff = UMA_SLAB_SIZE - totsize;
if (keg->uk_flags & UMA_ZONE_REFCNT)
totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
+ keg->uk_ipers * UMA_FRITMREF_SZ;
else
totsize = keg->uk_pgoff + sizeof(struct uma_slab)
+ keg->uk_ipers * UMA_FRITM_SZ;
/*
* 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.
*/
if (totsize > UMA_SLAB_SIZE) {
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.\n");
}
}
if (keg->uk_flags & UMA_ZONE_HASH)
hash_alloc(&keg->uk_hash);
#ifdef UMA_DEBUG
printf("%s(%p) size = %d ipers = %d ppera = %d pgoff = %d\n",
zone->uz_name, zone,
keg->uk_size, keg->uk_ipers,
keg->uk_ppera, keg->uk_pgoff);
#endif
LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
mtx_lock(&uma_mtx);
LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
mtx_unlock(&uma_mtx);
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_init = NULL;
zone->uz_fini = NULL;
zone->uz_allocs = 0;
zone->uz_frees = 0;
zone->uz_fails = 0;
zone->uz_fills = zone->uz_count = 0;
if (arg->flags & UMA_ZONE_SECONDARY) {
KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
keg = arg->keg;
zone->uz_keg = keg;
zone->uz_init = arg->uminit;
zone->uz_fini = arg->fini;
zone->uz_lock = &keg->uk_lock;
mtx_lock(&uma_mtx);
ZONE_LOCK(zone);
keg->uk_flags |= UMA_ZONE_SECONDARY;
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);
mtx_unlock(&uma_mtx);
} else if (arg->keg == NULL) {
if (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);
}
keg = zone->uz_keg;
zone->uz_lock = &keg->uk_lock;
/*
* 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((keg->uk_flags & UMA_ZONE_SECONDARY) == 0,
("Secondary zone requested UMA_ZFLAG_INTERNAL"));
return (0);
}
if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
zone->uz_count = BUCKET_MAX;
else if (keg->uk_ipers <= BUCKET_MAX)
zone->uz_count = keg->uk_ipers;
else
zone->uz_count = BUCKET_MAX;
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;
mtx_lock(&keg->uk_lock);
if (keg->uk_free != 0) {
printf("Freed UMA keg was not empty (%d items). "
" Lost %d pages of memory.\n",
keg->uk_free, keg->uk_pages);
}
mtx_unlock(&keg->uk_lock);
if (keg->uk_flags & UMA_ZONE_HASH)
hash_free(&keg->uk_hash);
mtx_destroy(&keg->uk_lock);
}
/*
* 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;
zone = (uma_zone_t)arg;
keg = zone->uz_keg;
if (!(keg->uk_flags & UMA_ZFLAG_INTERNAL))
cache_drain(zone);
mtx_lock(&uma_mtx);
zone_drain(zone);
if (keg->uk_flags & UMA_ZONE_SECONDARY) {
LIST_REMOVE(zone, uz_link);
/*
* 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_LOCK(zone);
if (LIST_EMPTY(&keg->uk_zones))
keg->uk_flags &= ~UMA_ZONE_SECONDARY;
ZONE_UNLOCK(zone);
mtx_unlock(&uma_mtx);
} else {
LIST_REMOVE(keg, uk_link);
LIST_REMOVE(zone, uz_link);
mtx_unlock(&uma_mtx);
uma_zfree_internal(kegs, keg, NULL, SKIP_NONE,
ZFREE_STATFREE);
}
zone->uz_keg = NULL;
}
/*
* 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;
mtx_lock(&uma_mtx);
LIST_FOREACH(keg, &uma_kegs, uk_link) {
LIST_FOREACH(zone, &keg->uk_zones, uz_link)
zfunc(zone);
}
mtx_unlock(&uma_mtx);
}
/* 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;
u_int objsize, totsize, wsize;
int i;
#ifdef UMA_DEBUG
printf("Creating uma keg headers zone and keg.\n");
#endif
mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
/*
* Figure out the maximum number of items-per-slab we'll have if
* we're using the OFFPAGE slab header to track free items, given
* all possible object sizes and the maximum desired wastage
* (UMA_MAX_WASTE).
*
* We iterate until we find an object size for
* which the calculated wastage in zone_small_init() will be
* enough to warrant OFFPAGE. Since wastedspace versus objsize
* is an overall increasing see-saw function, we find the smallest
* objsize such that the wastage is always acceptable for objects
* with that objsize or smaller. Since a smaller objsize always
* generates a larger possible uma_max_ipers, we use this computed
* objsize to calculate the largest ipers possible. Since the
* ipers calculated for OFFPAGE slab headers is always larger than
* the ipers initially calculated in zone_small_init(), we use
* the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
* obtain the maximum ipers possible for offpage slab headers.
*
* It should be noted that ipers versus objsize is an inversly
* proportional function which drops off rather quickly so as
* long as our UMA_MAX_WASTE is such that the objsize we calculate
* falls into the portion of the inverse relation AFTER the steep
* falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
*
* Note that we have 8-bits (1 byte) to use as a freelist index
* inside the actual slab header itself and this is enough to
* accomodate us. In the worst case, a UMA_SMALLEST_UNIT sized
* object with offpage slab header would have ipers =
* UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
* 1 greater than what our byte-integer freelist index can
* accomodate, but we know that this situation never occurs as
* for UMA_SMALLEST_UNIT-sized objects, we will never calculate
* that we need to go to offpage slab headers. Or, if we do,
* then we trap that condition below and panic in the INVARIANTS case.
*/
wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
totsize = wsize;
objsize = UMA_SMALLEST_UNIT;
while (totsize >= wsize) {
totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
(objsize + UMA_FRITM_SZ);
totsize *= (UMA_FRITM_SZ + objsize);
objsize++;
}
if (objsize > UMA_SMALLEST_UNIT)
objsize--;
uma_max_ipers = UMA_SLAB_SIZE / objsize;
wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
totsize = wsize;
objsize = UMA_SMALLEST_UNIT;
while (totsize >= wsize) {
totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
(objsize + UMA_FRITMREF_SZ);
totsize *= (UMA_FRITMREF_SZ + objsize);
objsize++;
}
if (objsize > UMA_SMALLEST_UNIT)
objsize--;
uma_max_ipers_ref = UMA_SLAB_SIZE / objsize;
KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
("uma_startup: calculated uma_max_ipers values too large!"));
#ifdef UMA_DEBUG
printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
printf("Calculated uma_max_ipers_slab (for OFFPAGE) is %d\n",
uma_max_ipers_ref);
#endif
/* "manually" create the initial zone */
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)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
slab->us_data = (u_int8_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("Initializing pcpu cache locks.\n");
#endif
#ifdef UMA_DEBUG
printf("Creating slab and hash zones.\n");
#endif
/*
* This is the max number of free list items we'll have with
* offpage slabs.
*/
slabsize = uma_max_ipers * UMA_FRITM_SZ;
slabsize += sizeof(struct uma_slab);
/* Now make a zone for slab headers */
slabzone = uma_zcreate("UMA Slabs",
slabsize,
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 = uma_max_ipers_ref * UMA_FRITMREF_SZ;
slabsize += sizeof(struct uma_slab_refcnt);
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();
#ifdef UMA_MD_SMALL_ALLOC
booted = 1;
#endif
#ifdef UMA_DEBUG
printf("UMA startup complete.\n");
#endif
}
/* see uma.h */
void
uma_startup2(void)
{
booted = 1;
bucket_enable();
#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, CALLOUT_MPSAFE);
callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
#ifdef UMA_DEBUG
printf("UMA startup3 complete.\n");
#endif
}
static uma_zone_t
uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
int align, u_int32_t flags)
{
struct uma_kctor_args args;
args.size = size;
args.uminit = uminit;
args.fini = fini;
args.align = align;
args.flags = flags;
args.zone = zone;
return (uma_zalloc_internal(kegs, &args, M_WAITOK));
}
/* See uma.h */
uma_zone_t
uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
uma_init uminit, uma_fini fini, int align, u_int32_t flags)
{
struct uma_zctor_args args;
/* This stuff is essential for the zone ctor */
args.name = name;
args.size = size;
args.ctor = ctor;
args.dtor = dtor;
args.uminit = uminit;
args.fini = fini;
args.align = align;
args.flags = flags;
args.keg = NULL;
return (uma_zalloc_internal(zones, &args, M_WAITOK));
}
/* 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;
args.name = name;
args.size = master->uz_keg->uk_size;
args.ctor = ctor;
args.dtor = dtor;
args.uminit = zinit;
args.fini = zfini;
args.align = master->uz_keg->uk_align;
args.flags = master->uz_keg->uk_flags | UMA_ZONE_SECONDARY;
args.keg = master->uz_keg;
return (uma_zalloc_internal(zones, &args, M_WAITOK));
}
/* See uma.h */
void
uma_zdestroy(uma_zone_t zone)
{
uma_zfree_internal(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
}
/* 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 cpu;
int badness;
/* 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_NOWAIT)) {
KASSERT(curthread->td_intr_nesting_level == 0,
("malloc(M_WAITOK) in interrupt context"));
if (nosleepwithlocks) {
#ifdef WITNESS
badness = WITNESS_CHECK(WARN_GIANTOK | WARN_SLEEPOK,
NULL,
"malloc(M_WAITOK) of \"%s\", forcing M_NOWAIT",
zone->uz_name);
#else
badness = 1;
#endif
} else {
badness = 0;
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"malloc(M_WAITOK) of \"%s\"", zone->uz_name);
}
if (badness) {
flags &= ~M_WAITOK;
flags |= M_NOWAIT;
}
}
/*
* 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.
*/
zalloc_restart:
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
zalloc_start:
bucket = cache->uc_allocbucket;
if (bucket) {
if (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();
#ifdef INVARIANTS
ZONE_LOCK(zone);
uma_dbg_alloc(zone, NULL, item);
ZONE_UNLOCK(zone);
#endif
if (zone->uz_ctor != NULL) {
if (zone->uz_ctor(item, zone->uz_keg->uk_size,
udata, flags) != 0) {
uma_zfree_internal(zone, item, udata,
SKIP_DTOR, ZFREE_STATFAIL |
ZFREE_STATFREE);
return (NULL);
}
}
if (flags & M_ZERO)
bzero(item, zone->uz_keg->uk_size);
return (item);
} else if (cache->uc_freebucket) {
/*
* We have run out of items in our allocbucket.
* See if we can switch with our free bucket.
*/
if (cache->uc_freebucket->ub_cnt > 0) {
#ifdef UMA_DEBUG_ALLOC
printf("uma_zalloc: Swapping empty with"
" alloc.\n");
#endif
bucket = cache->uc_freebucket;
cache->uc_freebucket = cache->uc_allocbucket;
cache->uc_allocbucket = bucket;
goto zalloc_start;
}
}
}
/*
* 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.
*/
critical_exit();
ZONE_LOCK(zone);
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
bucket = cache->uc_allocbucket;
if (bucket != NULL) {
if (bucket->ub_cnt > 0) {
ZONE_UNLOCK(zone);
goto zalloc_start;
}
bucket = cache->uc_freebucket;
if (bucket != NULL && bucket->ub_cnt > 0) {
ZONE_UNLOCK(zone);
goto zalloc_start;
}
}
/* Since we have locked the zone we may as well send back our stats */
zone->uz_allocs += cache->uc_allocs;
cache->uc_allocs = 0;
zone->uz_frees += cache->uc_frees;
cache->uc_frees = 0;
/* Our old one is now a free bucket */
if (cache->uc_allocbucket) {
KASSERT(cache->uc_allocbucket->ub_cnt == 0,
("uma_zalloc_arg: Freeing a non free bucket."));
LIST_INSERT_HEAD(&zone->uz_free_bucket,
cache->uc_allocbucket, ub_link);
cache->uc_allocbucket = NULL;
}
/* Check the free list for a new alloc bucket */
if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != 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();
/* Bump up our uz_count so we get here less */
if (zone->uz_count < BUCKET_MAX)
zone->uz_count++;
/*
* Now lets just fill a bucket and put it on the free list. If that
* works we'll restart the allocation from the begining.
*/
if (uma_zalloc_bucket(zone, flags)) {
ZONE_UNLOCK(zone);
goto zalloc_restart;
}
ZONE_UNLOCK(zone);
/*
* 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
return (uma_zalloc_internal(zone, udata, flags));
}
static uma_slab_t
uma_zone_slab(uma_zone_t zone, int flags)
{
uma_slab_t slab;
uma_keg_t keg;
keg = zone->uz_keg;
/*
* This is to prevent us from recursively trying to allocate
* buckets. The problem is that if an allocation forces us to
* grab a new bucket we will call page_alloc, which will go off
* and cause the vm to allocate vm_map_entries. If we need new
* buckets there too we will recurse in kmem_alloc and bad
* things happen. So instead we return a NULL bucket, and make
* the code that allocates buckets smart enough to deal with it
*
* XXX: While we want this protection for the bucket zones so that
* recursion from the VM is handled (and the calling code that
* allocates buckets knows how to deal with it), we do not want
* to prevent allocation from the slab header zones (slabzone
* and slabrefzone) if uk_recurse is not zero for them. The
* reason is that it could lead to NULL being returned for
* slab header allocations even in the M_WAITOK case, and the
* caller can't handle that.
*/
if (keg->uk_flags & UMA_ZFLAG_INTERNAL && keg->uk_recurse != 0)
if ((zone != slabzone) && (zone != slabrefzone))
return (NULL);
slab = NULL;
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 != 0) {
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);
}
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 (flags & M_NOWAIT)
break;
else
msleep(keg, &keg->uk_lock, PVM,
"zonelimit", 0);
continue;
}
keg->uk_recurse++;
slab = slab_zalloc(zone, flags);
keg->uk_recurse--;
/*
* 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) {
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.
*/
if (flags & M_NOWAIT)
flags |= M_NOVM;
}
return (slab);
}
static void *
uma_slab_alloc(uma_zone_t zone, uma_slab_t slab)
{
uma_keg_t keg;
uma_slabrefcnt_t slabref;
void *item;
u_int8_t freei;
keg = zone->uz_keg;
freei = slab->us_firstfree;
if (keg->uk_flags & UMA_ZONE_REFCNT) {
slabref = (uma_slabrefcnt_t)slab;
slab->us_firstfree = slabref->us_freelist[freei].us_item;
} else {
slab->us_firstfree = slab->us_freelist[freei].us_item;
}
item = slab->us_data + (keg->uk_rsize * freei);
slab->us_freecount--;
keg->uk_free--;
#ifdef INVARIANTS
uma_dbg_alloc(zone, slab, item);
#endif
/* 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
uma_zalloc_bucket(uma_zone_t zone, int flags)
{
uma_bucket_t bucket;
uma_slab_t slab;
int16_t saved;
int max, origflags = flags;
/*
* Try this zone's free list first so we don't allocate extra buckets.
*/
if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
KASSERT(bucket->ub_cnt == 0,
("uma_zalloc_bucket: Bucket on free list is not empty."));
LIST_REMOVE(bucket, ub_link);
} else {
int bflags;
bflags = (flags & ~M_ZERO);
if (zone->uz_keg->uk_flags & UMA_ZFLAG_CACHEONLY)
bflags |= M_NOVM;
ZONE_UNLOCK(zone);
bucket = bucket_alloc(zone->uz_count, bflags);
ZONE_LOCK(zone);
}
if (bucket == NULL)
return (0);
#ifdef SMP
/*
* This code is here to limit the number of simultaneous bucket fills
* for any given zone to the number of per cpu caches in this zone. This
* is done so that we don't allocate more memory than we really need.
*/
if (zone->uz_fills >= mp_ncpus)
goto done;
#endif
zone->uz_fills++;
max = MIN(bucket->ub_entries, zone->uz_count);
/* Try to keep the buckets totally full */
saved = bucket->ub_cnt;
while (bucket->ub_cnt < max &&
(slab = uma_zone_slab(zone, flags)) != NULL) {
while (slab->us_freecount && bucket->ub_cnt < max) {
bucket->ub_bucket[bucket->ub_cnt++] =
uma_slab_alloc(zone, slab);
}
/* Don't block on the next fill */
flags |= M_NOWAIT;
}
/*
* We unlock here because we need to call the zone's init.
* It should be safe to unlock because the slab dealt with
* above is already on the appropriate list within the keg
* and the bucket we filled is not yet on any list, so we
* own it.
*/
if (zone->uz_init != NULL) {
int i;
ZONE_UNLOCK(zone);
for (i = saved; i < bucket->ub_cnt; i++)
if (zone->uz_init(bucket->ub_bucket[i],
zone->uz_keg->uk_size, origflags) != 0)
break;
/*
* If we couldn't initialize the whole bucket, put the
* rest back onto the freelist.
*/
if (i != bucket->ub_cnt) {
int j;
for (j = i; j < bucket->ub_cnt; j++) {
uma_zfree_internal(zone, bucket->ub_bucket[j],
NULL, SKIP_FINI, 0);
#ifdef INVARIANTS
bucket->ub_bucket[j] = NULL;
#endif
}
bucket->ub_cnt = i;
}
ZONE_LOCK(zone);
}
zone->uz_fills--;
if (bucket->ub_cnt != 0) {
LIST_INSERT_HEAD(&zone->uz_full_bucket,
bucket, ub_link);
return (1);
}
#ifdef SMP
done:
#endif
bucket_free(bucket);
return (0);
}
/*
* Allocates an item for an internal 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 *
uma_zalloc_internal(uma_zone_t zone, void *udata, int flags)
{
uma_keg_t keg;
uma_slab_t slab;
void *item;
item = NULL;
keg = zone->uz_keg;
#ifdef UMA_DEBUG_ALLOC
printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
#endif
ZONE_LOCK(zone);
slab = uma_zone_slab(zone, flags);
if (slab == NULL) {
zone->uz_fails++;
ZONE_UNLOCK(zone);
return (NULL);
}
item = uma_slab_alloc(zone, slab);
zone->uz_allocs++;
ZONE_UNLOCK(zone);
/*
* 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, keg->uk_size, flags) != 0) {
uma_zfree_internal(zone, item, udata, SKIP_FINI,
ZFREE_STATFAIL | ZFREE_STATFREE);
return (NULL);
}
}
if (zone->uz_ctor != NULL) {
if (zone->uz_ctor(item, keg->uk_size, udata, flags) != 0) {
uma_zfree_internal(zone, item, udata, SKIP_DTOR,
ZFREE_STATFAIL | ZFREE_STATFREE);
return (NULL);
}
}
if (flags & M_ZERO)
bzero(item, keg->uk_size);
return (item);
}
/* See uma.h */
void
uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
{
uma_keg_t keg;
uma_cache_t cache;
uma_bucket_t bucket;
int bflags;
int cpu;
keg = zone->uz_keg;
#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);
if (zone->uz_dtor)
zone->uz_dtor(item, keg->uk_size, udata);
#ifdef INVARIANTS
ZONE_LOCK(zone);
if (keg->uk_flags & UMA_ZONE_MALLOC)
uma_dbg_free(zone, udata, item);
else
uma_dbg_free(zone, NULL, item);
ZONE_UNLOCK(zone);
#endif
/*
* 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 (keg->uk_flags & UMA_ZFLAG_FULL)
goto zfree_internal;
/*
* 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:
bucket = cache->uc_freebucket;
if (bucket) {
/*
* Do we have room in our bucket? It is OK for this uz count
* check to be slightly out of sync.
*/
if (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;
} else if (cache->uc_allocbucket) {
#ifdef UMA_DEBUG_ALLOC
printf("uma_zfree: Swapping buckets.\n");
#endif
/*
* We have run out of space in our freebucket.
* See if we can switch with our alloc bucket.
*/
if (cache->uc_allocbucket->ub_cnt <
cache->uc_freebucket->ub_cnt) {
bucket = cache->uc_freebucket;
cache->uc_freebucket = cache->uc_allocbucket;
cache->uc_allocbucket = bucket;
goto zfree_start;
}
}
}
/*
* We can get here for two reasons:
*
* 1) The buckets are NULL
* 2) The alloc and free buckets are both somewhat full.
*
* 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();
ZONE_LOCK(zone);
critical_enter();
cpu = curcpu;
cache = &zone->uz_cpu[cpu];
if (cache->uc_freebucket != NULL) {
if (cache->uc_freebucket->ub_cnt <
cache->uc_freebucket->ub_entries) {
ZONE_UNLOCK(zone);
goto zfree_start;
}
if (cache->uc_allocbucket != NULL &&
(cache->uc_allocbucket->ub_cnt <
cache->uc_freebucket->ub_cnt)) {
ZONE_UNLOCK(zone);
goto zfree_start;
}
}
/* Since we have locked the zone we may as well send back our stats */
zone->uz_allocs += cache->uc_allocs;
cache->uc_allocs = 0;
zone->uz_frees += cache->uc_frees;
cache->uc_frees = 0;
bucket = cache->uc_freebucket;
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_full_bucket,
bucket, ub_link);
}
if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
LIST_REMOVE(bucket, ub_link);
ZONE_UNLOCK(zone);
cache->uc_freebucket = bucket;
goto zfree_start;
}
/* We are no longer associated with this CPU. */
critical_exit();
/* And the zone.. */
ZONE_UNLOCK(zone);
#ifdef UMA_DEBUG_ALLOC
printf("uma_zfree: Allocating new free bucket.\n");
#endif
bflags = M_NOWAIT;
if (keg->uk_flags & UMA_ZFLAG_CACHEONLY)
bflags |= M_NOVM;
bucket = bucket_alloc(zone->uz_count, bflags);
if (bucket) {
ZONE_LOCK(zone);
LIST_INSERT_HEAD(&zone->uz_free_bucket,
bucket, ub_link);
ZONE_UNLOCK(zone);
goto zfree_restart;
}
/*
* If nothing else caught this, we'll just do an internal free.
*/
zfree_internal:
uma_zfree_internal(zone, item, udata, SKIP_DTOR, ZFREE_STATFAIL |
ZFREE_STATFREE);
return;
}
/*
* Frees an item to an INTERNAL zone or allocates a free bucket
*
* 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
uma_zfree_internal(uma_zone_t zone, void *item, void *udata,
enum zfreeskip skip, int flags)
{
uma_slab_t slab;
uma_slabrefcnt_t slabref;
uma_keg_t keg;
u_int8_t *mem;
u_int8_t freei;
keg = zone->uz_keg;
if (skip < SKIP_DTOR && zone->uz_dtor)
zone->uz_dtor(item, keg->uk_size, udata);
if (skip < SKIP_FINI && zone->uz_fini)
zone->uz_fini(item, keg->uk_size);
ZONE_LOCK(zone);
if (flags & ZFREE_STATFAIL)
zone->uz_fails++;
if (flags & ZFREE_STATFREE)
zone->uz_frees++;
if (!(keg->uk_flags & UMA_ZONE_MALLOC)) {
mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
if (keg->uk_flags & UMA_ZONE_HASH)
slab = hash_sfind(&keg->uk_hash, mem);
else {
mem += keg->uk_pgoff;
slab = (uma_slab_t)mem;
}
} else {
slab = (uma_slab_t)udata;
}
/* 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 stuff */
freei = ((unsigned long)item - (unsigned long)slab->us_data)
/ keg->uk_rsize;
#ifdef INVARIANTS
if (!skip)
uma_dbg_free(zone, slab, item);
#endif
if (keg->uk_flags & UMA_ZONE_REFCNT) {
slabref = (uma_slabrefcnt_t)slab;
slabref->us_freelist[freei].us_item = slab->us_firstfree;
} else {
slab->us_freelist[freei].us_item = slab->us_firstfree;
}
slab->us_firstfree = freei;
slab->us_freecount++;
/* Zone statistics */
keg->uk_free++;
if (keg->uk_flags & UMA_ZFLAG_FULL) {
if (keg->uk_pages < keg->uk_maxpages)
keg->uk_flags &= ~UMA_ZFLAG_FULL;
/* We can handle one more allocation */
wakeup_one(keg);
}
ZONE_UNLOCK(zone);
}
/* See uma.h */
void
uma_zone_set_max(uma_zone_t zone, int nitems)
{
uma_keg_t keg;
keg = zone->uz_keg;
ZONE_LOCK(zone);
if (keg->uk_ppera > 1)
keg->uk_maxpages = nitems * keg->uk_ppera;
else
keg->uk_maxpages = nitems / keg->uk_ipers;
if (keg->uk_maxpages * keg->uk_ipers < nitems)
keg->uk_maxpages++;
ZONE_UNLOCK(zone);
}
/* See uma.h */
void
uma_zone_set_init(uma_zone_t zone, uma_init uminit)
{
ZONE_LOCK(zone);
KASSERT(zone->uz_keg->uk_pages == 0,
("uma_zone_set_init on non-empty keg"));
zone->uz_keg->uk_init = uminit;
ZONE_UNLOCK(zone);
}
/* See uma.h */
void
uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
{
ZONE_LOCK(zone);
KASSERT(zone->uz_keg->uk_pages == 0,
("uma_zone_set_fini on non-empty keg"));
zone->uz_keg->uk_fini = fini;
ZONE_UNLOCK(zone);
}
/* See uma.h */
void
uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
{
ZONE_LOCK(zone);
KASSERT(zone->uz_keg->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->uz_keg->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)
{
ZONE_LOCK(zone);
zone->uz_keg->uk_freef = freef;
ZONE_UNLOCK(zone);
}
/* 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)
{
ZONE_LOCK(zone);
zone->uz_keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
zone->uz_keg->uk_allocf = allocf;
ZONE_UNLOCK(zone);
}
/* See uma.h */
int
uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int count)
{
uma_keg_t keg;
vm_offset_t kva;
int pages;
keg = zone->uz_keg;
pages = count / keg->uk_ipers;
if (pages * keg->uk_ipers < count)
pages++;
kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
if (kva == 0)
return (0);
if (obj == NULL) {
obj = vm_object_allocate(OBJT_DEFAULT,
pages);
} else {
VM_OBJECT_LOCK_INIT(obj, "uma object");
_vm_object_allocate(OBJT_DEFAULT,
pages, obj);
}
ZONE_LOCK(zone);
keg->uk_kva = kva;
keg->uk_obj = obj;
keg->uk_maxpages = pages;
keg->uk_allocf = obj_alloc;
keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
ZONE_UNLOCK(zone);
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->uz_keg;
ZONE_LOCK(zone);
slabs = items / keg->uk_ipers;
if (slabs * keg->uk_ipers < items)
slabs++;
while (slabs > 0) {
slab = slab_zalloc(zone, M_WAITOK);
LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
slabs--;
}
ZONE_UNLOCK(zone);
}
/* See uma.h */
u_int32_t *
uma_find_refcnt(uma_zone_t zone, void *item)
{
uma_slabrefcnt_t slabref;
uma_keg_t keg;
u_int32_t *refcnt;
int idx;
keg = zone->uz_keg;
slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
(~UMA_SLAB_MASK));
KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
idx = ((unsigned long)item - (unsigned long)slabref->us_data)
/ keg->uk_rsize;
refcnt = &slabref->us_freelist[idx].us_refcnt;
return refcnt;
}
/* See uma.h */
void
uma_reclaim(void)
{
#ifdef UMA_DEBUG
printf("UMA: vm asked us to release pages!\n");
#endif
bucket_enable();
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_large_malloc(int size, int wait)
{
void *mem;
uma_slab_t slab;
u_int8_t flags;
slab = uma_zalloc_internal(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 {
uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE,
ZFREE_STATFAIL | ZFREE_STATFREE);
}
return (mem);
}
void
uma_large_free(uma_slab_t slab)
{
vsetobj((vm_offset_t)slab->us_data, kmem_object);
page_free(slab->us_data, slab->us_size, slab->us_flags);
uma_zfree_internal(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
}
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, firstfree %d\n",
slab->us_keg, slab->us_data, slab->us_freecount,
slab->us_firstfree);
}
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);
}
void
uma_print_zone(uma_zone_t zone)
{
uma_cache_t cache;
uma_keg_t keg;
uma_slab_t slab;
int i;
keg = zone->uz_keg;
printf("%s(%p) size %d(%d) flags %d 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);
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);
for (i = 0; i <= mp_maxid; i++) {
if (CPU_ABSENT(i))
continue;
cache = &zone->uz_cpu[i];
printf("CPU %d Cache:\n", i);
cache_print(cache);
}
}
/*
* 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, u_int64_t *allocsp,
u_int64_t *freesp)
{
uma_cache_t cache;
u_int64_t allocs, frees;
int cachefree, cpu;
allocs = frees = 0;
cachefree = 0;
for (cpu = 0; cpu <= mp_maxid; cpu++) {
if (CPU_ABSENT(cpu))
continue;
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;
if (cachefreep != NULL)
*cachefreep = cachefree;
if (allocsp != NULL)
*allocsp = allocs;
if (freesp != NULL)
*freesp = frees;
}
/*
* Sysctl handler for vm.zone
*
* stolen from vm_zone.c
*/
static int
sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
{
int error, len, cnt;
const int linesize = 128; /* conservative */
int totalfree;
char *tmpbuf, *offset;
uma_zone_t z;
uma_keg_t zk;
char *p;
int cachefree;
uma_bucket_t bucket;
u_int64_t allocs, frees;
cnt = 0;
mtx_lock(&uma_mtx);
LIST_FOREACH(zk, &uma_kegs, uk_link) {
LIST_FOREACH(z, &zk->uk_zones, uz_link)
cnt++;
}
mtx_unlock(&uma_mtx);
MALLOC(tmpbuf, char *, (cnt == 0 ? 1 : cnt) * linesize,
M_TEMP, M_WAITOK);
len = snprintf(tmpbuf, linesize,
"\nITEM SIZE LIMIT USED FREE REQUESTS\n\n");
if (cnt == 0)
tmpbuf[len - 1] = '\0';
error = SYSCTL_OUT(req, tmpbuf, cnt == 0 ? len-1 : len);
if (error || cnt == 0)
goto out;
offset = tmpbuf;
mtx_lock(&uma_mtx);
LIST_FOREACH(zk, &uma_kegs, uk_link) {
LIST_FOREACH(z, &zk->uk_zones, uz_link) {
if (cnt == 0) /* list may have changed size */
break;
ZONE_LOCK(z);
cachefree = 0;
if (!(zk->uk_flags & UMA_ZFLAG_INTERNAL)) {
uma_zone_sumstat(z, &cachefree, &allocs, &frees);
} else {
allocs = z->uz_allocs;
frees = z->uz_frees;
}
LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link) {
cachefree += bucket->ub_cnt;
}
totalfree = zk->uk_free + cachefree;
len = snprintf(offset, linesize,
"%-12.12s %6.6u, %8.8u, %6.6u, %6.6u, %8.8llu\n",
z->uz_name, zk->uk_size,
zk->uk_maxpages * zk->uk_ipers,
(zk->uk_ipers * (zk->uk_pages / zk->uk_ppera)) - totalfree,
totalfree,
(unsigned long long)allocs);
ZONE_UNLOCK(z);
for (p = offset + 12; p > offset && *p == ' '; --p)
/* nothing */ ;
p[1] = ':';
cnt--;
offset += len;
}
}
mtx_unlock(&uma_mtx);
*offset++ = '\0';
error = SYSCTL_OUT(req, tmpbuf, offset - tmpbuf);
out:
FREE(tmpbuf, M_TEMP);
return (error);
}
static int
sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
{
uma_keg_t kz;
uma_zone_t z;
int count;
count = 0;
mtx_lock(&uma_mtx);
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
count++;
}
mtx_unlock(&uma_mtx);
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_keg_t kz;
uma_zone_t z;
char *buffer;
int buflen, count, error, i;
mtx_lock(&uma_mtx);
restart:
mtx_assert(&uma_mtx, MA_OWNED);
count = 0;
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
count++;
}
mtx_unlock(&uma_mtx);
buflen = sizeof(ush) + count * (sizeof(uth) + sizeof(ups) *
(mp_maxid + 1)) + 1;
buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
mtx_lock(&uma_mtx);
i = 0;
LIST_FOREACH(kz, &uma_kegs, uk_link) {
LIST_FOREACH(z, &kz->uk_zones, uz_link)
i++;
}
if (i > count) {
free(buffer, M_TEMP);
goto restart;
}
count = i;
sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
/*
* Insert stream header.
*/
bzero(&ush, sizeof(ush));
ush.ush_version = UMA_STREAM_VERSION;
ush.ush_maxcpus = (mp_maxid + 1);
ush.ush_count = count;
if (sbuf_bcat(&sbuf, &ush, sizeof(ush)) < 0) {
mtx_unlock(&uma_mtx);
error = ENOMEM;
goto out;
}
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_pages = kz->uk_pages;
uth.uth_keg_free = kz->uk_free;
uth.uth_size = kz->uk_size;
uth.uth_rsize = kz->uk_rsize;
uth.uth_maxpages = kz->uk_maxpages;
if (kz->uk_ppera > 1)
uth.uth_limit = kz->uk_maxpages /
kz->uk_ppera;
else
uth.uth_limit = kz->uk_maxpages *
kz->uk_ipers;
/*
* A zone is secondary is it is not the first entry
* on the keg's zone list.
*/
if ((kz->uk_flags & UMA_ZONE_SECONDARY) &&
(LIST_FIRST(&kz->uk_zones) != z))
uth.uth_zone_flags = UTH_ZONE_SECONDARY;
LIST_FOREACH(bucket, &z->uz_full_bucket, 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;
if (sbuf_bcat(&sbuf, &uth, sizeof(uth)) < 0) {
ZONE_UNLOCK(z);
mtx_unlock(&uma_mtx);
error = ENOMEM;
goto out;
}
/*
* 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:
if (sbuf_bcat(&sbuf, &ups, sizeof(ups)) < 0) {
ZONE_UNLOCK(z);
mtx_unlock(&uma_mtx);
error = ENOMEM;
goto out;
}
}
ZONE_UNLOCK(z);
}
}
mtx_unlock(&uma_mtx);
sbuf_finish(&sbuf);
error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
out:
free(buffer, M_TEMP);
return (error);
}
#ifdef DDB
DB_SHOW_COMMAND(uma, db_show_uma)
{
u_int64_t allocs, frees;
uma_bucket_t bucket;
uma_keg_t kz;
uma_zone_t z;
int cachefree;
db_printf("%18s %12s %12s %12s %8s\n", "Zone", "Allocs", "Frees",
"Used", "Cache");
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;
cachefree = 0;
} else
uma_zone_sumstat(z, &cachefree, &allocs,
&frees);
if (!((kz->uk_flags & UMA_ZONE_SECONDARY) &&
(LIST_FIRST(&kz->uk_zones) != z)))
cachefree += kz->uk_free;
LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
cachefree += bucket->ub_cnt;
db_printf("%18s %12ju %12ju %12ju %8d\n", z->uz_name,
allocs, frees, allocs - frees, cachefree);
}
}
}
#endif
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