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freebsd-dev/sys/vm/uma_core.c
Alan Cox 7630c26507 Reintroduce UMA_SLAB_KMAP; however, change its spelling to 
UMA_SLAB_KERNEL for consistency with its sibling UMA_SLAB_KMEM.
(UMA_SLAB_KMAP met its original demise in revision 1.30 of
vm/uma_core.c.)  UMA_SLAB_KERNEL is now required by the jumbo frame
allocators.  Without it, UMA cannot correctly return pages from the
jumbo frame zones to the VM system because it resets the pages' object
field to NULL instead of the kernel object.  In more detail, the jumbo
frame zones are created with the option UMA_ZONE_REFCNT.  This causes
UMA to overwrite the pages' object field with the address of the slab.
However, when UMA wants to release these pages, it doesn't know how to
restore the object field, so it sets it to NULL.  This change teaches
UMA how to reset the object field to the kernel object.

Crashes reported by: kris
Fix tested by: kris
Fix discussed with: jeff
MFC after: 6 weeks
2008-04-04 18:41:12 +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) 2004-2006 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 <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;
/* The boot-time adjusted value for cache line alignment. */
static int uma_align_cache = 16 - 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);
/* 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 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_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");
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.
*/
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 if (flags & UMA_SLAB_KERNEL)
obj = kernel_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 if (flags & UMA_SLAB_KERNEL)
obj = kernel_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 == UMA_ALIGN_CACHE) ? uma_align_cache : align;
args.flags = flags;
args.zone = zone;
return (uma_zalloc_internal(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(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;
/* 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);
}
/*
* 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 && zone != zones)
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_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. 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);
}
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();
}
/* See uma.h */
int
uma_zone_exhausted(uma_zone_t zone)
{
int full;
ZONE_LOCK(zone);
full = (zone->uz_keg->uk_flags & UMA_ZFLAG_FULL);
ZONE_UNLOCK(zone);
return (full);
}
int
uma_zone_exhausted_nolock(uma_zone_t zone)
{
return (zone->uz_keg->uk_flags & UMA_ZFLAG_FULL);
}
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);
}
}
#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, 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;
}
#endif /* DDB */
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 %8s %8s %8s %12s\n", "Zone", "Size", "Used", "Free",
"Requests");
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 %8ju %8jd %8d %12ju\n", z->uz_name,
(uintmax_t)kz->uk_size,
(intmax_t)(allocs - frees), cachefree,
(uintmax_t)allocs);
}
}
}
#endif
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