2 * Copyright (c) 2002-2005, 2009 Jeffrey Roberson <jeff@FreeBSD.org>
3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4 * Copyright (c) 2004-2006 Robert N. M. Watson
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 * uma_core.c Implementation of the Universal Memory allocator
32 * This allocator is intended to replace the multitude of similar object caches
33 * in the standard FreeBSD kernel. The intent is to be flexible as well as
34 * effecient. A primary design goal is to return unused memory to the rest of
35 * the system. This will make the system as a whole more flexible due to the
36 * ability to move memory to subsystems which most need it instead of leaving
37 * pools of reserved memory unused.
39 * The basic ideas stem from similar slab/zone based allocators whose algorithms
46 * - Improve memory usage for large allocations
47 * - Investigate cache size adjustments
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
53 /* I should really use ktr.. */
56 #define UMA_DEBUG_ALLOC 1
57 #define UMA_DEBUG_ALLOC_1 1
61 #include "opt_param.h"
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/kernel.h>
67 #include <sys/types.h>
68 #include <sys/queue.h>
69 #include <sys/malloc.h>
72 #include <sys/sysctl.h>
73 #include <sys/mutex.h>
75 #include <sys/rwlock.h>
78 #include <sys/vmmeter.h>
81 #include <vm/vm_object.h>
82 #include <vm/vm_page.h>
83 #include <vm/vm_pageout.h>
84 #include <vm/vm_param.h>
85 #include <vm/vm_map.h>
86 #include <vm/vm_kern.h>
87 #include <vm/vm_extern.h>
89 #include <vm/uma_int.h>
90 #include <vm/uma_dbg.h>
95 #include <vm/memguard.h>
99 * This is the zone and keg from which all zones are spawned. The idea is that
100 * even the zone & keg heads are allocated from the allocator, so we use the
101 * bss section to bootstrap us.
103 static struct uma_keg masterkeg;
104 static struct uma_zone masterzone_k;
105 static struct uma_zone masterzone_z;
106 static uma_zone_t kegs = &masterzone_k;
107 static uma_zone_t zones = &masterzone_z;
109 /* This is the zone from which all of uma_slab_t's are allocated. */
110 static uma_zone_t slabzone;
111 static uma_zone_t slabrefzone; /* With refcounters (for UMA_ZONE_REFCNT) */
114 * The initial hash tables come out of this zone so they can be allocated
115 * prior to malloc coming up.
117 static uma_zone_t hashzone;
119 /* The boot-time adjusted value for cache line alignment. */
120 int uma_align_cache = 64 - 1;
122 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
125 * Are we allowed to allocate buckets?
127 static int bucketdisable = 1;
129 /* Linked list of all kegs in the system */
130 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
132 /* This mutex protects the keg list */
133 static struct mtx uma_mtx;
135 /* Linked list of boot time pages */
136 static LIST_HEAD(,uma_slab) uma_boot_pages =
137 LIST_HEAD_INITIALIZER(uma_boot_pages);
139 /* This mutex protects the boot time pages list */
140 static struct mtx uma_boot_pages_mtx;
142 /* Is the VM done starting up? */
143 static int booted = 0;
144 #define UMA_STARTUP 1
145 #define UMA_STARTUP2 2
147 /* Maximum number of allowed items-per-slab if the slab header is OFFPAGE */
148 static u_int uma_max_ipers;
149 static u_int uma_max_ipers_ref;
152 * This is the handle used to schedule events that need to happen
153 * outside of the allocation fast path.
155 static struct callout uma_callout;
156 #define UMA_TIMEOUT 20 /* Seconds for callout interval. */
159 * This structure is passed as the zone ctor arg so that I don't have to create
160 * a special allocation function just for zones.
162 struct uma_zctor_args {
174 struct uma_kctor_args {
183 struct uma_bucket_zone {
189 #define BUCKET_MAX 128
191 struct uma_bucket_zone bucket_zones[] = {
192 { NULL, "16 Bucket", 16 },
193 { NULL, "32 Bucket", 32 },
194 { NULL, "64 Bucket", 64 },
195 { NULL, "128 Bucket", 128 },
199 #define BUCKET_SHIFT 4
200 #define BUCKET_ZONES ((BUCKET_MAX >> BUCKET_SHIFT) + 1)
203 * bucket_size[] maps requested bucket sizes to zones that allocate a bucket
204 * of approximately the right size.
206 static uint8_t bucket_size[BUCKET_ZONES];
209 * Flags and enumerations to be passed to internal functions.
211 enum zfreeskip { SKIP_NONE, SKIP_DTOR, SKIP_FINI };
213 #define ZFREE_STATFAIL 0x00000001 /* Update zone failure statistic. */
214 #define ZFREE_STATFREE 0x00000002 /* Update zone free statistic. */
218 static void *noobj_alloc(uma_zone_t, int, u_int8_t *, int);
219 static void *page_alloc(uma_zone_t, int, u_int8_t *, int);
220 static void *startup_alloc(uma_zone_t, int, u_int8_t *, int);
221 static void page_free(void *, int, u_int8_t);
222 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int);
223 static void cache_drain(uma_zone_t);
224 static void bucket_drain(uma_zone_t, uma_bucket_t);
225 static void bucket_cache_drain(uma_zone_t zone);
226 static int keg_ctor(void *, int, void *, int);
227 static void keg_dtor(void *, int, void *);
228 static int zone_ctor(void *, int, void *, int);
229 static void zone_dtor(void *, int, void *);
230 static int zero_init(void *, int, int);
231 static void keg_small_init(uma_keg_t keg);
232 static void keg_large_init(uma_keg_t keg);
233 static void zone_foreach(void (*zfunc)(uma_zone_t));
234 static void zone_timeout(uma_zone_t zone);
235 static int hash_alloc(struct uma_hash *);
236 static int hash_expand(struct uma_hash *, struct uma_hash *);
237 static void hash_free(struct uma_hash *hash);
238 static void uma_timeout(void *);
239 static void uma_startup3(void);
240 static void *zone_alloc_item(uma_zone_t, void *, int);
241 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip,
243 static void bucket_enable(void);
244 static void bucket_init(void);
245 static uma_bucket_t bucket_alloc(int, int);
246 static void bucket_free(uma_bucket_t);
247 static void bucket_zone_drain(void);
248 static int zone_alloc_bucket(uma_zone_t zone, int flags);
249 static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags);
250 static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags);
251 static void *slab_alloc_item(uma_zone_t zone, uma_slab_t slab);
252 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
253 uma_fini fini, int align, u_int32_t flags);
254 static inline void zone_relock(uma_zone_t zone, uma_keg_t keg);
255 static inline void keg_relock(uma_keg_t keg, uma_zone_t zone);
257 void uma_print_zone(uma_zone_t);
258 void uma_print_stats(void);
259 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
260 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
262 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
264 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
265 0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
267 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
268 0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
270 static int zone_warnings = 1;
271 TUNABLE_INT("vm.zone_warnings", &zone_warnings);
272 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RW, &zone_warnings, 0,
273 "Warn when UMA zones becomes full");
276 * This routine checks to see whether or not it's safe to enable buckets.
282 bucketdisable = vm_page_count_min();
286 * Initialize bucket_zones, the array of zones of buckets of various sizes.
288 * For each zone, calculate the memory required for each bucket, consisting
289 * of the header and an array of pointers. Initialize bucket_size[] to point
290 * the range of appropriate bucket sizes at the zone.
295 struct uma_bucket_zone *ubz;
299 for (i = 0, j = 0; bucket_zones[j].ubz_entries != 0; j++) {
302 ubz = &bucket_zones[j];
303 size = roundup(sizeof(struct uma_bucket), sizeof(void *));
304 size += sizeof(void *) * ubz->ubz_entries;
305 ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
306 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
307 UMA_ZFLAG_INTERNAL | UMA_ZFLAG_BUCKET);
308 for (; i <= ubz->ubz_entries; i += (1 << BUCKET_SHIFT))
309 bucket_size[i >> BUCKET_SHIFT] = j;
314 * Given a desired number of entries for a bucket, return the zone from which
315 * to allocate the bucket.
317 static struct uma_bucket_zone *
318 bucket_zone_lookup(int entries)
322 idx = howmany(entries, 1 << BUCKET_SHIFT);
323 return (&bucket_zones[bucket_size[idx]]);
327 bucket_alloc(int entries, int bflags)
329 struct uma_bucket_zone *ubz;
333 * This is to stop us from allocating per cpu buckets while we're
334 * running out of vm.boot_pages. Otherwise, we would exhaust the
335 * boot pages. This also prevents us from allocating buckets in
336 * low memory situations.
341 ubz = bucket_zone_lookup(entries);
342 bucket = zone_alloc_item(ubz->ubz_zone, NULL, bflags);
345 bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
348 bucket->ub_entries = ubz->ubz_entries;
355 bucket_free(uma_bucket_t bucket)
357 struct uma_bucket_zone *ubz;
359 ubz = bucket_zone_lookup(bucket->ub_entries);
360 zone_free_item(ubz->ubz_zone, bucket, NULL, SKIP_NONE,
365 bucket_zone_drain(void)
367 struct uma_bucket_zone *ubz;
369 for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
370 zone_drain(ubz->ubz_zone);
374 zone_log_warning(uma_zone_t zone)
376 static const struct timeval warninterval = { 300, 0 };
378 if (!zone_warnings || zone->uz_warning == NULL)
381 if (ratecheck(&zone->uz_ratecheck, &warninterval))
382 printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
385 static inline uma_keg_t
386 zone_first_keg(uma_zone_t zone)
389 return (LIST_FIRST(&zone->uz_kegs)->kl_keg);
393 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
397 LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
398 kegfn(klink->kl_keg);
402 * Routine called by timeout which is used to fire off some time interval
403 * based calculations. (stats, hash size, etc.)
412 uma_timeout(void *unused)
415 zone_foreach(zone_timeout);
417 /* Reschedule this event */
418 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
422 * Routine to perform timeout driven calculations. This expands the
423 * hashes and does per cpu statistics aggregation.
428 keg_timeout(uma_keg_t keg)
433 * Expand the keg hash table.
435 * This is done if the number of slabs is larger than the hash size.
436 * What I'm trying to do here is completely reduce collisions. This
437 * may be a little aggressive. Should I allow for two collisions max?
439 if (keg->uk_flags & UMA_ZONE_HASH &&
440 keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
441 struct uma_hash newhash;
442 struct uma_hash oldhash;
446 * This is so involved because allocating and freeing
447 * while the keg lock is held will lead to deadlock.
448 * I have to do everything in stages and check for
451 newhash = keg->uk_hash;
453 ret = hash_alloc(&newhash);
456 if (hash_expand(&keg->uk_hash, &newhash)) {
457 oldhash = keg->uk_hash;
458 keg->uk_hash = newhash;
471 zone_timeout(uma_zone_t zone)
474 zone_foreach_keg(zone, &keg_timeout);
478 * Allocate and zero fill the next sized hash table from the appropriate
482 * hash A new hash structure with the old hash size in uh_hashsize
485 * 1 on sucess and 0 on failure.
488 hash_alloc(struct uma_hash *hash)
493 oldsize = hash->uh_hashsize;
495 /* We're just going to go to a power of two greater */
497 hash->uh_hashsize = oldsize * 2;
498 alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
499 hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
500 M_UMAHASH, M_NOWAIT);
502 alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
503 hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
505 hash->uh_hashsize = UMA_HASH_SIZE_INIT;
507 if (hash->uh_slab_hash) {
508 bzero(hash->uh_slab_hash, alloc);
509 hash->uh_hashmask = hash->uh_hashsize - 1;
517 * Expands the hash table for HASH zones. This is done from zone_timeout
518 * to reduce collisions. This must not be done in the regular allocation
519 * path, otherwise, we can recurse on the vm while allocating pages.
522 * oldhash The hash you want to expand
523 * newhash The hash structure for the new table
531 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
537 if (!newhash->uh_slab_hash)
540 if (oldhash->uh_hashsize >= newhash->uh_hashsize)
544 * I need to investigate hash algorithms for resizing without a
548 for (i = 0; i < oldhash->uh_hashsize; i++)
549 while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
550 slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
551 SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
552 hval = UMA_HASH(newhash, slab->us_data);
553 SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
561 * Free the hash bucket to the appropriate backing store.
564 * slab_hash The hash bucket we're freeing
565 * hashsize The number of entries in that hash bucket
571 hash_free(struct uma_hash *hash)
573 if (hash->uh_slab_hash == NULL)
575 if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
576 zone_free_item(hashzone,
577 hash->uh_slab_hash, NULL, SKIP_NONE, ZFREE_STATFREE);
579 free(hash->uh_slab_hash, M_UMAHASH);
583 * Frees all outstanding items in a bucket
586 * zone The zone to free to, must be unlocked.
587 * bucket The free/alloc bucket with items, cpu queue must be locked.
594 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
601 while (bucket->ub_cnt > 0) {
603 item = bucket->ub_bucket[bucket->ub_cnt];
605 bucket->ub_bucket[bucket->ub_cnt] = NULL;
606 KASSERT(item != NULL,
607 ("bucket_drain: botched ptr, item is NULL"));
609 zone_free_item(zone, item, NULL, SKIP_DTOR, 0);
614 * Drains the per cpu caches for a zone.
616 * NOTE: This may only be called while the zone is being turn down, and not
617 * during normal operation. This is necessary in order that we do not have
618 * to migrate CPUs to drain the per-CPU caches.
621 * zone The zone to drain, must be unlocked.
627 cache_drain(uma_zone_t zone)
633 * XXX: It is safe to not lock the per-CPU caches, because we're
634 * tearing down the zone anyway. I.e., there will be no further use
635 * of the caches at this point.
637 * XXX: It would good to be able to assert that the zone is being
638 * torn down to prevent improper use of cache_drain().
640 * XXX: We lock the zone before passing into bucket_cache_drain() as
641 * it is used elsewhere. Should the tear-down path be made special
642 * there in some form?
645 cache = &zone->uz_cpu[cpu];
646 bucket_drain(zone, cache->uc_allocbucket);
647 bucket_drain(zone, cache->uc_freebucket);
648 if (cache->uc_allocbucket != NULL)
649 bucket_free(cache->uc_allocbucket);
650 if (cache->uc_freebucket != NULL)
651 bucket_free(cache->uc_freebucket);
652 cache->uc_allocbucket = cache->uc_freebucket = NULL;
655 bucket_cache_drain(zone);
660 * Drain the cached buckets from a zone. Expects a locked zone on entry.
663 bucket_cache_drain(uma_zone_t zone)
668 * Drain the bucket queues and free the buckets, we just keep two per
671 while ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
672 LIST_REMOVE(bucket, ub_link);
674 bucket_drain(zone, bucket);
679 /* Now we do the free queue.. */
680 while ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
681 LIST_REMOVE(bucket, ub_link);
687 * Frees pages from a keg back to the system. This is done on demand from
688 * the pageout daemon.
693 keg_drain(uma_keg_t keg)
695 struct slabhead freeslabs = { 0 };
703 * We don't want to take pages from statically allocated kegs at this
706 if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
710 printf("%s free items: %u\n", keg->uk_name, keg->uk_free);
713 if (keg->uk_free == 0)
716 slab = LIST_FIRST(&keg->uk_free_slab);
718 n = LIST_NEXT(slab, us_link);
720 /* We have no where to free these to */
721 if (slab->us_flags & UMA_SLAB_BOOT) {
726 LIST_REMOVE(slab, us_link);
727 keg->uk_pages -= keg->uk_ppera;
728 keg->uk_free -= keg->uk_ipers;
730 if (keg->uk_flags & UMA_ZONE_HASH)
731 UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
733 SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
740 while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
741 SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
743 for (i = 0; i < keg->uk_ipers; i++)
745 slab->us_data + (keg->uk_rsize * i),
747 flags = slab->us_flags;
750 if (keg->uk_flags & UMA_ZONE_VTOSLAB) {
753 if (flags & UMA_SLAB_KMEM)
755 else if (flags & UMA_SLAB_KERNEL)
759 for (i = 0; i < keg->uk_ppera; i++)
760 vsetobj((vm_offset_t)mem + (i * PAGE_SIZE),
763 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
764 zone_free_item(keg->uk_slabzone, slab, NULL,
765 SKIP_NONE, ZFREE_STATFREE);
767 printf("%s: Returning %d bytes.\n",
768 keg->uk_name, UMA_SLAB_SIZE * keg->uk_ppera);
770 keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera, flags);
775 zone_drain_wait(uma_zone_t zone, int waitok)
779 * Set draining to interlock with zone_dtor() so we can release our
780 * locks as we go. Only dtor() should do a WAITOK call since it
781 * is the only call that knows the structure will still be available
785 while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
786 if (waitok == M_NOWAIT)
788 mtx_unlock(&uma_mtx);
789 msleep(zone, zone->uz_lock, PVM, "zonedrain", 1);
792 zone->uz_flags |= UMA_ZFLAG_DRAINING;
793 bucket_cache_drain(zone);
796 * The DRAINING flag protects us from being freed while
797 * we're running. Normally the uma_mtx would protect us but we
798 * must be able to release and acquire the right lock for each keg.
800 zone_foreach_keg(zone, &keg_drain);
802 zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
809 zone_drain(uma_zone_t zone)
812 zone_drain_wait(zone, M_NOWAIT);
816 * Allocate a new slab for a keg. This does not insert the slab onto a list.
819 * wait Shall we wait?
822 * The slab that was allocated or NULL if there is no memory and the
823 * caller specified M_NOWAIT.
826 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int wait)
828 uma_slabrefcnt_t slabref;
835 mtx_assert(&keg->uk_lock, MA_OWNED);
839 printf("slab_zalloc: Allocating a new slab for %s\n", keg->uk_name);
841 allocf = keg->uk_allocf;
844 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
845 slab = zone_alloc_item(keg->uk_slabzone, NULL, wait);
853 * This reproduces the old vm_zone behavior of zero filling pages the
854 * first time they are added to a zone.
856 * Malloced items are zeroed in uma_zalloc.
859 if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
864 if (keg->uk_flags & UMA_ZONE_NODUMP)
867 /* zone is passed for legacy reasons. */
868 mem = allocf(zone, keg->uk_ppera * UMA_SLAB_SIZE, &flags, wait);
870 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
871 zone_free_item(keg->uk_slabzone, slab, NULL,
872 SKIP_NONE, ZFREE_STATFREE);
877 /* Point the slab into the allocated memory */
878 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
879 slab = (uma_slab_t )(mem + keg->uk_pgoff);
881 if (keg->uk_flags & UMA_ZONE_VTOSLAB)
882 for (i = 0; i < keg->uk_ppera; i++)
883 vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
887 slab->us_freecount = keg->uk_ipers;
888 slab->us_firstfree = 0;
889 slab->us_flags = flags;
891 if (keg->uk_flags & UMA_ZONE_REFCNT) {
892 slabref = (uma_slabrefcnt_t)slab;
893 for (i = 0; i < keg->uk_ipers; i++) {
894 slabref->us_freelist[i].us_refcnt = 0;
895 slabref->us_freelist[i].us_item = i+1;
898 for (i = 0; i < keg->uk_ipers; i++)
899 slab->us_freelist[i].us_item = i+1;
902 if (keg->uk_init != NULL) {
903 for (i = 0; i < keg->uk_ipers; i++)
904 if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
905 keg->uk_size, wait) != 0)
907 if (i != keg->uk_ipers) {
908 if (keg->uk_fini != NULL) {
909 for (i--; i > -1; i--)
910 keg->uk_fini(slab->us_data +
914 if (keg->uk_flags & UMA_ZONE_VTOSLAB) {
917 if (flags & UMA_SLAB_KMEM)
919 else if (flags & UMA_SLAB_KERNEL)
923 for (i = 0; i < keg->uk_ppera; i++)
924 vsetobj((vm_offset_t)mem +
925 (i * PAGE_SIZE), obj);
927 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
928 zone_free_item(keg->uk_slabzone, slab,
929 NULL, SKIP_NONE, ZFREE_STATFREE);
930 keg->uk_freef(mem, UMA_SLAB_SIZE * keg->uk_ppera,
938 if (keg->uk_flags & UMA_ZONE_HASH)
939 UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
941 keg->uk_pages += keg->uk_ppera;
942 keg->uk_free += keg->uk_ipers;
948 * This function is intended to be used early on in place of page_alloc() so
949 * that we may use the boot time page cache to satisfy allocations before
953 startup_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
957 int pages, check_pages;
959 keg = zone_first_keg(zone);
960 pages = howmany(bytes, PAGE_SIZE);
961 check_pages = pages - 1;
962 KASSERT(pages > 0, ("startup_alloc can't reserve 0 pages\n"));
965 * Check our small startup cache to see if it has pages remaining.
967 mtx_lock(&uma_boot_pages_mtx);
969 /* First check if we have enough room. */
970 tmps = LIST_FIRST(&uma_boot_pages);
971 while (tmps != NULL && check_pages-- > 0)
972 tmps = LIST_NEXT(tmps, us_link);
975 * It's ok to lose tmps references. The last one will
976 * have tmps->us_data pointing to the start address of
977 * "pages" contiguous pages of memory.
979 while (pages-- > 0) {
980 tmps = LIST_FIRST(&uma_boot_pages);
981 LIST_REMOVE(tmps, us_link);
983 mtx_unlock(&uma_boot_pages_mtx);
984 *pflag = tmps->us_flags;
985 return (tmps->us_data);
987 mtx_unlock(&uma_boot_pages_mtx);
988 if (booted < UMA_STARTUP2)
989 panic("UMA: Increase vm.boot_pages");
991 * Now that we've booted reset these users to their real allocator.
993 #ifdef UMA_MD_SMALL_ALLOC
994 keg->uk_allocf = (keg->uk_ppera > 1) ? page_alloc : uma_small_alloc;
996 keg->uk_allocf = page_alloc;
998 return keg->uk_allocf(zone, bytes, pflag, wait);
1002 * Allocates a number of pages from the system
1005 * bytes The number of bytes requested
1006 * wait Shall we wait?
1009 * A pointer to the alloced memory or possibly
1010 * NULL if M_NOWAIT is set.
1013 page_alloc(uma_zone_t zone, int bytes, u_int8_t *pflag, int wait)
1015 void *p; /* Returned page */
1017 *pflag = UMA_SLAB_KMEM;
1018 p = (void *) kmem_malloc(kmem_map, bytes, wait);
1024 * Allocates a number of pages from within an object
1027 * bytes The number of bytes requested
1028 * wait Shall we wait?
1031 * A pointer to the alloced memory or possibly
1032 * NULL if M_NOWAIT is set.
1035 noobj_alloc(uma_zone_t zone, int bytes, u_int8_t *flags, int wait)
1037 TAILQ_HEAD(, vm_page) alloctail;
1039 vm_offset_t retkva, zkva;
1040 vm_page_t p, p_next;
1043 TAILQ_INIT(&alloctail);
1044 keg = zone_first_keg(zone);
1046 npages = howmany(bytes, PAGE_SIZE);
1047 while (npages > 0) {
1048 p = vm_page_alloc(NULL, 0, VM_ALLOC_INTERRUPT |
1049 VM_ALLOC_WIRED | VM_ALLOC_NOOBJ);
1052 * Since the page does not belong to an object, its
1055 TAILQ_INSERT_TAIL(&alloctail, p, listq);
1059 if (wait & M_WAITOK) {
1065 * Page allocation failed, free intermediate pages and
1068 TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1069 vm_page_unwire(p, 0);
1074 *flags = UMA_SLAB_PRIV;
1075 zkva = keg->uk_kva +
1076 atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1078 TAILQ_FOREACH(p, &alloctail, listq) {
1079 pmap_qenter(zkva, &p, 1);
1083 return ((void *)retkva);
1087 * Frees a number of pages to the system
1090 * mem A pointer to the memory to be freed
1091 * size The size of the memory being freed
1092 * flags The original p->us_flags field
1098 page_free(void *mem, int size, u_int8_t flags)
1102 if (flags & UMA_SLAB_KMEM)
1104 else if (flags & UMA_SLAB_KERNEL)
1107 panic("UMA: page_free used with invalid flags %d", flags);
1109 kmem_free(map, (vm_offset_t)mem, size);
1113 * Zero fill initializer
1115 * Arguments/Returns follow uma_init specifications
1118 zero_init(void *mem, int size, int flags)
1125 * Finish creating a small uma keg. This calculates ipers, and the keg size.
1128 * keg The zone we should initialize
1134 keg_small_init(uma_keg_t keg)
1141 KASSERT(keg != NULL, ("Keg is null in keg_small_init"));
1142 rsize = keg->uk_size;
1144 if (rsize < UMA_SMALLEST_UNIT)
1145 rsize = UMA_SMALLEST_UNIT;
1146 if (rsize & keg->uk_align)
1147 rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1149 keg->uk_rsize = rsize;
1152 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1154 } else if (keg->uk_flags & UMA_ZONE_REFCNT) {
1155 rsize += UMA_FRITMREF_SZ; /* linkage & refcnt */
1156 shsize = sizeof(struct uma_slab_refcnt);
1158 rsize += UMA_FRITM_SZ; /* Account for linkage */
1159 shsize = sizeof(struct uma_slab);
1162 keg->uk_ipers = (UMA_SLAB_SIZE - shsize) / rsize;
1163 KASSERT(keg->uk_ipers != 0, ("keg_small_init: ipers is 0"));
1164 memused = keg->uk_ipers * rsize + shsize;
1165 wastedspace = UMA_SLAB_SIZE - memused;
1168 * We can't do OFFPAGE if we're internal or if we've been
1169 * asked to not go to the VM for buckets. If we do this we
1170 * may end up going to the VM (kmem_map) for slabs which we
1171 * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
1172 * result of UMA_ZONE_VM, which clearly forbids it.
1174 if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1175 (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1178 if ((wastedspace >= UMA_MAX_WASTE) &&
1179 (keg->uk_ipers < (UMA_SLAB_SIZE / keg->uk_rsize))) {
1180 keg->uk_ipers = UMA_SLAB_SIZE / keg->uk_rsize;
1181 KASSERT(keg->uk_ipers <= 255,
1182 ("keg_small_init: keg->uk_ipers too high!"));
1184 printf("UMA decided we need offpage slab headers for "
1185 "keg: %s, calculated wastedspace = %d, "
1186 "maximum wasted space allowed = %d, "
1187 "calculated ipers = %d, "
1188 "new wasted space = %d\n", keg->uk_name, wastedspace,
1189 UMA_MAX_WASTE, keg->uk_ipers,
1190 UMA_SLAB_SIZE - keg->uk_ipers * keg->uk_rsize);
1192 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1193 if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1194 keg->uk_flags |= UMA_ZONE_HASH;
1199 * Finish creating a large (> UMA_SLAB_SIZE) uma kegs. Just give in and do
1200 * OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
1204 * keg The keg we should initialize
1210 keg_large_init(uma_keg_t keg)
1214 KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1215 KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1216 ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1218 pages = keg->uk_size / UMA_SLAB_SIZE;
1220 /* Account for remainder */
1221 if ((pages * UMA_SLAB_SIZE) < keg->uk_size)
1224 keg->uk_ppera = pages;
1226 keg->uk_rsize = keg->uk_size;
1228 /* We can't do OFFPAGE if we're internal, bail out here. */
1229 if (keg->uk_flags & UMA_ZFLAG_INTERNAL)
1232 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1233 if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1234 keg->uk_flags |= UMA_ZONE_HASH;
1238 keg_cachespread_init(uma_keg_t keg)
1245 alignsize = keg->uk_align + 1;
1246 rsize = keg->uk_size;
1248 * We want one item to start on every align boundary in a page. To
1249 * do this we will span pages. We will also extend the item by the
1250 * size of align if it is an even multiple of align. Otherwise, it
1251 * would fall on the same boundary every time.
1253 if (rsize & keg->uk_align)
1254 rsize = (rsize & ~keg->uk_align) + alignsize;
1255 if ((rsize & alignsize) == 0)
1257 trailer = rsize - keg->uk_size;
1258 pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1259 pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1260 keg->uk_rsize = rsize;
1261 keg->uk_ppera = pages;
1262 keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1263 keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1264 KASSERT(keg->uk_ipers <= uma_max_ipers,
1265 ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1270 * Keg header ctor. This initializes all fields, locks, etc. And inserts
1271 * the keg onto the global keg list.
1273 * Arguments/Returns follow uma_ctor specifications
1274 * udata Actually uma_kctor_args
1277 keg_ctor(void *mem, int size, void *udata, int flags)
1279 struct uma_kctor_args *arg = udata;
1280 uma_keg_t keg = mem;
1284 keg->uk_size = arg->size;
1285 keg->uk_init = arg->uminit;
1286 keg->uk_fini = arg->fini;
1287 keg->uk_align = arg->align;
1290 keg->uk_flags = arg->flags;
1291 keg->uk_allocf = page_alloc;
1292 keg->uk_freef = page_free;
1293 keg->uk_recurse = 0;
1294 keg->uk_slabzone = NULL;
1297 * The master zone is passed to us at keg-creation time.
1300 keg->uk_name = zone->uz_name;
1302 if (arg->flags & UMA_ZONE_VM)
1303 keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1305 if (arg->flags & UMA_ZONE_ZINIT)
1306 keg->uk_init = zero_init;
1308 if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC)
1309 keg->uk_flags |= UMA_ZONE_VTOSLAB;
1312 * The +UMA_FRITM_SZ added to uk_size is to account for the
1313 * linkage that is added to the size in keg_small_init(). If
1314 * we don't account for this here then we may end up in
1315 * keg_small_init() with a calculated 'ipers' of 0.
1317 if (keg->uk_flags & UMA_ZONE_REFCNT) {
1318 if (keg->uk_flags & UMA_ZONE_CACHESPREAD)
1319 keg_cachespread_init(keg);
1320 else if ((keg->uk_size+UMA_FRITMREF_SZ) >
1321 (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
1322 keg_large_init(keg);
1324 keg_small_init(keg);
1326 if (keg->uk_flags & UMA_ZONE_CACHESPREAD)
1327 keg_cachespread_init(keg);
1328 else if ((keg->uk_size+UMA_FRITM_SZ) >
1329 (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1330 keg_large_init(keg);
1332 keg_small_init(keg);
1335 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1336 if (keg->uk_flags & UMA_ZONE_REFCNT)
1337 keg->uk_slabzone = slabrefzone;
1339 keg->uk_slabzone = slabzone;
1343 * If we haven't booted yet we need allocations to go through the
1344 * startup cache until the vm is ready.
1346 if (keg->uk_ppera == 1) {
1347 #ifdef UMA_MD_SMALL_ALLOC
1348 keg->uk_allocf = uma_small_alloc;
1349 keg->uk_freef = uma_small_free;
1351 if (booted < UMA_STARTUP)
1352 keg->uk_allocf = startup_alloc;
1354 if (booted < UMA_STARTUP2)
1355 keg->uk_allocf = startup_alloc;
1357 } else if (booted < UMA_STARTUP2 &&
1358 (keg->uk_flags & UMA_ZFLAG_INTERNAL))
1359 keg->uk_allocf = startup_alloc;
1362 * Initialize keg's lock (shared among zones).
1364 if (arg->flags & UMA_ZONE_MTXCLASS)
1365 KEG_LOCK_INIT(keg, 1);
1367 KEG_LOCK_INIT(keg, 0);
1370 * If we're putting the slab header in the actual page we need to
1371 * figure out where in each page it goes. This calculates a right
1372 * justified offset into the memory on an ALIGN_PTR boundary.
1374 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1377 /* Size of the slab struct and free list */
1378 if (keg->uk_flags & UMA_ZONE_REFCNT)
1379 totsize = sizeof(struct uma_slab_refcnt) +
1380 keg->uk_ipers * UMA_FRITMREF_SZ;
1382 totsize = sizeof(struct uma_slab) +
1383 keg->uk_ipers * UMA_FRITM_SZ;
1385 if (totsize & UMA_ALIGN_PTR)
1386 totsize = (totsize & ~UMA_ALIGN_PTR) +
1387 (UMA_ALIGN_PTR + 1);
1388 keg->uk_pgoff = (UMA_SLAB_SIZE * keg->uk_ppera) - totsize;
1390 if (keg->uk_flags & UMA_ZONE_REFCNT)
1391 totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
1392 + keg->uk_ipers * UMA_FRITMREF_SZ;
1394 totsize = keg->uk_pgoff + sizeof(struct uma_slab)
1395 + keg->uk_ipers * UMA_FRITM_SZ;
1398 * The only way the following is possible is if with our
1399 * UMA_ALIGN_PTR adjustments we are now bigger than
1400 * UMA_SLAB_SIZE. I haven't checked whether this is
1401 * mathematically possible for all cases, so we make
1404 if (totsize > UMA_SLAB_SIZE * keg->uk_ppera) {
1405 printf("zone %s ipers %d rsize %d size %d\n",
1406 zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1408 panic("UMA slab won't fit.");
1412 if (keg->uk_flags & UMA_ZONE_HASH)
1413 hash_alloc(&keg->uk_hash);
1416 printf("UMA: %s(%p) size %d(%d) flags %#x ipers %d ppera %d out %d free %d\n",
1417 zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
1418 keg->uk_ipers, keg->uk_ppera,
1419 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
1422 LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1425 LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1426 mtx_unlock(&uma_mtx);
1431 * Zone header ctor. This initializes all fields, locks, etc.
1433 * Arguments/Returns follow uma_ctor specifications
1434 * udata Actually uma_zctor_args
1437 zone_ctor(void *mem, int size, void *udata, int flags)
1439 struct uma_zctor_args *arg = udata;
1440 uma_zone_t zone = mem;
1445 zone->uz_name = arg->name;
1446 zone->uz_ctor = arg->ctor;
1447 zone->uz_dtor = arg->dtor;
1448 zone->uz_slab = zone_fetch_slab;
1449 zone->uz_init = NULL;
1450 zone->uz_fini = NULL;
1451 zone->uz_allocs = 0;
1454 zone->uz_sleeps = 0;
1455 zone->uz_fills = zone->uz_count = 0;
1457 zone->uz_warning = NULL;
1458 timevalclear(&zone->uz_ratecheck);
1461 if (arg->flags & UMA_ZONE_SECONDARY) {
1462 KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1463 zone->uz_init = arg->uminit;
1464 zone->uz_fini = arg->fini;
1465 zone->uz_lock = &keg->uk_lock;
1466 zone->uz_flags |= UMA_ZONE_SECONDARY;
1469 LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1470 if (LIST_NEXT(z, uz_link) == NULL) {
1471 LIST_INSERT_AFTER(z, zone, uz_link);
1476 mtx_unlock(&uma_mtx);
1477 } else if (keg == NULL) {
1478 if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1479 arg->align, arg->flags)) == NULL)
1482 struct uma_kctor_args karg;
1485 /* We should only be here from uma_startup() */
1486 karg.size = arg->size;
1487 karg.uminit = arg->uminit;
1488 karg.fini = arg->fini;
1489 karg.align = arg->align;
1490 karg.flags = arg->flags;
1492 error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1498 * Link in the first keg.
1500 zone->uz_klink.kl_keg = keg;
1501 LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1502 zone->uz_lock = &keg->uk_lock;
1503 zone->uz_size = keg->uk_size;
1504 zone->uz_flags |= (keg->uk_flags &
1505 (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1508 * Some internal zones don't have room allocated for the per cpu
1509 * caches. If we're internal, bail out here.
1511 if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1512 KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1513 ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1517 if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
1518 zone->uz_count = BUCKET_MAX;
1519 else if (keg->uk_ipers <= BUCKET_MAX)
1520 zone->uz_count = keg->uk_ipers;
1522 zone->uz_count = BUCKET_MAX;
1527 * Keg header dtor. This frees all data, destroys locks, frees the hash
1528 * table and removes the keg from the global list.
1530 * Arguments/Returns follow uma_dtor specifications
1534 keg_dtor(void *arg, int size, void *udata)
1538 keg = (uma_keg_t)arg;
1540 if (keg->uk_free != 0) {
1541 printf("Freed UMA keg was not empty (%d items). "
1542 " Lost %d pages of memory.\n",
1543 keg->uk_free, keg->uk_pages);
1547 hash_free(&keg->uk_hash);
1555 * Arguments/Returns follow uma_dtor specifications
1559 zone_dtor(void *arg, int size, void *udata)
1565 zone = (uma_zone_t)arg;
1566 keg = zone_first_keg(zone);
1568 if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1572 LIST_REMOVE(zone, uz_link);
1573 mtx_unlock(&uma_mtx);
1575 * XXX there are some races here where
1576 * the zone can be drained but zone lock
1577 * released and then refilled before we
1578 * remove it... we dont care for now
1580 zone_drain_wait(zone, M_WAITOK);
1582 * Unlink all of our kegs.
1584 while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1585 klink->kl_keg = NULL;
1586 LIST_REMOVE(klink, kl_link);
1587 if (klink == &zone->uz_klink)
1589 free(klink, M_TEMP);
1592 * We only destroy kegs from non secondary zones.
1594 if ((zone->uz_flags & UMA_ZONE_SECONDARY) == 0) {
1596 LIST_REMOVE(keg, uk_link);
1597 mtx_unlock(&uma_mtx);
1598 zone_free_item(kegs, keg, NULL, SKIP_NONE,
1604 * Traverses every zone in the system and calls a callback
1607 * zfunc A pointer to a function which accepts a zone
1614 zone_foreach(void (*zfunc)(uma_zone_t))
1620 LIST_FOREACH(keg, &uma_kegs, uk_link) {
1621 LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1624 mtx_unlock(&uma_mtx);
1627 /* Public functions */
1630 uma_startup(void *bootmem, int boot_pages)
1632 struct uma_zctor_args args;
1635 u_int objsize, totsize, wsize;
1639 printf("Creating uma keg headers zone and keg.\n");
1641 mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1644 * Figure out the maximum number of items-per-slab we'll have if
1645 * we're using the OFFPAGE slab header to track free items, given
1646 * all possible object sizes and the maximum desired wastage
1649 * We iterate until we find an object size for
1650 * which the calculated wastage in keg_small_init() will be
1651 * enough to warrant OFFPAGE. Since wastedspace versus objsize
1652 * is an overall increasing see-saw function, we find the smallest
1653 * objsize such that the wastage is always acceptable for objects
1654 * with that objsize or smaller. Since a smaller objsize always
1655 * generates a larger possible uma_max_ipers, we use this computed
1656 * objsize to calculate the largest ipers possible. Since the
1657 * ipers calculated for OFFPAGE slab headers is always larger than
1658 * the ipers initially calculated in keg_small_init(), we use
1659 * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
1660 * obtain the maximum ipers possible for offpage slab headers.
1662 * It should be noted that ipers versus objsize is an inversly
1663 * proportional function which drops off rather quickly so as
1664 * long as our UMA_MAX_WASTE is such that the objsize we calculate
1665 * falls into the portion of the inverse relation AFTER the steep
1666 * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
1668 * Note that we have 8-bits (1 byte) to use as a freelist index
1669 * inside the actual slab header itself and this is enough to
1670 * accomodate us. In the worst case, a UMA_SMALLEST_UNIT sized
1671 * object with offpage slab header would have ipers =
1672 * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
1673 * 1 greater than what our byte-integer freelist index can
1674 * accomodate, but we know that this situation never occurs as
1675 * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
1676 * that we need to go to offpage slab headers. Or, if we do,
1677 * then we trap that condition below and panic in the INVARIANTS case.
1679 wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) - UMA_MAX_WASTE;
1681 objsize = UMA_SMALLEST_UNIT;
1682 while (totsize >= wsize) {
1683 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
1684 (objsize + UMA_FRITM_SZ);
1685 totsize *= (UMA_FRITM_SZ + objsize);
1688 if (objsize > UMA_SMALLEST_UNIT)
1690 uma_max_ipers = MAX(UMA_SLAB_SIZE / objsize, 64);
1692 wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) - UMA_MAX_WASTE;
1694 objsize = UMA_SMALLEST_UNIT;
1695 while (totsize >= wsize) {
1696 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
1697 (objsize + UMA_FRITMREF_SZ);
1698 totsize *= (UMA_FRITMREF_SZ + objsize);
1701 if (objsize > UMA_SMALLEST_UNIT)
1703 uma_max_ipers_ref = MAX(UMA_SLAB_SIZE / objsize, 64);
1705 KASSERT((uma_max_ipers_ref <= 255) && (uma_max_ipers <= 255),
1706 ("uma_startup: calculated uma_max_ipers values too large!"));
1709 printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
1710 printf("Calculated uma_max_ipers_ref (for OFFPAGE) is %d\n",
1714 /* "manually" create the initial zone */
1715 args.name = "UMA Kegs";
1716 args.size = sizeof(struct uma_keg);
1717 args.ctor = keg_ctor;
1718 args.dtor = keg_dtor;
1719 args.uminit = zero_init;
1721 args.keg = &masterkeg;
1722 args.align = 32 - 1;
1723 args.flags = UMA_ZFLAG_INTERNAL;
1724 /* The initial zone has no Per cpu queues so it's smaller */
1725 zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1728 printf("Filling boot free list.\n");
1730 for (i = 0; i < boot_pages; i++) {
1731 slab = (uma_slab_t)((u_int8_t *)bootmem + (i * UMA_SLAB_SIZE));
1732 slab->us_data = (u_int8_t *)slab;
1733 slab->us_flags = UMA_SLAB_BOOT;
1734 LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1736 mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1739 printf("Creating uma zone headers zone and keg.\n");
1741 args.name = "UMA Zones";
1742 args.size = sizeof(struct uma_zone) +
1743 (sizeof(struct uma_cache) * (mp_maxid + 1));
1744 args.ctor = zone_ctor;
1745 args.dtor = zone_dtor;
1746 args.uminit = zero_init;
1749 args.align = 32 - 1;
1750 args.flags = UMA_ZFLAG_INTERNAL;
1751 /* The initial zone has no Per cpu queues so it's smaller */
1752 zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1755 printf("Initializing pcpu cache locks.\n");
1758 printf("Creating slab and hash zones.\n");
1762 * This is the max number of free list items we'll have with
1765 slabsize = uma_max_ipers * UMA_FRITM_SZ;
1766 slabsize += sizeof(struct uma_slab);
1768 /* Now make a zone for slab headers */
1769 slabzone = uma_zcreate("UMA Slabs",
1771 NULL, NULL, NULL, NULL,
1772 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1775 * We also create a zone for the bigger slabs with reference
1776 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1778 slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
1779 slabsize += sizeof(struct uma_slab_refcnt);
1780 slabrefzone = uma_zcreate("UMA RCntSlabs",
1782 NULL, NULL, NULL, NULL,
1784 UMA_ZFLAG_INTERNAL);
1786 hashzone = uma_zcreate("UMA Hash",
1787 sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1788 NULL, NULL, NULL, NULL,
1789 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1793 booted = UMA_STARTUP;
1796 printf("UMA startup complete.\n");
1804 booted = UMA_STARTUP2;
1807 printf("UMA startup2 complete.\n");
1812 * Initialize our callout handle
1820 printf("Starting callout.\n");
1822 callout_init(&uma_callout, CALLOUT_MPSAFE);
1823 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1825 printf("UMA startup3 complete.\n");
1830 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1831 int align, u_int32_t flags)
1833 struct uma_kctor_args args;
1836 args.uminit = uminit;
1838 args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1841 return (zone_alloc_item(kegs, &args, M_WAITOK));
1846 uma_set_align(int align)
1849 if (align != UMA_ALIGN_CACHE)
1850 uma_align_cache = align;
1855 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1856 uma_init uminit, uma_fini fini, int align, u_int32_t flags)
1859 struct uma_zctor_args args;
1861 /* This stuff is essential for the zone ctor */
1866 args.uminit = uminit;
1872 return (zone_alloc_item(zones, &args, M_WAITOK));
1877 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1878 uma_init zinit, uma_fini zfini, uma_zone_t master)
1880 struct uma_zctor_args args;
1883 keg = zone_first_keg(master);
1885 args.size = keg->uk_size;
1888 args.uminit = zinit;
1890 args.align = keg->uk_align;
1891 args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
1894 /* XXX Attaches only one keg of potentially many. */
1895 return (zone_alloc_item(zones, &args, M_WAITOK));
1899 zone_lock_pair(uma_zone_t a, uma_zone_t b)
1903 mtx_lock_flags(b->uz_lock, MTX_DUPOK);
1906 mtx_lock_flags(a->uz_lock, MTX_DUPOK);
1911 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
1919 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
1926 klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
1928 zone_lock_pair(zone, master);
1930 * zone must use vtoslab() to resolve objects and must already be
1933 if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
1934 != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
1939 * The new master must also use vtoslab().
1941 if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
1946 * Both must either be refcnt, or not be refcnt.
1948 if ((zone->uz_flags & UMA_ZONE_REFCNT) !=
1949 (master->uz_flags & UMA_ZONE_REFCNT)) {
1954 * The underlying object must be the same size. rsize
1957 if (master->uz_size != zone->uz_size) {
1962 * Put it at the end of the list.
1964 klink->kl_keg = zone_first_keg(master);
1965 LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
1966 if (LIST_NEXT(kl, kl_link) == NULL) {
1967 LIST_INSERT_AFTER(kl, klink, kl_link);
1972 zone->uz_flags |= UMA_ZFLAG_MULTI;
1973 zone->uz_slab = zone_fetch_slab_multi;
1976 zone_unlock_pair(zone, master);
1978 free(klink, M_TEMP);
1986 uma_zdestroy(uma_zone_t zone)
1989 zone_free_item(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
1994 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
1998 uma_bucket_t bucket;
2001 /* This is the fast path allocation */
2002 #ifdef UMA_DEBUG_ALLOC_1
2003 printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
2005 CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
2006 zone->uz_name, flags);
2008 if (flags & M_WAITOK) {
2009 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2010 "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2012 #ifdef DEBUG_MEMGUARD
2013 if (memguard_cmp_zone(zone)) {
2014 item = memguard_alloc(zone->uz_size, flags);
2017 * Avoid conflict with the use-after-free
2018 * protecting infrastructure from INVARIANTS.
2020 if (zone->uz_init != NULL &&
2021 zone->uz_init != mtrash_init &&
2022 zone->uz_init(item, zone->uz_size, flags) != 0)
2024 if (zone->uz_ctor != NULL &&
2025 zone->uz_ctor != mtrash_ctor &&
2026 zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2027 zone->uz_fini(item, zone->uz_size);
2032 /* This is unfortunate but should not be fatal. */
2036 * If possible, allocate from the per-CPU cache. There are two
2037 * requirements for safe access to the per-CPU cache: (1) the thread
2038 * accessing the cache must not be preempted or yield during access,
2039 * and (2) the thread must not migrate CPUs without switching which
2040 * cache it accesses. We rely on a critical section to prevent
2041 * preemption and migration. We release the critical section in
2042 * order to acquire the zone mutex if we are unable to allocate from
2043 * the current cache; when we re-acquire the critical section, we
2044 * must detect and handle migration if it has occurred.
2049 cache = &zone->uz_cpu[cpu];
2052 bucket = cache->uc_allocbucket;
2055 if (bucket->ub_cnt > 0) {
2057 item = bucket->ub_bucket[bucket->ub_cnt];
2059 bucket->ub_bucket[bucket->ub_cnt] = NULL;
2061 KASSERT(item != NULL,
2062 ("uma_zalloc: Bucket pointer mangled."));
2067 uma_dbg_alloc(zone, NULL, item);
2070 if (zone->uz_ctor != NULL) {
2071 if (zone->uz_ctor(item, zone->uz_size,
2072 udata, flags) != 0) {
2073 zone_free_item(zone, item, udata,
2074 SKIP_DTOR, ZFREE_STATFAIL |
2080 bzero(item, zone->uz_size);
2082 } else if (cache->uc_freebucket) {
2084 * We have run out of items in our allocbucket.
2085 * See if we can switch with our free bucket.
2087 if (cache->uc_freebucket->ub_cnt > 0) {
2088 #ifdef UMA_DEBUG_ALLOC
2089 printf("uma_zalloc: Swapping empty with"
2092 bucket = cache->uc_freebucket;
2093 cache->uc_freebucket = cache->uc_allocbucket;
2094 cache->uc_allocbucket = bucket;
2101 * Attempt to retrieve the item from the per-CPU cache has failed, so
2102 * we must go back to the zone. This requires the zone lock, so we
2103 * must drop the critical section, then re-acquire it when we go back
2104 * to the cache. Since the critical section is released, we may be
2105 * preempted or migrate. As such, make sure not to maintain any
2106 * thread-local state specific to the cache from prior to releasing
2107 * the critical section.
2113 cache = &zone->uz_cpu[cpu];
2114 bucket = cache->uc_allocbucket;
2115 if (bucket != NULL) {
2116 if (bucket->ub_cnt > 0) {
2120 bucket = cache->uc_freebucket;
2121 if (bucket != NULL && bucket->ub_cnt > 0) {
2127 /* Since we have locked the zone we may as well send back our stats */
2128 zone->uz_allocs += cache->uc_allocs;
2129 cache->uc_allocs = 0;
2130 zone->uz_frees += cache->uc_frees;
2131 cache->uc_frees = 0;
2133 /* Our old one is now a free bucket */
2134 if (cache->uc_allocbucket) {
2135 KASSERT(cache->uc_allocbucket->ub_cnt == 0,
2136 ("uma_zalloc_arg: Freeing a non free bucket."));
2137 LIST_INSERT_HEAD(&zone->uz_free_bucket,
2138 cache->uc_allocbucket, ub_link);
2139 cache->uc_allocbucket = NULL;
2142 /* Check the free list for a new alloc bucket */
2143 if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
2144 KASSERT(bucket->ub_cnt != 0,
2145 ("uma_zalloc_arg: Returning an empty bucket."));
2147 LIST_REMOVE(bucket, ub_link);
2148 cache->uc_allocbucket = bucket;
2152 /* We are no longer associated with this CPU. */
2155 /* Bump up our uz_count so we get here less */
2156 if (zone->uz_count < BUCKET_MAX)
2160 * Now lets just fill a bucket and put it on the free list. If that
2161 * works we'll restart the allocation from the begining.
2163 if (zone_alloc_bucket(zone, flags)) {
2165 goto zalloc_restart;
2169 * We may not be able to get a bucket so return an actual item.
2172 printf("uma_zalloc_arg: Bucketzone returned NULL\n");
2175 item = zone_alloc_item(zone, udata, flags);
2180 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
2184 mtx_assert(&keg->uk_lock, MA_OWNED);
2189 * Find a slab with some space. Prefer slabs that are partially
2190 * used over those that are totally full. This helps to reduce
2193 if (keg->uk_free != 0) {
2194 if (!LIST_EMPTY(&keg->uk_part_slab)) {
2195 slab = LIST_FIRST(&keg->uk_part_slab);
2197 slab = LIST_FIRST(&keg->uk_free_slab);
2198 LIST_REMOVE(slab, us_link);
2199 LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2202 MPASS(slab->us_keg == keg);
2207 * M_NOVM means don't ask at all!
2212 if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2213 keg->uk_flags |= UMA_ZFLAG_FULL;
2215 * If this is not a multi-zone, set the FULL bit.
2216 * Otherwise slab_multi() takes care of it.
2218 if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2219 zone->uz_flags |= UMA_ZFLAG_FULL;
2220 zone_log_warning(zone);
2222 if (flags & M_NOWAIT)
2225 msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2229 slab = keg_alloc_slab(keg, zone, flags);
2232 * If we got a slab here it's safe to mark it partially used
2233 * and return. We assume that the caller is going to remove
2234 * at least one item.
2237 MPASS(slab->us_keg == keg);
2238 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2242 * We might not have been able to get a slab but another cpu
2243 * could have while we were unlocked. Check again before we
2252 zone_relock(uma_zone_t zone, uma_keg_t keg)
2254 if (zone->uz_lock != &keg->uk_lock) {
2261 keg_relock(uma_keg_t keg, uma_zone_t zone)
2263 if (zone->uz_lock != &keg->uk_lock) {
2270 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
2275 keg = zone_first_keg(zone);
2277 * This is to prevent us from recursively trying to allocate
2278 * buckets. The problem is that if an allocation forces us to
2279 * grab a new bucket we will call page_alloc, which will go off
2280 * and cause the vm to allocate vm_map_entries. If we need new
2281 * buckets there too we will recurse in kmem_alloc and bad
2282 * things happen. So instead we return a NULL bucket, and make
2283 * the code that allocates buckets smart enough to deal with it
2285 if (keg->uk_flags & UMA_ZFLAG_BUCKET && keg->uk_recurse != 0)
2289 slab = keg_fetch_slab(keg, zone, flags);
2292 if (flags & (M_NOWAIT | M_NOVM))
2299 * uma_zone_fetch_slab_multi: Fetches a slab from one available keg. Returns
2300 * with the keg locked. Caller must call zone_relock() afterwards if the
2301 * zone lock is required. On NULL the zone lock is held.
2303 * The last pointer is used to seed the search. It is not required.
2306 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
2316 * Don't wait on the first pass. This will skip limit tests
2317 * as well. We don't want to block if we can find a provider
2320 flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2322 * Use the last slab allocated as a hint for where to start
2326 slab = keg_fetch_slab(last, zone, flags);
2329 zone_relock(zone, last);
2333 * Loop until we have a slab incase of transient failures
2334 * while M_WAITOK is specified. I'm not sure this is 100%
2335 * required but we've done it for so long now.
2341 * Search the available kegs for slabs. Be careful to hold the
2342 * correct lock while calling into the keg layer.
2344 LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2345 keg = klink->kl_keg;
2346 keg_relock(keg, zone);
2347 if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2348 slab = keg_fetch_slab(keg, zone, flags);
2352 if (keg->uk_flags & UMA_ZFLAG_FULL)
2356 zone_relock(zone, keg);
2358 if (rflags & (M_NOWAIT | M_NOVM))
2362 * All kegs are full. XXX We can't atomically check all kegs
2363 * and sleep so just sleep for a short period and retry.
2365 if (full && !empty) {
2366 zone->uz_flags |= UMA_ZFLAG_FULL;
2368 zone_log_warning(zone);
2369 msleep(zone, zone->uz_lock, PVM, "zonelimit", hz/100);
2370 zone->uz_flags &= ~UMA_ZFLAG_FULL;
2378 slab_alloc_item(uma_zone_t zone, uma_slab_t slab)
2381 uma_slabrefcnt_t slabref;
2386 mtx_assert(&keg->uk_lock, MA_OWNED);
2388 freei = slab->us_firstfree;
2389 if (keg->uk_flags & UMA_ZONE_REFCNT) {
2390 slabref = (uma_slabrefcnt_t)slab;
2391 slab->us_firstfree = slabref->us_freelist[freei].us_item;
2393 slab->us_firstfree = slab->us_freelist[freei].us_item;
2395 item = slab->us_data + (keg->uk_rsize * freei);
2397 slab->us_freecount--;
2400 uma_dbg_alloc(zone, slab, item);
2402 /* Move this slab to the full list */
2403 if (slab->us_freecount == 0) {
2404 LIST_REMOVE(slab, us_link);
2405 LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2412 zone_alloc_bucket(uma_zone_t zone, int flags)
2414 uma_bucket_t bucket;
2418 int max, origflags = flags;
2421 * Try this zone's free list first so we don't allocate extra buckets.
2423 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2424 KASSERT(bucket->ub_cnt == 0,
2425 ("zone_alloc_bucket: Bucket on free list is not empty."));
2426 LIST_REMOVE(bucket, ub_link);
2430 bflags = (flags & ~M_ZERO);
2431 if (zone->uz_flags & UMA_ZFLAG_CACHEONLY)
2435 bucket = bucket_alloc(zone->uz_count, bflags);
2439 if (bucket == NULL) {
2445 * This code is here to limit the number of simultaneous bucket fills
2446 * for any given zone to the number of per cpu caches in this zone. This
2447 * is done so that we don't allocate more memory than we really need.
2449 if (zone->uz_fills >= mp_ncpus)
2455 max = MIN(bucket->ub_entries, zone->uz_count);
2456 /* Try to keep the buckets totally full */
2457 saved = bucket->ub_cnt;
2460 while (bucket->ub_cnt < max &&
2461 (slab = zone->uz_slab(zone, keg, flags)) != NULL) {
2463 while (slab->us_freecount && bucket->ub_cnt < max) {
2464 bucket->ub_bucket[bucket->ub_cnt++] =
2465 slab_alloc_item(zone, slab);
2468 /* Don't block on the next fill */
2472 zone_relock(zone, keg);
2475 * We unlock here because we need to call the zone's init.
2476 * It should be safe to unlock because the slab dealt with
2477 * above is already on the appropriate list within the keg
2478 * and the bucket we filled is not yet on any list, so we
2481 if (zone->uz_init != NULL) {
2485 for (i = saved; i < bucket->ub_cnt; i++)
2486 if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2490 * If we couldn't initialize the whole bucket, put the
2491 * rest back onto the freelist.
2493 if (i != bucket->ub_cnt) {
2496 for (j = i; j < bucket->ub_cnt; j++) {
2497 zone_free_item(zone, bucket->ub_bucket[j],
2498 NULL, SKIP_FINI, 0);
2500 bucket->ub_bucket[j] = NULL;
2509 if (bucket->ub_cnt != 0) {
2510 LIST_INSERT_HEAD(&zone->uz_full_bucket,
2517 bucket_free(bucket);
2522 * Allocates an item for an internal zone
2525 * zone The zone to alloc for.
2526 * udata The data to be passed to the constructor.
2527 * flags M_WAITOK, M_NOWAIT, M_ZERO.
2530 * NULL if there is no memory and M_NOWAIT is set
2531 * An item if successful
2535 zone_alloc_item(uma_zone_t zone, void *udata, int flags)
2542 #ifdef UMA_DEBUG_ALLOC
2543 printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2547 slab = zone->uz_slab(zone, NULL, flags);
2554 item = slab_alloc_item(zone, slab);
2556 zone_relock(zone, slab->us_keg);
2561 * We have to call both the zone's init (not the keg's init)
2562 * and the zone's ctor. This is because the item is going from
2563 * a keg slab directly to the user, and the user is expecting it
2564 * to be both zone-init'd as well as zone-ctor'd.
2566 if (zone->uz_init != NULL) {
2567 if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2568 zone_free_item(zone, item, udata, SKIP_FINI,
2569 ZFREE_STATFAIL | ZFREE_STATFREE);
2573 if (zone->uz_ctor != NULL) {
2574 if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2575 zone_free_item(zone, item, udata, SKIP_DTOR,
2576 ZFREE_STATFAIL | ZFREE_STATFREE);
2581 bzero(item, zone->uz_size);
2588 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2591 uma_bucket_t bucket;
2595 #ifdef UMA_DEBUG_ALLOC_1
2596 printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2598 CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2601 /* uma_zfree(..., NULL) does nothing, to match free(9). */
2604 #ifdef DEBUG_MEMGUARD
2605 if (is_memguard_addr(item)) {
2606 if (zone->uz_dtor != NULL && zone->uz_dtor != mtrash_dtor)
2607 zone->uz_dtor(item, zone->uz_size, udata);
2608 if (zone->uz_fini != NULL && zone->uz_fini != mtrash_fini)
2609 zone->uz_fini(item, zone->uz_size);
2610 memguard_free(item);
2615 zone->uz_dtor(item, zone->uz_size, udata);
2619 if (zone->uz_flags & UMA_ZONE_MALLOC)
2620 uma_dbg_free(zone, udata, item);
2622 uma_dbg_free(zone, NULL, item);
2626 * The race here is acceptable. If we miss it we'll just have to wait
2627 * a little longer for the limits to be reset.
2629 if (zone->uz_flags & UMA_ZFLAG_FULL)
2630 goto zfree_internal;
2633 * If possible, free to the per-CPU cache. There are two
2634 * requirements for safe access to the per-CPU cache: (1) the thread
2635 * accessing the cache must not be preempted or yield during access,
2636 * and (2) the thread must not migrate CPUs without switching which
2637 * cache it accesses. We rely on a critical section to prevent
2638 * preemption and migration. We release the critical section in
2639 * order to acquire the zone mutex if we are unable to free to the
2640 * current cache; when we re-acquire the critical section, we must
2641 * detect and handle migration if it has occurred.
2646 cache = &zone->uz_cpu[cpu];
2649 bucket = cache->uc_freebucket;
2653 * Do we have room in our bucket? It is OK for this uz count
2654 * check to be slightly out of sync.
2657 if (bucket->ub_cnt < bucket->ub_entries) {
2658 KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2659 ("uma_zfree: Freeing to non free bucket index."));
2660 bucket->ub_bucket[bucket->ub_cnt] = item;
2665 } else if (cache->uc_allocbucket) {
2666 #ifdef UMA_DEBUG_ALLOC
2667 printf("uma_zfree: Swapping buckets.\n");
2670 * We have run out of space in our freebucket.
2671 * See if we can switch with our alloc bucket.
2673 if (cache->uc_allocbucket->ub_cnt <
2674 cache->uc_freebucket->ub_cnt) {
2675 bucket = cache->uc_freebucket;
2676 cache->uc_freebucket = cache->uc_allocbucket;
2677 cache->uc_allocbucket = bucket;
2683 * We can get here for two reasons:
2685 * 1) The buckets are NULL
2686 * 2) The alloc and free buckets are both somewhat full.
2688 * We must go back the zone, which requires acquiring the zone lock,
2689 * which in turn means we must release and re-acquire the critical
2690 * section. Since the critical section is released, we may be
2691 * preempted or migrate. As such, make sure not to maintain any
2692 * thread-local state specific to the cache from prior to releasing
2693 * the critical section.
2699 cache = &zone->uz_cpu[cpu];
2700 if (cache->uc_freebucket != NULL) {
2701 if (cache->uc_freebucket->ub_cnt <
2702 cache->uc_freebucket->ub_entries) {
2706 if (cache->uc_allocbucket != NULL &&
2707 (cache->uc_allocbucket->ub_cnt <
2708 cache->uc_freebucket->ub_cnt)) {
2714 /* Since we have locked the zone we may as well send back our stats */
2715 zone->uz_allocs += cache->uc_allocs;
2716 cache->uc_allocs = 0;
2717 zone->uz_frees += cache->uc_frees;
2718 cache->uc_frees = 0;
2720 bucket = cache->uc_freebucket;
2721 cache->uc_freebucket = NULL;
2723 /* Can we throw this on the zone full list? */
2724 if (bucket != NULL) {
2725 #ifdef UMA_DEBUG_ALLOC
2726 printf("uma_zfree: Putting old bucket on the free list.\n");
2728 /* ub_cnt is pointing to the last free item */
2729 KASSERT(bucket->ub_cnt != 0,
2730 ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2731 LIST_INSERT_HEAD(&zone->uz_full_bucket,
2734 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2735 LIST_REMOVE(bucket, ub_link);
2737 cache->uc_freebucket = bucket;
2740 /* We are no longer associated with this CPU. */
2743 /* And the zone.. */
2746 #ifdef UMA_DEBUG_ALLOC
2747 printf("uma_zfree: Allocating new free bucket.\n");
2751 if (zone->uz_flags & UMA_ZFLAG_CACHEONLY)
2753 bucket = bucket_alloc(zone->uz_count, bflags);
2756 LIST_INSERT_HEAD(&zone->uz_free_bucket,
2763 * If nothing else caught this, we'll just do an internal free.
2766 zone_free_item(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
2772 * Frees an item to an INTERNAL zone or allocates a free bucket
2775 * zone The zone to free to
2776 * item The item we're freeing
2777 * udata User supplied data for the dtor
2778 * skip Skip dtors and finis
2781 zone_free_item(uma_zone_t zone, void *item, void *udata,
2782 enum zfreeskip skip, int flags)
2785 uma_slabrefcnt_t slabref;
2791 if (skip < SKIP_DTOR && zone->uz_dtor)
2792 zone->uz_dtor(item, zone->uz_size, udata);
2794 if (skip < SKIP_FINI && zone->uz_fini)
2795 zone->uz_fini(item, zone->uz_size);
2799 if (flags & ZFREE_STATFAIL)
2801 if (flags & ZFREE_STATFREE)
2804 if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
2805 mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
2806 keg = zone_first_keg(zone); /* Must only be one. */
2807 if (zone->uz_flags & UMA_ZONE_HASH) {
2808 slab = hash_sfind(&keg->uk_hash, mem);
2810 mem += keg->uk_pgoff;
2811 slab = (uma_slab_t)mem;
2814 /* This prevents redundant lookups via free(). */
2815 if ((zone->uz_flags & UMA_ZONE_MALLOC) && udata != NULL)
2816 slab = (uma_slab_t)udata;
2818 slab = vtoslab((vm_offset_t)item);
2820 keg_relock(keg, zone);
2822 MPASS(keg == slab->us_keg);
2824 /* Do we need to remove from any lists? */
2825 if (slab->us_freecount+1 == keg->uk_ipers) {
2826 LIST_REMOVE(slab, us_link);
2827 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2828 } else if (slab->us_freecount == 0) {
2829 LIST_REMOVE(slab, us_link);
2830 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2833 /* Slab management stuff */
2834 freei = ((unsigned long)item - (unsigned long)slab->us_data)
2839 uma_dbg_free(zone, slab, item);
2842 if (keg->uk_flags & UMA_ZONE_REFCNT) {
2843 slabref = (uma_slabrefcnt_t)slab;
2844 slabref->us_freelist[freei].us_item = slab->us_firstfree;
2846 slab->us_freelist[freei].us_item = slab->us_firstfree;
2848 slab->us_firstfree = freei;
2849 slab->us_freecount++;
2851 /* Zone statistics */
2855 if (keg->uk_flags & UMA_ZFLAG_FULL) {
2856 if (keg->uk_pages < keg->uk_maxpages) {
2857 keg->uk_flags &= ~UMA_ZFLAG_FULL;
2862 * We can handle one more allocation. Since we're clearing ZFLAG_FULL,
2863 * wake up all procs blocked on pages. This should be uncommon, so
2864 * keeping this simple for now (rather than adding count of blocked
2870 zone_relock(zone, keg);
2871 zone->uz_flags &= ~UMA_ZFLAG_FULL;
2880 uma_zone_set_max(uma_zone_t zone, int nitems)
2885 keg = zone_first_keg(zone);
2886 keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
2887 if (keg->uk_maxpages * keg->uk_ipers < nitems)
2888 keg->uk_maxpages += keg->uk_ppera;
2889 nitems = keg->uk_maxpages * keg->uk_ipers;
2897 uma_zone_get_max(uma_zone_t zone)
2903 keg = zone_first_keg(zone);
2904 nitems = keg->uk_maxpages * keg->uk_ipers;
2912 uma_zone_set_warning(uma_zone_t zone, const char *warning)
2916 zone->uz_warning = warning;
2922 uma_zone_get_cur(uma_zone_t zone)
2928 nitems = zone->uz_allocs - zone->uz_frees;
2931 * See the comment in sysctl_vm_zone_stats() regarding the
2932 * safety of accessing the per-cpu caches. With the zone lock
2933 * held, it is safe, but can potentially result in stale data.
2935 nitems += zone->uz_cpu[i].uc_allocs -
2936 zone->uz_cpu[i].uc_frees;
2940 return (nitems < 0 ? 0 : nitems);
2945 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2950 keg = zone_first_keg(zone);
2951 KASSERT(keg->uk_pages == 0,
2952 ("uma_zone_set_init on non-empty keg"));
2953 keg->uk_init = uminit;
2959 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2964 keg = zone_first_keg(zone);
2965 KASSERT(keg->uk_pages == 0,
2966 ("uma_zone_set_fini on non-empty keg"));
2967 keg->uk_fini = fini;
2973 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
2976 KASSERT(zone_first_keg(zone)->uk_pages == 0,
2977 ("uma_zone_set_zinit on non-empty keg"));
2978 zone->uz_init = zinit;
2984 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
2987 KASSERT(zone_first_keg(zone)->uk_pages == 0,
2988 ("uma_zone_set_zfini on non-empty keg"));
2989 zone->uz_fini = zfini;
2994 /* XXX uk_freef is not actually used with the zone locked */
2996 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3000 zone_first_keg(zone)->uk_freef = freef;
3005 /* XXX uk_allocf is not actually used with the zone locked */
3007 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3012 keg = zone_first_keg(zone);
3013 keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
3014 keg->uk_allocf = allocf;
3020 uma_zone_reserve_kva(uma_zone_t zone, int count)
3026 keg = zone_first_keg(zone);
3027 pages = count / keg->uk_ipers;
3029 if (pages * keg->uk_ipers < count)
3032 #ifdef UMA_MD_SMALL_ALLOC
3033 if (keg->uk_ppera > 1) {
3037 kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
3045 keg->uk_maxpages = pages;
3046 #ifdef UMA_MD_SMALL_ALLOC
3047 keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3049 keg->uk_allocf = noobj_alloc;
3051 keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
3058 uma_prealloc(uma_zone_t zone, int items)
3064 keg = zone_first_keg(zone);
3066 slabs = items / keg->uk_ipers;
3067 if (slabs * keg->uk_ipers < items)
3070 slab = keg_alloc_slab(keg, zone, M_WAITOK);
3073 MPASS(slab->us_keg == keg);
3074 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
3082 uma_find_refcnt(uma_zone_t zone, void *item)
3084 uma_slabrefcnt_t slabref;
3089 slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
3091 keg = slabref->us_keg;
3092 KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
3093 ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
3094 idx = ((unsigned long)item - (unsigned long)slabref->us_data)
3096 refcnt = &slabref->us_freelist[idx].us_refcnt;
3105 printf("UMA: vm asked us to release pages!\n");
3108 zone_foreach(zone_drain);
3110 * Some slabs may have been freed but this zone will be visited early
3111 * we visit again so that we can free pages that are empty once other
3112 * zones are drained. We have to do the same for buckets.
3114 zone_drain(slabzone);
3115 zone_drain(slabrefzone);
3116 bucket_zone_drain();
3121 uma_zone_exhausted(uma_zone_t zone)
3126 full = (zone->uz_flags & UMA_ZFLAG_FULL);
3132 uma_zone_exhausted_nolock(uma_zone_t zone)
3134 return (zone->uz_flags & UMA_ZFLAG_FULL);
3138 uma_large_malloc(int size, int wait)
3144 slab = zone_alloc_item(slabzone, NULL, wait);
3147 mem = page_alloc(NULL, size, &flags, wait);
3149 vsetslab((vm_offset_t)mem, slab);
3150 slab->us_data = mem;
3151 slab->us_flags = flags | UMA_SLAB_MALLOC;
3152 slab->us_size = size;
3154 zone_free_item(slabzone, slab, NULL, SKIP_NONE,
3155 ZFREE_STATFAIL | ZFREE_STATFREE);
3162 uma_large_free(uma_slab_t slab)
3164 vsetobj((vm_offset_t)slab->us_data, kmem_object);
3165 page_free(slab->us_data, slab->us_size, slab->us_flags);
3166 zone_free_item(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
3170 uma_print_stats(void)
3172 zone_foreach(uma_print_zone);
3176 slab_print(uma_slab_t slab)
3178 printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
3179 slab->us_keg, slab->us_data, slab->us_freecount,
3180 slab->us_firstfree);
3184 cache_print(uma_cache_t cache)
3186 printf("alloc: %p(%d), free: %p(%d)\n",
3187 cache->uc_allocbucket,
3188 cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3189 cache->uc_freebucket,
3190 cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3194 uma_print_keg(uma_keg_t keg)
3198 printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3199 "out %d free %d limit %d\n",
3200 keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3201 keg->uk_ipers, keg->uk_ppera,
3202 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free,
3203 (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3204 printf("Part slabs:\n");
3205 LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
3207 printf("Free slabs:\n");
3208 LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
3210 printf("Full slabs:\n");
3211 LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
3216 uma_print_zone(uma_zone_t zone)
3222 printf("zone: %s(%p) size %d flags %#x\n",
3223 zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3224 LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3225 uma_print_keg(kl->kl_keg);
3227 cache = &zone->uz_cpu[i];
3228 printf("CPU %d Cache:\n", i);
3235 * Generate statistics across both the zone and its per-cpu cache's. Return
3236 * desired statistics if the pointer is non-NULL for that statistic.
3238 * Note: does not update the zone statistics, as it can't safely clear the
3239 * per-CPU cache statistic.
3241 * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3242 * safe from off-CPU; we should modify the caches to track this information
3243 * directly so that we don't have to.
3246 uma_zone_sumstat(uma_zone_t z, int *cachefreep, u_int64_t *allocsp,
3247 u_int64_t *freesp, u_int64_t *sleepsp)
3250 u_int64_t allocs, frees, sleeps;
3253 allocs = frees = sleeps = 0;
3256 cache = &z->uz_cpu[cpu];
3257 if (cache->uc_allocbucket != NULL)
3258 cachefree += cache->uc_allocbucket->ub_cnt;
3259 if (cache->uc_freebucket != NULL)
3260 cachefree += cache->uc_freebucket->ub_cnt;
3261 allocs += cache->uc_allocs;
3262 frees += cache->uc_frees;
3264 allocs += z->uz_allocs;
3265 frees += z->uz_frees;
3266 sleeps += z->uz_sleeps;
3267 if (cachefreep != NULL)
3268 *cachefreep = cachefree;
3269 if (allocsp != NULL)
3273 if (sleepsp != NULL)
3279 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3287 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3288 LIST_FOREACH(z, &kz->uk_zones, uz_link)
3291 mtx_unlock(&uma_mtx);
3292 return (sysctl_handle_int(oidp, &count, 0, req));
3296 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3298 struct uma_stream_header ush;
3299 struct uma_type_header uth;
3300 struct uma_percpu_stat ups;
3301 uma_bucket_t bucket;
3308 int count, error, i;
3310 error = sysctl_wire_old_buffer(req, 0);
3313 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3317 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3318 LIST_FOREACH(z, &kz->uk_zones, uz_link)
3323 * Insert stream header.
3325 bzero(&ush, sizeof(ush));
3326 ush.ush_version = UMA_STREAM_VERSION;
3327 ush.ush_maxcpus = (mp_maxid + 1);
3328 ush.ush_count = count;
3329 (void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3331 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3332 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3333 bzero(&uth, sizeof(uth));
3335 strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3336 uth.uth_align = kz->uk_align;
3337 uth.uth_size = kz->uk_size;
3338 uth.uth_rsize = kz->uk_rsize;
3339 LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3341 uth.uth_maxpages += k->uk_maxpages;
3342 uth.uth_pages += k->uk_pages;
3343 uth.uth_keg_free += k->uk_free;
3344 uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3349 * A zone is secondary is it is not the first entry
3350 * on the keg's zone list.
3352 if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3353 (LIST_FIRST(&kz->uk_zones) != z))
3354 uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3356 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3357 uth.uth_zone_free += bucket->ub_cnt;
3358 uth.uth_allocs = z->uz_allocs;
3359 uth.uth_frees = z->uz_frees;
3360 uth.uth_fails = z->uz_fails;
3361 uth.uth_sleeps = z->uz_sleeps;
3362 (void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3364 * While it is not normally safe to access the cache
3365 * bucket pointers while not on the CPU that owns the
3366 * cache, we only allow the pointers to be exchanged
3367 * without the zone lock held, not invalidated, so
3368 * accept the possible race associated with bucket
3369 * exchange during monitoring.
3371 for (i = 0; i < (mp_maxid + 1); i++) {
3372 bzero(&ups, sizeof(ups));
3373 if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3377 cache = &z->uz_cpu[i];
3378 if (cache->uc_allocbucket != NULL)
3379 ups.ups_cache_free +=
3380 cache->uc_allocbucket->ub_cnt;
3381 if (cache->uc_freebucket != NULL)
3382 ups.ups_cache_free +=
3383 cache->uc_freebucket->ub_cnt;
3384 ups.ups_allocs = cache->uc_allocs;
3385 ups.ups_frees = cache->uc_frees;
3387 (void)sbuf_bcat(&sbuf, &ups, sizeof(ups));
3392 mtx_unlock(&uma_mtx);
3393 error = sbuf_finish(&sbuf);
3399 DB_SHOW_COMMAND(uma, db_show_uma)
3401 u_int64_t allocs, frees, sleeps;
3402 uma_bucket_t bucket;
3407 db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3408 "Requests", "Sleeps");
3409 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3410 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3411 if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3412 allocs = z->uz_allocs;
3413 frees = z->uz_frees;
3414 sleeps = z->uz_sleeps;
3417 uma_zone_sumstat(z, &cachefree, &allocs,
3419 if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3420 (LIST_FIRST(&kz->uk_zones) != z)))
3421 cachefree += kz->uk_free;
3422 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3423 cachefree += bucket->ub_cnt;
3424 db_printf("%18s %8ju %8jd %8d %12ju %8ju\n", z->uz_name,
3425 (uintmax_t)kz->uk_size,
3426 (intmax_t)(allocs - frees), cachefree,
3427 (uintmax_t)allocs, sleeps);