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, uint8_t *, int);
219 static void *page_alloc(uma_zone_t, int, uint8_t *, int);
220 static void *startup_alloc(uma_zone_t, int, uint8_t *, int);
221 static void page_free(void *, int, uint8_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, uint32_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, PAGE_SIZE * keg->uk_ppera);
770 keg->uk_freef(mem, PAGE_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 * PAGE_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, PAGE_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, uint8_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, uint8_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, uint8_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, uint8_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 if (keg->uk_flags & UMA_ZONE_PCPU) {
1142 keg->uk_slabsize = sizeof(struct pcpu);
1143 keg->uk_ppera = howmany(mp_ncpus * sizeof(struct pcpu),
1146 keg->uk_slabsize = UMA_SLAB_SIZE;
1150 rsize = keg->uk_size;
1152 if (rsize & keg->uk_align)
1153 rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1154 if (rsize < keg->uk_slabsize / 256)
1155 rsize = keg->uk_slabsize / 256;
1157 keg->uk_rsize = rsize;
1159 KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1160 keg->uk_rsize < sizeof(struct pcpu),
1161 ("%s: size %u too large", __func__, keg->uk_rsize));
1163 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1165 } else if (keg->uk_flags & UMA_ZONE_REFCNT) {
1166 rsize += UMA_FRITMREF_SZ; /* linkage & refcnt */
1167 shsize = sizeof(struct uma_slab_refcnt);
1169 rsize += UMA_FRITM_SZ; /* Account for linkage */
1170 shsize = sizeof(struct uma_slab);
1173 keg->uk_ipers = (keg->uk_slabsize - shsize) / rsize;
1174 KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= 256,
1175 ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1177 memused = keg->uk_ipers * rsize + shsize;
1178 wastedspace = keg->uk_slabsize - memused;
1181 * We can't do OFFPAGE if we're internal or if we've been
1182 * asked to not go to the VM for buckets. If we do this we
1183 * may end up going to the VM (kmem_map) for slabs which we
1184 * do not want to do if we're UMA_ZFLAG_CACHEONLY as a
1185 * result of UMA_ZONE_VM, which clearly forbids it.
1187 if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1188 (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1191 if ((wastedspace >= keg->uk_slabsize / UMA_MAX_WASTE) &&
1192 (keg->uk_ipers < (keg->uk_slabsize / keg->uk_rsize))) {
1193 keg->uk_ipers = keg->uk_slabsize / keg->uk_rsize;
1194 KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= 256,
1195 ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1197 printf("UMA decided we need offpage slab headers for "
1198 "keg: %s, calculated wastedspace = %d, "
1199 "maximum wasted space allowed = %d, "
1200 "calculated ipers = %d, "
1201 "new wasted space = %d\n", keg->uk_name, wastedspace,
1202 keg->uk_slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1203 keg->uk_slabsize - keg->uk_ipers * keg->uk_rsize);
1205 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1208 if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1209 (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1210 keg->uk_flags |= UMA_ZONE_HASH;
1214 * Finish creating a large (> UMA_SLAB_SIZE) uma kegs. Just give in and do
1215 * OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
1219 * keg The keg we should initialize
1225 keg_large_init(uma_keg_t keg)
1228 KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1229 KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1230 ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1231 KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1232 ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1234 keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1235 keg->uk_slabsize = keg->uk_ppera * PAGE_SIZE;
1237 keg->uk_rsize = keg->uk_size;
1239 /* We can't do OFFPAGE if we're internal, bail out here. */
1240 if (keg->uk_flags & UMA_ZFLAG_INTERNAL)
1243 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1244 if ((keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1245 keg->uk_flags |= UMA_ZONE_HASH;
1249 keg_cachespread_init(uma_keg_t keg)
1256 KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1257 ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1259 alignsize = keg->uk_align + 1;
1260 rsize = keg->uk_size;
1262 * We want one item to start on every align boundary in a page. To
1263 * do this we will span pages. We will also extend the item by the
1264 * size of align if it is an even multiple of align. Otherwise, it
1265 * would fall on the same boundary every time.
1267 if (rsize & keg->uk_align)
1268 rsize = (rsize & ~keg->uk_align) + alignsize;
1269 if ((rsize & alignsize) == 0)
1271 trailer = rsize - keg->uk_size;
1272 pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1273 pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1274 keg->uk_rsize = rsize;
1275 keg->uk_ppera = pages;
1276 keg->uk_slabsize = UMA_SLAB_SIZE;
1277 keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1278 keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1279 KASSERT(keg->uk_ipers <= uma_max_ipers,
1280 ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1285 * Keg header ctor. This initializes all fields, locks, etc. And inserts
1286 * the keg onto the global keg list.
1288 * Arguments/Returns follow uma_ctor specifications
1289 * udata Actually uma_kctor_args
1292 keg_ctor(void *mem, int size, void *udata, int flags)
1294 struct uma_kctor_args *arg = udata;
1295 uma_keg_t keg = mem;
1299 keg->uk_size = arg->size;
1300 keg->uk_init = arg->uminit;
1301 keg->uk_fini = arg->fini;
1302 keg->uk_align = arg->align;
1305 keg->uk_flags = arg->flags;
1306 keg->uk_allocf = page_alloc;
1307 keg->uk_freef = page_free;
1308 keg->uk_recurse = 0;
1309 keg->uk_slabzone = NULL;
1312 * The master zone is passed to us at keg-creation time.
1315 keg->uk_name = zone->uz_name;
1317 if (arg->flags & UMA_ZONE_VM)
1318 keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1320 if (arg->flags & UMA_ZONE_ZINIT)
1321 keg->uk_init = zero_init;
1323 if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC)
1324 keg->uk_flags |= UMA_ZONE_VTOSLAB;
1326 if (arg->flags & UMA_ZONE_PCPU)
1328 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1330 keg->uk_flags &= ~UMA_ZONE_PCPU;
1334 * The +UMA_FRITM_SZ added to uk_size is to account for the
1335 * linkage that is added to the size in keg_small_init(). If
1336 * we don't account for this here then we may end up in
1337 * keg_small_init() with a calculated 'ipers' of 0.
1339 if (keg->uk_flags & UMA_ZONE_REFCNT) {
1340 if (keg->uk_flags & UMA_ZONE_CACHESPREAD)
1341 keg_cachespread_init(keg);
1342 else if ((keg->uk_size+UMA_FRITMREF_SZ) >
1343 (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)))
1344 keg_large_init(keg);
1346 keg_small_init(keg);
1348 if (keg->uk_flags & UMA_ZONE_CACHESPREAD)
1349 keg_cachespread_init(keg);
1350 else if ((keg->uk_size+UMA_FRITM_SZ) >
1351 (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1352 keg_large_init(keg);
1354 keg_small_init(keg);
1357 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1358 if (keg->uk_flags & UMA_ZONE_REFCNT)
1359 keg->uk_slabzone = slabrefzone;
1361 keg->uk_slabzone = slabzone;
1365 * If we haven't booted yet we need allocations to go through the
1366 * startup cache until the vm is ready.
1368 if (keg->uk_ppera == 1) {
1369 #ifdef UMA_MD_SMALL_ALLOC
1370 keg->uk_allocf = uma_small_alloc;
1371 keg->uk_freef = uma_small_free;
1373 if (booted < UMA_STARTUP)
1374 keg->uk_allocf = startup_alloc;
1376 if (booted < UMA_STARTUP2)
1377 keg->uk_allocf = startup_alloc;
1379 } else if (booted < UMA_STARTUP2 &&
1380 (keg->uk_flags & UMA_ZFLAG_INTERNAL))
1381 keg->uk_allocf = startup_alloc;
1384 * Initialize keg's lock (shared among zones).
1386 if (arg->flags & UMA_ZONE_MTXCLASS)
1387 KEG_LOCK_INIT(keg, 1);
1389 KEG_LOCK_INIT(keg, 0);
1392 * If we're putting the slab header in the actual page we need to
1393 * figure out where in each page it goes. This calculates a right
1394 * justified offset into the memory on an ALIGN_PTR boundary.
1396 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1399 /* Size of the slab struct and free list */
1400 if (keg->uk_flags & UMA_ZONE_REFCNT)
1401 totsize = sizeof(struct uma_slab_refcnt) +
1402 keg->uk_ipers * UMA_FRITMREF_SZ;
1404 totsize = sizeof(struct uma_slab) +
1405 keg->uk_ipers * UMA_FRITM_SZ;
1407 if (totsize & UMA_ALIGN_PTR)
1408 totsize = (totsize & ~UMA_ALIGN_PTR) +
1409 (UMA_ALIGN_PTR + 1);
1410 keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
1412 if (keg->uk_flags & UMA_ZONE_REFCNT)
1413 totsize = keg->uk_pgoff + sizeof(struct uma_slab_refcnt)
1414 + keg->uk_ipers * UMA_FRITMREF_SZ;
1416 totsize = keg->uk_pgoff + sizeof(struct uma_slab)
1417 + keg->uk_ipers * UMA_FRITM_SZ;
1420 * The only way the following is possible is if with our
1421 * UMA_ALIGN_PTR adjustments we are now bigger than
1422 * UMA_SLAB_SIZE. I haven't checked whether this is
1423 * mathematically possible for all cases, so we make
1426 if (totsize > PAGE_SIZE * keg->uk_ppera) {
1427 printf("zone %s ipers %d rsize %d size %d\n",
1428 zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1430 panic("UMA slab won't fit.");
1434 if (keg->uk_flags & UMA_ZONE_HASH)
1435 hash_alloc(&keg->uk_hash);
1438 printf("UMA: %s(%p) size %d(%d) flags %#x ipers %d ppera %d out %d free %d\n",
1439 zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
1440 keg->uk_ipers, keg->uk_ppera,
1441 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
1444 LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1447 LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1448 mtx_unlock(&uma_mtx);
1453 * Zone header ctor. This initializes all fields, locks, etc.
1455 * Arguments/Returns follow uma_ctor specifications
1456 * udata Actually uma_zctor_args
1459 zone_ctor(void *mem, int size, void *udata, int flags)
1461 struct uma_zctor_args *arg = udata;
1462 uma_zone_t zone = mem;
1467 zone->uz_name = arg->name;
1468 zone->uz_ctor = arg->ctor;
1469 zone->uz_dtor = arg->dtor;
1470 zone->uz_slab = zone_fetch_slab;
1471 zone->uz_init = NULL;
1472 zone->uz_fini = NULL;
1473 zone->uz_allocs = 0;
1476 zone->uz_sleeps = 0;
1477 zone->uz_fills = zone->uz_count = 0;
1479 zone->uz_warning = NULL;
1480 timevalclear(&zone->uz_ratecheck);
1483 if (arg->flags & UMA_ZONE_SECONDARY) {
1484 KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1485 zone->uz_init = arg->uminit;
1486 zone->uz_fini = arg->fini;
1487 zone->uz_lock = &keg->uk_lock;
1488 zone->uz_flags |= UMA_ZONE_SECONDARY;
1491 LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1492 if (LIST_NEXT(z, uz_link) == NULL) {
1493 LIST_INSERT_AFTER(z, zone, uz_link);
1498 mtx_unlock(&uma_mtx);
1499 } else if (keg == NULL) {
1500 if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1501 arg->align, arg->flags)) == NULL)
1504 struct uma_kctor_args karg;
1507 /* We should only be here from uma_startup() */
1508 karg.size = arg->size;
1509 karg.uminit = arg->uminit;
1510 karg.fini = arg->fini;
1511 karg.align = arg->align;
1512 karg.flags = arg->flags;
1514 error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1520 * Link in the first keg.
1522 zone->uz_klink.kl_keg = keg;
1523 LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1524 zone->uz_lock = &keg->uk_lock;
1525 zone->uz_size = keg->uk_size;
1526 zone->uz_flags |= (keg->uk_flags &
1527 (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1530 * Some internal zones don't have room allocated for the per cpu
1531 * caches. If we're internal, bail out here.
1533 if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1534 KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1535 ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1539 if (keg->uk_flags & UMA_ZONE_MAXBUCKET)
1540 zone->uz_count = BUCKET_MAX;
1541 else if (keg->uk_ipers <= BUCKET_MAX)
1542 zone->uz_count = keg->uk_ipers;
1544 zone->uz_count = BUCKET_MAX;
1549 * Keg header dtor. This frees all data, destroys locks, frees the hash
1550 * table and removes the keg from the global list.
1552 * Arguments/Returns follow uma_dtor specifications
1556 keg_dtor(void *arg, int size, void *udata)
1560 keg = (uma_keg_t)arg;
1562 if (keg->uk_free != 0) {
1563 printf("Freed UMA keg was not empty (%d items). "
1564 " Lost %d pages of memory.\n",
1565 keg->uk_free, keg->uk_pages);
1569 hash_free(&keg->uk_hash);
1577 * Arguments/Returns follow uma_dtor specifications
1581 zone_dtor(void *arg, int size, void *udata)
1587 zone = (uma_zone_t)arg;
1588 keg = zone_first_keg(zone);
1590 if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1594 LIST_REMOVE(zone, uz_link);
1595 mtx_unlock(&uma_mtx);
1597 * XXX there are some races here where
1598 * the zone can be drained but zone lock
1599 * released and then refilled before we
1600 * remove it... we dont care for now
1602 zone_drain_wait(zone, M_WAITOK);
1604 * Unlink all of our kegs.
1606 while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1607 klink->kl_keg = NULL;
1608 LIST_REMOVE(klink, kl_link);
1609 if (klink == &zone->uz_klink)
1611 free(klink, M_TEMP);
1614 * We only destroy kegs from non secondary zones.
1616 if ((zone->uz_flags & UMA_ZONE_SECONDARY) == 0) {
1618 LIST_REMOVE(keg, uk_link);
1619 mtx_unlock(&uma_mtx);
1620 zone_free_item(kegs, keg, NULL, SKIP_NONE,
1626 * Traverses every zone in the system and calls a callback
1629 * zfunc A pointer to a function which accepts a zone
1636 zone_foreach(void (*zfunc)(uma_zone_t))
1642 LIST_FOREACH(keg, &uma_kegs, uk_link) {
1643 LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1646 mtx_unlock(&uma_mtx);
1649 /* Public functions */
1652 uma_startup(void *bootmem, int boot_pages)
1654 struct uma_zctor_args args;
1657 u_int objsize, totsize, wsize;
1661 printf("Creating uma keg headers zone and keg.\n");
1663 mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1666 * Figure out the maximum number of items-per-slab we'll have if
1667 * we're using the OFFPAGE slab header to track free items, given
1668 * all possible object sizes and the maximum desired wastage
1671 * We iterate until we find an object size for
1672 * which the calculated wastage in keg_small_init() will be
1673 * enough to warrant OFFPAGE. Since wastedspace versus objsize
1674 * is an overall increasing see-saw function, we find the smallest
1675 * objsize such that the wastage is always acceptable for objects
1676 * with that objsize or smaller. Since a smaller objsize always
1677 * generates a larger possible uma_max_ipers, we use this computed
1678 * objsize to calculate the largest ipers possible. Since the
1679 * ipers calculated for OFFPAGE slab headers is always larger than
1680 * the ipers initially calculated in keg_small_init(), we use
1681 * the former's equation (UMA_SLAB_SIZE / keg->uk_rsize) to
1682 * obtain the maximum ipers possible for offpage slab headers.
1684 * It should be noted that ipers versus objsize is an inversly
1685 * proportional function which drops off rather quickly so as
1686 * long as our UMA_MAX_WASTE is such that the objsize we calculate
1687 * falls into the portion of the inverse relation AFTER the steep
1688 * falloff, then uma_max_ipers shouldn't be too high (~10 on i386).
1690 * Note that we have 8-bits (1 byte) to use as a freelist index
1691 * inside the actual slab header itself and this is enough to
1692 * accomodate us. In the worst case, a UMA_SMALLEST_UNIT sized
1693 * object with offpage slab header would have ipers =
1694 * UMA_SLAB_SIZE / UMA_SMALLEST_UNIT (currently = 256), which is
1695 * 1 greater than what our byte-integer freelist index can
1696 * accomodate, but we know that this situation never occurs as
1697 * for UMA_SMALLEST_UNIT-sized objects, we will never calculate
1698 * that we need to go to offpage slab headers. Or, if we do,
1699 * then we trap that condition below and panic in the INVARIANTS case.
1701 wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab) -
1702 (UMA_SLAB_SIZE / UMA_MAX_WASTE);
1704 objsize = UMA_SMALLEST_UNIT;
1705 while (totsize >= wsize) {
1706 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab)) /
1707 (objsize + UMA_FRITM_SZ);
1708 totsize *= (UMA_FRITM_SZ + objsize);
1711 if (objsize > UMA_SMALLEST_UNIT)
1713 uma_max_ipers = MAX(UMA_SLAB_SIZE / objsize, 64);
1715 wsize = UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) -
1716 (UMA_SLAB_SIZE / UMA_MAX_WASTE);
1718 objsize = UMA_SMALLEST_UNIT;
1719 while (totsize >= wsize) {
1720 totsize = (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt)) /
1721 (objsize + UMA_FRITMREF_SZ);
1722 totsize *= (UMA_FRITMREF_SZ + objsize);
1725 if (objsize > UMA_SMALLEST_UNIT)
1727 uma_max_ipers_ref = MAX(UMA_SLAB_SIZE / objsize, 64);
1729 KASSERT((uma_max_ipers_ref <= 256) && (uma_max_ipers <= 256),
1730 ("uma_startup: calculated uma_max_ipers values too large!"));
1733 printf("Calculated uma_max_ipers (for OFFPAGE) is %d\n", uma_max_ipers);
1734 printf("Calculated uma_max_ipers_ref (for OFFPAGE) is %d\n",
1738 /* "manually" create the initial zone */
1739 args.name = "UMA Kegs";
1740 args.size = sizeof(struct uma_keg);
1741 args.ctor = keg_ctor;
1742 args.dtor = keg_dtor;
1743 args.uminit = zero_init;
1745 args.keg = &masterkeg;
1746 args.align = 32 - 1;
1747 args.flags = UMA_ZFLAG_INTERNAL;
1748 /* The initial zone has no Per cpu queues so it's smaller */
1749 zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1752 printf("Filling boot free list.\n");
1754 for (i = 0; i < boot_pages; i++) {
1755 slab = (uma_slab_t)((uint8_t *)bootmem + (i * UMA_SLAB_SIZE));
1756 slab->us_data = (uint8_t *)slab;
1757 slab->us_flags = UMA_SLAB_BOOT;
1758 LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1760 mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1763 printf("Creating uma zone headers zone and keg.\n");
1765 args.name = "UMA Zones";
1766 args.size = sizeof(struct uma_zone) +
1767 (sizeof(struct uma_cache) * (mp_maxid + 1));
1768 args.ctor = zone_ctor;
1769 args.dtor = zone_dtor;
1770 args.uminit = zero_init;
1773 args.align = 32 - 1;
1774 args.flags = UMA_ZFLAG_INTERNAL;
1775 /* The initial zone has no Per cpu queues so it's smaller */
1776 zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1779 printf("Initializing pcpu cache locks.\n");
1782 printf("Creating slab and hash zones.\n");
1786 * This is the max number of free list items we'll have with
1789 slabsize = uma_max_ipers * UMA_FRITM_SZ;
1790 slabsize += sizeof(struct uma_slab);
1792 /* Now make a zone for slab headers */
1793 slabzone = uma_zcreate("UMA Slabs",
1795 NULL, NULL, NULL, NULL,
1796 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1799 * We also create a zone for the bigger slabs with reference
1800 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1802 slabsize = uma_max_ipers_ref * UMA_FRITMREF_SZ;
1803 slabsize += sizeof(struct uma_slab_refcnt);
1804 slabrefzone = uma_zcreate("UMA RCntSlabs",
1806 NULL, NULL, NULL, NULL,
1808 UMA_ZFLAG_INTERNAL);
1810 hashzone = uma_zcreate("UMA Hash",
1811 sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1812 NULL, NULL, NULL, NULL,
1813 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1817 booted = UMA_STARTUP;
1820 printf("UMA startup complete.\n");
1828 booted = UMA_STARTUP2;
1831 printf("UMA startup2 complete.\n");
1836 * Initialize our callout handle
1844 printf("Starting callout.\n");
1846 callout_init(&uma_callout, CALLOUT_MPSAFE);
1847 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1849 printf("UMA startup3 complete.\n");
1854 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1855 int align, uint32_t flags)
1857 struct uma_kctor_args args;
1860 args.uminit = uminit;
1862 args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1865 return (zone_alloc_item(kegs, &args, M_WAITOK));
1870 uma_set_align(int align)
1873 if (align != UMA_ALIGN_CACHE)
1874 uma_align_cache = align;
1879 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1880 uma_init uminit, uma_fini fini, int align, uint32_t flags)
1883 struct uma_zctor_args args;
1885 /* This stuff is essential for the zone ctor */
1890 args.uminit = uminit;
1896 return (zone_alloc_item(zones, &args, M_WAITOK));
1901 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1902 uma_init zinit, uma_fini zfini, uma_zone_t master)
1904 struct uma_zctor_args args;
1907 keg = zone_first_keg(master);
1909 args.size = keg->uk_size;
1912 args.uminit = zinit;
1914 args.align = keg->uk_align;
1915 args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
1918 /* XXX Attaches only one keg of potentially many. */
1919 return (zone_alloc_item(zones, &args, M_WAITOK));
1923 zone_lock_pair(uma_zone_t a, uma_zone_t b)
1927 mtx_lock_flags(b->uz_lock, MTX_DUPOK);
1930 mtx_lock_flags(a->uz_lock, MTX_DUPOK);
1935 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
1943 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
1950 klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
1952 zone_lock_pair(zone, master);
1954 * zone must use vtoslab() to resolve objects and must already be
1957 if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
1958 != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
1963 * The new master must also use vtoslab().
1965 if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
1970 * Both must either be refcnt, or not be refcnt.
1972 if ((zone->uz_flags & UMA_ZONE_REFCNT) !=
1973 (master->uz_flags & UMA_ZONE_REFCNT)) {
1978 * The underlying object must be the same size. rsize
1981 if (master->uz_size != zone->uz_size) {
1986 * Put it at the end of the list.
1988 klink->kl_keg = zone_first_keg(master);
1989 LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
1990 if (LIST_NEXT(kl, kl_link) == NULL) {
1991 LIST_INSERT_AFTER(kl, klink, kl_link);
1996 zone->uz_flags |= UMA_ZFLAG_MULTI;
1997 zone->uz_slab = zone_fetch_slab_multi;
2000 zone_unlock_pair(zone, master);
2002 free(klink, M_TEMP);
2010 uma_zdestroy(uma_zone_t zone)
2013 zone_free_item(zones, zone, NULL, SKIP_NONE, ZFREE_STATFREE);
2018 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2022 uma_bucket_t bucket;
2025 /* This is the fast path allocation */
2026 #ifdef UMA_DEBUG_ALLOC_1
2027 printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
2029 CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
2030 zone->uz_name, flags);
2032 if (flags & M_WAITOK) {
2033 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2034 "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2036 #ifdef DEBUG_MEMGUARD
2037 if (memguard_cmp_zone(zone)) {
2038 item = memguard_alloc(zone->uz_size, flags);
2041 * Avoid conflict with the use-after-free
2042 * protecting infrastructure from INVARIANTS.
2044 if (zone->uz_init != NULL &&
2045 zone->uz_init != mtrash_init &&
2046 zone->uz_init(item, zone->uz_size, flags) != 0)
2048 if (zone->uz_ctor != NULL &&
2049 zone->uz_ctor != mtrash_ctor &&
2050 zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2051 zone->uz_fini(item, zone->uz_size);
2056 /* This is unfortunate but should not be fatal. */
2060 * If possible, allocate from the per-CPU cache. There are two
2061 * requirements for safe access to the per-CPU cache: (1) the thread
2062 * accessing the cache must not be preempted or yield during access,
2063 * and (2) the thread must not migrate CPUs without switching which
2064 * cache it accesses. We rely on a critical section to prevent
2065 * preemption and migration. We release the critical section in
2066 * order to acquire the zone mutex if we are unable to allocate from
2067 * the current cache; when we re-acquire the critical section, we
2068 * must detect and handle migration if it has occurred.
2073 cache = &zone->uz_cpu[cpu];
2076 bucket = cache->uc_allocbucket;
2079 if (bucket->ub_cnt > 0) {
2081 item = bucket->ub_bucket[bucket->ub_cnt];
2083 bucket->ub_bucket[bucket->ub_cnt] = NULL;
2085 KASSERT(item != NULL,
2086 ("uma_zalloc: Bucket pointer mangled."));
2091 uma_dbg_alloc(zone, NULL, item);
2094 if (zone->uz_ctor != NULL) {
2095 if (zone->uz_ctor(item, zone->uz_size,
2096 udata, flags) != 0) {
2097 zone_free_item(zone, item, udata,
2098 SKIP_DTOR, ZFREE_STATFAIL |
2104 bzero(item, zone->uz_size);
2106 } else if (cache->uc_freebucket) {
2108 * We have run out of items in our allocbucket.
2109 * See if we can switch with our free bucket.
2111 if (cache->uc_freebucket->ub_cnt > 0) {
2112 #ifdef UMA_DEBUG_ALLOC
2113 printf("uma_zalloc: Swapping empty with"
2116 bucket = cache->uc_freebucket;
2117 cache->uc_freebucket = cache->uc_allocbucket;
2118 cache->uc_allocbucket = bucket;
2125 * Attempt to retrieve the item from the per-CPU cache has failed, so
2126 * we must go back to the zone. This requires the zone lock, so we
2127 * must drop the critical section, then re-acquire it when we go back
2128 * to the cache. Since the critical section is released, we may be
2129 * preempted or migrate. As such, make sure not to maintain any
2130 * thread-local state specific to the cache from prior to releasing
2131 * the critical section.
2137 cache = &zone->uz_cpu[cpu];
2138 bucket = cache->uc_allocbucket;
2139 if (bucket != NULL) {
2140 if (bucket->ub_cnt > 0) {
2144 bucket = cache->uc_freebucket;
2145 if (bucket != NULL && bucket->ub_cnt > 0) {
2151 /* Since we have locked the zone we may as well send back our stats */
2152 zone->uz_allocs += cache->uc_allocs;
2153 cache->uc_allocs = 0;
2154 zone->uz_frees += cache->uc_frees;
2155 cache->uc_frees = 0;
2157 /* Our old one is now a free bucket */
2158 if (cache->uc_allocbucket) {
2159 KASSERT(cache->uc_allocbucket->ub_cnt == 0,
2160 ("uma_zalloc_arg: Freeing a non free bucket."));
2161 LIST_INSERT_HEAD(&zone->uz_free_bucket,
2162 cache->uc_allocbucket, ub_link);
2163 cache->uc_allocbucket = NULL;
2166 /* Check the free list for a new alloc bucket */
2167 if ((bucket = LIST_FIRST(&zone->uz_full_bucket)) != NULL) {
2168 KASSERT(bucket->ub_cnt != 0,
2169 ("uma_zalloc_arg: Returning an empty bucket."));
2171 LIST_REMOVE(bucket, ub_link);
2172 cache->uc_allocbucket = bucket;
2176 /* We are no longer associated with this CPU. */
2179 /* Bump up our uz_count so we get here less */
2180 if (zone->uz_count < BUCKET_MAX)
2184 * Now lets just fill a bucket and put it on the free list. If that
2185 * works we'll restart the allocation from the begining.
2187 if (zone_alloc_bucket(zone, flags)) {
2189 goto zalloc_restart;
2193 * We may not be able to get a bucket so return an actual item.
2196 printf("uma_zalloc_arg: Bucketzone returned NULL\n");
2199 item = zone_alloc_item(zone, udata, flags);
2204 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
2208 mtx_assert(&keg->uk_lock, MA_OWNED);
2213 * Find a slab with some space. Prefer slabs that are partially
2214 * used over those that are totally full. This helps to reduce
2217 if (keg->uk_free != 0) {
2218 if (!LIST_EMPTY(&keg->uk_part_slab)) {
2219 slab = LIST_FIRST(&keg->uk_part_slab);
2221 slab = LIST_FIRST(&keg->uk_free_slab);
2222 LIST_REMOVE(slab, us_link);
2223 LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2226 MPASS(slab->us_keg == keg);
2231 * M_NOVM means don't ask at all!
2236 if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2237 keg->uk_flags |= UMA_ZFLAG_FULL;
2239 * If this is not a multi-zone, set the FULL bit.
2240 * Otherwise slab_multi() takes care of it.
2242 if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2243 zone->uz_flags |= UMA_ZFLAG_FULL;
2244 zone_log_warning(zone);
2246 if (flags & M_NOWAIT)
2249 msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2253 slab = keg_alloc_slab(keg, zone, flags);
2256 * If we got a slab here it's safe to mark it partially used
2257 * and return. We assume that the caller is going to remove
2258 * at least one item.
2261 MPASS(slab->us_keg == keg);
2262 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2266 * We might not have been able to get a slab but another cpu
2267 * could have while we were unlocked. Check again before we
2276 zone_relock(uma_zone_t zone, uma_keg_t keg)
2278 if (zone->uz_lock != &keg->uk_lock) {
2285 keg_relock(uma_keg_t keg, uma_zone_t zone)
2287 if (zone->uz_lock != &keg->uk_lock) {
2294 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
2299 keg = zone_first_keg(zone);
2301 * This is to prevent us from recursively trying to allocate
2302 * buckets. The problem is that if an allocation forces us to
2303 * grab a new bucket we will call page_alloc, which will go off
2304 * and cause the vm to allocate vm_map_entries. If we need new
2305 * buckets there too we will recurse in kmem_alloc and bad
2306 * things happen. So instead we return a NULL bucket, and make
2307 * the code that allocates buckets smart enough to deal with it
2309 if (keg->uk_flags & UMA_ZFLAG_BUCKET && keg->uk_recurse != 0)
2313 slab = keg_fetch_slab(keg, zone, flags);
2316 if (flags & (M_NOWAIT | M_NOVM))
2323 * uma_zone_fetch_slab_multi: Fetches a slab from one available keg. Returns
2324 * with the keg locked. Caller must call zone_relock() afterwards if the
2325 * zone lock is required. On NULL the zone lock is held.
2327 * The last pointer is used to seed the search. It is not required.
2330 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
2340 * Don't wait on the first pass. This will skip limit tests
2341 * as well. We don't want to block if we can find a provider
2344 flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2346 * Use the last slab allocated as a hint for where to start
2350 slab = keg_fetch_slab(last, zone, flags);
2353 zone_relock(zone, last);
2357 * Loop until we have a slab incase of transient failures
2358 * while M_WAITOK is specified. I'm not sure this is 100%
2359 * required but we've done it for so long now.
2365 * Search the available kegs for slabs. Be careful to hold the
2366 * correct lock while calling into the keg layer.
2368 LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2369 keg = klink->kl_keg;
2370 keg_relock(keg, zone);
2371 if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2372 slab = keg_fetch_slab(keg, zone, flags);
2376 if (keg->uk_flags & UMA_ZFLAG_FULL)
2380 zone_relock(zone, keg);
2382 if (rflags & (M_NOWAIT | M_NOVM))
2386 * All kegs are full. XXX We can't atomically check all kegs
2387 * and sleep so just sleep for a short period and retry.
2389 if (full && !empty) {
2390 zone->uz_flags |= UMA_ZFLAG_FULL;
2392 zone_log_warning(zone);
2393 msleep(zone, zone->uz_lock, PVM, "zonelimit", hz/100);
2394 zone->uz_flags &= ~UMA_ZFLAG_FULL;
2402 slab_alloc_item(uma_zone_t zone, uma_slab_t slab)
2405 uma_slabrefcnt_t slabref;
2410 mtx_assert(&keg->uk_lock, MA_OWNED);
2412 freei = slab->us_firstfree;
2413 if (keg->uk_flags & UMA_ZONE_REFCNT) {
2414 slabref = (uma_slabrefcnt_t)slab;
2415 slab->us_firstfree = slabref->us_freelist[freei].us_item;
2417 slab->us_firstfree = slab->us_freelist[freei].us_item;
2419 item = slab->us_data + (keg->uk_rsize * freei);
2421 slab->us_freecount--;
2424 uma_dbg_alloc(zone, slab, item);
2426 /* Move this slab to the full list */
2427 if (slab->us_freecount == 0) {
2428 LIST_REMOVE(slab, us_link);
2429 LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2436 zone_alloc_bucket(uma_zone_t zone, int flags)
2438 uma_bucket_t bucket;
2442 int max, origflags = flags;
2445 * Try this zone's free list first so we don't allocate extra buckets.
2447 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2448 KASSERT(bucket->ub_cnt == 0,
2449 ("zone_alloc_bucket: Bucket on free list is not empty."));
2450 LIST_REMOVE(bucket, ub_link);
2454 bflags = (flags & ~M_ZERO);
2455 if (zone->uz_flags & UMA_ZFLAG_CACHEONLY)
2459 bucket = bucket_alloc(zone->uz_count, bflags);
2463 if (bucket == NULL) {
2469 * This code is here to limit the number of simultaneous bucket fills
2470 * for any given zone to the number of per cpu caches in this zone. This
2471 * is done so that we don't allocate more memory than we really need.
2473 if (zone->uz_fills >= mp_ncpus)
2479 max = MIN(bucket->ub_entries, zone->uz_count);
2480 /* Try to keep the buckets totally full */
2481 saved = bucket->ub_cnt;
2484 while (bucket->ub_cnt < max &&
2485 (slab = zone->uz_slab(zone, keg, flags)) != NULL) {
2487 while (slab->us_freecount && bucket->ub_cnt < max) {
2488 bucket->ub_bucket[bucket->ub_cnt++] =
2489 slab_alloc_item(zone, slab);
2492 /* Don't block on the next fill */
2496 zone_relock(zone, keg);
2499 * We unlock here because we need to call the zone's init.
2500 * It should be safe to unlock because the slab dealt with
2501 * above is already on the appropriate list within the keg
2502 * and the bucket we filled is not yet on any list, so we
2505 if (zone->uz_init != NULL) {
2509 for (i = saved; i < bucket->ub_cnt; i++)
2510 if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2514 * If we couldn't initialize the whole bucket, put the
2515 * rest back onto the freelist.
2517 if (i != bucket->ub_cnt) {
2520 for (j = i; j < bucket->ub_cnt; j++) {
2521 zone_free_item(zone, bucket->ub_bucket[j],
2522 NULL, SKIP_FINI, 0);
2524 bucket->ub_bucket[j] = NULL;
2533 if (bucket->ub_cnt != 0) {
2534 LIST_INSERT_HEAD(&zone->uz_full_bucket,
2541 bucket_free(bucket);
2546 * Allocates an item for an internal zone
2549 * zone The zone to alloc for.
2550 * udata The data to be passed to the constructor.
2551 * flags M_WAITOK, M_NOWAIT, M_ZERO.
2554 * NULL if there is no memory and M_NOWAIT is set
2555 * An item if successful
2559 zone_alloc_item(uma_zone_t zone, void *udata, int flags)
2566 #ifdef UMA_DEBUG_ALLOC
2567 printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2571 slab = zone->uz_slab(zone, NULL, flags);
2578 item = slab_alloc_item(zone, slab);
2580 zone_relock(zone, slab->us_keg);
2585 * We have to call both the zone's init (not the keg's init)
2586 * and the zone's ctor. This is because the item is going from
2587 * a keg slab directly to the user, and the user is expecting it
2588 * to be both zone-init'd as well as zone-ctor'd.
2590 if (zone->uz_init != NULL) {
2591 if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2592 zone_free_item(zone, item, udata, SKIP_FINI,
2593 ZFREE_STATFAIL | ZFREE_STATFREE);
2597 if (zone->uz_ctor != NULL) {
2598 if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2599 zone_free_item(zone, item, udata, SKIP_DTOR,
2600 ZFREE_STATFAIL | ZFREE_STATFREE);
2605 bzero(item, zone->uz_size);
2612 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2615 uma_bucket_t bucket;
2619 #ifdef UMA_DEBUG_ALLOC_1
2620 printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2622 CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2625 /* uma_zfree(..., NULL) does nothing, to match free(9). */
2628 #ifdef DEBUG_MEMGUARD
2629 if (is_memguard_addr(item)) {
2630 if (zone->uz_dtor != NULL && zone->uz_dtor != mtrash_dtor)
2631 zone->uz_dtor(item, zone->uz_size, udata);
2632 if (zone->uz_fini != NULL && zone->uz_fini != mtrash_fini)
2633 zone->uz_fini(item, zone->uz_size);
2634 memguard_free(item);
2639 zone->uz_dtor(item, zone->uz_size, udata);
2643 if (zone->uz_flags & UMA_ZONE_MALLOC)
2644 uma_dbg_free(zone, udata, item);
2646 uma_dbg_free(zone, NULL, item);
2650 * The race here is acceptable. If we miss it we'll just have to wait
2651 * a little longer for the limits to be reset.
2653 if (zone->uz_flags & UMA_ZFLAG_FULL)
2654 goto zfree_internal;
2657 * If possible, free to the per-CPU cache. There are two
2658 * requirements for safe access to the per-CPU cache: (1) the thread
2659 * accessing the cache must not be preempted or yield during access,
2660 * and (2) the thread must not migrate CPUs without switching which
2661 * cache it accesses. We rely on a critical section to prevent
2662 * preemption and migration. We release the critical section in
2663 * order to acquire the zone mutex if we are unable to free to the
2664 * current cache; when we re-acquire the critical section, we must
2665 * detect and handle migration if it has occurred.
2670 cache = &zone->uz_cpu[cpu];
2673 bucket = cache->uc_freebucket;
2677 * Do we have room in our bucket? It is OK for this uz count
2678 * check to be slightly out of sync.
2681 if (bucket->ub_cnt < bucket->ub_entries) {
2682 KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2683 ("uma_zfree: Freeing to non free bucket index."));
2684 bucket->ub_bucket[bucket->ub_cnt] = item;
2689 } else if (cache->uc_allocbucket) {
2690 #ifdef UMA_DEBUG_ALLOC
2691 printf("uma_zfree: Swapping buckets.\n");
2694 * We have run out of space in our freebucket.
2695 * See if we can switch with our alloc bucket.
2697 if (cache->uc_allocbucket->ub_cnt <
2698 cache->uc_freebucket->ub_cnt) {
2699 bucket = cache->uc_freebucket;
2700 cache->uc_freebucket = cache->uc_allocbucket;
2701 cache->uc_allocbucket = bucket;
2707 * We can get here for two reasons:
2709 * 1) The buckets are NULL
2710 * 2) The alloc and free buckets are both somewhat full.
2712 * We must go back the zone, which requires acquiring the zone lock,
2713 * which in turn means we must release and re-acquire the critical
2714 * section. Since the critical section is released, we may be
2715 * preempted or migrate. As such, make sure not to maintain any
2716 * thread-local state specific to the cache from prior to releasing
2717 * the critical section.
2723 cache = &zone->uz_cpu[cpu];
2724 if (cache->uc_freebucket != NULL) {
2725 if (cache->uc_freebucket->ub_cnt <
2726 cache->uc_freebucket->ub_entries) {
2730 if (cache->uc_allocbucket != NULL &&
2731 (cache->uc_allocbucket->ub_cnt <
2732 cache->uc_freebucket->ub_cnt)) {
2738 /* Since we have locked the zone we may as well send back our stats */
2739 zone->uz_allocs += cache->uc_allocs;
2740 cache->uc_allocs = 0;
2741 zone->uz_frees += cache->uc_frees;
2742 cache->uc_frees = 0;
2744 bucket = cache->uc_freebucket;
2745 cache->uc_freebucket = NULL;
2747 /* Can we throw this on the zone full list? */
2748 if (bucket != NULL) {
2749 #ifdef UMA_DEBUG_ALLOC
2750 printf("uma_zfree: Putting old bucket on the free list.\n");
2752 /* ub_cnt is pointing to the last free item */
2753 KASSERT(bucket->ub_cnt != 0,
2754 ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2755 LIST_INSERT_HEAD(&zone->uz_full_bucket,
2758 if ((bucket = LIST_FIRST(&zone->uz_free_bucket)) != NULL) {
2759 LIST_REMOVE(bucket, ub_link);
2761 cache->uc_freebucket = bucket;
2764 /* We are no longer associated with this CPU. */
2767 /* And the zone.. */
2770 #ifdef UMA_DEBUG_ALLOC
2771 printf("uma_zfree: Allocating new free bucket.\n");
2775 if (zone->uz_flags & UMA_ZFLAG_CACHEONLY)
2777 bucket = bucket_alloc(zone->uz_count, bflags);
2780 LIST_INSERT_HEAD(&zone->uz_free_bucket,
2787 * If nothing else caught this, we'll just do an internal free.
2790 zone_free_item(zone, item, udata, SKIP_DTOR, ZFREE_STATFREE);
2796 * Frees an item to an INTERNAL zone or allocates a free bucket
2799 * zone The zone to free to
2800 * item The item we're freeing
2801 * udata User supplied data for the dtor
2802 * skip Skip dtors and finis
2805 zone_free_item(uma_zone_t zone, void *item, void *udata,
2806 enum zfreeskip skip, int flags)
2809 uma_slabrefcnt_t slabref;
2815 if (skip < SKIP_DTOR && zone->uz_dtor)
2816 zone->uz_dtor(item, zone->uz_size, udata);
2818 if (skip < SKIP_FINI && zone->uz_fini)
2819 zone->uz_fini(item, zone->uz_size);
2823 if (flags & ZFREE_STATFAIL)
2825 if (flags & ZFREE_STATFREE)
2828 if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
2829 mem = (uint8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
2830 keg = zone_first_keg(zone); /* Must only be one. */
2831 if (zone->uz_flags & UMA_ZONE_HASH) {
2832 slab = hash_sfind(&keg->uk_hash, mem);
2834 mem += keg->uk_pgoff;
2835 slab = (uma_slab_t)mem;
2838 /* This prevents redundant lookups via free(). */
2839 if ((zone->uz_flags & UMA_ZONE_MALLOC) && udata != NULL)
2840 slab = (uma_slab_t)udata;
2842 slab = vtoslab((vm_offset_t)item);
2844 keg_relock(keg, zone);
2846 MPASS(keg == slab->us_keg);
2848 /* Do we need to remove from any lists? */
2849 if (slab->us_freecount+1 == keg->uk_ipers) {
2850 LIST_REMOVE(slab, us_link);
2851 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2852 } else if (slab->us_freecount == 0) {
2853 LIST_REMOVE(slab, us_link);
2854 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2857 /* Slab management stuff */
2858 freei = ((unsigned long)item - (unsigned long)slab->us_data)
2863 uma_dbg_free(zone, slab, item);
2866 if (keg->uk_flags & UMA_ZONE_REFCNT) {
2867 slabref = (uma_slabrefcnt_t)slab;
2868 slabref->us_freelist[freei].us_item = slab->us_firstfree;
2870 slab->us_freelist[freei].us_item = slab->us_firstfree;
2872 slab->us_firstfree = freei;
2873 slab->us_freecount++;
2875 /* Zone statistics */
2879 if (keg->uk_flags & UMA_ZFLAG_FULL) {
2880 if (keg->uk_pages < keg->uk_maxpages) {
2881 keg->uk_flags &= ~UMA_ZFLAG_FULL;
2886 * We can handle one more allocation. Since we're clearing ZFLAG_FULL,
2887 * wake up all procs blocked on pages. This should be uncommon, so
2888 * keeping this simple for now (rather than adding count of blocked
2894 zone_relock(zone, keg);
2895 zone->uz_flags &= ~UMA_ZFLAG_FULL;
2904 uma_zone_set_max(uma_zone_t zone, int nitems)
2909 keg = zone_first_keg(zone);
2910 keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
2911 if (keg->uk_maxpages * keg->uk_ipers < nitems)
2912 keg->uk_maxpages += keg->uk_ppera;
2913 nitems = keg->uk_maxpages * keg->uk_ipers;
2921 uma_zone_get_max(uma_zone_t zone)
2927 keg = zone_first_keg(zone);
2928 nitems = keg->uk_maxpages * keg->uk_ipers;
2936 uma_zone_set_warning(uma_zone_t zone, const char *warning)
2940 zone->uz_warning = warning;
2946 uma_zone_get_cur(uma_zone_t zone)
2952 nitems = zone->uz_allocs - zone->uz_frees;
2955 * See the comment in sysctl_vm_zone_stats() regarding the
2956 * safety of accessing the per-cpu caches. With the zone lock
2957 * held, it is safe, but can potentially result in stale data.
2959 nitems += zone->uz_cpu[i].uc_allocs -
2960 zone->uz_cpu[i].uc_frees;
2964 return (nitems < 0 ? 0 : nitems);
2969 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2974 keg = zone_first_keg(zone);
2975 KASSERT(keg->uk_pages == 0,
2976 ("uma_zone_set_init on non-empty keg"));
2977 keg->uk_init = uminit;
2983 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
2988 keg = zone_first_keg(zone);
2989 KASSERT(keg->uk_pages == 0,
2990 ("uma_zone_set_fini on non-empty keg"));
2991 keg->uk_fini = fini;
2997 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
3000 KASSERT(zone_first_keg(zone)->uk_pages == 0,
3001 ("uma_zone_set_zinit on non-empty keg"));
3002 zone->uz_init = zinit;
3008 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
3011 KASSERT(zone_first_keg(zone)->uk_pages == 0,
3012 ("uma_zone_set_zfini on non-empty keg"));
3013 zone->uz_fini = zfini;
3018 /* XXX uk_freef is not actually used with the zone locked */
3020 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3024 zone_first_keg(zone)->uk_freef = freef;
3029 /* XXX uk_allocf is not actually used with the zone locked */
3031 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3036 keg = zone_first_keg(zone);
3037 keg->uk_flags |= UMA_ZFLAG_PRIVALLOC;
3038 keg->uk_allocf = allocf;
3044 uma_zone_reserve_kva(uma_zone_t zone, int count)
3050 keg = zone_first_keg(zone);
3051 pages = count / keg->uk_ipers;
3053 if (pages * keg->uk_ipers < count)
3056 #ifdef UMA_MD_SMALL_ALLOC
3057 if (keg->uk_ppera > 1) {
3061 kva = kmem_alloc_nofault(kernel_map, pages * UMA_SLAB_SIZE);
3069 keg->uk_maxpages = pages;
3070 #ifdef UMA_MD_SMALL_ALLOC
3071 keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3073 keg->uk_allocf = noobj_alloc;
3075 keg->uk_flags |= UMA_ZONE_NOFREE | UMA_ZFLAG_PRIVALLOC;
3082 uma_prealloc(uma_zone_t zone, int items)
3088 keg = zone_first_keg(zone);
3090 slabs = items / keg->uk_ipers;
3091 if (slabs * keg->uk_ipers < items)
3094 slab = keg_alloc_slab(keg, zone, M_WAITOK);
3097 MPASS(slab->us_keg == keg);
3098 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
3106 uma_find_refcnt(uma_zone_t zone, void *item)
3108 uma_slabrefcnt_t slabref;
3113 slabref = (uma_slabrefcnt_t)vtoslab((vm_offset_t)item &
3115 keg = slabref->us_keg;
3116 KASSERT(slabref != NULL && slabref->us_keg->uk_flags & UMA_ZONE_REFCNT,
3117 ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
3118 idx = ((unsigned long)item - (unsigned long)slabref->us_data)
3120 refcnt = &slabref->us_freelist[idx].us_refcnt;
3129 printf("UMA: vm asked us to release pages!\n");
3132 zone_foreach(zone_drain);
3134 * Some slabs may have been freed but this zone will be visited early
3135 * we visit again so that we can free pages that are empty once other
3136 * zones are drained. We have to do the same for buckets.
3138 zone_drain(slabzone);
3139 zone_drain(slabrefzone);
3140 bucket_zone_drain();
3145 uma_zone_exhausted(uma_zone_t zone)
3150 full = (zone->uz_flags & UMA_ZFLAG_FULL);
3156 uma_zone_exhausted_nolock(uma_zone_t zone)
3158 return (zone->uz_flags & UMA_ZFLAG_FULL);
3162 uma_large_malloc(int size, int wait)
3168 slab = zone_alloc_item(slabzone, NULL, wait);
3171 mem = page_alloc(NULL, size, &flags, wait);
3173 vsetslab((vm_offset_t)mem, slab);
3174 slab->us_data = mem;
3175 slab->us_flags = flags | UMA_SLAB_MALLOC;
3176 slab->us_size = size;
3178 zone_free_item(slabzone, slab, NULL, SKIP_NONE,
3179 ZFREE_STATFAIL | ZFREE_STATFREE);
3186 uma_large_free(uma_slab_t slab)
3188 vsetobj((vm_offset_t)slab->us_data, kmem_object);
3189 page_free(slab->us_data, slab->us_size, slab->us_flags);
3190 zone_free_item(slabzone, slab, NULL, SKIP_NONE, ZFREE_STATFREE);
3194 uma_print_stats(void)
3196 zone_foreach(uma_print_zone);
3200 slab_print(uma_slab_t slab)
3202 printf("slab: keg %p, data %p, freecount %d, firstfree %d\n",
3203 slab->us_keg, slab->us_data, slab->us_freecount,
3204 slab->us_firstfree);
3208 cache_print(uma_cache_t cache)
3210 printf("alloc: %p(%d), free: %p(%d)\n",
3211 cache->uc_allocbucket,
3212 cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3213 cache->uc_freebucket,
3214 cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3218 uma_print_keg(uma_keg_t keg)
3222 printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3223 "out %d free %d limit %d\n",
3224 keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3225 keg->uk_ipers, keg->uk_ppera,
3226 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free,
3227 (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3228 printf("Part slabs:\n");
3229 LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
3231 printf("Free slabs:\n");
3232 LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
3234 printf("Full slabs:\n");
3235 LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
3240 uma_print_zone(uma_zone_t zone)
3246 printf("zone: %s(%p) size %d flags %#x\n",
3247 zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3248 LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3249 uma_print_keg(kl->kl_keg);
3251 cache = &zone->uz_cpu[i];
3252 printf("CPU %d Cache:\n", i);
3259 * Generate statistics across both the zone and its per-cpu cache's. Return
3260 * desired statistics if the pointer is non-NULL for that statistic.
3262 * Note: does not update the zone statistics, as it can't safely clear the
3263 * per-CPU cache statistic.
3265 * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3266 * safe from off-CPU; we should modify the caches to track this information
3267 * directly so that we don't have to.
3270 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3271 uint64_t *freesp, uint64_t *sleepsp)
3274 uint64_t allocs, frees, sleeps;
3277 allocs = frees = sleeps = 0;
3280 cache = &z->uz_cpu[cpu];
3281 if (cache->uc_allocbucket != NULL)
3282 cachefree += cache->uc_allocbucket->ub_cnt;
3283 if (cache->uc_freebucket != NULL)
3284 cachefree += cache->uc_freebucket->ub_cnt;
3285 allocs += cache->uc_allocs;
3286 frees += cache->uc_frees;
3288 allocs += z->uz_allocs;
3289 frees += z->uz_frees;
3290 sleeps += z->uz_sleeps;
3291 if (cachefreep != NULL)
3292 *cachefreep = cachefree;
3293 if (allocsp != NULL)
3297 if (sleepsp != NULL)
3303 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3311 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3312 LIST_FOREACH(z, &kz->uk_zones, uz_link)
3315 mtx_unlock(&uma_mtx);
3316 return (sysctl_handle_int(oidp, &count, 0, req));
3320 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3322 struct uma_stream_header ush;
3323 struct uma_type_header uth;
3324 struct uma_percpu_stat ups;
3325 uma_bucket_t bucket;
3332 int count, error, i;
3334 error = sysctl_wire_old_buffer(req, 0);
3337 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3341 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3342 LIST_FOREACH(z, &kz->uk_zones, uz_link)
3347 * Insert stream header.
3349 bzero(&ush, sizeof(ush));
3350 ush.ush_version = UMA_STREAM_VERSION;
3351 ush.ush_maxcpus = (mp_maxid + 1);
3352 ush.ush_count = count;
3353 (void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3355 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3356 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3357 bzero(&uth, sizeof(uth));
3359 strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3360 uth.uth_align = kz->uk_align;
3361 uth.uth_size = kz->uk_size;
3362 uth.uth_rsize = kz->uk_rsize;
3363 LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3365 uth.uth_maxpages += k->uk_maxpages;
3366 uth.uth_pages += k->uk_pages;
3367 uth.uth_keg_free += k->uk_free;
3368 uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3373 * A zone is secondary is it is not the first entry
3374 * on the keg's zone list.
3376 if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3377 (LIST_FIRST(&kz->uk_zones) != z))
3378 uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3380 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3381 uth.uth_zone_free += bucket->ub_cnt;
3382 uth.uth_allocs = z->uz_allocs;
3383 uth.uth_frees = z->uz_frees;
3384 uth.uth_fails = z->uz_fails;
3385 uth.uth_sleeps = z->uz_sleeps;
3386 (void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3388 * While it is not normally safe to access the cache
3389 * bucket pointers while not on the CPU that owns the
3390 * cache, we only allow the pointers to be exchanged
3391 * without the zone lock held, not invalidated, so
3392 * accept the possible race associated with bucket
3393 * exchange during monitoring.
3395 for (i = 0; i < (mp_maxid + 1); i++) {
3396 bzero(&ups, sizeof(ups));
3397 if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3401 cache = &z->uz_cpu[i];
3402 if (cache->uc_allocbucket != NULL)
3403 ups.ups_cache_free +=
3404 cache->uc_allocbucket->ub_cnt;
3405 if (cache->uc_freebucket != NULL)
3406 ups.ups_cache_free +=
3407 cache->uc_freebucket->ub_cnt;
3408 ups.ups_allocs = cache->uc_allocs;
3409 ups.ups_frees = cache->uc_frees;
3411 (void)sbuf_bcat(&sbuf, &ups, sizeof(ups));
3416 mtx_unlock(&uma_mtx);
3417 error = sbuf_finish(&sbuf);
3423 DB_SHOW_COMMAND(uma, db_show_uma)
3425 uint64_t allocs, frees, sleeps;
3426 uma_bucket_t bucket;
3431 db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3432 "Requests", "Sleeps");
3433 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3434 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3435 if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3436 allocs = z->uz_allocs;
3437 frees = z->uz_frees;
3438 sleeps = z->uz_sleeps;
3441 uma_zone_sumstat(z, &cachefree, &allocs,
3443 if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3444 (LIST_FIRST(&kz->uk_zones) != z)))
3445 cachefree += kz->uk_free;
3446 LIST_FOREACH(bucket, &z->uz_full_bucket, ub_link)
3447 cachefree += bucket->ub_cnt;
3448 db_printf("%18s %8ju %8jd %8d %12ju %8ju\n", z->uz_name,
3449 (uintmax_t)kz->uk_size,
3450 (intmax_t)(allocs - frees), cachefree,
3451 (uintmax_t)allocs, sleeps);