2 * Copyright (c) 2002-2005, 2009, 2013 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/bitset.h>
67 #include <sys/kernel.h>
68 #include <sys/types.h>
69 #include <sys/queue.h>
70 #include <sys/malloc.h>
73 #include <sys/sysctl.h>
74 #include <sys/mutex.h>
76 #include <sys/rwlock.h>
78 #include <sys/sched.h>
80 #include <sys/vmmeter.h>
83 #include <vm/vm_object.h>
84 #include <vm/vm_page.h>
85 #include <vm/vm_pageout.h>
86 #include <vm/vm_param.h>
87 #include <vm/vm_map.h>
88 #include <vm/vm_kern.h>
89 #include <vm/vm_extern.h>
91 #include <vm/uma_int.h>
92 #include <vm/uma_dbg.h>
97 #include <vm/memguard.h>
101 * This is the zone and keg from which all zones are spawned. The idea is that
102 * even the zone & keg heads are allocated from the allocator, so we use the
103 * bss section to bootstrap us.
105 static struct uma_keg masterkeg;
106 static struct uma_zone masterzone_k;
107 static struct uma_zone masterzone_z;
108 static uma_zone_t kegs = &masterzone_k;
109 static uma_zone_t zones = &masterzone_z;
111 /* This is the zone from which all of uma_slab_t's are allocated. */
112 static uma_zone_t slabzone;
113 static uma_zone_t slabrefzone; /* With refcounters (for UMA_ZONE_REFCNT) */
116 * The initial hash tables come out of this zone so they can be allocated
117 * prior to malloc coming up.
119 static uma_zone_t hashzone;
121 /* The boot-time adjusted value for cache line alignment. */
122 int uma_align_cache = 64 - 1;
124 static MALLOC_DEFINE(M_UMAHASH, "UMAHash", "UMA Hash Buckets");
127 * Are we allowed to allocate buckets?
129 static int bucketdisable = 1;
131 /* Linked list of all kegs in the system */
132 static LIST_HEAD(,uma_keg) uma_kegs = LIST_HEAD_INITIALIZER(uma_kegs);
134 /* Linked list of all cache-only zones in the system */
135 static LIST_HEAD(,uma_zone) uma_cachezones =
136 LIST_HEAD_INITIALIZER(uma_cachezones);
138 /* This mutex protects the keg list */
139 static struct mtx_padalign uma_mtx;
141 /* Linked list of boot time pages */
142 static LIST_HEAD(,uma_slab) uma_boot_pages =
143 LIST_HEAD_INITIALIZER(uma_boot_pages);
145 /* This mutex protects the boot time pages list */
146 static struct mtx_padalign uma_boot_pages_mtx;
148 /* Is the VM done starting up? */
149 static int booted = 0;
150 #define UMA_STARTUP 1
151 #define UMA_STARTUP2 2
154 * Only mbuf clusters use ref zones. Just provide enough references
155 * to support the one user. New code should not use the ref facility.
157 static const u_int uma_max_ipers_ref = PAGE_SIZE / MCLBYTES;
160 * This is the handle used to schedule events that need to happen
161 * outside of the allocation fast path.
163 static struct callout uma_callout;
164 #define UMA_TIMEOUT 20 /* Seconds for callout interval. */
167 * This structure is passed as the zone ctor arg so that I don't have to create
168 * a special allocation function just for zones.
170 struct uma_zctor_args {
185 struct uma_kctor_args {
194 struct uma_bucket_zone {
197 int ubz_entries; /* Number of items it can hold. */
198 int ubz_maxsize; /* Maximum allocation size per-item. */
202 * Compute the actual number of bucket entries to pack them in power
203 * of two sizes for more efficient space utilization.
205 #define BUCKET_SIZE(n) \
206 (((sizeof(void *) * (n)) - sizeof(struct uma_bucket)) / sizeof(void *))
208 #define BUCKET_MAX BUCKET_SIZE(128)
210 struct uma_bucket_zone bucket_zones[] = {
211 { NULL, "4 Bucket", BUCKET_SIZE(4), 4096 },
212 { NULL, "6 Bucket", BUCKET_SIZE(6), 3072 },
213 { NULL, "8 Bucket", BUCKET_SIZE(8), 2048 },
214 { NULL, "12 Bucket", BUCKET_SIZE(12), 1536 },
215 { NULL, "16 Bucket", BUCKET_SIZE(16), 1024 },
216 { NULL, "32 Bucket", BUCKET_SIZE(32), 512 },
217 { NULL, "64 Bucket", BUCKET_SIZE(64), 256 },
218 { NULL, "128 Bucket", BUCKET_SIZE(128), 128 },
223 * Flags and enumerations to be passed to internal functions.
225 enum zfreeskip { SKIP_NONE = 0, SKIP_DTOR, SKIP_FINI };
229 static void *noobj_alloc(uma_zone_t, int, uint8_t *, int);
230 static void *page_alloc(uma_zone_t, int, uint8_t *, int);
231 static void *startup_alloc(uma_zone_t, int, uint8_t *, int);
232 static void page_free(void *, int, uint8_t);
233 static uma_slab_t keg_alloc_slab(uma_keg_t, uma_zone_t, int);
234 static void cache_drain(uma_zone_t);
235 static void bucket_drain(uma_zone_t, uma_bucket_t);
236 static void bucket_cache_drain(uma_zone_t zone);
237 static int keg_ctor(void *, int, void *, int);
238 static void keg_dtor(void *, int, void *);
239 static int zone_ctor(void *, int, void *, int);
240 static void zone_dtor(void *, int, void *);
241 static int zero_init(void *, int, int);
242 static void keg_small_init(uma_keg_t keg);
243 static void keg_large_init(uma_keg_t keg);
244 static void zone_foreach(void (*zfunc)(uma_zone_t));
245 static void zone_timeout(uma_zone_t zone);
246 static int hash_alloc(struct uma_hash *);
247 static int hash_expand(struct uma_hash *, struct uma_hash *);
248 static void hash_free(struct uma_hash *hash);
249 static void uma_timeout(void *);
250 static void uma_startup3(void);
251 static void *zone_alloc_item(uma_zone_t, void *, int);
252 static void zone_free_item(uma_zone_t, void *, void *, enum zfreeskip);
253 static void bucket_enable(void);
254 static void bucket_init(void);
255 static uma_bucket_t bucket_alloc(uma_zone_t zone, void *, int);
256 static void bucket_free(uma_zone_t zone, uma_bucket_t, void *);
257 static void bucket_zone_drain(void);
258 static uma_bucket_t zone_alloc_bucket(uma_zone_t zone, void *, int flags);
259 static uma_slab_t zone_fetch_slab(uma_zone_t zone, uma_keg_t last, int flags);
260 static uma_slab_t zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int flags);
261 static void *slab_alloc_item(uma_keg_t keg, uma_slab_t slab);
262 static void slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item);
263 static uma_keg_t uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit,
264 uma_fini fini, int align, uint32_t flags);
265 static int zone_import(uma_zone_t zone, void **bucket, int max, int flags);
266 static void zone_release(uma_zone_t zone, void **bucket, int cnt);
267 static void uma_zero_item(void *item, uma_zone_t zone);
269 void uma_print_zone(uma_zone_t);
270 void uma_print_stats(void);
271 static int sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS);
272 static int sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS);
274 SYSINIT(uma_startup3, SI_SUB_VM_CONF, SI_ORDER_SECOND, uma_startup3, NULL);
276 SYSCTL_PROC(_vm, OID_AUTO, zone_count, CTLFLAG_RD|CTLTYPE_INT,
277 0, 0, sysctl_vm_zone_count, "I", "Number of UMA zones");
279 SYSCTL_PROC(_vm, OID_AUTO, zone_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
280 0, 0, sysctl_vm_zone_stats, "s,struct uma_type_header", "Zone Stats");
282 static int zone_warnings = 1;
283 TUNABLE_INT("vm.zone_warnings", &zone_warnings);
284 SYSCTL_INT(_vm, OID_AUTO, zone_warnings, CTLFLAG_RW, &zone_warnings, 0,
285 "Warn when UMA zones becomes full");
288 * This routine checks to see whether or not it's safe to enable buckets.
293 bucketdisable = vm_page_count_min();
297 * Initialize bucket_zones, the array of zones of buckets of various sizes.
299 * For each zone, calculate the memory required for each bucket, consisting
300 * of the header and an array of pointers.
305 struct uma_bucket_zone *ubz;
309 for (i = 0, ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++) {
310 size = roundup(sizeof(struct uma_bucket), sizeof(void *));
311 size += sizeof(void *) * ubz->ubz_entries;
312 ubz->ubz_zone = uma_zcreate(ubz->ubz_name, size,
313 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
314 UMA_ZONE_MTXCLASS | UMA_ZFLAG_BUCKET);
319 * Given a desired number of entries for a bucket, return the zone from which
320 * to allocate the bucket.
322 static struct uma_bucket_zone *
323 bucket_zone_lookup(int entries)
325 struct uma_bucket_zone *ubz;
327 for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
328 if (ubz->ubz_entries >= entries)
335 bucket_select(int size)
337 struct uma_bucket_zone *ubz;
339 ubz = &bucket_zones[0];
340 if (size > ubz->ubz_maxsize)
341 return MAX((ubz->ubz_maxsize * ubz->ubz_entries) / size, 1);
343 for (; ubz->ubz_entries != 0; ubz++)
344 if (ubz->ubz_maxsize < size)
347 return (ubz->ubz_entries);
351 bucket_alloc(uma_zone_t zone, void *udata, int flags)
353 struct uma_bucket_zone *ubz;
357 * This is to stop us from allocating per cpu buckets while we're
358 * running out of vm.boot_pages. Otherwise, we would exhaust the
359 * boot pages. This also prevents us from allocating buckets in
360 * low memory situations.
365 * To limit bucket recursion we store the original zone flags
366 * in a cookie passed via zalloc_arg/zfree_arg. This allows the
367 * NOVM flag to persist even through deep recursions. We also
368 * store ZFLAG_BUCKET once we have recursed attempting to allocate
369 * a bucket for a bucket zone so we do not allow infinite bucket
370 * recursion. This cookie will even persist to frees of unused
371 * buckets via the allocation path or bucket allocations in the
374 if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
375 udata = (void *)(uintptr_t)zone->uz_flags;
377 if ((uintptr_t)udata & UMA_ZFLAG_BUCKET)
379 udata = (void *)((uintptr_t)udata | UMA_ZFLAG_BUCKET);
381 if ((uintptr_t)udata & UMA_ZFLAG_CACHEONLY)
383 ubz = bucket_zone_lookup(zone->uz_count);
384 bucket = uma_zalloc_arg(ubz->ubz_zone, udata, flags);
387 bzero(bucket->ub_bucket, sizeof(void *) * ubz->ubz_entries);
390 bucket->ub_entries = ubz->ubz_entries;
397 bucket_free(uma_zone_t zone, uma_bucket_t bucket, void *udata)
399 struct uma_bucket_zone *ubz;
401 KASSERT(bucket->ub_cnt == 0,
402 ("bucket_free: Freeing a non free bucket."));
403 if ((zone->uz_flags & UMA_ZFLAG_BUCKET) == 0)
404 udata = (void *)(uintptr_t)zone->uz_flags;
405 ubz = bucket_zone_lookup(bucket->ub_entries);
406 uma_zfree_arg(ubz->ubz_zone, bucket, udata);
410 bucket_zone_drain(void)
412 struct uma_bucket_zone *ubz;
414 for (ubz = &bucket_zones[0]; ubz->ubz_entries != 0; ubz++)
415 zone_drain(ubz->ubz_zone);
419 zone_log_warning(uma_zone_t zone)
421 static const struct timeval warninterval = { 300, 0 };
423 if (!zone_warnings || zone->uz_warning == NULL)
426 if (ratecheck(&zone->uz_ratecheck, &warninterval))
427 printf("[zone: %s] %s\n", zone->uz_name, zone->uz_warning);
431 zone_foreach_keg(uma_zone_t zone, void (*kegfn)(uma_keg_t))
435 LIST_FOREACH(klink, &zone->uz_kegs, kl_link)
436 kegfn(klink->kl_keg);
440 * Routine called by timeout which is used to fire off some time interval
441 * based calculations. (stats, hash size, etc.)
450 uma_timeout(void *unused)
453 zone_foreach(zone_timeout);
455 /* Reschedule this event */
456 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
460 * Routine to perform timeout driven calculations. This expands the
461 * hashes and does per cpu statistics aggregation.
466 keg_timeout(uma_keg_t keg)
471 * Expand the keg hash table.
473 * This is done if the number of slabs is larger than the hash size.
474 * What I'm trying to do here is completely reduce collisions. This
475 * may be a little aggressive. Should I allow for two collisions max?
477 if (keg->uk_flags & UMA_ZONE_HASH &&
478 keg->uk_pages / keg->uk_ppera >= keg->uk_hash.uh_hashsize) {
479 struct uma_hash newhash;
480 struct uma_hash oldhash;
484 * This is so involved because allocating and freeing
485 * while the keg lock is held will lead to deadlock.
486 * I have to do everything in stages and check for
489 newhash = keg->uk_hash;
491 ret = hash_alloc(&newhash);
494 if (hash_expand(&keg->uk_hash, &newhash)) {
495 oldhash = keg->uk_hash;
496 keg->uk_hash = newhash;
509 zone_timeout(uma_zone_t zone)
512 zone_foreach_keg(zone, &keg_timeout);
516 * Allocate and zero fill the next sized hash table from the appropriate
520 * hash A new hash structure with the old hash size in uh_hashsize
523 * 1 on sucess and 0 on failure.
526 hash_alloc(struct uma_hash *hash)
531 oldsize = hash->uh_hashsize;
533 /* We're just going to go to a power of two greater */
535 hash->uh_hashsize = oldsize * 2;
536 alloc = sizeof(hash->uh_slab_hash[0]) * hash->uh_hashsize;
537 hash->uh_slab_hash = (struct slabhead *)malloc(alloc,
538 M_UMAHASH, M_NOWAIT);
540 alloc = sizeof(hash->uh_slab_hash[0]) * UMA_HASH_SIZE_INIT;
541 hash->uh_slab_hash = zone_alloc_item(hashzone, NULL,
543 hash->uh_hashsize = UMA_HASH_SIZE_INIT;
545 if (hash->uh_slab_hash) {
546 bzero(hash->uh_slab_hash, alloc);
547 hash->uh_hashmask = hash->uh_hashsize - 1;
555 * Expands the hash table for HASH zones. This is done from zone_timeout
556 * to reduce collisions. This must not be done in the regular allocation
557 * path, otherwise, we can recurse on the vm while allocating pages.
560 * oldhash The hash you want to expand
561 * newhash The hash structure for the new table
569 hash_expand(struct uma_hash *oldhash, struct uma_hash *newhash)
575 if (!newhash->uh_slab_hash)
578 if (oldhash->uh_hashsize >= newhash->uh_hashsize)
582 * I need to investigate hash algorithms for resizing without a
586 for (i = 0; i < oldhash->uh_hashsize; i++)
587 while (!SLIST_EMPTY(&oldhash->uh_slab_hash[i])) {
588 slab = SLIST_FIRST(&oldhash->uh_slab_hash[i]);
589 SLIST_REMOVE_HEAD(&oldhash->uh_slab_hash[i], us_hlink);
590 hval = UMA_HASH(newhash, slab->us_data);
591 SLIST_INSERT_HEAD(&newhash->uh_slab_hash[hval],
599 * Free the hash bucket to the appropriate backing store.
602 * slab_hash The hash bucket we're freeing
603 * hashsize The number of entries in that hash bucket
609 hash_free(struct uma_hash *hash)
611 if (hash->uh_slab_hash == NULL)
613 if (hash->uh_hashsize == UMA_HASH_SIZE_INIT)
614 zone_free_item(hashzone, hash->uh_slab_hash, NULL, SKIP_NONE);
616 free(hash->uh_slab_hash, M_UMAHASH);
620 * Frees all outstanding items in a bucket
623 * zone The zone to free to, must be unlocked.
624 * bucket The free/alloc bucket with items, cpu queue must be locked.
631 bucket_drain(uma_zone_t zone, uma_bucket_t bucket)
639 for (i = 0; i < bucket->ub_cnt; i++)
640 zone->uz_fini(bucket->ub_bucket[i], zone->uz_size);
641 zone->uz_release(zone->uz_arg, bucket->ub_bucket, bucket->ub_cnt);
646 * Drains the per cpu caches for a zone.
648 * NOTE: This may only be called while the zone is being turn down, and not
649 * during normal operation. This is necessary in order that we do not have
650 * to migrate CPUs to drain the per-CPU caches.
653 * zone The zone to drain, must be unlocked.
659 cache_drain(uma_zone_t zone)
665 * XXX: It is safe to not lock the per-CPU caches, because we're
666 * tearing down the zone anyway. I.e., there will be no further use
667 * of the caches at this point.
669 * XXX: It would good to be able to assert that the zone is being
670 * torn down to prevent improper use of cache_drain().
672 * XXX: We lock the zone before passing into bucket_cache_drain() as
673 * it is used elsewhere. Should the tear-down path be made special
674 * there in some form?
677 cache = &zone->uz_cpu[cpu];
678 bucket_drain(zone, cache->uc_allocbucket);
679 bucket_drain(zone, cache->uc_freebucket);
680 if (cache->uc_allocbucket != NULL)
681 bucket_free(zone, cache->uc_allocbucket, NULL);
682 if (cache->uc_freebucket != NULL)
683 bucket_free(zone, cache->uc_freebucket, NULL);
684 cache->uc_allocbucket = cache->uc_freebucket = NULL;
687 bucket_cache_drain(zone);
692 cache_shrink(uma_zone_t zone)
695 if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
699 zone->uz_count = (zone->uz_count_min + zone->uz_count) / 2;
704 cache_drain_safe_cpu(uma_zone_t zone)
709 if (zone->uz_flags & UMA_ZFLAG_INTERNAL)
715 cache = &zone->uz_cpu[curcpu];
716 if (cache->uc_allocbucket) {
717 if (cache->uc_allocbucket->ub_cnt != 0)
718 LIST_INSERT_HEAD(&zone->uz_buckets,
719 cache->uc_allocbucket, ub_link);
721 b1 = cache->uc_allocbucket;
722 cache->uc_allocbucket = NULL;
724 if (cache->uc_freebucket) {
725 if (cache->uc_freebucket->ub_cnt != 0)
726 LIST_INSERT_HEAD(&zone->uz_buckets,
727 cache->uc_freebucket, ub_link);
729 b2 = cache->uc_freebucket;
730 cache->uc_freebucket = NULL;
735 bucket_free(zone, b1, NULL);
737 bucket_free(zone, b2, NULL);
741 * Safely drain per-CPU caches of a zone(s) to alloc bucket.
742 * This is an expensive call because it needs to bind to all CPUs
743 * one by one and enter a critical section on each of them in order
744 * to safely access their cache buckets.
745 * Zone lock must not be held on call this function.
748 cache_drain_safe(uma_zone_t zone)
753 * Polite bucket sizes shrinking was not enouth, shrink aggressively.
758 zone_foreach(cache_shrink);
761 thread_lock(curthread);
762 sched_bind(curthread, cpu);
763 thread_unlock(curthread);
766 cache_drain_safe_cpu(zone);
768 zone_foreach(cache_drain_safe_cpu);
770 thread_lock(curthread);
771 sched_unbind(curthread);
772 thread_unlock(curthread);
776 * Drain the cached buckets from a zone. Expects a locked zone on entry.
779 bucket_cache_drain(uma_zone_t zone)
784 * Drain the bucket queues and free the buckets, we just keep two per
787 while ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
788 LIST_REMOVE(bucket, ub_link);
790 bucket_drain(zone, bucket);
791 bucket_free(zone, bucket, NULL);
796 * Shrink further bucket sizes. Price of single zone lock collision
797 * is probably lower then price of global cache drain.
799 if (zone->uz_count > zone->uz_count_min)
804 keg_free_slab(uma_keg_t keg, uma_slab_t slab, int start)
811 flags = slab->us_flags;
813 if (keg->uk_fini != NULL) {
814 for (i--; i > -1; i--)
815 keg->uk_fini(slab->us_data + (keg->uk_rsize * i),
818 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
819 zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
821 printf("%s: Returning %d bytes.\n", keg->uk_name,
822 PAGE_SIZE * keg->uk_ppera);
824 keg->uk_freef(mem, PAGE_SIZE * keg->uk_ppera, flags);
828 * Frees pages from a keg back to the system. This is done on demand from
829 * the pageout daemon.
834 keg_drain(uma_keg_t keg)
836 struct slabhead freeslabs = { 0 };
841 * We don't want to take pages from statically allocated kegs at this
844 if (keg->uk_flags & UMA_ZONE_NOFREE || keg->uk_freef == NULL)
848 printf("%s free items: %u\n", keg->uk_name, keg->uk_free);
851 if (keg->uk_free == 0)
854 slab = LIST_FIRST(&keg->uk_free_slab);
856 n = LIST_NEXT(slab, us_link);
858 /* We have no where to free these to */
859 if (slab->us_flags & UMA_SLAB_BOOT) {
864 LIST_REMOVE(slab, us_link);
865 keg->uk_pages -= keg->uk_ppera;
866 keg->uk_free -= keg->uk_ipers;
868 if (keg->uk_flags & UMA_ZONE_HASH)
869 UMA_HASH_REMOVE(&keg->uk_hash, slab, slab->us_data);
871 SLIST_INSERT_HEAD(&freeslabs, slab, us_hlink);
878 while ((slab = SLIST_FIRST(&freeslabs)) != NULL) {
879 SLIST_REMOVE(&freeslabs, slab, uma_slab, us_hlink);
880 keg_free_slab(keg, slab, keg->uk_ipers);
885 zone_drain_wait(uma_zone_t zone, int waitok)
889 * Set draining to interlock with zone_dtor() so we can release our
890 * locks as we go. Only dtor() should do a WAITOK call since it
891 * is the only call that knows the structure will still be available
895 while (zone->uz_flags & UMA_ZFLAG_DRAINING) {
896 if (waitok == M_NOWAIT)
898 mtx_unlock(&uma_mtx);
899 msleep(zone, zone->uz_lockptr, PVM, "zonedrain", 1);
902 zone->uz_flags |= UMA_ZFLAG_DRAINING;
903 bucket_cache_drain(zone);
906 * The DRAINING flag protects us from being freed while
907 * we're running. Normally the uma_mtx would protect us but we
908 * must be able to release and acquire the right lock for each keg.
910 zone_foreach_keg(zone, &keg_drain);
912 zone->uz_flags &= ~UMA_ZFLAG_DRAINING;
919 zone_drain(uma_zone_t zone)
922 zone_drain_wait(zone, M_NOWAIT);
926 * Allocate a new slab for a keg. This does not insert the slab onto a list.
929 * wait Shall we wait?
932 * The slab that was allocated or NULL if there is no memory and the
933 * caller specified M_NOWAIT.
936 keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int wait)
938 uma_slabrefcnt_t slabref;
945 mtx_assert(&keg->uk_lock, MA_OWNED);
950 printf("alloc_slab: Allocating a new slab for %s\n", keg->uk_name);
952 allocf = keg->uk_allocf;
955 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
956 slab = zone_alloc_item(keg->uk_slabzone, NULL, wait);
962 * This reproduces the old vm_zone behavior of zero filling pages the
963 * first time they are added to a zone.
965 * Malloced items are zeroed in uma_zalloc.
968 if ((keg->uk_flags & UMA_ZONE_MALLOC) == 0)
973 if (keg->uk_flags & UMA_ZONE_NODUMP)
976 /* zone is passed for legacy reasons. */
977 mem = allocf(zone, keg->uk_ppera * PAGE_SIZE, &flags, wait);
979 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
980 zone_free_item(keg->uk_slabzone, slab, NULL, SKIP_NONE);
985 /* Point the slab into the allocated memory */
986 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE))
987 slab = (uma_slab_t )(mem + keg->uk_pgoff);
989 if (keg->uk_flags & UMA_ZONE_VTOSLAB)
990 for (i = 0; i < keg->uk_ppera; i++)
991 vsetslab((vm_offset_t)mem + (i * PAGE_SIZE), slab);
995 slab->us_freecount = keg->uk_ipers;
996 slab->us_flags = flags;
997 BIT_FILL(SLAB_SETSIZE, &slab->us_free);
999 BIT_ZERO(SLAB_SETSIZE, &slab->us_debugfree);
1001 if (keg->uk_flags & UMA_ZONE_REFCNT) {
1002 slabref = (uma_slabrefcnt_t)slab;
1003 for (i = 0; i < keg->uk_ipers; i++)
1004 slabref->us_refcnt[i] = 0;
1007 if (keg->uk_init != NULL) {
1008 for (i = 0; i < keg->uk_ipers; i++)
1009 if (keg->uk_init(slab->us_data + (keg->uk_rsize * i),
1010 keg->uk_size, wait) != 0)
1012 if (i != keg->uk_ipers) {
1013 keg_free_slab(keg, slab, i);
1022 if (keg->uk_flags & UMA_ZONE_HASH)
1023 UMA_HASH_INSERT(&keg->uk_hash, slab, mem);
1025 keg->uk_pages += keg->uk_ppera;
1026 keg->uk_free += keg->uk_ipers;
1033 * This function is intended to be used early on in place of page_alloc() so
1034 * that we may use the boot time page cache to satisfy allocations before
1038 startup_alloc(uma_zone_t zone, int bytes, uint8_t *pflag, int wait)
1042 int pages, check_pages;
1044 keg = zone_first_keg(zone);
1045 pages = howmany(bytes, PAGE_SIZE);
1046 check_pages = pages - 1;
1047 KASSERT(pages > 0, ("startup_alloc can't reserve 0 pages\n"));
1050 * Check our small startup cache to see if it has pages remaining.
1052 mtx_lock(&uma_boot_pages_mtx);
1054 /* First check if we have enough room. */
1055 tmps = LIST_FIRST(&uma_boot_pages);
1056 while (tmps != NULL && check_pages-- > 0)
1057 tmps = LIST_NEXT(tmps, us_link);
1060 * It's ok to lose tmps references. The last one will
1061 * have tmps->us_data pointing to the start address of
1062 * "pages" contiguous pages of memory.
1064 while (pages-- > 0) {
1065 tmps = LIST_FIRST(&uma_boot_pages);
1066 LIST_REMOVE(tmps, us_link);
1068 mtx_unlock(&uma_boot_pages_mtx);
1069 *pflag = tmps->us_flags;
1070 return (tmps->us_data);
1072 mtx_unlock(&uma_boot_pages_mtx);
1073 if (booted < UMA_STARTUP2)
1074 panic("UMA: Increase vm.boot_pages");
1076 * Now that we've booted reset these users to their real allocator.
1078 #ifdef UMA_MD_SMALL_ALLOC
1079 keg->uk_allocf = (keg->uk_ppera > 1) ? page_alloc : uma_small_alloc;
1081 keg->uk_allocf = page_alloc;
1083 return keg->uk_allocf(zone, bytes, pflag, wait);
1087 * Allocates a number of pages from the system
1090 * bytes The number of bytes requested
1091 * wait Shall we wait?
1094 * A pointer to the alloced memory or possibly
1095 * NULL if M_NOWAIT is set.
1098 page_alloc(uma_zone_t zone, int bytes, uint8_t *pflag, int wait)
1100 void *p; /* Returned page */
1102 *pflag = UMA_SLAB_KMEM;
1103 p = (void *) kmem_malloc(kmem_arena, bytes, wait);
1109 * Allocates a number of pages from within an object
1112 * bytes The number of bytes requested
1113 * wait Shall we wait?
1116 * A pointer to the alloced memory or possibly
1117 * NULL if M_NOWAIT is set.
1120 noobj_alloc(uma_zone_t zone, int bytes, uint8_t *flags, int wait)
1122 TAILQ_HEAD(, vm_page) alloctail;
1124 vm_offset_t retkva, zkva;
1125 vm_page_t p, p_next;
1128 TAILQ_INIT(&alloctail);
1129 keg = zone_first_keg(zone);
1131 npages = howmany(bytes, PAGE_SIZE);
1132 while (npages > 0) {
1133 p = vm_page_alloc(NULL, 0, VM_ALLOC_INTERRUPT |
1134 VM_ALLOC_WIRED | VM_ALLOC_NOOBJ);
1137 * Since the page does not belong to an object, its
1140 TAILQ_INSERT_TAIL(&alloctail, p, listq);
1144 if (wait & M_WAITOK) {
1150 * Page allocation failed, free intermediate pages and
1153 TAILQ_FOREACH_SAFE(p, &alloctail, listq, p_next) {
1154 vm_page_unwire(p, 0);
1159 *flags = UMA_SLAB_PRIV;
1160 zkva = keg->uk_kva +
1161 atomic_fetchadd_long(&keg->uk_offset, round_page(bytes));
1163 TAILQ_FOREACH(p, &alloctail, listq) {
1164 pmap_qenter(zkva, &p, 1);
1168 return ((void *)retkva);
1172 * Frees a number of pages to the system
1175 * mem A pointer to the memory to be freed
1176 * size The size of the memory being freed
1177 * flags The original p->us_flags field
1183 page_free(void *mem, int size, uint8_t flags)
1187 if (flags & UMA_SLAB_KMEM)
1189 else if (flags & UMA_SLAB_KERNEL)
1190 vmem = kernel_arena;
1192 panic("UMA: page_free used with invalid flags %d", flags);
1194 kmem_free(vmem, (vm_offset_t)mem, size);
1198 * Zero fill initializer
1200 * Arguments/Returns follow uma_init specifications
1203 zero_init(void *mem, int size, int flags)
1210 * Finish creating a small uma keg. This calculates ipers, and the keg size.
1213 * keg The zone we should initialize
1219 keg_small_init(uma_keg_t keg)
1226 if (keg->uk_flags & UMA_ZONE_PCPU) {
1227 u_int ncpus = mp_ncpus ? mp_ncpus : MAXCPU;
1229 keg->uk_slabsize = sizeof(struct pcpu);
1230 keg->uk_ppera = howmany(ncpus * sizeof(struct pcpu),
1233 keg->uk_slabsize = UMA_SLAB_SIZE;
1238 * Calculate the size of each allocation (rsize) according to
1239 * alignment. If the requested size is smaller than we have
1240 * allocation bits for we round it up.
1242 rsize = keg->uk_size;
1243 if (rsize < keg->uk_slabsize / SLAB_SETSIZE)
1244 rsize = keg->uk_slabsize / SLAB_SETSIZE;
1245 if (rsize & keg->uk_align)
1246 rsize = (rsize & ~keg->uk_align) + (keg->uk_align + 1);
1247 keg->uk_rsize = rsize;
1249 KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0 ||
1250 keg->uk_rsize < sizeof(struct pcpu),
1251 ("%s: size %u too large", __func__, keg->uk_rsize));
1253 if (keg->uk_flags & UMA_ZONE_REFCNT)
1254 rsize += sizeof(uint32_t);
1256 if (keg->uk_flags & UMA_ZONE_OFFPAGE)
1259 shsize = sizeof(struct uma_slab);
1261 keg->uk_ipers = (keg->uk_slabsize - shsize) / rsize;
1262 KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1263 ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1265 memused = keg->uk_ipers * rsize + shsize;
1266 wastedspace = keg->uk_slabsize - memused;
1269 * We can't do OFFPAGE if we're internal or if we've been
1270 * asked to not go to the VM for buckets. If we do this we
1271 * may end up going to the VM for slabs which we do not
1272 * want to do if we're UMA_ZFLAG_CACHEONLY as a result
1273 * of UMA_ZONE_VM, which clearly forbids it.
1275 if ((keg->uk_flags & UMA_ZFLAG_INTERNAL) ||
1276 (keg->uk_flags & UMA_ZFLAG_CACHEONLY))
1280 * See if using an OFFPAGE slab will limit our waste. Only do
1281 * this if it permits more items per-slab.
1283 * XXX We could try growing slabsize to limit max waste as well.
1284 * Historically this was not done because the VM could not
1285 * efficiently handle contiguous allocations.
1287 if ((wastedspace >= keg->uk_slabsize / UMA_MAX_WASTE) &&
1288 (keg->uk_ipers < (keg->uk_slabsize / keg->uk_rsize))) {
1289 keg->uk_ipers = keg->uk_slabsize / keg->uk_rsize;
1290 KASSERT(keg->uk_ipers > 0 && keg->uk_ipers <= SLAB_SETSIZE,
1291 ("%s: keg->uk_ipers %u", __func__, keg->uk_ipers));
1293 printf("UMA decided we need offpage slab headers for "
1294 "keg: %s, calculated wastedspace = %d, "
1295 "maximum wasted space allowed = %d, "
1296 "calculated ipers = %d, "
1297 "new wasted space = %d\n", keg->uk_name, wastedspace,
1298 keg->uk_slabsize / UMA_MAX_WASTE, keg->uk_ipers,
1299 keg->uk_slabsize - keg->uk_ipers * keg->uk_rsize);
1301 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1304 if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1305 (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1306 keg->uk_flags |= UMA_ZONE_HASH;
1310 * Finish creating a large (> UMA_SLAB_SIZE) uma kegs. Just give in and do
1311 * OFFPAGE for now. When I can allow for more dynamic slab sizes this will be
1315 * keg The keg we should initialize
1321 keg_large_init(uma_keg_t keg)
1325 KASSERT(keg != NULL, ("Keg is null in keg_large_init"));
1326 KASSERT((keg->uk_flags & UMA_ZFLAG_CACHEONLY) == 0,
1327 ("keg_large_init: Cannot large-init a UMA_ZFLAG_CACHEONLY keg"));
1328 KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1329 ("%s: Cannot large-init a UMA_ZONE_PCPU keg", __func__));
1331 keg->uk_ppera = howmany(keg->uk_size, PAGE_SIZE);
1332 keg->uk_slabsize = keg->uk_ppera * PAGE_SIZE;
1334 keg->uk_rsize = keg->uk_size;
1336 /* We can't do OFFPAGE if we're internal, bail out here. */
1337 if (keg->uk_flags & UMA_ZFLAG_INTERNAL)
1340 /* Check whether we have enough space to not do OFFPAGE. */
1341 if ((keg->uk_flags & UMA_ZONE_OFFPAGE) == 0) {
1342 shsize = sizeof(struct uma_slab);
1343 if (keg->uk_flags & UMA_ZONE_REFCNT)
1344 shsize += keg->uk_ipers * sizeof(uint32_t);
1345 if (shsize & UMA_ALIGN_PTR)
1346 shsize = (shsize & ~UMA_ALIGN_PTR) +
1347 (UMA_ALIGN_PTR + 1);
1349 if ((PAGE_SIZE * keg->uk_ppera) - keg->uk_rsize < shsize)
1350 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1353 if ((keg->uk_flags & UMA_ZONE_OFFPAGE) &&
1354 (keg->uk_flags & UMA_ZONE_VTOSLAB) == 0)
1355 keg->uk_flags |= UMA_ZONE_HASH;
1359 keg_cachespread_init(uma_keg_t keg)
1366 KASSERT((keg->uk_flags & UMA_ZONE_PCPU) == 0,
1367 ("%s: Cannot cachespread-init a UMA_ZONE_PCPU keg", __func__));
1369 alignsize = keg->uk_align + 1;
1370 rsize = keg->uk_size;
1372 * We want one item to start on every align boundary in a page. To
1373 * do this we will span pages. We will also extend the item by the
1374 * size of align if it is an even multiple of align. Otherwise, it
1375 * would fall on the same boundary every time.
1377 if (rsize & keg->uk_align)
1378 rsize = (rsize & ~keg->uk_align) + alignsize;
1379 if ((rsize & alignsize) == 0)
1381 trailer = rsize - keg->uk_size;
1382 pages = (rsize * (PAGE_SIZE / alignsize)) / PAGE_SIZE;
1383 pages = MIN(pages, (128 * 1024) / PAGE_SIZE);
1384 keg->uk_rsize = rsize;
1385 keg->uk_ppera = pages;
1386 keg->uk_slabsize = UMA_SLAB_SIZE;
1387 keg->uk_ipers = ((pages * PAGE_SIZE) + trailer) / rsize;
1388 keg->uk_flags |= UMA_ZONE_OFFPAGE | UMA_ZONE_VTOSLAB;
1389 KASSERT(keg->uk_ipers <= SLAB_SETSIZE,
1390 ("%s: keg->uk_ipers too high(%d) increase max_ipers", __func__,
1395 * Keg header ctor. This initializes all fields, locks, etc. And inserts
1396 * the keg onto the global keg list.
1398 * Arguments/Returns follow uma_ctor specifications
1399 * udata Actually uma_kctor_args
1402 keg_ctor(void *mem, int size, void *udata, int flags)
1404 struct uma_kctor_args *arg = udata;
1405 uma_keg_t keg = mem;
1409 keg->uk_size = arg->size;
1410 keg->uk_init = arg->uminit;
1411 keg->uk_fini = arg->fini;
1412 keg->uk_align = arg->align;
1414 keg->uk_reserve = 0;
1416 keg->uk_flags = arg->flags;
1417 keg->uk_allocf = page_alloc;
1418 keg->uk_freef = page_free;
1419 keg->uk_slabzone = NULL;
1422 * The master zone is passed to us at keg-creation time.
1425 keg->uk_name = zone->uz_name;
1427 if (arg->flags & UMA_ZONE_VM)
1428 keg->uk_flags |= UMA_ZFLAG_CACHEONLY;
1430 if (arg->flags & UMA_ZONE_ZINIT)
1431 keg->uk_init = zero_init;
1433 if (arg->flags & UMA_ZONE_REFCNT || arg->flags & UMA_ZONE_MALLOC)
1434 keg->uk_flags |= UMA_ZONE_VTOSLAB;
1436 if (arg->flags & UMA_ZONE_PCPU)
1438 keg->uk_flags |= UMA_ZONE_OFFPAGE;
1440 keg->uk_flags &= ~UMA_ZONE_PCPU;
1443 if (keg->uk_flags & UMA_ZONE_CACHESPREAD) {
1444 keg_cachespread_init(keg);
1445 } else if (keg->uk_flags & UMA_ZONE_REFCNT) {
1447 (UMA_SLAB_SIZE - sizeof(struct uma_slab_refcnt) -
1449 keg_large_init(keg);
1451 keg_small_init(keg);
1453 if (keg->uk_size > (UMA_SLAB_SIZE - sizeof(struct uma_slab)))
1454 keg_large_init(keg);
1456 keg_small_init(keg);
1459 if (keg->uk_flags & UMA_ZONE_OFFPAGE) {
1460 if (keg->uk_flags & UMA_ZONE_REFCNT) {
1461 if (keg->uk_ipers > uma_max_ipers_ref)
1462 panic("Too many ref items per zone: %d > %d\n",
1463 keg->uk_ipers, uma_max_ipers_ref);
1464 keg->uk_slabzone = slabrefzone;
1466 keg->uk_slabzone = slabzone;
1470 * If we haven't booted yet we need allocations to go through the
1471 * startup cache until the vm is ready.
1473 if (keg->uk_ppera == 1) {
1474 #ifdef UMA_MD_SMALL_ALLOC
1475 keg->uk_allocf = uma_small_alloc;
1476 keg->uk_freef = uma_small_free;
1478 if (booted < UMA_STARTUP)
1479 keg->uk_allocf = startup_alloc;
1481 if (booted < UMA_STARTUP2)
1482 keg->uk_allocf = startup_alloc;
1484 } else if (booted < UMA_STARTUP2 &&
1485 (keg->uk_flags & UMA_ZFLAG_INTERNAL))
1486 keg->uk_allocf = startup_alloc;
1489 * Initialize keg's lock
1491 KEG_LOCK_INIT(keg, (arg->flags & UMA_ZONE_MTXCLASS));
1494 * If we're putting the slab header in the actual page we need to
1495 * figure out where in each page it goes. This calculates a right
1496 * justified offset into the memory on an ALIGN_PTR boundary.
1498 if (!(keg->uk_flags & UMA_ZONE_OFFPAGE)) {
1501 /* Size of the slab struct and free list */
1502 totsize = sizeof(struct uma_slab);
1504 /* Size of the reference counts. */
1505 if (keg->uk_flags & UMA_ZONE_REFCNT)
1506 totsize += keg->uk_ipers * sizeof(uint32_t);
1508 if (totsize & UMA_ALIGN_PTR)
1509 totsize = (totsize & ~UMA_ALIGN_PTR) +
1510 (UMA_ALIGN_PTR + 1);
1511 keg->uk_pgoff = (PAGE_SIZE * keg->uk_ppera) - totsize;
1514 * The only way the following is possible is if with our
1515 * UMA_ALIGN_PTR adjustments we are now bigger than
1516 * UMA_SLAB_SIZE. I haven't checked whether this is
1517 * mathematically possible for all cases, so we make
1520 totsize = keg->uk_pgoff + sizeof(struct uma_slab);
1521 if (keg->uk_flags & UMA_ZONE_REFCNT)
1522 totsize += keg->uk_ipers * sizeof(uint32_t);
1523 if (totsize > PAGE_SIZE * keg->uk_ppera) {
1524 printf("zone %s ipers %d rsize %d size %d\n",
1525 zone->uz_name, keg->uk_ipers, keg->uk_rsize,
1527 panic("UMA slab won't fit.");
1531 if (keg->uk_flags & UMA_ZONE_HASH)
1532 hash_alloc(&keg->uk_hash);
1535 printf("UMA: %s(%p) size %d(%d) flags %#x ipers %d ppera %d out %d free %d\n",
1536 zone->uz_name, zone, keg->uk_size, keg->uk_rsize, keg->uk_flags,
1537 keg->uk_ipers, keg->uk_ppera,
1538 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free);
1541 LIST_INSERT_HEAD(&keg->uk_zones, zone, uz_link);
1544 LIST_INSERT_HEAD(&uma_kegs, keg, uk_link);
1545 mtx_unlock(&uma_mtx);
1550 * Zone header ctor. This initializes all fields, locks, etc.
1552 * Arguments/Returns follow uma_ctor specifications
1553 * udata Actually uma_zctor_args
1556 zone_ctor(void *mem, int size, void *udata, int flags)
1558 struct uma_zctor_args *arg = udata;
1559 uma_zone_t zone = mem;
1564 zone->uz_name = arg->name;
1565 zone->uz_ctor = arg->ctor;
1566 zone->uz_dtor = arg->dtor;
1567 zone->uz_slab = zone_fetch_slab;
1568 zone->uz_init = NULL;
1569 zone->uz_fini = NULL;
1570 zone->uz_allocs = 0;
1573 zone->uz_sleeps = 0;
1575 zone->uz_count_min = 0;
1577 zone->uz_warning = NULL;
1578 timevalclear(&zone->uz_ratecheck);
1581 ZONE_LOCK_INIT(zone, (arg->flags & UMA_ZONE_MTXCLASS));
1584 * This is a pure cache zone, no kegs.
1587 if (arg->flags & UMA_ZONE_VM)
1588 arg->flags |= UMA_ZFLAG_CACHEONLY;
1589 zone->uz_flags = arg->flags;
1590 zone->uz_size = arg->size;
1591 zone->uz_import = arg->import;
1592 zone->uz_release = arg->release;
1593 zone->uz_arg = arg->arg;
1594 zone->uz_lockptr = &zone->uz_lock;
1596 LIST_INSERT_HEAD(&uma_cachezones, zone, uz_link);
1597 mtx_unlock(&uma_mtx);
1602 * Use the regular zone/keg/slab allocator.
1604 zone->uz_import = (uma_import)zone_import;
1605 zone->uz_release = (uma_release)zone_release;
1606 zone->uz_arg = zone;
1608 if (arg->flags & UMA_ZONE_SECONDARY) {
1609 KASSERT(arg->keg != NULL, ("Secondary zone on zero'd keg"));
1610 zone->uz_init = arg->uminit;
1611 zone->uz_fini = arg->fini;
1612 zone->uz_lockptr = &keg->uk_lock;
1613 zone->uz_flags |= UMA_ZONE_SECONDARY;
1616 LIST_FOREACH(z, &keg->uk_zones, uz_link) {
1617 if (LIST_NEXT(z, uz_link) == NULL) {
1618 LIST_INSERT_AFTER(z, zone, uz_link);
1623 mtx_unlock(&uma_mtx);
1624 } else if (keg == NULL) {
1625 if ((keg = uma_kcreate(zone, arg->size, arg->uminit, arg->fini,
1626 arg->align, arg->flags)) == NULL)
1629 struct uma_kctor_args karg;
1632 /* We should only be here from uma_startup() */
1633 karg.size = arg->size;
1634 karg.uminit = arg->uminit;
1635 karg.fini = arg->fini;
1636 karg.align = arg->align;
1637 karg.flags = arg->flags;
1639 error = keg_ctor(arg->keg, sizeof(struct uma_keg), &karg,
1646 * Link in the first keg.
1648 zone->uz_klink.kl_keg = keg;
1649 LIST_INSERT_HEAD(&zone->uz_kegs, &zone->uz_klink, kl_link);
1650 zone->uz_lockptr = &keg->uk_lock;
1651 zone->uz_size = keg->uk_size;
1652 zone->uz_flags |= (keg->uk_flags &
1653 (UMA_ZONE_INHERIT | UMA_ZFLAG_INHERIT));
1656 * Some internal zones don't have room allocated for the per cpu
1657 * caches. If we're internal, bail out here.
1659 if (keg->uk_flags & UMA_ZFLAG_INTERNAL) {
1660 KASSERT((zone->uz_flags & UMA_ZONE_SECONDARY) == 0,
1661 ("Secondary zone requested UMA_ZFLAG_INTERNAL"));
1666 if ((arg->flags & UMA_ZONE_MAXBUCKET) == 0)
1667 zone->uz_count = bucket_select(zone->uz_size);
1669 zone->uz_count = BUCKET_MAX;
1670 zone->uz_count_min = zone->uz_count;
1676 * Keg header dtor. This frees all data, destroys locks, frees the hash
1677 * table and removes the keg from the global list.
1679 * Arguments/Returns follow uma_dtor specifications
1683 keg_dtor(void *arg, int size, void *udata)
1687 keg = (uma_keg_t)arg;
1689 if (keg->uk_free != 0) {
1690 printf("Freed UMA keg (%s) was not empty (%d items). "
1691 " Lost %d pages of memory.\n",
1692 keg->uk_name ? keg->uk_name : "",
1693 keg->uk_free, keg->uk_pages);
1697 hash_free(&keg->uk_hash);
1705 * Arguments/Returns follow uma_dtor specifications
1709 zone_dtor(void *arg, int size, void *udata)
1715 zone = (uma_zone_t)arg;
1716 keg = zone_first_keg(zone);
1718 if (!(zone->uz_flags & UMA_ZFLAG_INTERNAL))
1722 LIST_REMOVE(zone, uz_link);
1723 mtx_unlock(&uma_mtx);
1725 * XXX there are some races here where
1726 * the zone can be drained but zone lock
1727 * released and then refilled before we
1728 * remove it... we dont care for now
1730 zone_drain_wait(zone, M_WAITOK);
1732 * Unlink all of our kegs.
1734 while ((klink = LIST_FIRST(&zone->uz_kegs)) != NULL) {
1735 klink->kl_keg = NULL;
1736 LIST_REMOVE(klink, kl_link);
1737 if (klink == &zone->uz_klink)
1739 free(klink, M_TEMP);
1742 * We only destroy kegs from non secondary zones.
1744 if (keg != NULL && (zone->uz_flags & UMA_ZONE_SECONDARY) == 0) {
1746 LIST_REMOVE(keg, uk_link);
1747 mtx_unlock(&uma_mtx);
1748 zone_free_item(kegs, keg, NULL, SKIP_NONE);
1750 ZONE_LOCK_FINI(zone);
1754 * Traverses every zone in the system and calls a callback
1757 * zfunc A pointer to a function which accepts a zone
1764 zone_foreach(void (*zfunc)(uma_zone_t))
1770 LIST_FOREACH(keg, &uma_kegs, uk_link) {
1771 LIST_FOREACH(zone, &keg->uk_zones, uz_link)
1774 mtx_unlock(&uma_mtx);
1777 /* Public functions */
1780 uma_startup(void *bootmem, int boot_pages)
1782 struct uma_zctor_args args;
1788 printf("Creating uma keg headers zone and keg.\n");
1790 mtx_init(&uma_mtx, "UMA lock", NULL, MTX_DEF);
1792 /* "manually" create the initial zone */
1793 memset(&args, 0, sizeof(args));
1794 args.name = "UMA Kegs";
1795 args.size = sizeof(struct uma_keg);
1796 args.ctor = keg_ctor;
1797 args.dtor = keg_dtor;
1798 args.uminit = zero_init;
1800 args.keg = &masterkeg;
1801 args.align = 32 - 1;
1802 args.flags = UMA_ZFLAG_INTERNAL;
1803 /* The initial zone has no Per cpu queues so it's smaller */
1804 zone_ctor(kegs, sizeof(struct uma_zone), &args, M_WAITOK);
1807 printf("Filling boot free list.\n");
1809 for (i = 0; i < boot_pages; i++) {
1810 slab = (uma_slab_t)((uint8_t *)bootmem + (i * UMA_SLAB_SIZE));
1811 slab->us_data = (uint8_t *)slab;
1812 slab->us_flags = UMA_SLAB_BOOT;
1813 LIST_INSERT_HEAD(&uma_boot_pages, slab, us_link);
1815 mtx_init(&uma_boot_pages_mtx, "UMA boot pages", NULL, MTX_DEF);
1818 printf("Creating uma zone headers zone and keg.\n");
1820 args.name = "UMA Zones";
1821 args.size = sizeof(struct uma_zone) +
1822 (sizeof(struct uma_cache) * (mp_maxid + 1));
1823 args.ctor = zone_ctor;
1824 args.dtor = zone_dtor;
1825 args.uminit = zero_init;
1828 args.align = 32 - 1;
1829 args.flags = UMA_ZFLAG_INTERNAL;
1830 /* The initial zone has no Per cpu queues so it's smaller */
1831 zone_ctor(zones, sizeof(struct uma_zone), &args, M_WAITOK);
1834 printf("Initializing pcpu cache locks.\n");
1837 printf("Creating slab and hash zones.\n");
1840 /* Now make a zone for slab headers */
1841 slabzone = uma_zcreate("UMA Slabs",
1842 sizeof(struct uma_slab),
1843 NULL, NULL, NULL, NULL,
1844 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1847 * We also create a zone for the bigger slabs with reference
1848 * counts in them, to accomodate UMA_ZONE_REFCNT zones.
1850 slabsize = sizeof(struct uma_slab_refcnt);
1851 slabsize += uma_max_ipers_ref * sizeof(uint32_t);
1852 slabrefzone = uma_zcreate("UMA RCntSlabs",
1854 NULL, NULL, NULL, NULL,
1856 UMA_ZFLAG_INTERNAL);
1858 hashzone = uma_zcreate("UMA Hash",
1859 sizeof(struct slabhead *) * UMA_HASH_SIZE_INIT,
1860 NULL, NULL, NULL, NULL,
1861 UMA_ALIGN_PTR, UMA_ZFLAG_INTERNAL);
1865 booted = UMA_STARTUP;
1868 printf("UMA startup complete.\n");
1876 booted = UMA_STARTUP2;
1879 printf("UMA startup2 complete.\n");
1884 * Initialize our callout handle
1892 printf("Starting callout.\n");
1894 callout_init(&uma_callout, CALLOUT_MPSAFE);
1895 callout_reset(&uma_callout, UMA_TIMEOUT * hz, uma_timeout, NULL);
1897 printf("UMA startup3 complete.\n");
1902 uma_kcreate(uma_zone_t zone, size_t size, uma_init uminit, uma_fini fini,
1903 int align, uint32_t flags)
1905 struct uma_kctor_args args;
1908 args.uminit = uminit;
1910 args.align = (align == UMA_ALIGN_CACHE) ? uma_align_cache : align;
1913 return (zone_alloc_item(kegs, &args, M_WAITOK));
1918 uma_set_align(int align)
1921 if (align != UMA_ALIGN_CACHE)
1922 uma_align_cache = align;
1927 uma_zcreate(const char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
1928 uma_init uminit, uma_fini fini, int align, uint32_t flags)
1931 struct uma_zctor_args args;
1933 /* This stuff is essential for the zone ctor */
1934 memset(&args, 0, sizeof(args));
1939 args.uminit = uminit;
1945 return (zone_alloc_item(zones, &args, M_WAITOK));
1950 uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
1951 uma_init zinit, uma_fini zfini, uma_zone_t master)
1953 struct uma_zctor_args args;
1956 keg = zone_first_keg(master);
1957 memset(&args, 0, sizeof(args));
1959 args.size = keg->uk_size;
1962 args.uminit = zinit;
1964 args.align = keg->uk_align;
1965 args.flags = keg->uk_flags | UMA_ZONE_SECONDARY;
1968 /* XXX Attaches only one keg of potentially many. */
1969 return (zone_alloc_item(zones, &args, M_WAITOK));
1974 uma_zcache_create(char *name, int size, uma_ctor ctor, uma_dtor dtor,
1975 uma_init zinit, uma_fini zfini, uma_import zimport,
1976 uma_release zrelease, void *arg, int flags)
1978 struct uma_zctor_args args;
1980 memset(&args, 0, sizeof(args));
1985 args.uminit = zinit;
1987 args.import = zimport;
1988 args.release = zrelease;
1993 return (zone_alloc_item(zones, &args, M_WAITOK));
1997 zone_lock_pair(uma_zone_t a, uma_zone_t b)
2001 mtx_lock_flags(b->uz_lockptr, MTX_DUPOK);
2004 mtx_lock_flags(a->uz_lockptr, MTX_DUPOK);
2009 zone_unlock_pair(uma_zone_t a, uma_zone_t b)
2017 uma_zsecond_add(uma_zone_t zone, uma_zone_t master)
2024 klink = malloc(sizeof(*klink), M_TEMP, M_WAITOK | M_ZERO);
2026 zone_lock_pair(zone, master);
2028 * zone must use vtoslab() to resolve objects and must already be
2031 if ((zone->uz_flags & (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY))
2032 != (UMA_ZONE_VTOSLAB | UMA_ZONE_SECONDARY)) {
2037 * The new master must also use vtoslab().
2039 if ((zone->uz_flags & UMA_ZONE_VTOSLAB) != UMA_ZONE_VTOSLAB) {
2044 * Both must either be refcnt, or not be refcnt.
2046 if ((zone->uz_flags & UMA_ZONE_REFCNT) !=
2047 (master->uz_flags & UMA_ZONE_REFCNT)) {
2052 * The underlying object must be the same size. rsize
2055 if (master->uz_size != zone->uz_size) {
2060 * Put it at the end of the list.
2062 klink->kl_keg = zone_first_keg(master);
2063 LIST_FOREACH(kl, &zone->uz_kegs, kl_link) {
2064 if (LIST_NEXT(kl, kl_link) == NULL) {
2065 LIST_INSERT_AFTER(kl, klink, kl_link);
2070 zone->uz_flags |= UMA_ZFLAG_MULTI;
2071 zone->uz_slab = zone_fetch_slab_multi;
2074 zone_unlock_pair(zone, master);
2076 free(klink, M_TEMP);
2084 uma_zdestroy(uma_zone_t zone)
2087 zone_free_item(zones, zone, NULL, SKIP_NONE);
2092 uma_zalloc_arg(uma_zone_t zone, void *udata, int flags)
2096 uma_bucket_t bucket;
2100 /* This is the fast path allocation */
2101 #ifdef UMA_DEBUG_ALLOC_1
2102 printf("Allocating one item from %s(%p)\n", zone->uz_name, zone);
2104 CTR3(KTR_UMA, "uma_zalloc_arg thread %x zone %s flags %d", curthread,
2105 zone->uz_name, flags);
2107 if (flags & M_WAITOK) {
2108 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2109 "uma_zalloc_arg: zone \"%s\"", zone->uz_name);
2111 #ifdef DEBUG_MEMGUARD
2112 if (memguard_cmp_zone(zone)) {
2113 item = memguard_alloc(zone->uz_size, flags);
2116 * Avoid conflict with the use-after-free
2117 * protecting infrastructure from INVARIANTS.
2119 if (zone->uz_init != NULL &&
2120 zone->uz_init != mtrash_init &&
2121 zone->uz_init(item, zone->uz_size, flags) != 0)
2123 if (zone->uz_ctor != NULL &&
2124 zone->uz_ctor != mtrash_ctor &&
2125 zone->uz_ctor(item, zone->uz_size, udata,
2127 zone->uz_fini(item, zone->uz_size);
2132 /* This is unfortunate but should not be fatal. */
2136 * If possible, allocate from the per-CPU cache. There are two
2137 * requirements for safe access to the per-CPU cache: (1) the thread
2138 * accessing the cache must not be preempted or yield during access,
2139 * and (2) the thread must not migrate CPUs without switching which
2140 * cache it accesses. We rely on a critical section to prevent
2141 * preemption and migration. We release the critical section in
2142 * order to acquire the zone mutex if we are unable to allocate from
2143 * the current cache; when we re-acquire the critical section, we
2144 * must detect and handle migration if it has occurred.
2148 cache = &zone->uz_cpu[cpu];
2151 bucket = cache->uc_allocbucket;
2152 if (bucket != NULL && bucket->ub_cnt > 0) {
2154 item = bucket->ub_bucket[bucket->ub_cnt];
2156 bucket->ub_bucket[bucket->ub_cnt] = NULL;
2158 KASSERT(item != NULL, ("uma_zalloc: Bucket pointer mangled."));
2161 if (zone->uz_ctor != NULL &&
2162 zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2163 atomic_add_long(&zone->uz_fails, 1);
2164 zone_free_item(zone, item, udata, SKIP_DTOR);
2168 uma_dbg_alloc(zone, NULL, item);
2171 uma_zero_item(item, zone);
2176 * We have run out of items in our alloc bucket.
2177 * See if we can switch with our free bucket.
2179 bucket = cache->uc_freebucket;
2180 if (bucket != NULL && bucket->ub_cnt > 0) {
2181 #ifdef UMA_DEBUG_ALLOC
2182 printf("uma_zalloc: Swapping empty with alloc.\n");
2184 cache->uc_freebucket = cache->uc_allocbucket;
2185 cache->uc_allocbucket = bucket;
2190 * Discard any empty allocation bucket while we hold no locks.
2192 bucket = cache->uc_allocbucket;
2193 cache->uc_allocbucket = NULL;
2196 bucket_free(zone, bucket, udata);
2198 /* Short-circuit for zones without buckets and low memory. */
2199 if (zone->uz_count == 0 || bucketdisable)
2203 * Attempt to retrieve the item from the per-CPU cache has failed, so
2204 * we must go back to the zone. This requires the zone lock, so we
2205 * must drop the critical section, then re-acquire it when we go back
2206 * to the cache. Since the critical section is released, we may be
2207 * preempted or migrate. As such, make sure not to maintain any
2208 * thread-local state specific to the cache from prior to releasing
2209 * the critical section.
2212 if (ZONE_TRYLOCK(zone) == 0) {
2213 /* Record contention to size the buckets. */
2219 cache = &zone->uz_cpu[cpu];
2222 * Since we have locked the zone we may as well send back our stats.
2224 atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2225 atomic_add_long(&zone->uz_frees, cache->uc_frees);
2226 cache->uc_allocs = 0;
2227 cache->uc_frees = 0;
2229 /* See if we lost the race to fill the cache. */
2230 if (cache->uc_allocbucket != NULL) {
2236 * Check the zone's cache of buckets.
2238 if ((bucket = LIST_FIRST(&zone->uz_buckets)) != NULL) {
2239 KASSERT(bucket->ub_cnt != 0,
2240 ("uma_zalloc_arg: Returning an empty bucket."));
2242 LIST_REMOVE(bucket, ub_link);
2243 cache->uc_allocbucket = bucket;
2247 /* We are no longer associated with this CPU. */
2251 * We bump the uz count when the cache size is insufficient to
2252 * handle the working set.
2254 if (lockfail && zone->uz_count < BUCKET_MAX)
2259 * Now lets just fill a bucket and put it on the free list. If that
2260 * works we'll restart the allocation from the begining and it
2261 * will use the just filled bucket.
2263 bucket = zone_alloc_bucket(zone, udata, flags);
2264 if (bucket != NULL) {
2268 cache = &zone->uz_cpu[cpu];
2270 * See if we lost the race or were migrated. Cache the
2271 * initialized bucket to make this less likely or claim
2272 * the memory directly.
2274 if (cache->uc_allocbucket == NULL)
2275 cache->uc_allocbucket = bucket;
2277 LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
2283 * We may not be able to get a bucket so return an actual item.
2286 printf("uma_zalloc_arg: Bucketzone returned NULL\n");
2290 item = zone_alloc_item(zone, udata, flags);
2296 keg_fetch_slab(uma_keg_t keg, uma_zone_t zone, int flags)
2301 mtx_assert(&keg->uk_lock, MA_OWNED);
2304 if ((flags & M_USE_RESERVE) == 0)
2305 reserve = keg->uk_reserve;
2309 * Find a slab with some space. Prefer slabs that are partially
2310 * used over those that are totally full. This helps to reduce
2313 if (keg->uk_free > reserve) {
2314 if (!LIST_EMPTY(&keg->uk_part_slab)) {
2315 slab = LIST_FIRST(&keg->uk_part_slab);
2317 slab = LIST_FIRST(&keg->uk_free_slab);
2318 LIST_REMOVE(slab, us_link);
2319 LIST_INSERT_HEAD(&keg->uk_part_slab, slab,
2322 MPASS(slab->us_keg == keg);
2327 * M_NOVM means don't ask at all!
2332 if (keg->uk_maxpages && keg->uk_pages >= keg->uk_maxpages) {
2333 keg->uk_flags |= UMA_ZFLAG_FULL;
2335 * If this is not a multi-zone, set the FULL bit.
2336 * Otherwise slab_multi() takes care of it.
2338 if ((zone->uz_flags & UMA_ZFLAG_MULTI) == 0) {
2339 zone->uz_flags |= UMA_ZFLAG_FULL;
2340 zone_log_warning(zone);
2342 if (flags & M_NOWAIT)
2345 msleep(keg, &keg->uk_lock, PVM, "keglimit", 0);
2348 slab = keg_alloc_slab(keg, zone, flags);
2350 * If we got a slab here it's safe to mark it partially used
2351 * and return. We assume that the caller is going to remove
2352 * at least one item.
2355 MPASS(slab->us_keg == keg);
2356 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2360 * We might not have been able to get a slab but another cpu
2361 * could have while we were unlocked. Check again before we
2370 zone_fetch_slab(uma_zone_t zone, uma_keg_t keg, int flags)
2375 keg = zone_first_keg(zone);
2380 slab = keg_fetch_slab(keg, zone, flags);
2383 if (flags & (M_NOWAIT | M_NOVM))
2391 * uma_zone_fetch_slab_multi: Fetches a slab from one available keg. Returns
2392 * with the keg locked. On NULL no lock is held.
2394 * The last pointer is used to seed the search. It is not required.
2397 zone_fetch_slab_multi(uma_zone_t zone, uma_keg_t last, int rflags)
2407 * Don't wait on the first pass. This will skip limit tests
2408 * as well. We don't want to block if we can find a provider
2411 flags = (rflags & ~M_WAITOK) | M_NOWAIT;
2413 * Use the last slab allocated as a hint for where to start
2417 slab = keg_fetch_slab(last, zone, flags);
2423 * Loop until we have a slab incase of transient failures
2424 * while M_WAITOK is specified. I'm not sure this is 100%
2425 * required but we've done it for so long now.
2431 * Search the available kegs for slabs. Be careful to hold the
2432 * correct lock while calling into the keg layer.
2434 LIST_FOREACH(klink, &zone->uz_kegs, kl_link) {
2435 keg = klink->kl_keg;
2437 if ((keg->uk_flags & UMA_ZFLAG_FULL) == 0) {
2438 slab = keg_fetch_slab(keg, zone, flags);
2442 if (keg->uk_flags & UMA_ZFLAG_FULL)
2448 if (rflags & (M_NOWAIT | M_NOVM))
2452 * All kegs are full. XXX We can't atomically check all kegs
2453 * and sleep so just sleep for a short period and retry.
2455 if (full && !empty) {
2457 zone->uz_flags |= UMA_ZFLAG_FULL;
2459 zone_log_warning(zone);
2460 msleep(zone, zone->uz_lockptr, PVM,
2461 "zonelimit", hz/100);
2462 zone->uz_flags &= ~UMA_ZFLAG_FULL;
2471 slab_alloc_item(uma_keg_t keg, uma_slab_t slab)
2476 MPASS(keg == slab->us_keg);
2477 mtx_assert(&keg->uk_lock, MA_OWNED);
2479 freei = BIT_FFS(SLAB_SETSIZE, &slab->us_free) - 1;
2480 BIT_CLR(SLAB_SETSIZE, freei, &slab->us_free);
2481 item = slab->us_data + (keg->uk_rsize * freei);
2482 slab->us_freecount--;
2485 /* Move this slab to the full list */
2486 if (slab->us_freecount == 0) {
2487 LIST_REMOVE(slab, us_link);
2488 LIST_INSERT_HEAD(&keg->uk_full_slab, slab, us_link);
2495 zone_import(uma_zone_t zone, void **bucket, int max, int flags)
2503 /* Try to keep the buckets totally full */
2504 for (i = 0; i < max; ) {
2505 if ((slab = zone->uz_slab(zone, keg, flags)) == NULL)
2508 while (slab->us_freecount && i < max) {
2509 bucket[i++] = slab_alloc_item(keg, slab);
2510 if (keg->uk_free <= keg->uk_reserve)
2513 /* Don't grab more than one slab at a time. */
2524 zone_alloc_bucket(uma_zone_t zone, void *udata, int flags)
2526 uma_bucket_t bucket;
2529 /* Don't wait for buckets, preserve caller's NOVM setting. */
2530 bucket = bucket_alloc(zone, udata, M_NOWAIT | (flags & M_NOVM));
2534 max = MIN(bucket->ub_entries, zone->uz_count);
2535 bucket->ub_cnt = zone->uz_import(zone->uz_arg, bucket->ub_bucket,
2539 * Initialize the memory if necessary.
2541 if (bucket->ub_cnt != 0 && zone->uz_init != NULL) {
2544 for (i = 0; i < bucket->ub_cnt; i++)
2545 if (zone->uz_init(bucket->ub_bucket[i], zone->uz_size,
2549 * If we couldn't initialize the whole bucket, put the
2550 * rest back onto the freelist.
2552 if (i != bucket->ub_cnt) {
2553 zone->uz_release(zone->uz_arg, &bucket->ub_bucket[i],
2554 bucket->ub_cnt - i);
2556 bzero(&bucket->ub_bucket[i],
2557 sizeof(void *) * (bucket->ub_cnt - i));
2563 if (bucket->ub_cnt == 0) {
2564 bucket_free(zone, bucket, udata);
2565 atomic_add_long(&zone->uz_fails, 1);
2573 * Allocates a single item from a zone.
2576 * zone The zone to alloc for.
2577 * udata The data to be passed to the constructor.
2578 * flags M_WAITOK, M_NOWAIT, M_ZERO.
2581 * NULL if there is no memory and M_NOWAIT is set
2582 * An item if successful
2586 zone_alloc_item(uma_zone_t zone, void *udata, int flags)
2592 #ifdef UMA_DEBUG_ALLOC
2593 printf("INTERNAL: Allocating one item from %s(%p)\n", zone->uz_name, zone);
2595 if (zone->uz_import(zone->uz_arg, &item, 1, flags) != 1)
2597 atomic_add_long(&zone->uz_allocs, 1);
2600 * We have to call both the zone's init (not the keg's init)
2601 * and the zone's ctor. This is because the item is going from
2602 * a keg slab directly to the user, and the user is expecting it
2603 * to be both zone-init'd as well as zone-ctor'd.
2605 if (zone->uz_init != NULL) {
2606 if (zone->uz_init(item, zone->uz_size, flags) != 0) {
2607 zone_free_item(zone, item, udata, SKIP_FINI);
2611 if (zone->uz_ctor != NULL) {
2612 if (zone->uz_ctor(item, zone->uz_size, udata, flags) != 0) {
2613 zone_free_item(zone, item, udata, SKIP_DTOR);
2618 uma_dbg_alloc(zone, NULL, item);
2621 uma_zero_item(item, zone);
2626 atomic_add_long(&zone->uz_fails, 1);
2632 uma_zfree_arg(uma_zone_t zone, void *item, void *udata)
2635 uma_bucket_t bucket;
2639 #ifdef UMA_DEBUG_ALLOC_1
2640 printf("Freeing item %p to %s(%p)\n", item, zone->uz_name, zone);
2642 CTR2(KTR_UMA, "uma_zfree_arg thread %x zone %s", curthread,
2645 /* uma_zfree(..., NULL) does nothing, to match free(9). */
2648 #ifdef DEBUG_MEMGUARD
2649 if (is_memguard_addr(item)) {
2650 if (zone->uz_dtor != NULL && zone->uz_dtor != mtrash_dtor)
2651 zone->uz_dtor(item, zone->uz_size, udata);
2652 if (zone->uz_fini != NULL && zone->uz_fini != mtrash_fini)
2653 zone->uz_fini(item, zone->uz_size);
2654 memguard_free(item);
2659 if (zone->uz_flags & UMA_ZONE_MALLOC)
2660 uma_dbg_free(zone, udata, item);
2662 uma_dbg_free(zone, NULL, item);
2664 if (zone->uz_dtor != NULL)
2665 zone->uz_dtor(item, zone->uz_size, udata);
2668 * The race here is acceptable. If we miss it we'll just have to wait
2669 * a little longer for the limits to be reset.
2671 if (zone->uz_flags & UMA_ZFLAG_FULL)
2675 * If possible, free to the per-CPU cache. There are two
2676 * requirements for safe access to the per-CPU cache: (1) the thread
2677 * accessing the cache must not be preempted or yield during access,
2678 * and (2) the thread must not migrate CPUs without switching which
2679 * cache it accesses. We rely on a critical section to prevent
2680 * preemption and migration. We release the critical section in
2681 * order to acquire the zone mutex if we are unable to free to the
2682 * current cache; when we re-acquire the critical section, we must
2683 * detect and handle migration if it has occurred.
2688 cache = &zone->uz_cpu[cpu];
2692 * Try to free into the allocbucket first to give LIFO ordering
2693 * for cache-hot datastructures. Spill over into the freebucket
2694 * if necessary. Alloc will swap them if one runs dry.
2696 bucket = cache->uc_allocbucket;
2697 if (bucket == NULL || bucket->ub_cnt >= bucket->ub_entries)
2698 bucket = cache->uc_freebucket;
2699 if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2700 KASSERT(bucket->ub_bucket[bucket->ub_cnt] == NULL,
2701 ("uma_zfree: Freeing to non free bucket index."));
2702 bucket->ub_bucket[bucket->ub_cnt] = item;
2710 * We must go back the zone, which requires acquiring the zone lock,
2711 * which in turn means we must release and re-acquire the critical
2712 * section. Since the critical section is released, we may be
2713 * preempted or migrate. As such, make sure not to maintain any
2714 * thread-local state specific to the cache from prior to releasing
2715 * the critical section.
2718 if (zone->uz_count == 0 || bucketdisable)
2722 if (ZONE_TRYLOCK(zone) == 0) {
2723 /* Record contention to size the buckets. */
2729 cache = &zone->uz_cpu[cpu];
2732 * Since we have locked the zone we may as well send back our stats.
2734 atomic_add_long(&zone->uz_allocs, cache->uc_allocs);
2735 atomic_add_long(&zone->uz_frees, cache->uc_frees);
2736 cache->uc_allocs = 0;
2737 cache->uc_frees = 0;
2739 bucket = cache->uc_freebucket;
2740 if (bucket != NULL && bucket->ub_cnt < bucket->ub_entries) {
2744 cache->uc_freebucket = NULL;
2746 /* Can we throw this on the zone full list? */
2747 if (bucket != NULL) {
2748 #ifdef UMA_DEBUG_ALLOC
2749 printf("uma_zfree: Putting old bucket on the free list.\n");
2751 /* ub_cnt is pointing to the last free item */
2752 KASSERT(bucket->ub_cnt != 0,
2753 ("uma_zfree: Attempting to insert an empty bucket onto the full list.\n"));
2754 LIST_INSERT_HEAD(&zone->uz_buckets, bucket, ub_link);
2757 /* We are no longer associated with this CPU. */
2761 * We bump the uz count when the cache size is insufficient to
2762 * handle the working set.
2764 if (lockfail && zone->uz_count < BUCKET_MAX)
2768 #ifdef UMA_DEBUG_ALLOC
2769 printf("uma_zfree: Allocating new free bucket.\n");
2771 bucket = bucket_alloc(zone, udata, M_NOWAIT);
2775 cache = &zone->uz_cpu[cpu];
2776 if (cache->uc_freebucket == NULL) {
2777 cache->uc_freebucket = bucket;
2781 * We lost the race, start over. We have to drop our
2782 * critical section to free the bucket.
2785 bucket_free(zone, bucket, udata);
2790 * If nothing else caught this, we'll just do an internal free.
2793 zone_free_item(zone, item, udata, SKIP_DTOR);
2799 slab_free_item(uma_keg_t keg, uma_slab_t slab, void *item)
2803 mtx_assert(&keg->uk_lock, MA_OWNED);
2804 MPASS(keg == slab->us_keg);
2806 /* Do we need to remove from any lists? */
2807 if (slab->us_freecount+1 == keg->uk_ipers) {
2808 LIST_REMOVE(slab, us_link);
2809 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
2810 } else if (slab->us_freecount == 0) {
2811 LIST_REMOVE(slab, us_link);
2812 LIST_INSERT_HEAD(&keg->uk_part_slab, slab, us_link);
2815 /* Slab management. */
2816 freei = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
2817 BIT_SET(SLAB_SETSIZE, freei, &slab->us_free);
2818 slab->us_freecount++;
2820 /* Keg statistics. */
2825 zone_release(uma_zone_t zone, void **bucket, int cnt)
2835 keg = zone_first_keg(zone);
2837 for (i = 0; i < cnt; i++) {
2839 if (!(zone->uz_flags & UMA_ZONE_VTOSLAB)) {
2840 mem = (uint8_t *)((uintptr_t)item & (~UMA_SLAB_MASK));
2841 if (zone->uz_flags & UMA_ZONE_HASH) {
2842 slab = hash_sfind(&keg->uk_hash, mem);
2844 mem += keg->uk_pgoff;
2845 slab = (uma_slab_t)mem;
2848 slab = vtoslab((vm_offset_t)item);
2849 if (slab->us_keg != keg) {
2855 slab_free_item(keg, slab, item);
2856 if (keg->uk_flags & UMA_ZFLAG_FULL) {
2857 if (keg->uk_pages < keg->uk_maxpages) {
2858 keg->uk_flags &= ~UMA_ZFLAG_FULL;
2863 * We can handle one more allocation. Since we're
2864 * clearing ZFLAG_FULL, wake up all procs blocked
2865 * on pages. This should be uncommon, so keeping this
2866 * simple for now (rather than adding count of blocked
2875 zone->uz_flags &= ~UMA_ZFLAG_FULL;
2883 * Frees a single item to any zone.
2886 * zone The zone to free to
2887 * item The item we're freeing
2888 * udata User supplied data for the dtor
2889 * skip Skip dtors and finis
2892 zone_free_item(uma_zone_t zone, void *item, void *udata, enum zfreeskip skip)
2896 if (skip == SKIP_NONE) {
2897 if (zone->uz_flags & UMA_ZONE_MALLOC)
2898 uma_dbg_free(zone, udata, item);
2900 uma_dbg_free(zone, NULL, item);
2903 if (skip < SKIP_DTOR && zone->uz_dtor)
2904 zone->uz_dtor(item, zone->uz_size, udata);
2906 if (skip < SKIP_FINI && zone->uz_fini)
2907 zone->uz_fini(item, zone->uz_size);
2909 atomic_add_long(&zone->uz_frees, 1);
2910 zone->uz_release(zone->uz_arg, &item, 1);
2915 uma_zone_set_max(uma_zone_t zone, int nitems)
2919 keg = zone_first_keg(zone);
2923 keg->uk_maxpages = (nitems / keg->uk_ipers) * keg->uk_ppera;
2924 if (keg->uk_maxpages * keg->uk_ipers < nitems)
2925 keg->uk_maxpages += keg->uk_ppera;
2926 nitems = keg->uk_maxpages * keg->uk_ipers;
2934 uma_zone_get_max(uma_zone_t zone)
2939 keg = zone_first_keg(zone);
2943 nitems = keg->uk_maxpages * keg->uk_ipers;
2951 uma_zone_set_warning(uma_zone_t zone, const char *warning)
2955 zone->uz_warning = warning;
2961 uma_zone_get_cur(uma_zone_t zone)
2967 nitems = zone->uz_allocs - zone->uz_frees;
2970 * See the comment in sysctl_vm_zone_stats() regarding the
2971 * safety of accessing the per-cpu caches. With the zone lock
2972 * held, it is safe, but can potentially result in stale data.
2974 nitems += zone->uz_cpu[i].uc_allocs -
2975 zone->uz_cpu[i].uc_frees;
2979 return (nitems < 0 ? 0 : nitems);
2984 uma_zone_set_init(uma_zone_t zone, uma_init uminit)
2988 keg = zone_first_keg(zone);
2989 KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
2991 KASSERT(keg->uk_pages == 0,
2992 ("uma_zone_set_init on non-empty keg"));
2993 keg->uk_init = uminit;
2999 uma_zone_set_fini(uma_zone_t zone, uma_fini fini)
3003 keg = zone_first_keg(zone);
3004 KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
3006 KASSERT(keg->uk_pages == 0,
3007 ("uma_zone_set_fini on non-empty keg"));
3008 keg->uk_fini = fini;
3014 uma_zone_set_zinit(uma_zone_t zone, uma_init zinit)
3018 KASSERT(zone_first_keg(zone)->uk_pages == 0,
3019 ("uma_zone_set_zinit on non-empty keg"));
3020 zone->uz_init = zinit;
3026 uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini)
3030 KASSERT(zone_first_keg(zone)->uk_pages == 0,
3031 ("uma_zone_set_zfini on non-empty keg"));
3032 zone->uz_fini = zfini;
3037 /* XXX uk_freef is not actually used with the zone locked */
3039 uma_zone_set_freef(uma_zone_t zone, uma_free freef)
3043 keg = zone_first_keg(zone);
3044 KASSERT(keg != NULL, ("uma_zone_set_init: Invalid zone type"));
3046 keg->uk_freef = freef;
3051 /* XXX uk_allocf is not actually used with the zone locked */
3053 uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf)
3057 keg = zone_first_keg(zone);
3059 keg->uk_allocf = allocf;
3065 uma_zone_reserve(uma_zone_t zone, int items)
3069 keg = zone_first_keg(zone);
3073 keg->uk_reserve = items;
3081 uma_zone_reserve_kva(uma_zone_t zone, int count)
3087 keg = zone_first_keg(zone);
3090 pages = count / keg->uk_ipers;
3092 if (pages * keg->uk_ipers < count)
3095 #ifdef UMA_MD_SMALL_ALLOC
3096 if (keg->uk_ppera > 1) {
3100 kva = kva_alloc(pages * UMA_SLAB_SIZE);
3108 keg->uk_maxpages = pages;
3109 #ifdef UMA_MD_SMALL_ALLOC
3110 keg->uk_allocf = (keg->uk_ppera > 1) ? noobj_alloc : uma_small_alloc;
3112 keg->uk_allocf = noobj_alloc;
3114 keg->uk_flags |= UMA_ZONE_NOFREE;
3122 uma_prealloc(uma_zone_t zone, int items)
3128 keg = zone_first_keg(zone);
3132 slabs = items / keg->uk_ipers;
3133 if (slabs * keg->uk_ipers < items)
3136 slab = keg_alloc_slab(keg, zone, M_WAITOK);
3139 MPASS(slab->us_keg == keg);
3140 LIST_INSERT_HEAD(&keg->uk_free_slab, slab, us_link);
3148 uma_find_refcnt(uma_zone_t zone, void *item)
3150 uma_slabrefcnt_t slabref;
3156 slab = vtoslab((vm_offset_t)item & (~UMA_SLAB_MASK));
3157 slabref = (uma_slabrefcnt_t)slab;
3159 KASSERT(keg->uk_flags & UMA_ZONE_REFCNT,
3160 ("uma_find_refcnt(): zone possibly not UMA_ZONE_REFCNT"));
3161 idx = ((uintptr_t)item - (uintptr_t)slab->us_data) / keg->uk_rsize;
3162 refcnt = &slabref->us_refcnt[idx];
3171 printf("UMA: vm asked us to release pages!\n");
3174 zone_foreach(zone_drain);
3175 if (vm_page_count_min()) {
3176 cache_drain_safe(NULL);
3177 zone_foreach(zone_drain);
3180 * Some slabs may have been freed but this zone will be visited early
3181 * we visit again so that we can free pages that are empty once other
3182 * zones are drained. We have to do the same for buckets.
3184 zone_drain(slabzone);
3185 zone_drain(slabrefzone);
3186 bucket_zone_drain();
3191 uma_zone_exhausted(uma_zone_t zone)
3196 full = (zone->uz_flags & UMA_ZFLAG_FULL);
3202 uma_zone_exhausted_nolock(uma_zone_t zone)
3204 return (zone->uz_flags & UMA_ZFLAG_FULL);
3208 uma_large_malloc(int size, int wait)
3214 slab = zone_alloc_item(slabzone, NULL, wait);
3217 mem = page_alloc(NULL, size, &flags, wait);
3219 vsetslab((vm_offset_t)mem, slab);
3220 slab->us_data = mem;
3221 slab->us_flags = flags | UMA_SLAB_MALLOC;
3222 slab->us_size = size;
3224 zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3231 uma_large_free(uma_slab_t slab)
3234 page_free(slab->us_data, slab->us_size, slab->us_flags);
3235 zone_free_item(slabzone, slab, NULL, SKIP_NONE);
3239 uma_zero_item(void *item, uma_zone_t zone)
3242 if (zone->uz_flags & UMA_ZONE_PCPU) {
3243 for (int i = 0; i < mp_ncpus; i++)
3244 bzero(zpcpu_get_cpu(item, i), zone->uz_size);
3246 bzero(item, zone->uz_size);
3250 uma_print_stats(void)
3252 zone_foreach(uma_print_zone);
3256 slab_print(uma_slab_t slab)
3258 printf("slab: keg %p, data %p, freecount %d\n",
3259 slab->us_keg, slab->us_data, slab->us_freecount);
3263 cache_print(uma_cache_t cache)
3265 printf("alloc: %p(%d), free: %p(%d)\n",
3266 cache->uc_allocbucket,
3267 cache->uc_allocbucket?cache->uc_allocbucket->ub_cnt:0,
3268 cache->uc_freebucket,
3269 cache->uc_freebucket?cache->uc_freebucket->ub_cnt:0);
3273 uma_print_keg(uma_keg_t keg)
3277 printf("keg: %s(%p) size %d(%d) flags %#x ipers %d ppera %d "
3278 "out %d free %d limit %d\n",
3279 keg->uk_name, keg, keg->uk_size, keg->uk_rsize, keg->uk_flags,
3280 keg->uk_ipers, keg->uk_ppera,
3281 (keg->uk_ipers * keg->uk_pages) - keg->uk_free, keg->uk_free,
3282 (keg->uk_maxpages / keg->uk_ppera) * keg->uk_ipers);
3283 printf("Part slabs:\n");
3284 LIST_FOREACH(slab, &keg->uk_part_slab, us_link)
3286 printf("Free slabs:\n");
3287 LIST_FOREACH(slab, &keg->uk_free_slab, us_link)
3289 printf("Full slabs:\n");
3290 LIST_FOREACH(slab, &keg->uk_full_slab, us_link)
3295 uma_print_zone(uma_zone_t zone)
3301 printf("zone: %s(%p) size %d flags %#x\n",
3302 zone->uz_name, zone, zone->uz_size, zone->uz_flags);
3303 LIST_FOREACH(kl, &zone->uz_kegs, kl_link)
3304 uma_print_keg(kl->kl_keg);
3306 cache = &zone->uz_cpu[i];
3307 printf("CPU %d Cache:\n", i);
3314 * Generate statistics across both the zone and its per-cpu cache's. Return
3315 * desired statistics if the pointer is non-NULL for that statistic.
3317 * Note: does not update the zone statistics, as it can't safely clear the
3318 * per-CPU cache statistic.
3320 * XXXRW: Following the uc_allocbucket and uc_freebucket pointers here isn't
3321 * safe from off-CPU; we should modify the caches to track this information
3322 * directly so that we don't have to.
3325 uma_zone_sumstat(uma_zone_t z, int *cachefreep, uint64_t *allocsp,
3326 uint64_t *freesp, uint64_t *sleepsp)
3329 uint64_t allocs, frees, sleeps;
3332 allocs = frees = sleeps = 0;
3335 cache = &z->uz_cpu[cpu];
3336 if (cache->uc_allocbucket != NULL)
3337 cachefree += cache->uc_allocbucket->ub_cnt;
3338 if (cache->uc_freebucket != NULL)
3339 cachefree += cache->uc_freebucket->ub_cnt;
3340 allocs += cache->uc_allocs;
3341 frees += cache->uc_frees;
3343 allocs += z->uz_allocs;
3344 frees += z->uz_frees;
3345 sleeps += z->uz_sleeps;
3346 if (cachefreep != NULL)
3347 *cachefreep = cachefree;
3348 if (allocsp != NULL)
3352 if (sleepsp != NULL)
3358 sysctl_vm_zone_count(SYSCTL_HANDLER_ARGS)
3366 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3367 LIST_FOREACH(z, &kz->uk_zones, uz_link)
3370 mtx_unlock(&uma_mtx);
3371 return (sysctl_handle_int(oidp, &count, 0, req));
3375 sysctl_vm_zone_stats(SYSCTL_HANDLER_ARGS)
3377 struct uma_stream_header ush;
3378 struct uma_type_header uth;
3379 struct uma_percpu_stat ups;
3380 uma_bucket_t bucket;
3387 int count, error, i;
3389 error = sysctl_wire_old_buffer(req, 0);
3392 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
3396 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3397 LIST_FOREACH(z, &kz->uk_zones, uz_link)
3402 * Insert stream header.
3404 bzero(&ush, sizeof(ush));
3405 ush.ush_version = UMA_STREAM_VERSION;
3406 ush.ush_maxcpus = (mp_maxid + 1);
3407 ush.ush_count = count;
3408 (void)sbuf_bcat(&sbuf, &ush, sizeof(ush));
3410 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3411 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3412 bzero(&uth, sizeof(uth));
3414 strlcpy(uth.uth_name, z->uz_name, UTH_MAX_NAME);
3415 uth.uth_align = kz->uk_align;
3416 uth.uth_size = kz->uk_size;
3417 uth.uth_rsize = kz->uk_rsize;
3418 LIST_FOREACH(kl, &z->uz_kegs, kl_link) {
3420 uth.uth_maxpages += k->uk_maxpages;
3421 uth.uth_pages += k->uk_pages;
3422 uth.uth_keg_free += k->uk_free;
3423 uth.uth_limit = (k->uk_maxpages / k->uk_ppera)
3428 * A zone is secondary is it is not the first entry
3429 * on the keg's zone list.
3431 if ((z->uz_flags & UMA_ZONE_SECONDARY) &&
3432 (LIST_FIRST(&kz->uk_zones) != z))
3433 uth.uth_zone_flags = UTH_ZONE_SECONDARY;
3435 LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3436 uth.uth_zone_free += bucket->ub_cnt;
3437 uth.uth_allocs = z->uz_allocs;
3438 uth.uth_frees = z->uz_frees;
3439 uth.uth_fails = z->uz_fails;
3440 uth.uth_sleeps = z->uz_sleeps;
3441 (void)sbuf_bcat(&sbuf, &uth, sizeof(uth));
3443 * While it is not normally safe to access the cache
3444 * bucket pointers while not on the CPU that owns the
3445 * cache, we only allow the pointers to be exchanged
3446 * without the zone lock held, not invalidated, so
3447 * accept the possible race associated with bucket
3448 * exchange during monitoring.
3450 for (i = 0; i < (mp_maxid + 1); i++) {
3451 bzero(&ups, sizeof(ups));
3452 if (kz->uk_flags & UMA_ZFLAG_INTERNAL)
3456 cache = &z->uz_cpu[i];
3457 if (cache->uc_allocbucket != NULL)
3458 ups.ups_cache_free +=
3459 cache->uc_allocbucket->ub_cnt;
3460 if (cache->uc_freebucket != NULL)
3461 ups.ups_cache_free +=
3462 cache->uc_freebucket->ub_cnt;
3463 ups.ups_allocs = cache->uc_allocs;
3464 ups.ups_frees = cache->uc_frees;
3466 (void)sbuf_bcat(&sbuf, &ups, sizeof(ups));
3471 mtx_unlock(&uma_mtx);
3472 error = sbuf_finish(&sbuf);
3478 sysctl_handle_uma_zone_max(SYSCTL_HANDLER_ARGS)
3480 uma_zone_t zone = *(uma_zone_t *)arg1;
3481 int error, max, old;
3483 old = max = uma_zone_get_max(zone);
3484 error = sysctl_handle_int(oidp, &max, 0, req);
3485 if (error || !req->newptr)
3491 uma_zone_set_max(zone, max);
3497 sysctl_handle_uma_zone_cur(SYSCTL_HANDLER_ARGS)
3499 uma_zone_t zone = *(uma_zone_t *)arg1;
3502 cur = uma_zone_get_cur(zone);
3503 return (sysctl_handle_int(oidp, &cur, 0, req));
3507 DB_SHOW_COMMAND(uma, db_show_uma)
3509 uint64_t allocs, frees, sleeps;
3510 uma_bucket_t bucket;
3515 db_printf("%18s %8s %8s %8s %12s %8s %8s\n", "Zone", "Size", "Used",
3516 "Free", "Requests", "Sleeps", "Bucket");
3517 LIST_FOREACH(kz, &uma_kegs, uk_link) {
3518 LIST_FOREACH(z, &kz->uk_zones, uz_link) {
3519 if (kz->uk_flags & UMA_ZFLAG_INTERNAL) {
3520 allocs = z->uz_allocs;
3521 frees = z->uz_frees;
3522 sleeps = z->uz_sleeps;
3525 uma_zone_sumstat(z, &cachefree, &allocs,
3527 if (!((z->uz_flags & UMA_ZONE_SECONDARY) &&
3528 (LIST_FIRST(&kz->uk_zones) != z)))
3529 cachefree += kz->uk_free;
3530 LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3531 cachefree += bucket->ub_cnt;
3532 db_printf("%18s %8ju %8jd %8d %12ju %8ju %8u\n",
3533 z->uz_name, (uintmax_t)kz->uk_size,
3534 (intmax_t)(allocs - frees), cachefree,
3535 (uintmax_t)allocs, sleeps, z->uz_count);
3542 DB_SHOW_COMMAND(umacache, db_show_umacache)
3544 uint64_t allocs, frees;
3545 uma_bucket_t bucket;
3549 db_printf("%18s %8s %8s %8s %12s %8s\n", "Zone", "Size", "Used", "Free",
3550 "Requests", "Bucket");
3551 LIST_FOREACH(z, &uma_cachezones, uz_link) {
3552 uma_zone_sumstat(z, &cachefree, &allocs, &frees, NULL);
3553 LIST_FOREACH(bucket, &z->uz_buckets, ub_link)
3554 cachefree += bucket->ub_cnt;
3555 db_printf("%18s %8ju %8jd %8d %12ju %8u\n",
3556 z->uz_name, (uintmax_t)z->uz_size,
3557 (intmax_t)(allocs - frees), cachefree,
3558 (uintmax_t)allocs, z->uz_count);