1 // SPDX-License-Identifier: GPL-2.0
3 * Slab allocator functions that are independent of the allocator strategy
5 * (C) 2012 Christoph Lameter <cl@linux.com>
7 #include <linux/slab.h>
10 #include <linux/poison.h>
11 #include <linux/interrupt.h>
12 #include <linux/memory.h>
13 #include <linux/cache.h>
14 #include <linux/compiler.h>
15 #include <linux/module.h>
16 #include <linux/cpu.h>
17 #include <linux/uaccess.h>
18 #include <linux/seq_file.h>
19 #include <linux/proc_fs.h>
20 #include <linux/debugfs.h>
21 #include <asm/cacheflush.h>
22 #include <asm/tlbflush.h>
24 #include <linux/memcontrol.h>
26 #define CREATE_TRACE_POINTS
27 #include <trace/events/kmem.h>
31 enum slab_state slab_state;
32 LIST_HEAD(slab_caches);
33 DEFINE_MUTEX(slab_mutex);
34 struct kmem_cache *kmem_cache;
36 #ifdef CONFIG_HARDENED_USERCOPY
37 bool usercopy_fallback __ro_after_init =
38 IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK);
39 module_param(usercopy_fallback, bool, 0400);
40 MODULE_PARM_DESC(usercopy_fallback,
41 "WARN instead of reject usercopy whitelist violations");
44 static LIST_HEAD(slab_caches_to_rcu_destroy);
45 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work);
46 static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
47 slab_caches_to_rcu_destroy_workfn);
50 * Set of flags that will prevent slab merging
52 #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
53 SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \
54 SLAB_FAILSLAB | SLAB_KASAN)
56 #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
57 SLAB_CACHE_DMA32 | SLAB_ACCOUNT)
60 * Merge control. If this is set then no merging of slab caches will occur.
62 static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT);
64 static int __init setup_slab_nomerge(char *str)
71 __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
74 __setup("slab_nomerge", setup_slab_nomerge);
77 * Determine the size of a slab object
79 unsigned int kmem_cache_size(struct kmem_cache *s)
81 return s->object_size;
83 EXPORT_SYMBOL(kmem_cache_size);
85 #ifdef CONFIG_DEBUG_VM
86 static int kmem_cache_sanity_check(const char *name, unsigned int size)
88 if (!name || in_interrupt() || size < sizeof(void *) ||
89 size > KMALLOC_MAX_SIZE) {
90 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
94 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
98 static inline int kmem_cache_sanity_check(const char *name, unsigned int size)
104 void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
108 for (i = 0; i < nr; i++) {
110 kmem_cache_free(s, p[i]);
116 int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
121 for (i = 0; i < nr; i++) {
122 void *x = p[i] = kmem_cache_alloc(s, flags);
124 __kmem_cache_free_bulk(s, i, p);
131 #ifdef CONFIG_MEMCG_KMEM
133 LIST_HEAD(slab_root_caches);
134 static DEFINE_SPINLOCK(memcg_kmem_wq_lock);
136 static void kmemcg_cache_shutdown(struct percpu_ref *percpu_ref);
138 void slab_init_memcg_params(struct kmem_cache *s)
140 s->memcg_params.root_cache = NULL;
141 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
142 INIT_LIST_HEAD(&s->memcg_params.children);
143 s->memcg_params.dying = false;
146 static int init_memcg_params(struct kmem_cache *s,
147 struct kmem_cache *root_cache)
149 struct memcg_cache_array *arr;
152 int ret = percpu_ref_init(&s->memcg_params.refcnt,
153 kmemcg_cache_shutdown,
158 s->memcg_params.root_cache = root_cache;
159 INIT_LIST_HEAD(&s->memcg_params.children_node);
160 INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node);
164 slab_init_memcg_params(s);
166 if (!memcg_nr_cache_ids)
169 arr = kvzalloc(sizeof(struct memcg_cache_array) +
170 memcg_nr_cache_ids * sizeof(void *),
175 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
179 static void destroy_memcg_params(struct kmem_cache *s)
181 if (is_root_cache(s)) {
182 kvfree(rcu_access_pointer(s->memcg_params.memcg_caches));
184 mem_cgroup_put(s->memcg_params.memcg);
185 WRITE_ONCE(s->memcg_params.memcg, NULL);
186 percpu_ref_exit(&s->memcg_params.refcnt);
190 static void free_memcg_params(struct rcu_head *rcu)
192 struct memcg_cache_array *old;
194 old = container_of(rcu, struct memcg_cache_array, rcu);
198 static int update_memcg_params(struct kmem_cache *s, int new_array_size)
200 struct memcg_cache_array *old, *new;
202 new = kvzalloc(sizeof(struct memcg_cache_array) +
203 new_array_size * sizeof(void *), GFP_KERNEL);
207 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
208 lockdep_is_held(&slab_mutex));
210 memcpy(new->entries, old->entries,
211 memcg_nr_cache_ids * sizeof(void *));
213 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
215 call_rcu(&old->rcu, free_memcg_params);
219 int memcg_update_all_caches(int num_memcgs)
221 struct kmem_cache *s;
224 mutex_lock(&slab_mutex);
225 list_for_each_entry(s, &slab_root_caches, root_caches_node) {
226 ret = update_memcg_params(s, num_memcgs);
228 * Instead of freeing the memory, we'll just leave the caches
229 * up to this point in an updated state.
234 mutex_unlock(&slab_mutex);
238 void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg)
240 if (is_root_cache(s)) {
241 list_add(&s->root_caches_node, &slab_root_caches);
243 css_get(&memcg->css);
244 s->memcg_params.memcg = memcg;
245 list_add(&s->memcg_params.children_node,
246 &s->memcg_params.root_cache->memcg_params.children);
247 list_add(&s->memcg_params.kmem_caches_node,
248 &s->memcg_params.memcg->kmem_caches);
252 static void memcg_unlink_cache(struct kmem_cache *s)
254 if (is_root_cache(s)) {
255 list_del(&s->root_caches_node);
257 list_del(&s->memcg_params.children_node);
258 list_del(&s->memcg_params.kmem_caches_node);
262 static inline int init_memcg_params(struct kmem_cache *s,
263 struct kmem_cache *root_cache)
268 static inline void destroy_memcg_params(struct kmem_cache *s)
272 static inline void memcg_unlink_cache(struct kmem_cache *s)
275 #endif /* CONFIG_MEMCG_KMEM */
278 * Figure out what the alignment of the objects will be given a set of
279 * flags, a user specified alignment and the size of the objects.
281 static unsigned int calculate_alignment(slab_flags_t flags,
282 unsigned int align, unsigned int size)
285 * If the user wants hardware cache aligned objects then follow that
286 * suggestion if the object is sufficiently large.
288 * The hardware cache alignment cannot override the specified
289 * alignment though. If that is greater then use it.
291 if (flags & SLAB_HWCACHE_ALIGN) {
294 ralign = cache_line_size();
295 while (size <= ralign / 2)
297 align = max(align, ralign);
300 if (align < ARCH_SLAB_MINALIGN)
301 align = ARCH_SLAB_MINALIGN;
303 return ALIGN(align, sizeof(void *));
307 * Find a mergeable slab cache
309 int slab_unmergeable(struct kmem_cache *s)
311 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
314 if (!is_root_cache(s))
324 * We may have set a slab to be unmergeable during bootstrap.
332 struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
333 slab_flags_t flags, const char *name, void (*ctor)(void *))
335 struct kmem_cache *s;
343 size = ALIGN(size, sizeof(void *));
344 align = calculate_alignment(flags, align, size);
345 size = ALIGN(size, align);
346 flags = kmem_cache_flags(size, flags, name, NULL);
348 if (flags & SLAB_NEVER_MERGE)
351 list_for_each_entry_reverse(s, &slab_root_caches, root_caches_node) {
352 if (slab_unmergeable(s))
358 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
361 * Check if alignment is compatible.
362 * Courtesy of Adrian Drzewiecki
364 if ((s->size & ~(align - 1)) != s->size)
367 if (s->size - size >= sizeof(void *))
370 if (IS_ENABLED(CONFIG_SLAB) && align &&
371 (align > s->align || s->align % align))
379 static struct kmem_cache *create_cache(const char *name,
380 unsigned int object_size, unsigned int align,
381 slab_flags_t flags, unsigned int useroffset,
382 unsigned int usersize, void (*ctor)(void *),
383 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
385 struct kmem_cache *s;
388 if (WARN_ON(useroffset + usersize > object_size))
389 useroffset = usersize = 0;
392 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
397 s->size = s->object_size = object_size;
400 s->useroffset = useroffset;
401 s->usersize = usersize;
403 err = init_memcg_params(s, root_cache);
407 err = __kmem_cache_create(s, flags);
412 list_add(&s->list, &slab_caches);
413 memcg_link_cache(s, memcg);
420 destroy_memcg_params(s);
421 kmem_cache_free(kmem_cache, s);
426 * kmem_cache_create_usercopy - Create a cache with a region suitable
427 * for copying to userspace
428 * @name: A string which is used in /proc/slabinfo to identify this cache.
429 * @size: The size of objects to be created in this cache.
430 * @align: The required alignment for the objects.
432 * @useroffset: Usercopy region offset
433 * @usersize: Usercopy region size
434 * @ctor: A constructor for the objects.
436 * Cannot be called within a interrupt, but can be interrupted.
437 * The @ctor is run when new pages are allocated by the cache.
441 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
442 * to catch references to uninitialised memory.
444 * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
445 * for buffer overruns.
447 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
448 * cacheline. This can be beneficial if you're counting cycles as closely
451 * Return: a pointer to the cache on success, NULL on failure.
454 kmem_cache_create_usercopy(const char *name,
455 unsigned int size, unsigned int align,
457 unsigned int useroffset, unsigned int usersize,
458 void (*ctor)(void *))
460 struct kmem_cache *s = NULL;
461 const char *cache_name;
466 memcg_get_cache_ids();
468 mutex_lock(&slab_mutex);
470 err = kmem_cache_sanity_check(name, size);
475 /* Refuse requests with allocator specific flags */
476 if (flags & ~SLAB_FLAGS_PERMITTED) {
482 * Some allocators will constraint the set of valid flags to a subset
483 * of all flags. We expect them to define CACHE_CREATE_MASK in this
484 * case, and we'll just provide them with a sanitized version of the
487 flags &= CACHE_CREATE_MASK;
489 /* Fail closed on bad usersize of useroffset values. */
490 if (WARN_ON(!usersize && useroffset) ||
491 WARN_ON(size < usersize || size - usersize < useroffset))
492 usersize = useroffset = 0;
495 s = __kmem_cache_alias(name, size, align, flags, ctor);
499 cache_name = kstrdup_const(name, GFP_KERNEL);
505 s = create_cache(cache_name, size,
506 calculate_alignment(flags, align, size),
507 flags, useroffset, usersize, ctor, NULL, NULL);
510 kfree_const(cache_name);
514 mutex_unlock(&slab_mutex);
516 memcg_put_cache_ids();
521 if (flags & SLAB_PANIC)
522 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
525 pr_warn("kmem_cache_create(%s) failed with error %d\n",
533 EXPORT_SYMBOL(kmem_cache_create_usercopy);
536 * kmem_cache_create - Create a cache.
537 * @name: A string which is used in /proc/slabinfo to identify this cache.
538 * @size: The size of objects to be created in this cache.
539 * @align: The required alignment for the objects.
541 * @ctor: A constructor for the objects.
543 * Cannot be called within a interrupt, but can be interrupted.
544 * The @ctor is run when new pages are allocated by the cache.
548 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
549 * to catch references to uninitialised memory.
551 * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
552 * for buffer overruns.
554 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
555 * cacheline. This can be beneficial if you're counting cycles as closely
558 * Return: a pointer to the cache on success, NULL on failure.
561 kmem_cache_create(const char *name, unsigned int size, unsigned int align,
562 slab_flags_t flags, void (*ctor)(void *))
564 return kmem_cache_create_usercopy(name, size, align, flags, 0, 0,
567 EXPORT_SYMBOL(kmem_cache_create);
569 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
571 LIST_HEAD(to_destroy);
572 struct kmem_cache *s, *s2;
575 * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
576 * @slab_caches_to_rcu_destroy list. The slab pages are freed
577 * through RCU and and the associated kmem_cache are dereferenced
578 * while freeing the pages, so the kmem_caches should be freed only
579 * after the pending RCU operations are finished. As rcu_barrier()
580 * is a pretty slow operation, we batch all pending destructions
583 mutex_lock(&slab_mutex);
584 list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
585 mutex_unlock(&slab_mutex);
587 if (list_empty(&to_destroy))
592 list_for_each_entry_safe(s, s2, &to_destroy, list) {
593 #ifdef SLAB_SUPPORTS_SYSFS
594 sysfs_slab_release(s);
596 slab_kmem_cache_release(s);
601 static int shutdown_cache(struct kmem_cache *s)
603 /* free asan quarantined objects */
604 kasan_cache_shutdown(s);
606 if (__kmem_cache_shutdown(s) != 0)
609 memcg_unlink_cache(s);
612 if (s->flags & SLAB_TYPESAFE_BY_RCU) {
613 #ifdef SLAB_SUPPORTS_SYSFS
614 sysfs_slab_unlink(s);
616 list_add_tail(&s->list, &slab_caches_to_rcu_destroy);
617 schedule_work(&slab_caches_to_rcu_destroy_work);
619 #ifdef SLAB_SUPPORTS_SYSFS
620 sysfs_slab_unlink(s);
621 sysfs_slab_release(s);
623 slab_kmem_cache_release(s);
630 #ifdef CONFIG_MEMCG_KMEM
632 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
633 * @memcg: The memory cgroup the new cache is for.
634 * @root_cache: The parent of the new cache.
636 * This function attempts to create a kmem cache that will serve allocation
637 * requests going from @memcg to @root_cache. The new cache inherits properties
640 void memcg_create_kmem_cache(struct mem_cgroup *memcg,
641 struct kmem_cache *root_cache)
643 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
644 struct cgroup_subsys_state *css = &memcg->css;
645 struct memcg_cache_array *arr;
646 struct kmem_cache *s = NULL;
653 mutex_lock(&slab_mutex);
656 * The memory cgroup could have been offlined while the cache
657 * creation work was pending.
659 if (memcg->kmem_state != KMEM_ONLINE)
662 idx = memcg_cache_id(memcg);
663 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
664 lockdep_is_held(&slab_mutex));
667 * Since per-memcg caches are created asynchronously on first
668 * allocation (see memcg_kmem_get_cache()), several threads can try to
669 * create the same cache, but only one of them may succeed.
671 if (arr->entries[idx])
674 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
675 cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name,
676 css->serial_nr, memcg_name_buf);
680 s = create_cache(cache_name, root_cache->object_size,
682 root_cache->flags & CACHE_CREATE_MASK,
683 root_cache->useroffset, root_cache->usersize,
684 root_cache->ctor, memcg, root_cache);
686 * If we could not create a memcg cache, do not complain, because
687 * that's not critical at all as we can always proceed with the root
696 * Since readers won't lock (see memcg_kmem_get_cache()), we need a
697 * barrier here to ensure nobody will see the kmem_cache partially
701 arr->entries[idx] = s;
704 mutex_unlock(&slab_mutex);
710 static void kmemcg_workfn(struct work_struct *work)
712 struct kmem_cache *s = container_of(work, struct kmem_cache,
718 mutex_lock(&slab_mutex);
719 s->memcg_params.work_fn(s);
720 mutex_unlock(&slab_mutex);
726 static void kmemcg_rcufn(struct rcu_head *head)
728 struct kmem_cache *s = container_of(head, struct kmem_cache,
729 memcg_params.rcu_head);
732 * We need to grab blocking locks. Bounce to ->work. The
733 * work item shares the space with the RCU head and can't be
734 * initialized earlier.
736 INIT_WORK(&s->memcg_params.work, kmemcg_workfn);
737 queue_work(memcg_kmem_cache_wq, &s->memcg_params.work);
740 static void kmemcg_cache_shutdown_fn(struct kmem_cache *s)
742 WARN_ON(shutdown_cache(s));
745 static void kmemcg_cache_shutdown(struct percpu_ref *percpu_ref)
747 struct kmem_cache *s = container_of(percpu_ref, struct kmem_cache,
748 memcg_params.refcnt);
751 spin_lock_irqsave(&memcg_kmem_wq_lock, flags);
752 if (s->memcg_params.root_cache->memcg_params.dying)
755 s->memcg_params.work_fn = kmemcg_cache_shutdown_fn;
756 INIT_WORK(&s->memcg_params.work, kmemcg_workfn);
757 queue_work(memcg_kmem_cache_wq, &s->memcg_params.work);
760 spin_unlock_irqrestore(&memcg_kmem_wq_lock, flags);
763 static void kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s)
765 __kmemcg_cache_deactivate_after_rcu(s);
766 percpu_ref_kill(&s->memcg_params.refcnt);
769 static void kmemcg_cache_deactivate(struct kmem_cache *s)
771 if (WARN_ON_ONCE(is_root_cache(s)))
774 __kmemcg_cache_deactivate(s);
775 s->flags |= SLAB_DEACTIVATED;
778 * memcg_kmem_wq_lock is used to synchronize memcg_params.dying
779 * flag and make sure that no new kmem_cache deactivation tasks
780 * are queued (see flush_memcg_workqueue() ).
782 spin_lock_irq(&memcg_kmem_wq_lock);
783 if (s->memcg_params.root_cache->memcg_params.dying)
786 s->memcg_params.work_fn = kmemcg_cache_deactivate_after_rcu;
787 call_rcu(&s->memcg_params.rcu_head, kmemcg_rcufn);
789 spin_unlock_irq(&memcg_kmem_wq_lock);
792 void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg,
793 struct mem_cgroup *parent)
796 struct memcg_cache_array *arr;
797 struct kmem_cache *s, *c;
798 unsigned int nr_reparented;
800 idx = memcg_cache_id(memcg);
805 mutex_lock(&slab_mutex);
806 list_for_each_entry(s, &slab_root_caches, root_caches_node) {
807 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
808 lockdep_is_held(&slab_mutex));
809 c = arr->entries[idx];
813 kmemcg_cache_deactivate(c);
814 arr->entries[idx] = NULL;
817 list_for_each_entry(s, &memcg->kmem_caches,
818 memcg_params.kmem_caches_node) {
819 WRITE_ONCE(s->memcg_params.memcg, parent);
820 css_put(&memcg->css);
824 list_splice_init(&memcg->kmem_caches,
825 &parent->kmem_caches);
826 css_get_many(&parent->css, nr_reparented);
828 mutex_unlock(&slab_mutex);
834 static int shutdown_memcg_caches(struct kmem_cache *s)
836 struct memcg_cache_array *arr;
837 struct kmem_cache *c, *c2;
841 BUG_ON(!is_root_cache(s));
844 * First, shutdown active caches, i.e. caches that belong to online
847 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
848 lockdep_is_held(&slab_mutex));
849 for_each_memcg_cache_index(i) {
853 if (shutdown_cache(c))
855 * The cache still has objects. Move it to a temporary
856 * list so as not to try to destroy it for a second
857 * time while iterating over inactive caches below.
859 list_move(&c->memcg_params.children_node, &busy);
862 * The cache is empty and will be destroyed soon. Clear
863 * the pointer to it in the memcg_caches array so that
864 * it will never be accessed even if the root cache
867 arr->entries[i] = NULL;
871 * Second, shutdown all caches left from memory cgroups that are now
874 list_for_each_entry_safe(c, c2, &s->memcg_params.children,
875 memcg_params.children_node)
878 list_splice(&busy, &s->memcg_params.children);
881 * A cache being destroyed must be empty. In particular, this means
882 * that all per memcg caches attached to it must be empty too.
884 if (!list_empty(&s->memcg_params.children))
889 static void flush_memcg_workqueue(struct kmem_cache *s)
891 spin_lock_irq(&memcg_kmem_wq_lock);
892 s->memcg_params.dying = true;
893 spin_unlock_irq(&memcg_kmem_wq_lock);
896 * SLAB and SLUB deactivate the kmem_caches through call_rcu. Make
897 * sure all registered rcu callbacks have been invoked.
902 * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB
903 * deactivates the memcg kmem_caches through workqueue. Make sure all
904 * previous workitems on workqueue are processed.
906 if (likely(memcg_kmem_cache_wq))
907 flush_workqueue(memcg_kmem_cache_wq);
910 * If we're racing with children kmem_cache deactivation, it might
911 * take another rcu grace period to complete their destruction.
912 * At this moment the corresponding percpu_ref_kill() call should be
913 * done, but it might take another rcu grace period to complete
914 * switching to the atomic mode.
915 * Please, note that we check without grabbing the slab_mutex. It's safe
916 * because at this moment the children list can't grow.
918 if (!list_empty(&s->memcg_params.children))
922 static inline int shutdown_memcg_caches(struct kmem_cache *s)
927 static inline void flush_memcg_workqueue(struct kmem_cache *s)
930 #endif /* CONFIG_MEMCG_KMEM */
932 void slab_kmem_cache_release(struct kmem_cache *s)
934 __kmem_cache_release(s);
935 destroy_memcg_params(s);
936 kfree_const(s->name);
937 kmem_cache_free(kmem_cache, s);
940 void kmem_cache_destroy(struct kmem_cache *s)
947 flush_memcg_workqueue(s);
952 mutex_lock(&slab_mutex);
958 err = shutdown_memcg_caches(s);
960 err = shutdown_cache(s);
963 pr_err("kmem_cache_destroy %s: Slab cache still has objects\n",
968 mutex_unlock(&slab_mutex);
973 EXPORT_SYMBOL(kmem_cache_destroy);
976 * kmem_cache_shrink - Shrink a cache.
977 * @cachep: The cache to shrink.
979 * Releases as many slabs as possible for a cache.
980 * To help debugging, a zero exit status indicates all slabs were released.
982 * Return: %0 if all slabs were released, non-zero otherwise
984 int kmem_cache_shrink(struct kmem_cache *cachep)
990 kasan_cache_shrink(cachep);
991 ret = __kmem_cache_shrink(cachep);
996 EXPORT_SYMBOL(kmem_cache_shrink);
999 * kmem_cache_shrink_all - shrink a cache and all memcg caches for root cache
1000 * @s: The cache pointer
1002 void kmem_cache_shrink_all(struct kmem_cache *s)
1004 struct kmem_cache *c;
1006 if (!IS_ENABLED(CONFIG_MEMCG_KMEM) || !is_root_cache(s)) {
1007 kmem_cache_shrink(s);
1013 kasan_cache_shrink(s);
1014 __kmem_cache_shrink(s);
1017 * We have to take the slab_mutex to protect from the memcg list
1020 mutex_lock(&slab_mutex);
1021 for_each_memcg_cache(c, s) {
1023 * Don't need to shrink deactivated memcg caches.
1025 if (s->flags & SLAB_DEACTIVATED)
1027 kasan_cache_shrink(c);
1028 __kmem_cache_shrink(c);
1030 mutex_unlock(&slab_mutex);
1035 bool slab_is_available(void)
1037 return slab_state >= UP;
1041 /* Create a cache during boot when no slab services are available yet */
1042 void __init create_boot_cache(struct kmem_cache *s, const char *name,
1043 unsigned int size, slab_flags_t flags,
1044 unsigned int useroffset, unsigned int usersize)
1047 unsigned int align = ARCH_KMALLOC_MINALIGN;
1050 s->size = s->object_size = size;
1053 * For power of two sizes, guarantee natural alignment for kmalloc
1054 * caches, regardless of SL*B debugging options.
1056 if (is_power_of_2(size))
1057 align = max(align, size);
1058 s->align = calculate_alignment(flags, align, size);
1060 s->useroffset = useroffset;
1061 s->usersize = usersize;
1063 slab_init_memcg_params(s);
1065 err = __kmem_cache_create(s, flags);
1068 panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n",
1071 s->refcount = -1; /* Exempt from merging for now */
1074 struct kmem_cache *__init create_kmalloc_cache(const char *name,
1075 unsigned int size, slab_flags_t flags,
1076 unsigned int useroffset, unsigned int usersize)
1078 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
1081 panic("Out of memory when creating slab %s\n", name);
1083 create_boot_cache(s, name, size, flags, useroffset, usersize);
1084 list_add(&s->list, &slab_caches);
1085 memcg_link_cache(s, NULL);
1091 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init =
1092 { /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ };
1093 EXPORT_SYMBOL(kmalloc_caches);
1096 * Conversion table for small slabs sizes / 8 to the index in the
1097 * kmalloc array. This is necessary for slabs < 192 since we have non power
1098 * of two cache sizes there. The size of larger slabs can be determined using
1101 static u8 size_index[24] __ro_after_init = {
1128 static inline unsigned int size_index_elem(unsigned int bytes)
1130 return (bytes - 1) / 8;
1134 * Find the kmem_cache structure that serves a given size of
1137 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
1143 return ZERO_SIZE_PTR;
1145 index = size_index[size_index_elem(size)];
1147 if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE))
1149 index = fls(size - 1);
1152 return kmalloc_caches[kmalloc_type(flags)][index];
1155 #ifdef CONFIG_ZONE_DMA
1156 #define INIT_KMALLOC_INFO(__size, __short_size) \
1158 .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
1159 .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \
1160 .name[KMALLOC_DMA] = "dma-kmalloc-" #__short_size, \
1164 #define INIT_KMALLOC_INFO(__size, __short_size) \
1166 .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
1167 .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \
1173 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
1174 * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
1177 const struct kmalloc_info_struct kmalloc_info[] __initconst = {
1178 INIT_KMALLOC_INFO(0, 0),
1179 INIT_KMALLOC_INFO(96, 96),
1180 INIT_KMALLOC_INFO(192, 192),
1181 INIT_KMALLOC_INFO(8, 8),
1182 INIT_KMALLOC_INFO(16, 16),
1183 INIT_KMALLOC_INFO(32, 32),
1184 INIT_KMALLOC_INFO(64, 64),
1185 INIT_KMALLOC_INFO(128, 128),
1186 INIT_KMALLOC_INFO(256, 256),
1187 INIT_KMALLOC_INFO(512, 512),
1188 INIT_KMALLOC_INFO(1024, 1k),
1189 INIT_KMALLOC_INFO(2048, 2k),
1190 INIT_KMALLOC_INFO(4096, 4k),
1191 INIT_KMALLOC_INFO(8192, 8k),
1192 INIT_KMALLOC_INFO(16384, 16k),
1193 INIT_KMALLOC_INFO(32768, 32k),
1194 INIT_KMALLOC_INFO(65536, 64k),
1195 INIT_KMALLOC_INFO(131072, 128k),
1196 INIT_KMALLOC_INFO(262144, 256k),
1197 INIT_KMALLOC_INFO(524288, 512k),
1198 INIT_KMALLOC_INFO(1048576, 1M),
1199 INIT_KMALLOC_INFO(2097152, 2M),
1200 INIT_KMALLOC_INFO(4194304, 4M),
1201 INIT_KMALLOC_INFO(8388608, 8M),
1202 INIT_KMALLOC_INFO(16777216, 16M),
1203 INIT_KMALLOC_INFO(33554432, 32M),
1204 INIT_KMALLOC_INFO(67108864, 64M)
1208 * Patch up the size_index table if we have strange large alignment
1209 * requirements for the kmalloc array. This is only the case for
1210 * MIPS it seems. The standard arches will not generate any code here.
1212 * Largest permitted alignment is 256 bytes due to the way we
1213 * handle the index determination for the smaller caches.
1215 * Make sure that nothing crazy happens if someone starts tinkering
1216 * around with ARCH_KMALLOC_MINALIGN
1218 void __init setup_kmalloc_cache_index_table(void)
1222 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
1223 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
1225 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
1226 unsigned int elem = size_index_elem(i);
1228 if (elem >= ARRAY_SIZE(size_index))
1230 size_index[elem] = KMALLOC_SHIFT_LOW;
1233 if (KMALLOC_MIN_SIZE >= 64) {
1235 * The 96 byte size cache is not used if the alignment
1238 for (i = 64 + 8; i <= 96; i += 8)
1239 size_index[size_index_elem(i)] = 7;
1243 if (KMALLOC_MIN_SIZE >= 128) {
1245 * The 192 byte sized cache is not used if the alignment
1246 * is 128 byte. Redirect kmalloc to use the 256 byte cache
1249 for (i = 128 + 8; i <= 192; i += 8)
1250 size_index[size_index_elem(i)] = 8;
1255 new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
1257 if (type == KMALLOC_RECLAIM)
1258 flags |= SLAB_RECLAIM_ACCOUNT;
1260 kmalloc_caches[type][idx] = create_kmalloc_cache(
1261 kmalloc_info[idx].name[type],
1262 kmalloc_info[idx].size, flags, 0,
1263 kmalloc_info[idx].size);
1267 * Create the kmalloc array. Some of the regular kmalloc arrays
1268 * may already have been created because they were needed to
1269 * enable allocations for slab creation.
1271 void __init create_kmalloc_caches(slab_flags_t flags)
1274 enum kmalloc_cache_type type;
1276 for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) {
1277 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
1278 if (!kmalloc_caches[type][i])
1279 new_kmalloc_cache(i, type, flags);
1282 * Caches that are not of the two-to-the-power-of size.
1283 * These have to be created immediately after the
1284 * earlier power of two caches
1286 if (KMALLOC_MIN_SIZE <= 32 && i == 6 &&
1287 !kmalloc_caches[type][1])
1288 new_kmalloc_cache(1, type, flags);
1289 if (KMALLOC_MIN_SIZE <= 64 && i == 7 &&
1290 !kmalloc_caches[type][2])
1291 new_kmalloc_cache(2, type, flags);
1295 /* Kmalloc array is now usable */
1298 #ifdef CONFIG_ZONE_DMA
1299 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
1300 struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i];
1303 kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
1304 kmalloc_info[i].name[KMALLOC_DMA],
1305 kmalloc_info[i].size,
1306 SLAB_CACHE_DMA | flags, 0,
1307 kmalloc_info[i].size);
1312 #endif /* !CONFIG_SLOB */
1315 * To avoid unnecessary overhead, we pass through large allocation requests
1316 * directly to the page allocator. We use __GFP_COMP, because we will need to
1317 * know the allocation order to free the pages properly in kfree.
1319 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
1324 flags |= __GFP_COMP;
1325 page = alloc_pages(flags, order);
1327 ret = page_address(page);
1328 mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE,
1331 ret = kasan_kmalloc_large(ret, size, flags);
1332 /* As ret might get tagged, call kmemleak hook after KASAN. */
1333 kmemleak_alloc(ret, size, 1, flags);
1336 EXPORT_SYMBOL(kmalloc_order);
1338 #ifdef CONFIG_TRACING
1339 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1341 void *ret = kmalloc_order(size, flags, order);
1342 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1345 EXPORT_SYMBOL(kmalloc_order_trace);
1348 #ifdef CONFIG_SLAB_FREELIST_RANDOM
1349 /* Randomize a generic freelist */
1350 static void freelist_randomize(struct rnd_state *state, unsigned int *list,
1356 for (i = 0; i < count; i++)
1359 /* Fisher-Yates shuffle */
1360 for (i = count - 1; i > 0; i--) {
1361 rand = prandom_u32_state(state);
1363 swap(list[i], list[rand]);
1367 /* Create a random sequence per cache */
1368 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
1371 struct rnd_state state;
1373 if (count < 2 || cachep->random_seq)
1376 cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
1377 if (!cachep->random_seq)
1380 /* Get best entropy at this stage of boot */
1381 prandom_seed_state(&state, get_random_long());
1383 freelist_randomize(&state, cachep->random_seq, count);
1387 /* Destroy the per-cache random freelist sequence */
1388 void cache_random_seq_destroy(struct kmem_cache *cachep)
1390 kfree(cachep->random_seq);
1391 cachep->random_seq = NULL;
1393 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
1395 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
1397 #define SLABINFO_RIGHTS (0600)
1399 #define SLABINFO_RIGHTS (0400)
1402 static void print_slabinfo_header(struct seq_file *m)
1405 * Output format version, so at least we can change it
1406 * without _too_ many complaints.
1408 #ifdef CONFIG_DEBUG_SLAB
1409 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
1411 seq_puts(m, "slabinfo - version: 2.1\n");
1413 seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
1414 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
1415 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
1416 #ifdef CONFIG_DEBUG_SLAB
1417 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
1418 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
1423 void *slab_start(struct seq_file *m, loff_t *pos)
1425 mutex_lock(&slab_mutex);
1426 return seq_list_start(&slab_root_caches, *pos);
1429 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
1431 return seq_list_next(p, &slab_root_caches, pos);
1434 void slab_stop(struct seq_file *m, void *p)
1436 mutex_unlock(&slab_mutex);
1440 memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
1442 struct kmem_cache *c;
1443 struct slabinfo sinfo;
1445 if (!is_root_cache(s))
1448 for_each_memcg_cache(c, s) {
1449 memset(&sinfo, 0, sizeof(sinfo));
1450 get_slabinfo(c, &sinfo);
1452 info->active_slabs += sinfo.active_slabs;
1453 info->num_slabs += sinfo.num_slabs;
1454 info->shared_avail += sinfo.shared_avail;
1455 info->active_objs += sinfo.active_objs;
1456 info->num_objs += sinfo.num_objs;
1460 static void cache_show(struct kmem_cache *s, struct seq_file *m)
1462 struct slabinfo sinfo;
1464 memset(&sinfo, 0, sizeof(sinfo));
1465 get_slabinfo(s, &sinfo);
1467 memcg_accumulate_slabinfo(s, &sinfo);
1469 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
1470 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
1471 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1473 seq_printf(m, " : tunables %4u %4u %4u",
1474 sinfo.limit, sinfo.batchcount, sinfo.shared);
1475 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1476 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1477 slabinfo_show_stats(m, s);
1481 static int slab_show(struct seq_file *m, void *p)
1483 struct kmem_cache *s = list_entry(p, struct kmem_cache, root_caches_node);
1485 if (p == slab_root_caches.next)
1486 print_slabinfo_header(m);
1491 void dump_unreclaimable_slab(void)
1493 struct kmem_cache *s, *s2;
1494 struct slabinfo sinfo;
1497 * Here acquiring slab_mutex is risky since we don't prefer to get
1498 * sleep in oom path. But, without mutex hold, it may introduce a
1500 * Use mutex_trylock to protect the list traverse, dump nothing
1501 * without acquiring the mutex.
1503 if (!mutex_trylock(&slab_mutex)) {
1504 pr_warn("excessive unreclaimable slab but cannot dump stats\n");
1508 pr_info("Unreclaimable slab info:\n");
1509 pr_info("Name Used Total\n");
1511 list_for_each_entry_safe(s, s2, &slab_caches, list) {
1512 if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT))
1515 get_slabinfo(s, &sinfo);
1517 if (sinfo.num_objs > 0)
1518 pr_info("%-17s %10luKB %10luKB\n", cache_name(s),
1519 (sinfo.active_objs * s->size) / 1024,
1520 (sinfo.num_objs * s->size) / 1024);
1522 mutex_unlock(&slab_mutex);
1525 #if defined(CONFIG_MEMCG_KMEM)
1526 void *memcg_slab_start(struct seq_file *m, loff_t *pos)
1528 struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
1530 mutex_lock(&slab_mutex);
1531 return seq_list_start(&memcg->kmem_caches, *pos);
1534 void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos)
1536 struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
1538 return seq_list_next(p, &memcg->kmem_caches, pos);
1541 void memcg_slab_stop(struct seq_file *m, void *p)
1543 mutex_unlock(&slab_mutex);
1546 int memcg_slab_show(struct seq_file *m, void *p)
1548 struct kmem_cache *s = list_entry(p, struct kmem_cache,
1549 memcg_params.kmem_caches_node);
1550 struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
1552 if (p == memcg->kmem_caches.next)
1553 print_slabinfo_header(m);
1560 * slabinfo_op - iterator that generates /proc/slabinfo
1569 * num-pages-per-slab
1570 * + further values on SMP and with statistics enabled
1572 static const struct seq_operations slabinfo_op = {
1573 .start = slab_start,
1579 static int slabinfo_open(struct inode *inode, struct file *file)
1581 return seq_open(file, &slabinfo_op);
1584 static const struct proc_ops slabinfo_proc_ops = {
1585 .proc_flags = PROC_ENTRY_PERMANENT,
1586 .proc_open = slabinfo_open,
1587 .proc_read = seq_read,
1588 .proc_write = slabinfo_write,
1589 .proc_lseek = seq_lseek,
1590 .proc_release = seq_release,
1593 static int __init slab_proc_init(void)
1595 proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops);
1598 module_init(slab_proc_init);
1600 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_MEMCG_KMEM)
1602 * Display information about kmem caches that have child memcg caches.
1604 static int memcg_slabinfo_show(struct seq_file *m, void *unused)
1606 struct kmem_cache *s, *c;
1607 struct slabinfo sinfo;
1609 mutex_lock(&slab_mutex);
1610 seq_puts(m, "# <name> <css_id[:dead|deact]> <active_objs> <num_objs>");
1611 seq_puts(m, " <active_slabs> <num_slabs>\n");
1612 list_for_each_entry(s, &slab_root_caches, root_caches_node) {
1614 * Skip kmem caches that don't have any memcg children.
1616 if (list_empty(&s->memcg_params.children))
1619 memset(&sinfo, 0, sizeof(sinfo));
1620 get_slabinfo(s, &sinfo);
1621 seq_printf(m, "%-17s root %6lu %6lu %6lu %6lu\n",
1622 cache_name(s), sinfo.active_objs, sinfo.num_objs,
1623 sinfo.active_slabs, sinfo.num_slabs);
1625 for_each_memcg_cache(c, s) {
1626 struct cgroup_subsys_state *css;
1629 css = &c->memcg_params.memcg->css;
1630 if (!(css->flags & CSS_ONLINE))
1632 else if (c->flags & SLAB_DEACTIVATED)
1635 memset(&sinfo, 0, sizeof(sinfo));
1636 get_slabinfo(c, &sinfo);
1637 seq_printf(m, "%-17s %4d%-6s %6lu %6lu %6lu %6lu\n",
1638 cache_name(c), css->id, status,
1639 sinfo.active_objs, sinfo.num_objs,
1640 sinfo.active_slabs, sinfo.num_slabs);
1643 mutex_unlock(&slab_mutex);
1646 DEFINE_SHOW_ATTRIBUTE(memcg_slabinfo);
1648 static int __init memcg_slabinfo_init(void)
1650 debugfs_create_file("memcg_slabinfo", S_IFREG | S_IRUGO,
1651 NULL, NULL, &memcg_slabinfo_fops);
1655 late_initcall(memcg_slabinfo_init);
1656 #endif /* CONFIG_DEBUG_FS && CONFIG_MEMCG_KMEM */
1657 #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */
1659 static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1668 if (ks >= new_size) {
1669 p = kasan_krealloc((void *)p, new_size, flags);
1673 ret = kmalloc_track_caller(new_size, flags);
1681 * krealloc - reallocate memory. The contents will remain unchanged.
1682 * @p: object to reallocate memory for.
1683 * @new_size: how many bytes of memory are required.
1684 * @flags: the type of memory to allocate.
1686 * The contents of the object pointed to are preserved up to the
1687 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1688 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1689 * %NULL pointer, the object pointed to is freed.
1691 * Return: pointer to the allocated memory or %NULL in case of error
1693 void *krealloc(const void *p, size_t new_size, gfp_t flags)
1697 if (unlikely(!new_size)) {
1699 return ZERO_SIZE_PTR;
1702 ret = __do_krealloc(p, new_size, flags);
1703 if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret))
1708 EXPORT_SYMBOL(krealloc);
1711 * kzfree - like kfree but zero memory
1712 * @p: object to free memory of
1714 * The memory of the object @p points to is zeroed before freed.
1715 * If @p is %NULL, kzfree() does nothing.
1717 * Note: this function zeroes the whole allocated buffer which can be a good
1718 * deal bigger than the requested buffer size passed to kmalloc(). So be
1719 * careful when using this function in performance sensitive code.
1721 void kzfree(const void *p)
1724 void *mem = (void *)p;
1726 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1732 EXPORT_SYMBOL(kzfree);
1735 * ksize - get the actual amount of memory allocated for a given object
1736 * @objp: Pointer to the object
1738 * kmalloc may internally round up allocations and return more memory
1739 * than requested. ksize() can be used to determine the actual amount of
1740 * memory allocated. The caller may use this additional memory, even though
1741 * a smaller amount of memory was initially specified with the kmalloc call.
1742 * The caller must guarantee that objp points to a valid object previously
1743 * allocated with either kmalloc() or kmem_cache_alloc(). The object
1744 * must not be freed during the duration of the call.
1746 * Return: size of the actual memory used by @objp in bytes
1748 size_t ksize(const void *objp)
1752 if (WARN_ON_ONCE(!objp))
1755 * We need to check that the pointed to object is valid, and only then
1756 * unpoison the shadow memory below. We use __kasan_check_read(), to
1757 * generate a more useful report at the time ksize() is called (rather
1758 * than later where behaviour is undefined due to potential
1759 * use-after-free or double-free).
1761 * If the pointed to memory is invalid we return 0, to avoid users of
1762 * ksize() writing to and potentially corrupting the memory region.
1764 * We want to perform the check before __ksize(), to avoid potentially
1765 * crashing in __ksize() due to accessing invalid metadata.
1767 if (unlikely(objp == ZERO_SIZE_PTR) || !__kasan_check_read(objp, 1))
1770 size = __ksize(objp);
1772 * We assume that ksize callers could use whole allocated area,
1773 * so we need to unpoison this area.
1775 kasan_unpoison_shadow(objp, size);
1778 EXPORT_SYMBOL(ksize);
1780 /* Tracepoints definitions. */
1781 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1782 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1783 EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1784 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1785 EXPORT_TRACEPOINT_SYMBOL(kfree);
1786 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
1788 int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
1790 if (__should_failslab(s, gfpflags))
1794 ALLOW_ERROR_INJECTION(should_failslab, ERRNO);