2 * Slab allocator functions that are independent of the allocator strategy
4 * (C) 2012 Christoph Lameter <cl@linux.com>
6 #include <linux/slab.h>
9 #include <linux/poison.h>
10 #include <linux/interrupt.h>
11 #include <linux/memory.h>
12 #include <linux/compiler.h>
13 #include <linux/module.h>
14 #include <linux/cpu.h>
15 #include <linux/uaccess.h>
16 #include <linux/seq_file.h>
17 #include <linux/proc_fs.h>
18 #include <asm/cacheflush.h>
19 #include <asm/tlbflush.h>
21 #include <linux/memcontrol.h>
23 #define CREATE_TRACE_POINTS
24 #include <trace/events/kmem.h>
28 enum slab_state slab_state;
29 LIST_HEAD(slab_caches);
30 DEFINE_MUTEX(slab_mutex);
31 struct kmem_cache *kmem_cache;
34 * Set of flags that will prevent slab merging
36 #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
37 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
40 #define SLAB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
41 SLAB_CACHE_DMA | SLAB_NOTRACK)
44 * Merge control. If this is set then no merging of slab caches will occur.
45 * (Could be removed. This was introduced to pacify the merge skeptics.)
47 static int slab_nomerge;
49 static int __init setup_slab_nomerge(char *str)
56 __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
59 __setup("slab_nomerge", setup_slab_nomerge);
62 * Determine the size of a slab object
64 unsigned int kmem_cache_size(struct kmem_cache *s)
66 return s->object_size;
68 EXPORT_SYMBOL(kmem_cache_size);
70 #ifdef CONFIG_DEBUG_VM
71 static int kmem_cache_sanity_check(const char *name, size_t size)
73 struct kmem_cache *s = NULL;
75 if (!name || in_interrupt() || size < sizeof(void *) ||
76 size > KMALLOC_MAX_SIZE) {
77 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
81 list_for_each_entry(s, &slab_caches, list) {
86 * This happens when the module gets unloaded and doesn't
87 * destroy its slab cache and no-one else reuses the vmalloc
88 * area of the module. Print a warning.
90 res = probe_kernel_address(s->name, tmp);
92 pr_err("Slab cache with size %d has lost its name\n",
98 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
102 static inline int kmem_cache_sanity_check(const char *name, size_t size)
108 void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
112 for (i = 0; i < nr; i++)
113 kmem_cache_free(s, p[i]);
116 bool __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
132 void slab_init_memcg_params(struct kmem_cache *s)
134 s->memcg_params.is_root_cache = true;
135 INIT_LIST_HEAD(&s->memcg_params.list);
136 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
139 static int init_memcg_params(struct kmem_cache *s,
140 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
142 struct memcg_cache_array *arr;
145 s->memcg_params.is_root_cache = false;
146 s->memcg_params.memcg = memcg;
147 s->memcg_params.root_cache = root_cache;
151 slab_init_memcg_params(s);
153 if (!memcg_nr_cache_ids)
156 arr = kzalloc(sizeof(struct memcg_cache_array) +
157 memcg_nr_cache_ids * sizeof(void *),
162 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
166 static void destroy_memcg_params(struct kmem_cache *s)
168 if (is_root_cache(s))
169 kfree(rcu_access_pointer(s->memcg_params.memcg_caches));
172 static int update_memcg_params(struct kmem_cache *s, int new_array_size)
174 struct memcg_cache_array *old, *new;
176 if (!is_root_cache(s))
179 new = kzalloc(sizeof(struct memcg_cache_array) +
180 new_array_size * sizeof(void *), GFP_KERNEL);
184 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
185 lockdep_is_held(&slab_mutex));
187 memcpy(new->entries, old->entries,
188 memcg_nr_cache_ids * sizeof(void *));
190 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
196 int memcg_update_all_caches(int num_memcgs)
198 struct kmem_cache *s;
201 mutex_lock(&slab_mutex);
202 list_for_each_entry(s, &slab_caches, list) {
203 ret = update_memcg_params(s, num_memcgs);
205 * Instead of freeing the memory, we'll just leave the caches
206 * up to this point in an updated state.
211 mutex_unlock(&slab_mutex);
215 static inline int init_memcg_params(struct kmem_cache *s,
216 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
221 static inline void destroy_memcg_params(struct kmem_cache *s)
224 #endif /* CONFIG_MEMCG_KMEM */
227 * Find a mergeable slab cache
229 int slab_unmergeable(struct kmem_cache *s)
231 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
234 if (!is_root_cache(s))
241 * We may have set a slab to be unmergeable during bootstrap.
249 struct kmem_cache *find_mergeable(size_t size, size_t align,
250 unsigned long flags, const char *name, void (*ctor)(void *))
252 struct kmem_cache *s;
254 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
260 size = ALIGN(size, sizeof(void *));
261 align = calculate_alignment(flags, align, size);
262 size = ALIGN(size, align);
263 flags = kmem_cache_flags(size, flags, name, NULL);
265 list_for_each_entry_reverse(s, &slab_caches, list) {
266 if (slab_unmergeable(s))
272 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
275 * Check if alignment is compatible.
276 * Courtesy of Adrian Drzewiecki
278 if ((s->size & ~(align - 1)) != s->size)
281 if (s->size - size >= sizeof(void *))
284 if (IS_ENABLED(CONFIG_SLAB) && align &&
285 (align > s->align || s->align % align))
294 * Figure out what the alignment of the objects will be given a set of
295 * flags, a user specified alignment and the size of the objects.
297 unsigned long calculate_alignment(unsigned long flags,
298 unsigned long align, unsigned long size)
301 * If the user wants hardware cache aligned objects then follow that
302 * suggestion if the object is sufficiently large.
304 * The hardware cache alignment cannot override the specified
305 * alignment though. If that is greater then use it.
307 if (flags & SLAB_HWCACHE_ALIGN) {
308 unsigned long ralign = cache_line_size();
309 while (size <= ralign / 2)
311 align = max(align, ralign);
314 if (align < ARCH_SLAB_MINALIGN)
315 align = ARCH_SLAB_MINALIGN;
317 return ALIGN(align, sizeof(void *));
320 static struct kmem_cache *
321 do_kmem_cache_create(const char *name, size_t object_size, size_t size,
322 size_t align, unsigned long flags, void (*ctor)(void *),
323 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
325 struct kmem_cache *s;
329 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
334 s->object_size = object_size;
339 err = init_memcg_params(s, memcg, root_cache);
343 err = __kmem_cache_create(s, flags);
348 list_add(&s->list, &slab_caches);
355 destroy_memcg_params(s);
356 kmem_cache_free(kmem_cache, s);
361 * kmem_cache_create - Create a cache.
362 * @name: A string which is used in /proc/slabinfo to identify this cache.
363 * @size: The size of objects to be created in this cache.
364 * @align: The required alignment for the objects.
366 * @ctor: A constructor for the objects.
368 * Returns a ptr to the cache on success, NULL on failure.
369 * Cannot be called within a interrupt, but can be interrupted.
370 * The @ctor is run when new pages are allocated by the cache.
374 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
375 * to catch references to uninitialised memory.
377 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
378 * for buffer overruns.
380 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
381 * cacheline. This can be beneficial if you're counting cycles as closely
385 kmem_cache_create(const char *name, size_t size, size_t align,
386 unsigned long flags, void (*ctor)(void *))
388 struct kmem_cache *s;
389 const char *cache_name;
394 memcg_get_cache_ids();
396 mutex_lock(&slab_mutex);
398 err = kmem_cache_sanity_check(name, size);
400 s = NULL; /* suppress uninit var warning */
405 * Some allocators will constraint the set of valid flags to a subset
406 * of all flags. We expect them to define CACHE_CREATE_MASK in this
407 * case, and we'll just provide them with a sanitized version of the
410 flags &= CACHE_CREATE_MASK;
412 s = __kmem_cache_alias(name, size, align, flags, ctor);
416 cache_name = kstrdup_const(name, GFP_KERNEL);
422 s = do_kmem_cache_create(cache_name, size, size,
423 calculate_alignment(flags, align, size),
424 flags, ctor, NULL, NULL);
427 kfree_const(cache_name);
431 mutex_unlock(&slab_mutex);
433 memcg_put_cache_ids();
438 if (flags & SLAB_PANIC)
439 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
442 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
450 EXPORT_SYMBOL(kmem_cache_create);
452 static int do_kmem_cache_shutdown(struct kmem_cache *s,
453 struct list_head *release, bool *need_rcu_barrier)
455 if (__kmem_cache_shutdown(s) != 0) {
456 printk(KERN_ERR "kmem_cache_destroy %s: "
457 "Slab cache still has objects\n", s->name);
462 if (s->flags & SLAB_DESTROY_BY_RCU)
463 *need_rcu_barrier = true;
465 #ifdef CONFIG_MEMCG_KMEM
466 if (!is_root_cache(s))
467 list_del(&s->memcg_params.list);
469 list_move(&s->list, release);
473 static void do_kmem_cache_release(struct list_head *release,
474 bool need_rcu_barrier)
476 struct kmem_cache *s, *s2;
478 if (need_rcu_barrier)
481 list_for_each_entry_safe(s, s2, release, list) {
482 #ifdef SLAB_SUPPORTS_SYSFS
483 sysfs_slab_remove(s);
485 slab_kmem_cache_release(s);
490 #ifdef CONFIG_MEMCG_KMEM
492 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
493 * @memcg: The memory cgroup the new cache is for.
494 * @root_cache: The parent of the new cache.
496 * This function attempts to create a kmem cache that will serve allocation
497 * requests going from @memcg to @root_cache. The new cache inherits properties
500 void memcg_create_kmem_cache(struct mem_cgroup *memcg,
501 struct kmem_cache *root_cache)
503 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
504 struct cgroup_subsys_state *css = mem_cgroup_css(memcg);
505 struct memcg_cache_array *arr;
506 struct kmem_cache *s = NULL;
513 mutex_lock(&slab_mutex);
516 * The memory cgroup could have been deactivated while the cache
517 * creation work was pending.
519 if (!memcg_kmem_is_active(memcg))
522 idx = memcg_cache_id(memcg);
523 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
524 lockdep_is_held(&slab_mutex));
527 * Since per-memcg caches are created asynchronously on first
528 * allocation (see memcg_kmem_get_cache()), several threads can try to
529 * create the same cache, but only one of them may succeed.
531 if (arr->entries[idx])
534 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
535 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
536 css->id, memcg_name_buf);
540 s = do_kmem_cache_create(cache_name, root_cache->object_size,
541 root_cache->size, root_cache->align,
542 root_cache->flags, root_cache->ctor,
545 * If we could not create a memcg cache, do not complain, because
546 * that's not critical at all as we can always proceed with the root
554 list_add(&s->memcg_params.list, &root_cache->memcg_params.list);
557 * Since readers won't lock (see cache_from_memcg_idx()), we need a
558 * barrier here to ensure nobody will see the kmem_cache partially
562 arr->entries[idx] = s;
565 mutex_unlock(&slab_mutex);
571 void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
574 struct memcg_cache_array *arr;
575 struct kmem_cache *s, *c;
577 idx = memcg_cache_id(memcg);
582 mutex_lock(&slab_mutex);
583 list_for_each_entry(s, &slab_caches, list) {
584 if (!is_root_cache(s))
587 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
588 lockdep_is_held(&slab_mutex));
589 c = arr->entries[idx];
593 __kmem_cache_shrink(c, true);
594 arr->entries[idx] = NULL;
596 mutex_unlock(&slab_mutex);
602 void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
605 bool need_rcu_barrier = false;
606 struct kmem_cache *s, *s2;
611 mutex_lock(&slab_mutex);
612 list_for_each_entry_safe(s, s2, &slab_caches, list) {
613 if (is_root_cache(s) || s->memcg_params.memcg != memcg)
616 * The cgroup is about to be freed and therefore has no charges
617 * left. Hence, all its caches must be empty by now.
619 BUG_ON(do_kmem_cache_shutdown(s, &release, &need_rcu_barrier));
621 mutex_unlock(&slab_mutex);
626 do_kmem_cache_release(&release, need_rcu_barrier);
628 #endif /* CONFIG_MEMCG_KMEM */
630 void slab_kmem_cache_release(struct kmem_cache *s)
632 destroy_memcg_params(s);
633 kfree_const(s->name);
634 kmem_cache_free(kmem_cache, s);
637 void kmem_cache_destroy(struct kmem_cache *s)
639 struct kmem_cache *c, *c2;
641 bool need_rcu_barrier = false;
644 BUG_ON(!is_root_cache(s));
649 mutex_lock(&slab_mutex);
655 for_each_memcg_cache_safe(c, c2, s) {
656 if (do_kmem_cache_shutdown(c, &release, &need_rcu_barrier))
661 do_kmem_cache_shutdown(s, &release, &need_rcu_barrier);
664 mutex_unlock(&slab_mutex);
669 do_kmem_cache_release(&release, need_rcu_barrier);
671 EXPORT_SYMBOL(kmem_cache_destroy);
674 * kmem_cache_shrink - Shrink a cache.
675 * @cachep: The cache to shrink.
677 * Releases as many slabs as possible for a cache.
678 * To help debugging, a zero exit status indicates all slabs were released.
680 int kmem_cache_shrink(struct kmem_cache *cachep)
686 ret = __kmem_cache_shrink(cachep, false);
691 EXPORT_SYMBOL(kmem_cache_shrink);
693 int slab_is_available(void)
695 return slab_state >= UP;
699 /* Create a cache during boot when no slab services are available yet */
700 void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
706 s->size = s->object_size = size;
707 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
709 slab_init_memcg_params(s);
711 err = __kmem_cache_create(s, flags);
714 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
717 s->refcount = -1; /* Exempt from merging for now */
720 struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
723 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
726 panic("Out of memory when creating slab %s\n", name);
728 create_boot_cache(s, name, size, flags);
729 list_add(&s->list, &slab_caches);
734 struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
735 EXPORT_SYMBOL(kmalloc_caches);
737 #ifdef CONFIG_ZONE_DMA
738 struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
739 EXPORT_SYMBOL(kmalloc_dma_caches);
743 * Conversion table for small slabs sizes / 8 to the index in the
744 * kmalloc array. This is necessary for slabs < 192 since we have non power
745 * of two cache sizes there. The size of larger slabs can be determined using
748 static s8 size_index[24] = {
775 static inline int size_index_elem(size_t bytes)
777 return (bytes - 1) / 8;
781 * Find the kmem_cache structure that serves a given size of
784 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
788 if (unlikely(size > KMALLOC_MAX_SIZE)) {
789 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
795 return ZERO_SIZE_PTR;
797 index = size_index[size_index_elem(size)];
799 index = fls(size - 1);
801 #ifdef CONFIG_ZONE_DMA
802 if (unlikely((flags & GFP_DMA)))
803 return kmalloc_dma_caches[index];
806 return kmalloc_caches[index];
810 * Create the kmalloc array. Some of the regular kmalloc arrays
811 * may already have been created because they were needed to
812 * enable allocations for slab creation.
814 void __init create_kmalloc_caches(unsigned long flags)
819 * Patch up the size_index table if we have strange large alignment
820 * requirements for the kmalloc array. This is only the case for
821 * MIPS it seems. The standard arches will not generate any code here.
823 * Largest permitted alignment is 256 bytes due to the way we
824 * handle the index determination for the smaller caches.
826 * Make sure that nothing crazy happens if someone starts tinkering
827 * around with ARCH_KMALLOC_MINALIGN
829 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
830 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
832 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
833 int elem = size_index_elem(i);
835 if (elem >= ARRAY_SIZE(size_index))
837 size_index[elem] = KMALLOC_SHIFT_LOW;
840 if (KMALLOC_MIN_SIZE >= 64) {
842 * The 96 byte size cache is not used if the alignment
845 for (i = 64 + 8; i <= 96; i += 8)
846 size_index[size_index_elem(i)] = 7;
850 if (KMALLOC_MIN_SIZE >= 128) {
852 * The 192 byte sized cache is not used if the alignment
853 * is 128 byte. Redirect kmalloc to use the 256 byte cache
856 for (i = 128 + 8; i <= 192; i += 8)
857 size_index[size_index_elem(i)] = 8;
859 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
860 if (!kmalloc_caches[i]) {
861 kmalloc_caches[i] = create_kmalloc_cache(NULL,
866 * Caches that are not of the two-to-the-power-of size.
867 * These have to be created immediately after the
868 * earlier power of two caches
870 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
871 kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);
873 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
874 kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
877 /* Kmalloc array is now usable */
880 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
881 struct kmem_cache *s = kmalloc_caches[i];
885 n = kasprintf(GFP_NOWAIT, "kmalloc-%d", kmalloc_size(i));
892 #ifdef CONFIG_ZONE_DMA
893 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
894 struct kmem_cache *s = kmalloc_caches[i];
897 int size = kmalloc_size(i);
898 char *n = kasprintf(GFP_NOWAIT,
899 "dma-kmalloc-%d", size);
902 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
903 size, SLAB_CACHE_DMA | flags);
908 #endif /* !CONFIG_SLOB */
911 * To avoid unnecessary overhead, we pass through large allocation requests
912 * directly to the page allocator. We use __GFP_COMP, because we will need to
913 * know the allocation order to free the pages properly in kfree.
915 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
921 page = alloc_kmem_pages(flags, order);
922 ret = page ? page_address(page) : NULL;
923 kmemleak_alloc(ret, size, 1, flags);
924 kasan_kmalloc_large(ret, size);
927 EXPORT_SYMBOL(kmalloc_order);
929 #ifdef CONFIG_TRACING
930 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
932 void *ret = kmalloc_order(size, flags, order);
933 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
936 EXPORT_SYMBOL(kmalloc_order_trace);
939 #ifdef CONFIG_SLABINFO
942 #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
944 #define SLABINFO_RIGHTS S_IRUSR
947 static void print_slabinfo_header(struct seq_file *m)
950 * Output format version, so at least we can change it
951 * without _too_ many complaints.
953 #ifdef CONFIG_DEBUG_SLAB
954 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
956 seq_puts(m, "slabinfo - version: 2.1\n");
958 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
959 "<objperslab> <pagesperslab>");
960 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
961 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
962 #ifdef CONFIG_DEBUG_SLAB
963 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
964 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
965 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
970 void *slab_start(struct seq_file *m, loff_t *pos)
972 mutex_lock(&slab_mutex);
973 return seq_list_start(&slab_caches, *pos);
976 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
978 return seq_list_next(p, &slab_caches, pos);
981 void slab_stop(struct seq_file *m, void *p)
983 mutex_unlock(&slab_mutex);
987 memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
989 struct kmem_cache *c;
990 struct slabinfo sinfo;
992 if (!is_root_cache(s))
995 for_each_memcg_cache(c, s) {
996 memset(&sinfo, 0, sizeof(sinfo));
997 get_slabinfo(c, &sinfo);
999 info->active_slabs += sinfo.active_slabs;
1000 info->num_slabs += sinfo.num_slabs;
1001 info->shared_avail += sinfo.shared_avail;
1002 info->active_objs += sinfo.active_objs;
1003 info->num_objs += sinfo.num_objs;
1007 static void cache_show(struct kmem_cache *s, struct seq_file *m)
1009 struct slabinfo sinfo;
1011 memset(&sinfo, 0, sizeof(sinfo));
1012 get_slabinfo(s, &sinfo);
1014 memcg_accumulate_slabinfo(s, &sinfo);
1016 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
1017 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
1018 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1020 seq_printf(m, " : tunables %4u %4u %4u",
1021 sinfo.limit, sinfo.batchcount, sinfo.shared);
1022 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1023 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1024 slabinfo_show_stats(m, s);
1028 static int slab_show(struct seq_file *m, void *p)
1030 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1032 if (p == slab_caches.next)
1033 print_slabinfo_header(m);
1034 if (is_root_cache(s))
1039 #ifdef CONFIG_MEMCG_KMEM
1040 int memcg_slab_show(struct seq_file *m, void *p)
1042 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1043 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
1045 if (p == slab_caches.next)
1046 print_slabinfo_header(m);
1047 if (!is_root_cache(s) && s->memcg_params.memcg == memcg)
1054 * slabinfo_op - iterator that generates /proc/slabinfo
1063 * num-pages-per-slab
1064 * + further values on SMP and with statistics enabled
1066 static const struct seq_operations slabinfo_op = {
1067 .start = slab_start,
1073 static int slabinfo_open(struct inode *inode, struct file *file)
1075 return seq_open(file, &slabinfo_op);
1078 static const struct file_operations proc_slabinfo_operations = {
1079 .open = slabinfo_open,
1081 .write = slabinfo_write,
1082 .llseek = seq_lseek,
1083 .release = seq_release,
1086 static int __init slab_proc_init(void)
1088 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1089 &proc_slabinfo_operations);
1092 module_init(slab_proc_init);
1093 #endif /* CONFIG_SLABINFO */
1095 static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1104 if (ks >= new_size) {
1105 kasan_krealloc((void *)p, new_size);
1109 ret = kmalloc_track_caller(new_size, flags);
1117 * __krealloc - like krealloc() but don't free @p.
1118 * @p: object to reallocate memory for.
1119 * @new_size: how many bytes of memory are required.
1120 * @flags: the type of memory to allocate.
1122 * This function is like krealloc() except it never frees the originally
1123 * allocated buffer. Use this if you don't want to free the buffer immediately
1124 * like, for example, with RCU.
1126 void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1128 if (unlikely(!new_size))
1129 return ZERO_SIZE_PTR;
1131 return __do_krealloc(p, new_size, flags);
1134 EXPORT_SYMBOL(__krealloc);
1137 * krealloc - reallocate memory. The contents will remain unchanged.
1138 * @p: object to reallocate memory for.
1139 * @new_size: how many bytes of memory are required.
1140 * @flags: the type of memory to allocate.
1142 * The contents of the object pointed to are preserved up to the
1143 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1144 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1145 * %NULL pointer, the object pointed to is freed.
1147 void *krealloc(const void *p, size_t new_size, gfp_t flags)
1151 if (unlikely(!new_size)) {
1153 return ZERO_SIZE_PTR;
1156 ret = __do_krealloc(p, new_size, flags);
1157 if (ret && p != ret)
1162 EXPORT_SYMBOL(krealloc);
1165 * kzfree - like kfree but zero memory
1166 * @p: object to free memory of
1168 * The memory of the object @p points to is zeroed before freed.
1169 * If @p is %NULL, kzfree() does nothing.
1171 * Note: this function zeroes the whole allocated buffer which can be a good
1172 * deal bigger than the requested buffer size passed to kmalloc(). So be
1173 * careful when using this function in performance sensitive code.
1175 void kzfree(const void *p)
1178 void *mem = (void *)p;
1180 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1186 EXPORT_SYMBOL(kzfree);
1188 /* Tracepoints definitions. */
1189 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1190 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1191 EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1192 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1193 EXPORT_TRACEPOINT_SYMBOL(kfree);
1194 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);