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_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | SLAB_NOTRACK)
43 * Merge control. If this is set then no merging of slab caches will occur.
44 * (Could be removed. This was introduced to pacify the merge skeptics.)
46 static int slab_nomerge;
48 static int __init setup_slab_nomerge(char *str)
55 __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
58 __setup("slab_nomerge", setup_slab_nomerge);
61 * Determine the size of a slab object
63 unsigned int kmem_cache_size(struct kmem_cache *s)
65 return s->object_size;
67 EXPORT_SYMBOL(kmem_cache_size);
69 #ifdef CONFIG_DEBUG_VM
70 static int kmem_cache_sanity_check(const char *name, size_t size)
72 struct kmem_cache *s = NULL;
74 if (!name || in_interrupt() || size < sizeof(void *) ||
75 size > KMALLOC_MAX_SIZE) {
76 pr_err("kmem_cache_create(%s) integrity check failed\n", name);
80 list_for_each_entry(s, &slab_caches, list) {
85 * This happens when the module gets unloaded and doesn't
86 * destroy its slab cache and no-one else reuses the vmalloc
87 * area of the module. Print a warning.
89 res = probe_kernel_address(s->name, tmp);
91 pr_err("Slab cache with size %d has lost its name\n",
97 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
101 static inline int kmem_cache_sanity_check(const char *name, size_t size)
107 #ifdef CONFIG_MEMCG_KMEM
108 void slab_init_memcg_params(struct kmem_cache *s)
110 s->memcg_params.is_root_cache = true;
111 INIT_LIST_HEAD(&s->memcg_params.list);
112 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
115 static int init_memcg_params(struct kmem_cache *s,
116 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
118 struct memcg_cache_array *arr;
121 s->memcg_params.is_root_cache = false;
122 s->memcg_params.memcg = memcg;
123 s->memcg_params.root_cache = root_cache;
127 slab_init_memcg_params(s);
129 if (!memcg_nr_cache_ids)
132 arr = kzalloc(sizeof(struct memcg_cache_array) +
133 memcg_nr_cache_ids * sizeof(void *),
138 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
142 static void destroy_memcg_params(struct kmem_cache *s)
144 if (is_root_cache(s))
145 kfree(rcu_access_pointer(s->memcg_params.memcg_caches));
148 static int update_memcg_params(struct kmem_cache *s, int new_array_size)
150 struct memcg_cache_array *old, *new;
152 if (!is_root_cache(s))
155 new = kzalloc(sizeof(struct memcg_cache_array) +
156 new_array_size * sizeof(void *), GFP_KERNEL);
160 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
161 lockdep_is_held(&slab_mutex));
163 memcpy(new->entries, old->entries,
164 memcg_nr_cache_ids * sizeof(void *));
166 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
172 int memcg_update_all_caches(int num_memcgs)
174 struct kmem_cache *s;
177 mutex_lock(&slab_mutex);
178 list_for_each_entry(s, &slab_caches, list) {
179 ret = update_memcg_params(s, num_memcgs);
181 * Instead of freeing the memory, we'll just leave the caches
182 * up to this point in an updated state.
187 mutex_unlock(&slab_mutex);
191 static inline int init_memcg_params(struct kmem_cache *s,
192 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
197 static inline void destroy_memcg_params(struct kmem_cache *s)
200 #endif /* CONFIG_MEMCG_KMEM */
203 * Find a mergeable slab cache
205 int slab_unmergeable(struct kmem_cache *s)
207 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
210 if (!is_root_cache(s))
217 * We may have set a slab to be unmergeable during bootstrap.
225 struct kmem_cache *find_mergeable(size_t size, size_t align,
226 unsigned long flags, const char *name, void (*ctor)(void *))
228 struct kmem_cache *s;
230 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
236 size = ALIGN(size, sizeof(void *));
237 align = calculate_alignment(flags, align, size);
238 size = ALIGN(size, align);
239 flags = kmem_cache_flags(size, flags, name, NULL);
241 list_for_each_entry_reverse(s, &slab_caches, list) {
242 if (slab_unmergeable(s))
248 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
251 * Check if alignment is compatible.
252 * Courtesy of Adrian Drzewiecki
254 if ((s->size & ~(align - 1)) != s->size)
257 if (s->size - size >= sizeof(void *))
260 if (IS_ENABLED(CONFIG_SLAB) && align &&
261 (align > s->align || s->align % align))
270 * Figure out what the alignment of the objects will be given a set of
271 * flags, a user specified alignment and the size of the objects.
273 unsigned long calculate_alignment(unsigned long flags,
274 unsigned long align, unsigned long size)
277 * If the user wants hardware cache aligned objects then follow that
278 * suggestion if the object is sufficiently large.
280 * The hardware cache alignment cannot override the specified
281 * alignment though. If that is greater then use it.
283 if (flags & SLAB_HWCACHE_ALIGN) {
284 unsigned long ralign = cache_line_size();
285 while (size <= ralign / 2)
287 align = max(align, ralign);
290 if (align < ARCH_SLAB_MINALIGN)
291 align = ARCH_SLAB_MINALIGN;
293 return ALIGN(align, sizeof(void *));
296 static struct kmem_cache *
297 do_kmem_cache_create(const char *name, size_t object_size, size_t size,
298 size_t align, unsigned long flags, void (*ctor)(void *),
299 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
301 struct kmem_cache *s;
305 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
310 s->object_size = object_size;
315 err = init_memcg_params(s, memcg, root_cache);
319 err = __kmem_cache_create(s, flags);
324 list_add(&s->list, &slab_caches);
331 destroy_memcg_params(s);
332 kmem_cache_free(kmem_cache, s);
337 * kmem_cache_create - Create a cache.
338 * @name: A string which is used in /proc/slabinfo to identify this cache.
339 * @size: The size of objects to be created in this cache.
340 * @align: The required alignment for the objects.
342 * @ctor: A constructor for the objects.
344 * Returns a ptr to the cache on success, NULL on failure.
345 * Cannot be called within a interrupt, but can be interrupted.
346 * The @ctor is run when new pages are allocated by the cache.
350 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
351 * to catch references to uninitialised memory.
353 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
354 * for buffer overruns.
356 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
357 * cacheline. This can be beneficial if you're counting cycles as closely
361 kmem_cache_create(const char *name, size_t size, size_t align,
362 unsigned long flags, void (*ctor)(void *))
364 struct kmem_cache *s;
365 const char *cache_name;
370 memcg_get_cache_ids();
372 mutex_lock(&slab_mutex);
374 err = kmem_cache_sanity_check(name, size);
376 s = NULL; /* suppress uninit var warning */
381 * Some allocators will constraint the set of valid flags to a subset
382 * of all flags. We expect them to define CACHE_CREATE_MASK in this
383 * case, and we'll just provide them with a sanitized version of the
386 flags &= CACHE_CREATE_MASK;
388 s = __kmem_cache_alias(name, size, align, flags, ctor);
392 cache_name = kstrdup_const(name, GFP_KERNEL);
398 s = do_kmem_cache_create(cache_name, size, size,
399 calculate_alignment(flags, align, size),
400 flags, ctor, NULL, NULL);
403 kfree_const(cache_name);
407 mutex_unlock(&slab_mutex);
409 memcg_put_cache_ids();
414 if (flags & SLAB_PANIC)
415 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
418 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
426 EXPORT_SYMBOL(kmem_cache_create);
428 static int do_kmem_cache_shutdown(struct kmem_cache *s,
429 struct list_head *release, bool *need_rcu_barrier)
431 if (__kmem_cache_shutdown(s) != 0) {
432 printk(KERN_ERR "kmem_cache_destroy %s: "
433 "Slab cache still has objects\n", s->name);
438 if (s->flags & SLAB_DESTROY_BY_RCU)
439 *need_rcu_barrier = true;
441 #ifdef CONFIG_MEMCG_KMEM
442 if (!is_root_cache(s))
443 list_del(&s->memcg_params.list);
445 list_move(&s->list, release);
449 static void do_kmem_cache_release(struct list_head *release,
450 bool need_rcu_barrier)
452 struct kmem_cache *s, *s2;
454 if (need_rcu_barrier)
457 list_for_each_entry_safe(s, s2, release, list) {
458 #ifdef SLAB_SUPPORTS_SYSFS
459 sysfs_slab_remove(s);
461 slab_kmem_cache_release(s);
466 #ifdef CONFIG_MEMCG_KMEM
468 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
469 * @memcg: The memory cgroup the new cache is for.
470 * @root_cache: The parent of the new cache.
472 * This function attempts to create a kmem cache that will serve allocation
473 * requests going from @memcg to @root_cache. The new cache inherits properties
476 void memcg_create_kmem_cache(struct mem_cgroup *memcg,
477 struct kmem_cache *root_cache)
479 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
480 struct cgroup_subsys_state *css = mem_cgroup_css(memcg);
481 struct memcg_cache_array *arr;
482 struct kmem_cache *s = NULL;
489 mutex_lock(&slab_mutex);
492 * The memory cgroup could have been deactivated while the cache
493 * creation work was pending.
495 if (!memcg_kmem_is_active(memcg))
498 idx = memcg_cache_id(memcg);
499 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
500 lockdep_is_held(&slab_mutex));
503 * Since per-memcg caches are created asynchronously on first
504 * allocation (see memcg_kmem_get_cache()), several threads can try to
505 * create the same cache, but only one of them may succeed.
507 if (arr->entries[idx])
510 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
511 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
512 css->id, memcg_name_buf);
516 s = do_kmem_cache_create(cache_name, root_cache->object_size,
517 root_cache->size, root_cache->align,
518 root_cache->flags, root_cache->ctor,
521 * If we could not create a memcg cache, do not complain, because
522 * that's not critical at all as we can always proceed with the root
530 list_add(&s->memcg_params.list, &root_cache->memcg_params.list);
533 * Since readers won't lock (see cache_from_memcg_idx()), we need a
534 * barrier here to ensure nobody will see the kmem_cache partially
538 arr->entries[idx] = s;
541 mutex_unlock(&slab_mutex);
547 void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
550 struct memcg_cache_array *arr;
551 struct kmem_cache *s, *c;
553 idx = memcg_cache_id(memcg);
558 mutex_lock(&slab_mutex);
559 list_for_each_entry(s, &slab_caches, list) {
560 if (!is_root_cache(s))
563 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
564 lockdep_is_held(&slab_mutex));
565 c = arr->entries[idx];
569 __kmem_cache_shrink(c, true);
570 arr->entries[idx] = NULL;
572 mutex_unlock(&slab_mutex);
578 void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
581 bool need_rcu_barrier = false;
582 struct kmem_cache *s, *s2;
587 mutex_lock(&slab_mutex);
588 list_for_each_entry_safe(s, s2, &slab_caches, list) {
589 if (is_root_cache(s) || s->memcg_params.memcg != memcg)
592 * The cgroup is about to be freed and therefore has no charges
593 * left. Hence, all its caches must be empty by now.
595 BUG_ON(do_kmem_cache_shutdown(s, &release, &need_rcu_barrier));
597 mutex_unlock(&slab_mutex);
602 do_kmem_cache_release(&release, need_rcu_barrier);
604 #endif /* CONFIG_MEMCG_KMEM */
606 void slab_kmem_cache_release(struct kmem_cache *s)
608 destroy_memcg_params(s);
609 kfree_const(s->name);
610 kmem_cache_free(kmem_cache, s);
613 void kmem_cache_destroy(struct kmem_cache *s)
615 struct kmem_cache *c, *c2;
617 bool need_rcu_barrier = false;
620 BUG_ON(!is_root_cache(s));
625 mutex_lock(&slab_mutex);
631 for_each_memcg_cache_safe(c, c2, s) {
632 if (do_kmem_cache_shutdown(c, &release, &need_rcu_barrier))
637 do_kmem_cache_shutdown(s, &release, &need_rcu_barrier);
640 mutex_unlock(&slab_mutex);
645 do_kmem_cache_release(&release, need_rcu_barrier);
647 EXPORT_SYMBOL(kmem_cache_destroy);
650 * kmem_cache_shrink - Shrink a cache.
651 * @cachep: The cache to shrink.
653 * Releases as many slabs as possible for a cache.
654 * To help debugging, a zero exit status indicates all slabs were released.
656 int kmem_cache_shrink(struct kmem_cache *cachep)
662 ret = __kmem_cache_shrink(cachep, false);
667 EXPORT_SYMBOL(kmem_cache_shrink);
669 int slab_is_available(void)
671 return slab_state >= UP;
675 /* Create a cache during boot when no slab services are available yet */
676 void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
682 s->size = s->object_size = size;
683 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
685 slab_init_memcg_params(s);
687 err = __kmem_cache_create(s, flags);
690 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
693 s->refcount = -1; /* Exempt from merging for now */
696 struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
699 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
702 panic("Out of memory when creating slab %s\n", name);
704 create_boot_cache(s, name, size, flags);
705 list_add(&s->list, &slab_caches);
710 struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
711 EXPORT_SYMBOL(kmalloc_caches);
713 #ifdef CONFIG_ZONE_DMA
714 struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
715 EXPORT_SYMBOL(kmalloc_dma_caches);
719 * Conversion table for small slabs sizes / 8 to the index in the
720 * kmalloc array. This is necessary for slabs < 192 since we have non power
721 * of two cache sizes there. The size of larger slabs can be determined using
724 static s8 size_index[24] = {
751 static inline int size_index_elem(size_t bytes)
753 return (bytes - 1) / 8;
757 * Find the kmem_cache structure that serves a given size of
760 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
764 if (unlikely(size > KMALLOC_MAX_SIZE)) {
765 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
771 return ZERO_SIZE_PTR;
773 index = size_index[size_index_elem(size)];
775 index = fls(size - 1);
777 #ifdef CONFIG_ZONE_DMA
778 if (unlikely((flags & GFP_DMA)))
779 return kmalloc_dma_caches[index];
782 return kmalloc_caches[index];
786 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
787 * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
793 } const kmalloc_info[] __initconst = {
794 {NULL, 0}, {"kmalloc-96", 96},
795 {"kmalloc-192", 192}, {"kmalloc-8", 8},
796 {"kmalloc-16", 16}, {"kmalloc-32", 32},
797 {"kmalloc-64", 64}, {"kmalloc-128", 128},
798 {"kmalloc-256", 256}, {"kmalloc-512", 512},
799 {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048},
800 {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192},
801 {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768},
802 {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072},
803 {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288},
804 {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152},
805 {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608},
806 {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432},
807 {"kmalloc-67108864", 67108864}
811 * Patch up the size_index table if we have strange large alignment
812 * requirements for the kmalloc array. This is only the case for
813 * MIPS it seems. The standard arches will not generate any code here.
815 * Largest permitted alignment is 256 bytes due to the way we
816 * handle the index determination for the smaller caches.
818 * Make sure that nothing crazy happens if someone starts tinkering
819 * around with ARCH_KMALLOC_MINALIGN
821 void __init setup_kmalloc_cache_index_table(void)
825 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
826 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
828 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
829 int elem = size_index_elem(i);
831 if (elem >= ARRAY_SIZE(size_index))
833 size_index[elem] = KMALLOC_SHIFT_LOW;
836 if (KMALLOC_MIN_SIZE >= 64) {
838 * The 96 byte size cache is not used if the alignment
841 for (i = 64 + 8; i <= 96; i += 8)
842 size_index[size_index_elem(i)] = 7;
846 if (KMALLOC_MIN_SIZE >= 128) {
848 * The 192 byte sized cache is not used if the alignment
849 * is 128 byte. Redirect kmalloc to use the 256 byte cache
852 for (i = 128 + 8; i <= 192; i += 8)
853 size_index[size_index_elem(i)] = 8;
857 static void __init new_kmalloc_cache(int idx, unsigned long flags)
859 kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
860 kmalloc_info[idx].size, flags);
864 * Create the kmalloc array. Some of the regular kmalloc arrays
865 * may already have been created because they were needed to
866 * enable allocations for slab creation.
868 void __init create_kmalloc_caches(unsigned long flags)
872 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
873 if (!kmalloc_caches[i])
874 new_kmalloc_cache(i, flags);
877 * Caches that are not of the two-to-the-power-of size.
878 * These have to be created immediately after the
879 * earlier power of two caches
881 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
882 new_kmalloc_cache(1, flags);
883 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
884 new_kmalloc_cache(2, flags);
887 /* Kmalloc array is now usable */
890 #ifdef CONFIG_ZONE_DMA
891 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
892 struct kmem_cache *s = kmalloc_caches[i];
895 int size = kmalloc_size(i);
896 char *n = kasprintf(GFP_NOWAIT,
897 "dma-kmalloc-%d", size);
900 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
901 size, SLAB_CACHE_DMA | flags);
906 #endif /* !CONFIG_SLOB */
909 * To avoid unnecessary overhead, we pass through large allocation requests
910 * directly to the page allocator. We use __GFP_COMP, because we will need to
911 * know the allocation order to free the pages properly in kfree.
913 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
919 page = alloc_kmem_pages(flags, order);
920 ret = page ? page_address(page) : NULL;
921 kmemleak_alloc(ret, size, 1, flags);
922 kasan_kmalloc_large(ret, size);
925 EXPORT_SYMBOL(kmalloc_order);
927 #ifdef CONFIG_TRACING
928 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
930 void *ret = kmalloc_order(size, flags, order);
931 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
934 EXPORT_SYMBOL(kmalloc_order_trace);
937 #ifdef CONFIG_SLABINFO
940 #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
942 #define SLABINFO_RIGHTS S_IRUSR
945 static void print_slabinfo_header(struct seq_file *m)
948 * Output format version, so at least we can change it
949 * without _too_ many complaints.
951 #ifdef CONFIG_DEBUG_SLAB
952 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
954 seq_puts(m, "slabinfo - version: 2.1\n");
956 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
957 "<objperslab> <pagesperslab>");
958 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
959 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
960 #ifdef CONFIG_DEBUG_SLAB
961 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
962 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
963 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
968 void *slab_start(struct seq_file *m, loff_t *pos)
970 mutex_lock(&slab_mutex);
971 return seq_list_start(&slab_caches, *pos);
974 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
976 return seq_list_next(p, &slab_caches, pos);
979 void slab_stop(struct seq_file *m, void *p)
981 mutex_unlock(&slab_mutex);
985 memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
987 struct kmem_cache *c;
988 struct slabinfo sinfo;
990 if (!is_root_cache(s))
993 for_each_memcg_cache(c, s) {
994 memset(&sinfo, 0, sizeof(sinfo));
995 get_slabinfo(c, &sinfo);
997 info->active_slabs += sinfo.active_slabs;
998 info->num_slabs += sinfo.num_slabs;
999 info->shared_avail += sinfo.shared_avail;
1000 info->active_objs += sinfo.active_objs;
1001 info->num_objs += sinfo.num_objs;
1005 static void cache_show(struct kmem_cache *s, struct seq_file *m)
1007 struct slabinfo sinfo;
1009 memset(&sinfo, 0, sizeof(sinfo));
1010 get_slabinfo(s, &sinfo);
1012 memcg_accumulate_slabinfo(s, &sinfo);
1014 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
1015 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
1016 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1018 seq_printf(m, " : tunables %4u %4u %4u",
1019 sinfo.limit, sinfo.batchcount, sinfo.shared);
1020 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1021 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1022 slabinfo_show_stats(m, s);
1026 static int slab_show(struct seq_file *m, void *p)
1028 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1030 if (p == slab_caches.next)
1031 print_slabinfo_header(m);
1032 if (is_root_cache(s))
1037 #ifdef CONFIG_MEMCG_KMEM
1038 int memcg_slab_show(struct seq_file *m, void *p)
1040 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1041 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
1043 if (p == slab_caches.next)
1044 print_slabinfo_header(m);
1045 if (!is_root_cache(s) && s->memcg_params.memcg == memcg)
1052 * slabinfo_op - iterator that generates /proc/slabinfo
1061 * num-pages-per-slab
1062 * + further values on SMP and with statistics enabled
1064 static const struct seq_operations slabinfo_op = {
1065 .start = slab_start,
1071 static int slabinfo_open(struct inode *inode, struct file *file)
1073 return seq_open(file, &slabinfo_op);
1076 static const struct file_operations proc_slabinfo_operations = {
1077 .open = slabinfo_open,
1079 .write = slabinfo_write,
1080 .llseek = seq_lseek,
1081 .release = seq_release,
1084 static int __init slab_proc_init(void)
1086 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1087 &proc_slabinfo_operations);
1090 module_init(slab_proc_init);
1091 #endif /* CONFIG_SLABINFO */
1093 static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1102 if (ks >= new_size) {
1103 kasan_krealloc((void *)p, new_size);
1107 ret = kmalloc_track_caller(new_size, flags);
1115 * __krealloc - like krealloc() but don't free @p.
1116 * @p: object to reallocate memory for.
1117 * @new_size: how many bytes of memory are required.
1118 * @flags: the type of memory to allocate.
1120 * This function is like krealloc() except it never frees the originally
1121 * allocated buffer. Use this if you don't want to free the buffer immediately
1122 * like, for example, with RCU.
1124 void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1126 if (unlikely(!new_size))
1127 return ZERO_SIZE_PTR;
1129 return __do_krealloc(p, new_size, flags);
1132 EXPORT_SYMBOL(__krealloc);
1135 * krealloc - reallocate memory. The contents will remain unchanged.
1136 * @p: object to reallocate memory for.
1137 * @new_size: how many bytes of memory are required.
1138 * @flags: the type of memory to allocate.
1140 * The contents of the object pointed to are preserved up to the
1141 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1142 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1143 * %NULL pointer, the object pointed to is freed.
1145 void *krealloc(const void *p, size_t new_size, gfp_t flags)
1149 if (unlikely(!new_size)) {
1151 return ZERO_SIZE_PTR;
1154 ret = __do_krealloc(p, new_size, flags);
1155 if (ret && p != ret)
1160 EXPORT_SYMBOL(krealloc);
1163 * kzfree - like kfree but zero memory
1164 * @p: object to free memory of
1166 * The memory of the object @p points to is zeroed before freed.
1167 * If @p is %NULL, kzfree() does nothing.
1169 * Note: this function zeroes the whole allocated buffer which can be a good
1170 * deal bigger than the requested buffer size passed to kmalloc(). So be
1171 * careful when using this function in performance sensitive code.
1173 void kzfree(const void *p)
1176 void *mem = (void *)p;
1178 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1184 EXPORT_SYMBOL(kzfree);
1186 /* Tracepoints definitions. */
1187 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1188 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1189 EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1190 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1191 EXPORT_TRACEPOINT_SYMBOL(kfree);
1192 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);