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 void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
111 for (i = 0; i < nr; i++)
112 kmem_cache_free(s, p[i]);
115 bool __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
120 for (i = 0; i < nr; i++) {
121 void *x = p[i] = kmem_cache_alloc(s, flags);
123 __kmem_cache_free_bulk(s, i, p);
130 #ifdef CONFIG_MEMCG_KMEM
131 void slab_init_memcg_params(struct kmem_cache *s)
133 s->memcg_params.is_root_cache = true;
134 INIT_LIST_HEAD(&s->memcg_params.list);
135 RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL);
138 static int init_memcg_params(struct kmem_cache *s,
139 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
141 struct memcg_cache_array *arr;
144 s->memcg_params.is_root_cache = false;
145 s->memcg_params.memcg = memcg;
146 s->memcg_params.root_cache = root_cache;
150 slab_init_memcg_params(s);
152 if (!memcg_nr_cache_ids)
155 arr = kzalloc(sizeof(struct memcg_cache_array) +
156 memcg_nr_cache_ids * sizeof(void *),
161 RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr);
165 static void destroy_memcg_params(struct kmem_cache *s)
167 if (is_root_cache(s))
168 kfree(rcu_access_pointer(s->memcg_params.memcg_caches));
171 static int update_memcg_params(struct kmem_cache *s, int new_array_size)
173 struct memcg_cache_array *old, *new;
175 if (!is_root_cache(s))
178 new = kzalloc(sizeof(struct memcg_cache_array) +
179 new_array_size * sizeof(void *), GFP_KERNEL);
183 old = rcu_dereference_protected(s->memcg_params.memcg_caches,
184 lockdep_is_held(&slab_mutex));
186 memcpy(new->entries, old->entries,
187 memcg_nr_cache_ids * sizeof(void *));
189 rcu_assign_pointer(s->memcg_params.memcg_caches, new);
195 int memcg_update_all_caches(int num_memcgs)
197 struct kmem_cache *s;
200 mutex_lock(&slab_mutex);
201 list_for_each_entry(s, &slab_caches, list) {
202 ret = update_memcg_params(s, num_memcgs);
204 * Instead of freeing the memory, we'll just leave the caches
205 * up to this point in an updated state.
210 mutex_unlock(&slab_mutex);
214 static inline int init_memcg_params(struct kmem_cache *s,
215 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
220 static inline void destroy_memcg_params(struct kmem_cache *s)
223 #endif /* CONFIG_MEMCG_KMEM */
226 * Find a mergeable slab cache
228 int slab_unmergeable(struct kmem_cache *s)
230 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
233 if (!is_root_cache(s))
240 * We may have set a slab to be unmergeable during bootstrap.
248 struct kmem_cache *find_mergeable(size_t size, size_t align,
249 unsigned long flags, const char *name, void (*ctor)(void *))
251 struct kmem_cache *s;
253 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
259 size = ALIGN(size, sizeof(void *));
260 align = calculate_alignment(flags, align, size);
261 size = ALIGN(size, align);
262 flags = kmem_cache_flags(size, flags, name, NULL);
264 list_for_each_entry_reverse(s, &slab_caches, list) {
265 if (slab_unmergeable(s))
271 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
274 * Check if alignment is compatible.
275 * Courtesy of Adrian Drzewiecki
277 if ((s->size & ~(align - 1)) != s->size)
280 if (s->size - size >= sizeof(void *))
283 if (IS_ENABLED(CONFIG_SLAB) && align &&
284 (align > s->align || s->align % align))
293 * Figure out what the alignment of the objects will be given a set of
294 * flags, a user specified alignment and the size of the objects.
296 unsigned long calculate_alignment(unsigned long flags,
297 unsigned long align, unsigned long size)
300 * If the user wants hardware cache aligned objects then follow that
301 * suggestion if the object is sufficiently large.
303 * The hardware cache alignment cannot override the specified
304 * alignment though. If that is greater then use it.
306 if (flags & SLAB_HWCACHE_ALIGN) {
307 unsigned long ralign = cache_line_size();
308 while (size <= ralign / 2)
310 align = max(align, ralign);
313 if (align < ARCH_SLAB_MINALIGN)
314 align = ARCH_SLAB_MINALIGN;
316 return ALIGN(align, sizeof(void *));
319 static struct kmem_cache *
320 do_kmem_cache_create(const char *name, size_t object_size, size_t size,
321 size_t align, unsigned long flags, void (*ctor)(void *),
322 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
324 struct kmem_cache *s;
328 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
333 s->object_size = object_size;
338 err = init_memcg_params(s, memcg, root_cache);
342 err = __kmem_cache_create(s, flags);
347 list_add(&s->list, &slab_caches);
354 destroy_memcg_params(s);
355 kmem_cache_free(kmem_cache, s);
360 * kmem_cache_create - Create a cache.
361 * @name: A string which is used in /proc/slabinfo to identify this cache.
362 * @size: The size of objects to be created in this cache.
363 * @align: The required alignment for the objects.
365 * @ctor: A constructor for the objects.
367 * Returns a ptr to the cache on success, NULL on failure.
368 * Cannot be called within a interrupt, but can be interrupted.
369 * The @ctor is run when new pages are allocated by the cache.
373 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
374 * to catch references to uninitialised memory.
376 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
377 * for buffer overruns.
379 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
380 * cacheline. This can be beneficial if you're counting cycles as closely
384 kmem_cache_create(const char *name, size_t size, size_t align,
385 unsigned long flags, void (*ctor)(void *))
387 struct kmem_cache *s;
388 const char *cache_name;
393 memcg_get_cache_ids();
395 mutex_lock(&slab_mutex);
397 err = kmem_cache_sanity_check(name, size);
399 s = NULL; /* suppress uninit var warning */
404 * Some allocators will constraint the set of valid flags to a subset
405 * of all flags. We expect them to define CACHE_CREATE_MASK in this
406 * case, and we'll just provide them with a sanitized version of the
409 flags &= CACHE_CREATE_MASK;
411 s = __kmem_cache_alias(name, size, align, flags, ctor);
415 cache_name = kstrdup_const(name, GFP_KERNEL);
421 s = do_kmem_cache_create(cache_name, size, size,
422 calculate_alignment(flags, align, size),
423 flags, ctor, NULL, NULL);
426 kfree_const(cache_name);
430 mutex_unlock(&slab_mutex);
432 memcg_put_cache_ids();
437 if (flags & SLAB_PANIC)
438 panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
441 printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d",
449 EXPORT_SYMBOL(kmem_cache_create);
451 static int do_kmem_cache_shutdown(struct kmem_cache *s,
452 struct list_head *release, bool *need_rcu_barrier)
454 if (__kmem_cache_shutdown(s) != 0) {
455 printk(KERN_ERR "kmem_cache_destroy %s: "
456 "Slab cache still has objects\n", s->name);
461 if (s->flags & SLAB_DESTROY_BY_RCU)
462 *need_rcu_barrier = true;
464 #ifdef CONFIG_MEMCG_KMEM
465 if (!is_root_cache(s))
466 list_del(&s->memcg_params.list);
468 list_move(&s->list, release);
472 static void do_kmem_cache_release(struct list_head *release,
473 bool need_rcu_barrier)
475 struct kmem_cache *s, *s2;
477 if (need_rcu_barrier)
480 list_for_each_entry_safe(s, s2, release, list) {
481 #ifdef SLAB_SUPPORTS_SYSFS
482 sysfs_slab_remove(s);
484 slab_kmem_cache_release(s);
489 #ifdef CONFIG_MEMCG_KMEM
491 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
492 * @memcg: The memory cgroup the new cache is for.
493 * @root_cache: The parent of the new cache.
495 * This function attempts to create a kmem cache that will serve allocation
496 * requests going from @memcg to @root_cache. The new cache inherits properties
499 void memcg_create_kmem_cache(struct mem_cgroup *memcg,
500 struct kmem_cache *root_cache)
502 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
503 struct cgroup_subsys_state *css = mem_cgroup_css(memcg);
504 struct memcg_cache_array *arr;
505 struct kmem_cache *s = NULL;
512 mutex_lock(&slab_mutex);
515 * The memory cgroup could have been deactivated while the cache
516 * creation work was pending.
518 if (!memcg_kmem_is_active(memcg))
521 idx = memcg_cache_id(memcg);
522 arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches,
523 lockdep_is_held(&slab_mutex));
526 * Since per-memcg caches are created asynchronously on first
527 * allocation (see memcg_kmem_get_cache()), several threads can try to
528 * create the same cache, but only one of them may succeed.
530 if (arr->entries[idx])
533 cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf));
534 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
535 css->id, memcg_name_buf);
539 s = do_kmem_cache_create(cache_name, root_cache->object_size,
540 root_cache->size, root_cache->align,
541 root_cache->flags, root_cache->ctor,
544 * If we could not create a memcg cache, do not complain, because
545 * that's not critical at all as we can always proceed with the root
553 list_add(&s->memcg_params.list, &root_cache->memcg_params.list);
556 * Since readers won't lock (see cache_from_memcg_idx()), we need a
557 * barrier here to ensure nobody will see the kmem_cache partially
561 arr->entries[idx] = s;
564 mutex_unlock(&slab_mutex);
570 void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
573 struct memcg_cache_array *arr;
574 struct kmem_cache *s, *c;
576 idx = memcg_cache_id(memcg);
581 mutex_lock(&slab_mutex);
582 list_for_each_entry(s, &slab_caches, list) {
583 if (!is_root_cache(s))
586 arr = rcu_dereference_protected(s->memcg_params.memcg_caches,
587 lockdep_is_held(&slab_mutex));
588 c = arr->entries[idx];
592 __kmem_cache_shrink(c, true);
593 arr->entries[idx] = NULL;
595 mutex_unlock(&slab_mutex);
601 void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
604 bool need_rcu_barrier = false;
605 struct kmem_cache *s, *s2;
610 mutex_lock(&slab_mutex);
611 list_for_each_entry_safe(s, s2, &slab_caches, list) {
612 if (is_root_cache(s) || s->memcg_params.memcg != memcg)
615 * The cgroup is about to be freed and therefore has no charges
616 * left. Hence, all its caches must be empty by now.
618 BUG_ON(do_kmem_cache_shutdown(s, &release, &need_rcu_barrier));
620 mutex_unlock(&slab_mutex);
625 do_kmem_cache_release(&release, need_rcu_barrier);
627 #endif /* CONFIG_MEMCG_KMEM */
629 void slab_kmem_cache_release(struct kmem_cache *s)
631 destroy_memcg_params(s);
632 kfree_const(s->name);
633 kmem_cache_free(kmem_cache, s);
636 void kmem_cache_destroy(struct kmem_cache *s)
638 struct kmem_cache *c, *c2;
640 bool need_rcu_barrier = false;
643 BUG_ON(!is_root_cache(s));
648 mutex_lock(&slab_mutex);
654 for_each_memcg_cache_safe(c, c2, s) {
655 if (do_kmem_cache_shutdown(c, &release, &need_rcu_barrier))
660 do_kmem_cache_shutdown(s, &release, &need_rcu_barrier);
663 mutex_unlock(&slab_mutex);
668 do_kmem_cache_release(&release, need_rcu_barrier);
670 EXPORT_SYMBOL(kmem_cache_destroy);
673 * kmem_cache_shrink - Shrink a cache.
674 * @cachep: The cache to shrink.
676 * Releases as many slabs as possible for a cache.
677 * To help debugging, a zero exit status indicates all slabs were released.
679 int kmem_cache_shrink(struct kmem_cache *cachep)
685 ret = __kmem_cache_shrink(cachep, false);
690 EXPORT_SYMBOL(kmem_cache_shrink);
692 int slab_is_available(void)
694 return slab_state >= UP;
698 /* Create a cache during boot when no slab services are available yet */
699 void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
705 s->size = s->object_size = size;
706 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
708 slab_init_memcg_params(s);
710 err = __kmem_cache_create(s, flags);
713 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
716 s->refcount = -1; /* Exempt from merging for now */
719 struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
722 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
725 panic("Out of memory when creating slab %s\n", name);
727 create_boot_cache(s, name, size, flags);
728 list_add(&s->list, &slab_caches);
733 struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
734 EXPORT_SYMBOL(kmalloc_caches);
736 #ifdef CONFIG_ZONE_DMA
737 struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
738 EXPORT_SYMBOL(kmalloc_dma_caches);
742 * Conversion table for small slabs sizes / 8 to the index in the
743 * kmalloc array. This is necessary for slabs < 192 since we have non power
744 * of two cache sizes there. The size of larger slabs can be determined using
747 static s8 size_index[24] = {
774 static inline int size_index_elem(size_t bytes)
776 return (bytes - 1) / 8;
780 * Find the kmem_cache structure that serves a given size of
783 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
787 if (unlikely(size > KMALLOC_MAX_SIZE)) {
788 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
794 return ZERO_SIZE_PTR;
796 index = size_index[size_index_elem(size)];
798 index = fls(size - 1);
800 #ifdef CONFIG_ZONE_DMA
801 if (unlikely((flags & GFP_DMA)))
802 return kmalloc_dma_caches[index];
805 return kmalloc_caches[index];
809 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
810 * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is
816 } const kmalloc_info[] __initconst = {
817 {NULL, 0}, {"kmalloc-96", 96},
818 {"kmalloc-192", 192}, {"kmalloc-8", 8},
819 {"kmalloc-16", 16}, {"kmalloc-32", 32},
820 {"kmalloc-64", 64}, {"kmalloc-128", 128},
821 {"kmalloc-256", 256}, {"kmalloc-512", 512},
822 {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048},
823 {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192},
824 {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768},
825 {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072},
826 {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288},
827 {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152},
828 {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608},
829 {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432},
830 {"kmalloc-67108864", 67108864}
834 * Patch up the size_index table if we have strange large alignment
835 * requirements for the kmalloc array. This is only the case for
836 * MIPS it seems. The standard arches will not generate any code here.
838 * Largest permitted alignment is 256 bytes due to the way we
839 * handle the index determination for the smaller caches.
841 * Make sure that nothing crazy happens if someone starts tinkering
842 * around with ARCH_KMALLOC_MINALIGN
844 void __init setup_kmalloc_cache_index_table(void)
848 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
849 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
851 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
852 int elem = size_index_elem(i);
854 if (elem >= ARRAY_SIZE(size_index))
856 size_index[elem] = KMALLOC_SHIFT_LOW;
859 if (KMALLOC_MIN_SIZE >= 64) {
861 * The 96 byte size cache is not used if the alignment
864 for (i = 64 + 8; i <= 96; i += 8)
865 size_index[size_index_elem(i)] = 7;
869 if (KMALLOC_MIN_SIZE >= 128) {
871 * The 192 byte sized cache is not used if the alignment
872 * is 128 byte. Redirect kmalloc to use the 256 byte cache
875 for (i = 128 + 8; i <= 192; i += 8)
876 size_index[size_index_elem(i)] = 8;
880 static void __init new_kmalloc_cache(int idx, unsigned long flags)
882 kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name,
883 kmalloc_info[idx].size, flags);
887 * Create the kmalloc array. Some of the regular kmalloc arrays
888 * may already have been created because they were needed to
889 * enable allocations for slab creation.
891 void __init create_kmalloc_caches(unsigned long flags)
895 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
896 if (!kmalloc_caches[i])
897 new_kmalloc_cache(i, flags);
900 * Caches that are not of the two-to-the-power-of size.
901 * These have to be created immediately after the
902 * earlier power of two caches
904 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
905 new_kmalloc_cache(1, flags);
906 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
907 new_kmalloc_cache(2, flags);
910 /* Kmalloc array is now usable */
913 #ifdef CONFIG_ZONE_DMA
914 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
915 struct kmem_cache *s = kmalloc_caches[i];
918 int size = kmalloc_size(i);
919 char *n = kasprintf(GFP_NOWAIT,
920 "dma-kmalloc-%d", size);
923 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
924 size, SLAB_CACHE_DMA | flags);
929 #endif /* !CONFIG_SLOB */
932 * To avoid unnecessary overhead, we pass through large allocation requests
933 * directly to the page allocator. We use __GFP_COMP, because we will need to
934 * know the allocation order to free the pages properly in kfree.
936 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
942 page = alloc_kmem_pages(flags, order);
943 ret = page ? page_address(page) : NULL;
944 kmemleak_alloc(ret, size, 1, flags);
945 kasan_kmalloc_large(ret, size);
948 EXPORT_SYMBOL(kmalloc_order);
950 #ifdef CONFIG_TRACING
951 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
953 void *ret = kmalloc_order(size, flags, order);
954 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
957 EXPORT_SYMBOL(kmalloc_order_trace);
960 #ifdef CONFIG_SLABINFO
963 #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
965 #define SLABINFO_RIGHTS S_IRUSR
968 static void print_slabinfo_header(struct seq_file *m)
971 * Output format version, so at least we can change it
972 * without _too_ many complaints.
974 #ifdef CONFIG_DEBUG_SLAB
975 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
977 seq_puts(m, "slabinfo - version: 2.1\n");
979 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
980 "<objperslab> <pagesperslab>");
981 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
982 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
983 #ifdef CONFIG_DEBUG_SLAB
984 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
985 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
986 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
991 void *slab_start(struct seq_file *m, loff_t *pos)
993 mutex_lock(&slab_mutex);
994 return seq_list_start(&slab_caches, *pos);
997 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
999 return seq_list_next(p, &slab_caches, pos);
1002 void slab_stop(struct seq_file *m, void *p)
1004 mutex_unlock(&slab_mutex);
1008 memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
1010 struct kmem_cache *c;
1011 struct slabinfo sinfo;
1013 if (!is_root_cache(s))
1016 for_each_memcg_cache(c, s) {
1017 memset(&sinfo, 0, sizeof(sinfo));
1018 get_slabinfo(c, &sinfo);
1020 info->active_slabs += sinfo.active_slabs;
1021 info->num_slabs += sinfo.num_slabs;
1022 info->shared_avail += sinfo.shared_avail;
1023 info->active_objs += sinfo.active_objs;
1024 info->num_objs += sinfo.num_objs;
1028 static void cache_show(struct kmem_cache *s, struct seq_file *m)
1030 struct slabinfo sinfo;
1032 memset(&sinfo, 0, sizeof(sinfo));
1033 get_slabinfo(s, &sinfo);
1035 memcg_accumulate_slabinfo(s, &sinfo);
1037 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
1038 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
1039 sinfo.objects_per_slab, (1 << sinfo.cache_order));
1041 seq_printf(m, " : tunables %4u %4u %4u",
1042 sinfo.limit, sinfo.batchcount, sinfo.shared);
1043 seq_printf(m, " : slabdata %6lu %6lu %6lu",
1044 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1045 slabinfo_show_stats(m, s);
1049 static int slab_show(struct seq_file *m, void *p)
1051 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1053 if (p == slab_caches.next)
1054 print_slabinfo_header(m);
1055 if (is_root_cache(s))
1060 #ifdef CONFIG_MEMCG_KMEM
1061 int memcg_slab_show(struct seq_file *m, void *p)
1063 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1064 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
1066 if (p == slab_caches.next)
1067 print_slabinfo_header(m);
1068 if (!is_root_cache(s) && s->memcg_params.memcg == memcg)
1075 * slabinfo_op - iterator that generates /proc/slabinfo
1084 * num-pages-per-slab
1085 * + further values on SMP and with statistics enabled
1087 static const struct seq_operations slabinfo_op = {
1088 .start = slab_start,
1094 static int slabinfo_open(struct inode *inode, struct file *file)
1096 return seq_open(file, &slabinfo_op);
1099 static const struct file_operations proc_slabinfo_operations = {
1100 .open = slabinfo_open,
1102 .write = slabinfo_write,
1103 .llseek = seq_lseek,
1104 .release = seq_release,
1107 static int __init slab_proc_init(void)
1109 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1110 &proc_slabinfo_operations);
1113 module_init(slab_proc_init);
1114 #endif /* CONFIG_SLABINFO */
1116 static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1125 if (ks >= new_size) {
1126 kasan_krealloc((void *)p, new_size);
1130 ret = kmalloc_track_caller(new_size, flags);
1138 * __krealloc - like krealloc() but don't free @p.
1139 * @p: object to reallocate memory for.
1140 * @new_size: how many bytes of memory are required.
1141 * @flags: the type of memory to allocate.
1143 * This function is like krealloc() except it never frees the originally
1144 * allocated buffer. Use this if you don't want to free the buffer immediately
1145 * like, for example, with RCU.
1147 void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1149 if (unlikely(!new_size))
1150 return ZERO_SIZE_PTR;
1152 return __do_krealloc(p, new_size, flags);
1155 EXPORT_SYMBOL(__krealloc);
1158 * krealloc - reallocate memory. The contents will remain unchanged.
1159 * @p: object to reallocate memory for.
1160 * @new_size: how many bytes of memory are required.
1161 * @flags: the type of memory to allocate.
1163 * The contents of the object pointed to are preserved up to the
1164 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1165 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1166 * %NULL pointer, the object pointed to is freed.
1168 void *krealloc(const void *p, size_t new_size, gfp_t flags)
1172 if (unlikely(!new_size)) {
1174 return ZERO_SIZE_PTR;
1177 ret = __do_krealloc(p, new_size, flags);
1178 if (ret && p != ret)
1183 EXPORT_SYMBOL(krealloc);
1186 * kzfree - like kfree but zero memory
1187 * @p: object to free memory of
1189 * The memory of the object @p points to is zeroed before freed.
1190 * If @p is %NULL, kzfree() does nothing.
1192 * Note: this function zeroes the whole allocated buffer which can be a good
1193 * deal bigger than the requested buffer size passed to kmalloc(). So be
1194 * careful when using this function in performance sensitive code.
1196 void kzfree(const void *p)
1199 void *mem = (void *)p;
1201 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1207 EXPORT_SYMBOL(kzfree);
1209 /* Tracepoints definitions. */
1210 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1211 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1212 EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1213 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1214 EXPORT_TRACEPOINT_SYMBOL(kfree);
1215 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);