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 #ifdef CONFIG_MEMCG_KMEM
109 static int memcg_alloc_cache_params(struct mem_cgroup *memcg,
110 struct kmem_cache *s, struct kmem_cache *root_cache)
114 if (!memcg_kmem_enabled())
118 size = offsetof(struct memcg_cache_params, memcg_caches);
119 size += memcg_limited_groups_array_size * sizeof(void *);
121 size = sizeof(struct memcg_cache_params);
123 s->memcg_params = kzalloc(size, GFP_KERNEL);
124 if (!s->memcg_params)
128 s->memcg_params->memcg = memcg;
129 s->memcg_params->root_cache = root_cache;
131 s->memcg_params->is_root_cache = true;
136 static void memcg_free_cache_params(struct kmem_cache *s)
138 kfree(s->memcg_params);
141 static int memcg_update_cache_params(struct kmem_cache *s, int num_memcgs)
144 struct memcg_cache_params *new_params, *cur_params;
146 BUG_ON(!is_root_cache(s));
148 size = offsetof(struct memcg_cache_params, memcg_caches);
149 size += num_memcgs * sizeof(void *);
151 new_params = kzalloc(size, GFP_KERNEL);
155 cur_params = s->memcg_params;
156 memcpy(new_params->memcg_caches, cur_params->memcg_caches,
157 memcg_limited_groups_array_size * sizeof(void *));
159 new_params->is_root_cache = true;
161 rcu_assign_pointer(s->memcg_params, new_params);
163 kfree_rcu(cur_params, rcu_head);
168 int memcg_update_all_caches(int num_memcgs)
170 struct kmem_cache *s;
172 mutex_lock(&slab_mutex);
174 list_for_each_entry(s, &slab_caches, list) {
175 if (!is_root_cache(s))
178 ret = memcg_update_cache_params(s, num_memcgs);
180 * Instead of freeing the memory, we'll just leave the caches
181 * up to this point in an updated state.
187 memcg_update_array_size(num_memcgs);
189 mutex_unlock(&slab_mutex);
193 static inline int memcg_alloc_cache_params(struct mem_cgroup *memcg,
194 struct kmem_cache *s, struct kmem_cache *root_cache)
199 static inline void memcg_free_cache_params(struct kmem_cache *s)
202 #endif /* CONFIG_MEMCG_KMEM */
205 * Find a mergeable slab cache
207 int slab_unmergeable(struct kmem_cache *s)
209 if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
212 if (!is_root_cache(s))
219 * We may have set a slab to be unmergeable during bootstrap.
227 struct kmem_cache *find_mergeable(size_t size, size_t align,
228 unsigned long flags, const char *name, void (*ctor)(void *))
230 struct kmem_cache *s;
232 if (slab_nomerge || (flags & SLAB_NEVER_MERGE))
238 size = ALIGN(size, sizeof(void *));
239 align = calculate_alignment(flags, align, size);
240 size = ALIGN(size, align);
241 flags = kmem_cache_flags(size, flags, name, NULL);
243 list_for_each_entry_reverse(s, &slab_caches, list) {
244 if (slab_unmergeable(s))
250 if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
253 * Check if alignment is compatible.
254 * Courtesy of Adrian Drzewiecki
256 if ((s->size & ~(align - 1)) != s->size)
259 if (s->size - size >= sizeof(void *))
262 if (IS_ENABLED(CONFIG_SLAB) && align &&
263 (align > s->align || s->align % align))
272 * Figure out what the alignment of the objects will be given a set of
273 * flags, a user specified alignment and the size of the objects.
275 unsigned long calculate_alignment(unsigned long flags,
276 unsigned long align, unsigned long size)
279 * If the user wants hardware cache aligned objects then follow that
280 * suggestion if the object is sufficiently large.
282 * The hardware cache alignment cannot override the specified
283 * alignment though. If that is greater then use it.
285 if (flags & SLAB_HWCACHE_ALIGN) {
286 unsigned long ralign = cache_line_size();
287 while (size <= ralign / 2)
289 align = max(align, ralign);
292 if (align < ARCH_SLAB_MINALIGN)
293 align = ARCH_SLAB_MINALIGN;
295 return ALIGN(align, sizeof(void *));
298 static struct kmem_cache *
299 do_kmem_cache_create(char *name, size_t object_size, size_t size, size_t align,
300 unsigned long flags, void (*ctor)(void *),
301 struct mem_cgroup *memcg, struct kmem_cache *root_cache)
303 struct kmem_cache *s;
307 s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
312 s->object_size = object_size;
317 err = memcg_alloc_cache_params(memcg, s, root_cache);
321 err = __kmem_cache_create(s, flags);
326 list_add(&s->list, &slab_caches);
333 memcg_free_cache_params(s);
334 kmem_cache_free(kmem_cache, s);
339 * kmem_cache_create - Create a cache.
340 * @name: A string which is used in /proc/slabinfo to identify this cache.
341 * @size: The size of objects to be created in this cache.
342 * @align: The required alignment for the objects.
344 * @ctor: A constructor for the objects.
346 * Returns a ptr to the cache on success, NULL on failure.
347 * Cannot be called within a interrupt, but can be interrupted.
348 * The @ctor is run when new pages are allocated by the cache.
352 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
353 * to catch references to uninitialised memory.
355 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
356 * for buffer overruns.
358 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
359 * cacheline. This can be beneficial if you're counting cycles as closely
363 kmem_cache_create(const char *name, size_t size, size_t align,
364 unsigned long flags, void (*ctor)(void *))
366 struct kmem_cache *s;
373 mutex_lock(&slab_mutex);
375 err = kmem_cache_sanity_check(name, size);
377 s = NULL; /* suppress uninit var warning */
382 * Some allocators will constraint the set of valid flags to a subset
383 * of all flags. We expect them to define CACHE_CREATE_MASK in this
384 * case, and we'll just provide them with a sanitized version of the
387 flags &= CACHE_CREATE_MASK;
389 s = __kmem_cache_alias(name, size, align, flags, ctor);
393 cache_name = kstrdup(name, GFP_KERNEL);
399 s = do_kmem_cache_create(cache_name, size, size,
400 calculate_alignment(flags, align, size),
401 flags, ctor, NULL, NULL);
408 mutex_unlock(&slab_mutex);
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 struct kmem_cache *root_cache = s->memcg_params->root_cache;
444 int memcg_id = memcg_cache_id(s->memcg_params->memcg);
446 BUG_ON(root_cache->memcg_params->memcg_caches[memcg_id] != s);
447 root_cache->memcg_params->memcg_caches[memcg_id] = NULL;
450 list_move(&s->list, release);
454 static void do_kmem_cache_release(struct list_head *release,
455 bool need_rcu_barrier)
457 struct kmem_cache *s, *s2;
459 if (need_rcu_barrier)
462 list_for_each_entry_safe(s, s2, release, list) {
463 #ifdef SLAB_SUPPORTS_SYSFS
464 sysfs_slab_remove(s);
466 slab_kmem_cache_release(s);
471 #ifdef CONFIG_MEMCG_KMEM
473 * memcg_create_kmem_cache - Create a cache for a memory cgroup.
474 * @memcg: The memory cgroup the new cache is for.
475 * @root_cache: The parent of the new cache.
477 * This function attempts to create a kmem cache that will serve allocation
478 * requests going from @memcg to @root_cache. The new cache inherits properties
481 void memcg_create_kmem_cache(struct mem_cgroup *memcg,
482 struct kmem_cache *root_cache)
484 static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
485 int memcg_id = memcg_cache_id(memcg);
486 struct kmem_cache *s = NULL;
492 mutex_lock(&slab_mutex);
495 * Since per-memcg caches are created asynchronously on first
496 * allocation (see memcg_kmem_get_cache()), several threads can try to
497 * create the same cache, but only one of them may succeed.
499 if (cache_from_memcg_idx(root_cache, memcg_id))
502 cgroup_name(mem_cgroup_css(memcg)->cgroup,
503 memcg_name_buf, sizeof(memcg_name_buf));
504 cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
505 memcg_cache_id(memcg), memcg_name_buf);
509 s = do_kmem_cache_create(cache_name, root_cache->object_size,
510 root_cache->size, root_cache->align,
511 root_cache->flags, root_cache->ctor,
514 * If we could not create a memcg cache, do not complain, because
515 * that's not critical at all as we can always proceed with the root
524 * Since readers won't lock (see cache_from_memcg_idx()), we need a
525 * barrier here to ensure nobody will see the kmem_cache partially
529 root_cache->memcg_params->memcg_caches[memcg_id] = s;
532 mutex_unlock(&slab_mutex);
538 void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
541 bool need_rcu_barrier = false;
542 struct kmem_cache *s, *s2;
547 mutex_lock(&slab_mutex);
548 list_for_each_entry_safe(s, s2, &slab_caches, list) {
549 if (is_root_cache(s) || s->memcg_params->memcg != memcg)
552 * The cgroup is about to be freed and therefore has no charges
553 * left. Hence, all its caches must be empty by now.
555 BUG_ON(do_kmem_cache_shutdown(s, &release, &need_rcu_barrier));
557 mutex_unlock(&slab_mutex);
562 do_kmem_cache_release(&release, need_rcu_barrier);
564 #endif /* CONFIG_MEMCG_KMEM */
566 void slab_kmem_cache_release(struct kmem_cache *s)
568 memcg_free_cache_params(s);
570 kmem_cache_free(kmem_cache, s);
573 void kmem_cache_destroy(struct kmem_cache *s)
577 bool need_rcu_barrier = false;
583 mutex_lock(&slab_mutex);
589 for_each_memcg_cache_index(i) {
590 struct kmem_cache *c = cache_from_memcg_idx(s, i);
592 if (c && do_kmem_cache_shutdown(c, &release, &need_rcu_barrier))
597 do_kmem_cache_shutdown(s, &release, &need_rcu_barrier);
600 mutex_unlock(&slab_mutex);
605 do_kmem_cache_release(&release, need_rcu_barrier);
607 EXPORT_SYMBOL(kmem_cache_destroy);
610 * kmem_cache_shrink - Shrink a cache.
611 * @cachep: The cache to shrink.
613 * Releases as many slabs as possible for a cache.
614 * To help debugging, a zero exit status indicates all slabs were released.
616 int kmem_cache_shrink(struct kmem_cache *cachep)
622 ret = __kmem_cache_shrink(cachep);
627 EXPORT_SYMBOL(kmem_cache_shrink);
629 int slab_is_available(void)
631 return slab_state >= UP;
635 /* Create a cache during boot when no slab services are available yet */
636 void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
642 s->size = s->object_size = size;
643 s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
644 err = __kmem_cache_create(s, flags);
647 panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n",
650 s->refcount = -1; /* Exempt from merging for now */
653 struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
656 struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
659 panic("Out of memory when creating slab %s\n", name);
661 create_boot_cache(s, name, size, flags);
662 list_add(&s->list, &slab_caches);
667 struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
668 EXPORT_SYMBOL(kmalloc_caches);
670 #ifdef CONFIG_ZONE_DMA
671 struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
672 EXPORT_SYMBOL(kmalloc_dma_caches);
676 * Conversion table for small slabs sizes / 8 to the index in the
677 * kmalloc array. This is necessary for slabs < 192 since we have non power
678 * of two cache sizes there. The size of larger slabs can be determined using
681 static s8 size_index[24] = {
708 static inline int size_index_elem(size_t bytes)
710 return (bytes - 1) / 8;
714 * Find the kmem_cache structure that serves a given size of
717 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
721 if (unlikely(size > KMALLOC_MAX_SIZE)) {
722 WARN_ON_ONCE(!(flags & __GFP_NOWARN));
728 return ZERO_SIZE_PTR;
730 index = size_index[size_index_elem(size)];
732 index = fls(size - 1);
734 #ifdef CONFIG_ZONE_DMA
735 if (unlikely((flags & GFP_DMA)))
736 return kmalloc_dma_caches[index];
739 return kmalloc_caches[index];
743 * Create the kmalloc array. Some of the regular kmalloc arrays
744 * may already have been created because they were needed to
745 * enable allocations for slab creation.
747 void __init create_kmalloc_caches(unsigned long flags)
752 * Patch up the size_index table if we have strange large alignment
753 * requirements for the kmalloc array. This is only the case for
754 * MIPS it seems. The standard arches will not generate any code here.
756 * Largest permitted alignment is 256 bytes due to the way we
757 * handle the index determination for the smaller caches.
759 * Make sure that nothing crazy happens if someone starts tinkering
760 * around with ARCH_KMALLOC_MINALIGN
762 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
763 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
765 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
766 int elem = size_index_elem(i);
768 if (elem >= ARRAY_SIZE(size_index))
770 size_index[elem] = KMALLOC_SHIFT_LOW;
773 if (KMALLOC_MIN_SIZE >= 64) {
775 * The 96 byte size cache is not used if the alignment
778 for (i = 64 + 8; i <= 96; i += 8)
779 size_index[size_index_elem(i)] = 7;
783 if (KMALLOC_MIN_SIZE >= 128) {
785 * The 192 byte sized cache is not used if the alignment
786 * is 128 byte. Redirect kmalloc to use the 256 byte cache
789 for (i = 128 + 8; i <= 192; i += 8)
790 size_index[size_index_elem(i)] = 8;
792 for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
793 if (!kmalloc_caches[i]) {
794 kmalloc_caches[i] = create_kmalloc_cache(NULL,
799 * Caches that are not of the two-to-the-power-of size.
800 * These have to be created immediately after the
801 * earlier power of two caches
803 if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6)
804 kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags);
806 if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7)
807 kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags);
810 /* Kmalloc array is now usable */
813 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
814 struct kmem_cache *s = kmalloc_caches[i];
818 n = kasprintf(GFP_NOWAIT, "kmalloc-%d", kmalloc_size(i));
825 #ifdef CONFIG_ZONE_DMA
826 for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
827 struct kmem_cache *s = kmalloc_caches[i];
830 int size = kmalloc_size(i);
831 char *n = kasprintf(GFP_NOWAIT,
832 "dma-kmalloc-%d", size);
835 kmalloc_dma_caches[i] = create_kmalloc_cache(n,
836 size, SLAB_CACHE_DMA | flags);
841 #endif /* !CONFIG_SLOB */
844 * To avoid unnecessary overhead, we pass through large allocation requests
845 * directly to the page allocator. We use __GFP_COMP, because we will need to
846 * know the allocation order to free the pages properly in kfree.
848 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
854 page = alloc_kmem_pages(flags, order);
855 ret = page ? page_address(page) : NULL;
856 kmemleak_alloc(ret, size, 1, flags);
859 EXPORT_SYMBOL(kmalloc_order);
861 #ifdef CONFIG_TRACING
862 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
864 void *ret = kmalloc_order(size, flags, order);
865 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
868 EXPORT_SYMBOL(kmalloc_order_trace);
871 #ifdef CONFIG_SLABINFO
874 #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR)
876 #define SLABINFO_RIGHTS S_IRUSR
879 static void print_slabinfo_header(struct seq_file *m)
882 * Output format version, so at least we can change it
883 * without _too_ many complaints.
885 #ifdef CONFIG_DEBUG_SLAB
886 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
888 seq_puts(m, "slabinfo - version: 2.1\n");
890 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
891 "<objperslab> <pagesperslab>");
892 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
893 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
894 #ifdef CONFIG_DEBUG_SLAB
895 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
896 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
897 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
902 void *slab_start(struct seq_file *m, loff_t *pos)
904 mutex_lock(&slab_mutex);
905 return seq_list_start(&slab_caches, *pos);
908 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
910 return seq_list_next(p, &slab_caches, pos);
913 void slab_stop(struct seq_file *m, void *p)
915 mutex_unlock(&slab_mutex);
919 memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info)
921 struct kmem_cache *c;
922 struct slabinfo sinfo;
925 if (!is_root_cache(s))
928 for_each_memcg_cache_index(i) {
929 c = cache_from_memcg_idx(s, i);
933 memset(&sinfo, 0, sizeof(sinfo));
934 get_slabinfo(c, &sinfo);
936 info->active_slabs += sinfo.active_slabs;
937 info->num_slabs += sinfo.num_slabs;
938 info->shared_avail += sinfo.shared_avail;
939 info->active_objs += sinfo.active_objs;
940 info->num_objs += sinfo.num_objs;
944 static void cache_show(struct kmem_cache *s, struct seq_file *m)
946 struct slabinfo sinfo;
948 memset(&sinfo, 0, sizeof(sinfo));
949 get_slabinfo(s, &sinfo);
951 memcg_accumulate_slabinfo(s, &sinfo);
953 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
954 cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size,
955 sinfo.objects_per_slab, (1 << sinfo.cache_order));
957 seq_printf(m, " : tunables %4u %4u %4u",
958 sinfo.limit, sinfo.batchcount, sinfo.shared);
959 seq_printf(m, " : slabdata %6lu %6lu %6lu",
960 sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
961 slabinfo_show_stats(m, s);
965 static int slab_show(struct seq_file *m, void *p)
967 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
969 if (p == slab_caches.next)
970 print_slabinfo_header(m);
971 if (is_root_cache(s))
976 #ifdef CONFIG_MEMCG_KMEM
977 int memcg_slab_show(struct seq_file *m, void *p)
979 struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
980 struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
982 if (p == slab_caches.next)
983 print_slabinfo_header(m);
984 if (!is_root_cache(s) && s->memcg_params->memcg == memcg)
991 * slabinfo_op - iterator that generates /proc/slabinfo
1000 * num-pages-per-slab
1001 * + further values on SMP and with statistics enabled
1003 static const struct seq_operations slabinfo_op = {
1004 .start = slab_start,
1010 static int slabinfo_open(struct inode *inode, struct file *file)
1012 return seq_open(file, &slabinfo_op);
1015 static const struct file_operations proc_slabinfo_operations = {
1016 .open = slabinfo_open,
1018 .write = slabinfo_write,
1019 .llseek = seq_lseek,
1020 .release = seq_release,
1023 static int __init slab_proc_init(void)
1025 proc_create("slabinfo", SLABINFO_RIGHTS, NULL,
1026 &proc_slabinfo_operations);
1029 module_init(slab_proc_init);
1030 #endif /* CONFIG_SLABINFO */
1032 static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1044 ret = kmalloc_track_caller(new_size, flags);
1052 * __krealloc - like krealloc() but don't free @p.
1053 * @p: object to reallocate memory for.
1054 * @new_size: how many bytes of memory are required.
1055 * @flags: the type of memory to allocate.
1057 * This function is like krealloc() except it never frees the originally
1058 * allocated buffer. Use this if you don't want to free the buffer immediately
1059 * like, for example, with RCU.
1061 void *__krealloc(const void *p, size_t new_size, gfp_t flags)
1063 if (unlikely(!new_size))
1064 return ZERO_SIZE_PTR;
1066 return __do_krealloc(p, new_size, flags);
1069 EXPORT_SYMBOL(__krealloc);
1072 * krealloc - reallocate memory. The contents will remain unchanged.
1073 * @p: object to reallocate memory for.
1074 * @new_size: how many bytes of memory are required.
1075 * @flags: the type of memory to allocate.
1077 * The contents of the object pointed to are preserved up to the
1078 * lesser of the new and old sizes. If @p is %NULL, krealloc()
1079 * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
1080 * %NULL pointer, the object pointed to is freed.
1082 void *krealloc(const void *p, size_t new_size, gfp_t flags)
1086 if (unlikely(!new_size)) {
1088 return ZERO_SIZE_PTR;
1091 ret = __do_krealloc(p, new_size, flags);
1092 if (ret && p != ret)
1097 EXPORT_SYMBOL(krealloc);
1100 * kzfree - like kfree but zero memory
1101 * @p: object to free memory of
1103 * The memory of the object @p points to is zeroed before freed.
1104 * If @p is %NULL, kzfree() does nothing.
1106 * Note: this function zeroes the whole allocated buffer which can be a good
1107 * deal bigger than the requested buffer size passed to kmalloc(). So be
1108 * careful when using this function in performance sensitive code.
1110 void kzfree(const void *p)
1113 void *mem = (void *)p;
1115 if (unlikely(ZERO_OR_NULL_PTR(mem)))
1121 EXPORT_SYMBOL(kzfree);
1123 /* Tracepoints definitions. */
1124 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1125 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1126 EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1127 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1128 EXPORT_TRACEPOINT_SYMBOL(kfree);
1129 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);