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
);