1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
5 * (C) SGI 2006, Christoph Lameter
6 * Cleaned up and restructured to ease the addition of alternative
7 * implementations of SLAB allocators.
8 * (C) Linux Foundation 2008-2013
9 * Unified interface for all slab allocators
15 #include <linux/gfp.h>
16 #include <linux/types.h>
17 #include <linux/workqueue.h>
21 * Flags to pass to kmem_cache_create().
22 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
24 /* DEBUG: Perform (expensive) checks on alloc/free */
25 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U)
26 /* DEBUG: Red zone objs in a cache */
27 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U)
28 /* DEBUG: Poison objects */
29 #define SLAB_POISON ((slab_flags_t __force)0x00000800U)
30 /* Align objs on cache lines */
31 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U)
32 /* Use GFP_DMA memory */
33 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U)
34 /* Use GFP_DMA32 memory */
35 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
36 /* DEBUG: Store the last owner for bug hunting */
37 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U)
38 /* Panic if kmem_cache_create() fails */
39 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U)
41 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
43 * This delays freeing the SLAB page by a grace period, it does _NOT_
44 * delay object freeing. This means that if you do kmem_cache_free()
45 * that memory location is free to be reused at any time. Thus it may
46 * be possible to see another object there in the same RCU grace period.
48 * This feature only ensures the memory location backing the object
49 * stays valid, the trick to using this is relying on an independent
50 * object validation pass. Something like:
54 * obj = lockless_lookup(key);
56 * if (!try_get_ref(obj)) // might fail for free objects
59 * if (obj->key != key) { // not the object we expected
66 * This is useful if we need to approach a kernel structure obliquely,
67 * from its address obtained without the usual locking. We can lock
68 * the structure to stabilize it and check it's still at the given address,
69 * only if we can be sure that the memory has not been meanwhile reused
70 * for some other kind of object (which our subsystem's lock might corrupt).
72 * rcu_read_lock before reading the address, then rcu_read_unlock after
73 * taking the spinlock within the structure expected at that address.
75 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
77 /* Defer freeing slabs to RCU */
78 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
79 /* Spread some memory over cpuset */
80 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
81 /* Trace allocations and frees */
82 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
84 /* Flag to prevent checks on free */
85 #ifdef CONFIG_DEBUG_OBJECTS
86 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
88 # define SLAB_DEBUG_OBJECTS 0
91 /* Avoid kmemleak tracing */
92 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
94 /* Fault injection mark */
95 #ifdef CONFIG_FAILSLAB
96 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
98 # define SLAB_FAILSLAB 0
100 /* Account to memcg */
101 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
102 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
104 # define SLAB_ACCOUNT 0
108 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
113 /* The following flags affect the page allocator grouping pages by mobility */
114 /* Objects are reclaimable */
115 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
116 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
118 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
120 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
122 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
123 * Both make kfree a no-op.
125 #define ZERO_SIZE_PTR ((void *)16)
127 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
128 (unsigned long)ZERO_SIZE_PTR)
130 #include <linux/kmemleak.h>
131 #include <linux/kasan.h>
135 * struct kmem_cache related prototypes
137 void __init
kmem_cache_init(void);
138 bool slab_is_available(void);
140 struct kmem_cache
*kmem_cache_create(const char *, size_t, size_t,
143 void kmem_cache_destroy(struct kmem_cache
*);
144 int kmem_cache_shrink(struct kmem_cache
*);
146 void memcg_create_kmem_cache(struct mem_cgroup
*, struct kmem_cache
*);
147 void memcg_deactivate_kmem_caches(struct mem_cgroup
*);
148 void memcg_destroy_kmem_caches(struct mem_cgroup
*);
151 * Please use this macro to create slab caches. Simply specify the
152 * name of the structure and maybe some flags that are listed above.
154 * The alignment of the struct determines object alignment. If you
155 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
156 * then the objects will be properly aligned in SMP configurations.
158 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
159 sizeof(struct __struct), __alignof__(struct __struct),\
163 * Common kmalloc functions provided by all allocators
165 void * __must_check
__krealloc(const void *, size_t, gfp_t
);
166 void * __must_check
krealloc(const void *, size_t, gfp_t
);
167 void kfree(const void *);
168 void kzfree(const void *);
169 size_t ksize(const void *);
171 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
172 const char *__check_heap_object(const void *ptr
, unsigned long n
,
175 static inline const char *__check_heap_object(const void *ptr
,
184 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
185 * alignment larger than the alignment of a 64-bit integer.
186 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
188 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
189 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
190 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
191 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
193 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
197 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
198 * Intended for arches that get misalignment faults even for 64 bit integer
201 #ifndef ARCH_SLAB_MINALIGN
202 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
206 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
207 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
210 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
211 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
212 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
215 * Kmalloc array related definitions
220 * The largest kmalloc size supported by the SLAB allocators is
221 * 32 megabyte (2^25) or the maximum allocatable page order if that is
224 * WARNING: Its not easy to increase this value since the allocators have
225 * to do various tricks to work around compiler limitations in order to
226 * ensure proper constant folding.
228 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
229 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
230 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
231 #ifndef KMALLOC_SHIFT_LOW
232 #define KMALLOC_SHIFT_LOW 5
238 * SLUB directly allocates requests fitting in to an order-1 page
239 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
241 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
242 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
243 #ifndef KMALLOC_SHIFT_LOW
244 #define KMALLOC_SHIFT_LOW 3
250 * SLOB passes all requests larger than one page to the page allocator.
251 * No kmalloc array is necessary since objects of different sizes can
252 * be allocated from the same page.
254 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
255 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
256 #ifndef KMALLOC_SHIFT_LOW
257 #define KMALLOC_SHIFT_LOW 3
261 /* Maximum allocatable size */
262 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
263 /* Maximum size for which we actually use a slab cache */
264 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
265 /* Maximum order allocatable via the slab allocagtor */
266 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
271 #ifndef KMALLOC_MIN_SIZE
272 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
276 * This restriction comes from byte sized index implementation.
277 * Page size is normally 2^12 bytes and, in this case, if we want to use
278 * byte sized index which can represent 2^8 entries, the size of the object
279 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
280 * If minimum size of kmalloc is less than 16, we use it as minimum object
281 * size and give up to use byte sized index.
283 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
284 (KMALLOC_MIN_SIZE) : 16)
287 extern struct kmem_cache
*kmalloc_caches
[KMALLOC_SHIFT_HIGH
+ 1];
288 #ifdef CONFIG_ZONE_DMA
289 extern struct kmem_cache
*kmalloc_dma_caches
[KMALLOC_SHIFT_HIGH
+ 1];
293 * Figure out which kmalloc slab an allocation of a certain size
297 * 2 = 129 .. 192 bytes
298 * n = 2^(n-1)+1 .. 2^n
300 static __always_inline
int kmalloc_index(size_t size
)
305 if (size
<= KMALLOC_MIN_SIZE
)
306 return KMALLOC_SHIFT_LOW
;
308 if (KMALLOC_MIN_SIZE
<= 32 && size
> 64 && size
<= 96)
310 if (KMALLOC_MIN_SIZE
<= 64 && size
> 128 && size
<= 192)
312 if (size
<= 8) return 3;
313 if (size
<= 16) return 4;
314 if (size
<= 32) return 5;
315 if (size
<= 64) return 6;
316 if (size
<= 128) return 7;
317 if (size
<= 256) return 8;
318 if (size
<= 512) return 9;
319 if (size
<= 1024) return 10;
320 if (size
<= 2 * 1024) return 11;
321 if (size
<= 4 * 1024) return 12;
322 if (size
<= 8 * 1024) return 13;
323 if (size
<= 16 * 1024) return 14;
324 if (size
<= 32 * 1024) return 15;
325 if (size
<= 64 * 1024) return 16;
326 if (size
<= 128 * 1024) return 17;
327 if (size
<= 256 * 1024) return 18;
328 if (size
<= 512 * 1024) return 19;
329 if (size
<= 1024 * 1024) return 20;
330 if (size
<= 2 * 1024 * 1024) return 21;
331 if (size
<= 4 * 1024 * 1024) return 22;
332 if (size
<= 8 * 1024 * 1024) return 23;
333 if (size
<= 16 * 1024 * 1024) return 24;
334 if (size
<= 32 * 1024 * 1024) return 25;
335 if (size
<= 64 * 1024 * 1024) return 26;
338 /* Will never be reached. Needed because the compiler may complain */
341 #endif /* !CONFIG_SLOB */
343 void *__kmalloc(size_t size
, gfp_t flags
) __assume_kmalloc_alignment __malloc
;
344 void *kmem_cache_alloc(struct kmem_cache
*, gfp_t flags
) __assume_slab_alignment __malloc
;
345 void kmem_cache_free(struct kmem_cache
*, void *);
348 * Bulk allocation and freeing operations. These are accelerated in an
349 * allocator specific way to avoid taking locks repeatedly or building
350 * metadata structures unnecessarily.
352 * Note that interrupts must be enabled when calling these functions.
354 void kmem_cache_free_bulk(struct kmem_cache
*, size_t, void **);
355 int kmem_cache_alloc_bulk(struct kmem_cache
*, gfp_t
, size_t, void **);
358 * Caller must not use kfree_bulk() on memory not originally allocated
359 * by kmalloc(), because the SLOB allocator cannot handle this.
361 static __always_inline
void kfree_bulk(size_t size
, void **p
)
363 kmem_cache_free_bulk(NULL
, size
, p
);
367 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
) __assume_kmalloc_alignment __malloc
;
368 void *kmem_cache_alloc_node(struct kmem_cache
*, gfp_t flags
, int node
) __assume_slab_alignment __malloc
;
370 static __always_inline
void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
372 return __kmalloc(size
, flags
);
375 static __always_inline
void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t flags
, int node
)
377 return kmem_cache_alloc(s
, flags
);
381 #ifdef CONFIG_TRACING
382 extern void *kmem_cache_alloc_trace(struct kmem_cache
*, gfp_t
, size_t) __assume_slab_alignment __malloc
;
385 extern void *kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
387 int node
, size_t size
) __assume_slab_alignment __malloc
;
389 static __always_inline
void *
390 kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
392 int node
, size_t size
)
394 return kmem_cache_alloc_trace(s
, gfpflags
, size
);
396 #endif /* CONFIG_NUMA */
398 #else /* CONFIG_TRACING */
399 static __always_inline
void *kmem_cache_alloc_trace(struct kmem_cache
*s
,
400 gfp_t flags
, size_t size
)
402 void *ret
= kmem_cache_alloc(s
, flags
);
404 kasan_kmalloc(s
, ret
, size
, flags
);
408 static __always_inline
void *
409 kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
411 int node
, size_t size
)
413 void *ret
= kmem_cache_alloc_node(s
, gfpflags
, node
);
415 kasan_kmalloc(s
, ret
, size
, gfpflags
);
418 #endif /* CONFIG_TRACING */
420 extern void *kmalloc_order(size_t size
, gfp_t flags
, unsigned int order
) __assume_page_alignment __malloc
;
422 #ifdef CONFIG_TRACING
423 extern void *kmalloc_order_trace(size_t size
, gfp_t flags
, unsigned int order
) __assume_page_alignment __malloc
;
425 static __always_inline
void *
426 kmalloc_order_trace(size_t size
, gfp_t flags
, unsigned int order
)
428 return kmalloc_order(size
, flags
, order
);
432 static __always_inline
void *kmalloc_large(size_t size
, gfp_t flags
)
434 unsigned int order
= get_order(size
);
435 return kmalloc_order_trace(size
, flags
, order
);
439 * kmalloc - allocate memory
440 * @size: how many bytes of memory are required.
441 * @flags: the type of memory to allocate.
443 * kmalloc is the normal method of allocating memory
444 * for objects smaller than page size in the kernel.
446 * The @flags argument may be one of:
448 * %GFP_USER - Allocate memory on behalf of user. May sleep.
450 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
452 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
453 * For example, use this inside interrupt handlers.
455 * %GFP_HIGHUSER - Allocate pages from high memory.
457 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
459 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
461 * %GFP_NOWAIT - Allocation will not sleep.
463 * %__GFP_THISNODE - Allocate node-local memory only.
465 * %GFP_DMA - Allocation suitable for DMA.
466 * Should only be used for kmalloc() caches. Otherwise, use a
467 * slab created with SLAB_DMA.
469 * Also it is possible to set different flags by OR'ing
470 * in one or more of the following additional @flags:
472 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
474 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
475 * (think twice before using).
477 * %__GFP_NORETRY - If memory is not immediately available,
478 * then give up at once.
480 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
482 * %__GFP_RETRY_MAYFAIL - Try really hard to succeed the allocation but fail
485 * There are other flags available as well, but these are not intended
486 * for general use, and so are not documented here. For a full list of
487 * potential flags, always refer to linux/gfp.h.
489 static __always_inline
void *kmalloc(size_t size
, gfp_t flags
)
491 if (__builtin_constant_p(size
)) {
492 if (size
> KMALLOC_MAX_CACHE_SIZE
)
493 return kmalloc_large(size
, flags
);
495 if (!(flags
& GFP_DMA
)) {
496 int index
= kmalloc_index(size
);
499 return ZERO_SIZE_PTR
;
501 return kmem_cache_alloc_trace(kmalloc_caches
[index
],
506 return __kmalloc(size
, flags
);
510 * Determine size used for the nth kmalloc cache.
511 * return size or 0 if a kmalloc cache for that
512 * size does not exist
514 static __always_inline
int kmalloc_size(int n
)
520 if (n
== 1 && KMALLOC_MIN_SIZE
<= 32)
523 if (n
== 2 && KMALLOC_MIN_SIZE
<= 64)
529 static __always_inline
void *kmalloc_node(size_t size
, gfp_t flags
, int node
)
532 if (__builtin_constant_p(size
) &&
533 size
<= KMALLOC_MAX_CACHE_SIZE
&& !(flags
& GFP_DMA
)) {
534 int i
= kmalloc_index(size
);
537 return ZERO_SIZE_PTR
;
539 return kmem_cache_alloc_node_trace(kmalloc_caches
[i
],
543 return __kmalloc_node(size
, flags
, node
);
546 struct memcg_cache_array
{
548 struct kmem_cache
*entries
[0];
552 * This is the main placeholder for memcg-related information in kmem caches.
553 * Both the root cache and the child caches will have it. For the root cache,
554 * this will hold a dynamically allocated array large enough to hold
555 * information about the currently limited memcgs in the system. To allow the
556 * array to be accessed without taking any locks, on relocation we free the old
557 * version only after a grace period.
559 * Root and child caches hold different metadata.
561 * @root_cache: Common to root and child caches. NULL for root, pointer to
562 * the root cache for children.
564 * The following fields are specific to root caches.
566 * @memcg_caches: kmemcg ID indexed table of child caches. This table is
567 * used to index child cachces during allocation and cleared
568 * early during shutdown.
570 * @root_caches_node: List node for slab_root_caches list.
572 * @children: List of all child caches. While the child caches are also
573 * reachable through @memcg_caches, a child cache remains on
574 * this list until it is actually destroyed.
576 * The following fields are specific to child caches.
578 * @memcg: Pointer to the memcg this cache belongs to.
580 * @children_node: List node for @root_cache->children list.
582 * @kmem_caches_node: List node for @memcg->kmem_caches list.
584 struct memcg_cache_params
{
585 struct kmem_cache
*root_cache
;
588 struct memcg_cache_array __rcu
*memcg_caches
;
589 struct list_head __root_caches_node
;
590 struct list_head children
;
593 struct mem_cgroup
*memcg
;
594 struct list_head children_node
;
595 struct list_head kmem_caches_node
;
597 void (*deact_fn
)(struct kmem_cache
*);
599 struct rcu_head deact_rcu_head
;
600 struct work_struct deact_work
;
606 int memcg_update_all_caches(int num_memcgs
);
609 * kmalloc_array - allocate memory for an array.
610 * @n: number of elements.
611 * @size: element size.
612 * @flags: the type of memory to allocate (see kmalloc).
614 static inline void *kmalloc_array(size_t n
, size_t size
, gfp_t flags
)
616 if (size
!= 0 && n
> SIZE_MAX
/ size
)
618 if (__builtin_constant_p(n
) && __builtin_constant_p(size
))
619 return kmalloc(n
* size
, flags
);
620 return __kmalloc(n
* size
, flags
);
624 * kcalloc - allocate memory for an array. The memory is set to zero.
625 * @n: number of elements.
626 * @size: element size.
627 * @flags: the type of memory to allocate (see kmalloc).
629 static inline void *kcalloc(size_t n
, size_t size
, gfp_t flags
)
631 return kmalloc_array(n
, size
, flags
| __GFP_ZERO
);
635 * kmalloc_track_caller is a special version of kmalloc that records the
636 * calling function of the routine calling it for slab leak tracking instead
637 * of just the calling function (confusing, eh?).
638 * It's useful when the call to kmalloc comes from a widely-used standard
639 * allocator where we care about the real place the memory allocation
640 * request comes from.
642 extern void *__kmalloc_track_caller(size_t, gfp_t
, unsigned long);
643 #define kmalloc_track_caller(size, flags) \
644 __kmalloc_track_caller(size, flags, _RET_IP_)
646 static inline void *kmalloc_array_node(size_t n
, size_t size
, gfp_t flags
,
649 if (size
!= 0 && n
> SIZE_MAX
/ size
)
651 if (__builtin_constant_p(n
) && __builtin_constant_p(size
))
652 return kmalloc_node(n
* size
, flags
, node
);
653 return __kmalloc_node(n
* size
, flags
, node
);
656 static inline void *kcalloc_node(size_t n
, size_t size
, gfp_t flags
, int node
)
658 return kmalloc_array_node(n
, size
, flags
| __GFP_ZERO
, node
);
663 extern void *__kmalloc_node_track_caller(size_t, gfp_t
, int, unsigned long);
664 #define kmalloc_node_track_caller(size, flags, node) \
665 __kmalloc_node_track_caller(size, flags, node, \
668 #else /* CONFIG_NUMA */
670 #define kmalloc_node_track_caller(size, flags, node) \
671 kmalloc_track_caller(size, flags)
673 #endif /* CONFIG_NUMA */
678 static inline void *kmem_cache_zalloc(struct kmem_cache
*k
, gfp_t flags
)
680 return kmem_cache_alloc(k
, flags
| __GFP_ZERO
);
684 * kzalloc - allocate memory. The memory is set to zero.
685 * @size: how many bytes of memory are required.
686 * @flags: the type of memory to allocate (see kmalloc).
688 static inline void *kzalloc(size_t size
, gfp_t flags
)
690 return kmalloc(size
, flags
| __GFP_ZERO
);
694 * kzalloc_node - allocate zeroed memory from a particular memory node.
695 * @size: how many bytes of memory are required.
696 * @flags: the type of memory to allocate (see kmalloc).
697 * @node: memory node from which to allocate
699 static inline void *kzalloc_node(size_t size
, gfp_t flags
, int node
)
701 return kmalloc_node(size
, flags
| __GFP_ZERO
, node
);
704 unsigned int kmem_cache_size(struct kmem_cache
*s
);
705 void __init
kmem_cache_init_late(void);
707 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
708 int slab_prepare_cpu(unsigned int cpu
);
709 int slab_dead_cpu(unsigned int cpu
);
711 #define slab_prepare_cpu NULL
712 #define slab_dead_cpu NULL
715 #endif /* _LINUX_SLAB_H */