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/overflow.h>
17 #include <linux/types.h>
18 #include <linux/workqueue.h>
22 * Flags to pass to kmem_cache_create().
23 * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
25 /* DEBUG: Perform (expensive) checks on alloc/free */
26 #define SLAB_CONSISTENCY_CHECKS ((slab_flags_t __force)0x00000100U)
27 /* DEBUG: Red zone objs in a cache */
28 #define SLAB_RED_ZONE ((slab_flags_t __force)0x00000400U)
29 /* DEBUG: Poison objects */
30 #define SLAB_POISON ((slab_flags_t __force)0x00000800U)
31 /* Align objs on cache lines */
32 #define SLAB_HWCACHE_ALIGN ((slab_flags_t __force)0x00002000U)
33 /* Use GFP_DMA memory */
34 #define SLAB_CACHE_DMA ((slab_flags_t __force)0x00004000U)
35 /* Use GFP_DMA32 memory */
36 #define SLAB_CACHE_DMA32 ((slab_flags_t __force)0x00008000U)
37 /* DEBUG: Store the last owner for bug hunting */
38 #define SLAB_STORE_USER ((slab_flags_t __force)0x00010000U)
39 /* Panic if kmem_cache_create() fails */
40 #define SLAB_PANIC ((slab_flags_t __force)0x00040000U)
42 * SLAB_TYPESAFE_BY_RCU - **WARNING** READ THIS!
44 * This delays freeing the SLAB page by a grace period, it does _NOT_
45 * delay object freeing. This means that if you do kmem_cache_free()
46 * that memory location is free to be reused at any time. Thus it may
47 * be possible to see another object there in the same RCU grace period.
49 * This feature only ensures the memory location backing the object
50 * stays valid, the trick to using this is relying on an independent
51 * object validation pass. Something like:
55 * obj = lockless_lookup(key);
57 * if (!try_get_ref(obj)) // might fail for free objects
60 * if (obj->key != key) { // not the object we expected
67 * This is useful if we need to approach a kernel structure obliquely,
68 * from its address obtained without the usual locking. We can lock
69 * the structure to stabilize it and check it's still at the given address,
70 * only if we can be sure that the memory has not been meanwhile reused
71 * for some other kind of object (which our subsystem's lock might corrupt).
73 * rcu_read_lock before reading the address, then rcu_read_unlock after
74 * taking the spinlock within the structure expected at that address.
76 * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU.
78 /* Defer freeing slabs to RCU */
79 #define SLAB_TYPESAFE_BY_RCU ((slab_flags_t __force)0x00080000U)
80 /* Spread some memory over cpuset */
81 #define SLAB_MEM_SPREAD ((slab_flags_t __force)0x00100000U)
82 /* Trace allocations and frees */
83 #define SLAB_TRACE ((slab_flags_t __force)0x00200000U)
85 /* Flag to prevent checks on free */
86 #ifdef CONFIG_DEBUG_OBJECTS
87 # define SLAB_DEBUG_OBJECTS ((slab_flags_t __force)0x00400000U)
89 # define SLAB_DEBUG_OBJECTS 0
92 /* Avoid kmemleak tracing */
93 #define SLAB_NOLEAKTRACE ((slab_flags_t __force)0x00800000U)
95 /* Fault injection mark */
96 #ifdef CONFIG_FAILSLAB
97 # define SLAB_FAILSLAB ((slab_flags_t __force)0x02000000U)
99 # define SLAB_FAILSLAB 0
101 /* Account to memcg */
102 #ifdef CONFIG_MEMCG_KMEM
103 # define SLAB_ACCOUNT ((slab_flags_t __force)0x04000000U)
105 # define SLAB_ACCOUNT 0
109 #define SLAB_KASAN ((slab_flags_t __force)0x08000000U)
114 /* The following flags affect the page allocator grouping pages by mobility */
115 /* Objects are reclaimable */
116 #define SLAB_RECLAIM_ACCOUNT ((slab_flags_t __force)0x00020000U)
117 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
119 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
121 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
123 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
124 * Both make kfree a no-op.
126 #define ZERO_SIZE_PTR ((void *)16)
128 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
129 (unsigned long)ZERO_SIZE_PTR)
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 extern bool usercopy_fallback;
142 struct kmem_cache *kmem_cache_create(const char *name, unsigned int size,
143 unsigned int align, slab_flags_t flags,
144 void (*ctor)(void *));
145 struct kmem_cache *kmem_cache_create_usercopy(const char *name,
146 unsigned int size, unsigned int align,
148 unsigned int useroffset, unsigned int usersize,
149 void (*ctor)(void *));
150 void kmem_cache_destroy(struct kmem_cache *);
151 int kmem_cache_shrink(struct kmem_cache *);
153 void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
154 void memcg_deactivate_kmem_caches(struct mem_cgroup *);
155 void memcg_destroy_kmem_caches(struct mem_cgroup *);
158 * Please use this macro to create slab caches. Simply specify the
159 * name of the structure and maybe some flags that are listed above.
161 * The alignment of the struct determines object alignment. If you
162 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
163 * then the objects will be properly aligned in SMP configurations.
165 #define KMEM_CACHE(__struct, __flags) \
166 kmem_cache_create(#__struct, sizeof(struct __struct), \
167 __alignof__(struct __struct), (__flags), NULL)
170 * To whitelist a single field for copying to/from usercopy, use this
171 * macro instead for KMEM_CACHE() above.
173 #define KMEM_CACHE_USERCOPY(__struct, __flags, __field) \
174 kmem_cache_create_usercopy(#__struct, \
175 sizeof(struct __struct), \
176 __alignof__(struct __struct), (__flags), \
177 offsetof(struct __struct, __field), \
178 sizeof_field(struct __struct, __field), NULL)
181 * Common kmalloc functions provided by all allocators
183 void * __must_check __krealloc(const void *, size_t, gfp_t);
184 void * __must_check krealloc(const void *, size_t, gfp_t);
185 void kfree(const void *);
186 void kzfree(const void *);
187 size_t __ksize(const void *);
188 size_t ksize(const void *);
190 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
191 void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
194 static inline void __check_heap_object(const void *ptr, unsigned long n,
195 struct page *page, bool to_user) { }
199 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
200 * alignment larger than the alignment of a 64-bit integer.
201 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
203 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
204 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
205 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
206 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
208 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
212 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
213 * Intended for arches that get misalignment faults even for 64 bit integer
216 #ifndef ARCH_SLAB_MINALIGN
217 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
221 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
222 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
225 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
226 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
227 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
230 * Kmalloc array related definitions
235 * The largest kmalloc size supported by the SLAB allocators is
236 * 32 megabyte (2^25) or the maximum allocatable page order if that is
239 * WARNING: Its not easy to increase this value since the allocators have
240 * to do various tricks to work around compiler limitations in order to
241 * ensure proper constant folding.
243 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
244 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
245 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
246 #ifndef KMALLOC_SHIFT_LOW
247 #define KMALLOC_SHIFT_LOW 5
253 * SLUB directly allocates requests fitting in to an order-1 page
254 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
256 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
257 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
258 #ifndef KMALLOC_SHIFT_LOW
259 #define KMALLOC_SHIFT_LOW 3
265 * SLOB passes all requests larger than one page to the page allocator.
266 * No kmalloc array is necessary since objects of different sizes can
267 * be allocated from the same page.
269 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
270 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
271 #ifndef KMALLOC_SHIFT_LOW
272 #define KMALLOC_SHIFT_LOW 3
276 /* Maximum allocatable size */
277 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
278 /* Maximum size for which we actually use a slab cache */
279 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
280 /* Maximum order allocatable via the slab allocagtor */
281 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
286 #ifndef KMALLOC_MIN_SIZE
287 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
291 * This restriction comes from byte sized index implementation.
292 * Page size is normally 2^12 bytes and, in this case, if we want to use
293 * byte sized index which can represent 2^8 entries, the size of the object
294 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
295 * If minimum size of kmalloc is less than 16, we use it as minimum object
296 * size and give up to use byte sized index.
298 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
299 (KMALLOC_MIN_SIZE) : 16)
302 * Whenever changing this, take care of that kmalloc_type() and
303 * create_kmalloc_caches() still work as intended.
305 enum kmalloc_cache_type {
308 #ifdef CONFIG_ZONE_DMA
315 extern struct kmem_cache *
316 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1];
318 static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags)
320 #ifdef CONFIG_ZONE_DMA
322 * The most common case is KMALLOC_NORMAL, so test for it
323 * with a single branch for both flags.
325 if (likely((flags & (__GFP_DMA | __GFP_RECLAIMABLE)) == 0))
326 return KMALLOC_NORMAL;
329 * At least one of the flags has to be set. If both are, __GFP_DMA
332 return flags & __GFP_DMA ? KMALLOC_DMA : KMALLOC_RECLAIM;
334 return flags & __GFP_RECLAIMABLE ? KMALLOC_RECLAIM : KMALLOC_NORMAL;
339 * Figure out which kmalloc slab an allocation of a certain size
343 * 2 = 129 .. 192 bytes
344 * n = 2^(n-1)+1 .. 2^n
346 static __always_inline unsigned int kmalloc_index(size_t size)
351 if (size <= KMALLOC_MIN_SIZE)
352 return KMALLOC_SHIFT_LOW;
354 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
356 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
358 if (size <= 8) return 3;
359 if (size <= 16) return 4;
360 if (size <= 32) return 5;
361 if (size <= 64) return 6;
362 if (size <= 128) return 7;
363 if (size <= 256) return 8;
364 if (size <= 512) return 9;
365 if (size <= 1024) return 10;
366 if (size <= 2 * 1024) return 11;
367 if (size <= 4 * 1024) return 12;
368 if (size <= 8 * 1024) return 13;
369 if (size <= 16 * 1024) return 14;
370 if (size <= 32 * 1024) return 15;
371 if (size <= 64 * 1024) return 16;
372 if (size <= 128 * 1024) return 17;
373 if (size <= 256 * 1024) return 18;
374 if (size <= 512 * 1024) return 19;
375 if (size <= 1024 * 1024) return 20;
376 if (size <= 2 * 1024 * 1024) return 21;
377 if (size <= 4 * 1024 * 1024) return 22;
378 if (size <= 8 * 1024 * 1024) return 23;
379 if (size <= 16 * 1024 * 1024) return 24;
380 if (size <= 32 * 1024 * 1024) return 25;
381 if (size <= 64 * 1024 * 1024) return 26;
384 /* Will never be reached. Needed because the compiler may complain */
387 #endif /* !CONFIG_SLOB */
389 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc;
390 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment __malloc;
391 void kmem_cache_free(struct kmem_cache *, void *);
394 * Bulk allocation and freeing operations. These are accelerated in an
395 * allocator specific way to avoid taking locks repeatedly or building
396 * metadata structures unnecessarily.
398 * Note that interrupts must be enabled when calling these functions.
400 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
401 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
404 * Caller must not use kfree_bulk() on memory not originally allocated
405 * by kmalloc(), because the SLOB allocator cannot handle this.
407 static __always_inline void kfree_bulk(size_t size, void **p)
409 kmem_cache_free_bulk(NULL, size, p);
413 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment __malloc;
414 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment __malloc;
416 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
418 return __kmalloc(size, flags);
421 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
423 return kmem_cache_alloc(s, flags);
427 #ifdef CONFIG_TRACING
428 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment __malloc;
431 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
433 int node, size_t size) __assume_slab_alignment __malloc;
435 static __always_inline void *
436 kmem_cache_alloc_node_trace(struct kmem_cache *s,
438 int node, size_t size)
440 return kmem_cache_alloc_trace(s, gfpflags, size);
442 #endif /* CONFIG_NUMA */
444 #else /* CONFIG_TRACING */
445 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
446 gfp_t flags, size_t size)
448 void *ret = kmem_cache_alloc(s, flags);
450 ret = kasan_kmalloc(s, ret, size, flags);
454 static __always_inline void *
455 kmem_cache_alloc_node_trace(struct kmem_cache *s,
457 int node, size_t size)
459 void *ret = kmem_cache_alloc_node(s, gfpflags, node);
461 ret = kasan_kmalloc(s, ret, size, gfpflags);
464 #endif /* CONFIG_TRACING */
466 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
468 #ifdef CONFIG_TRACING
469 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment __malloc;
471 static __always_inline void *
472 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
474 return kmalloc_order(size, flags, order);
478 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
480 unsigned int order = get_order(size);
481 return kmalloc_order_trace(size, flags, order);
485 * kmalloc - allocate memory
486 * @size: how many bytes of memory are required.
487 * @flags: the type of memory to allocate.
489 * kmalloc is the normal method of allocating memory
490 * for objects smaller than page size in the kernel.
492 * The @flags argument may be one of the GFP flags defined at
493 * include/linux/gfp.h and described at
494 * :ref:`Documentation/core-api/mm-api.rst <mm-api-gfp-flags>`
496 * The recommended usage of the @flags is described at
497 * :ref:`Documentation/core-api/memory-allocation.rst <memory-allocation>`
499 * Below is a brief outline of the most useful GFP flags
502 * Allocate normal kernel ram. May sleep.
505 * Allocation will not sleep.
508 * Allocation will not sleep. May use emergency pools.
511 * Allocate memory from high memory on behalf of user.
513 * Also it is possible to set different flags by OR'ing
514 * in one or more of the following additional @flags:
517 * This allocation has high priority and may use emergency pools.
520 * Indicate that this allocation is in no way allowed to fail
521 * (think twice before using).
524 * If memory is not immediately available,
525 * then give up at once.
528 * If allocation fails, don't issue any warnings.
530 * %__GFP_RETRY_MAYFAIL
531 * Try really hard to succeed the allocation but fail
534 static __always_inline void *kmalloc(size_t size, gfp_t flags)
536 if (__builtin_constant_p(size)) {
540 if (size > KMALLOC_MAX_CACHE_SIZE)
541 return kmalloc_large(size, flags);
543 index = kmalloc_index(size);
546 return ZERO_SIZE_PTR;
548 return kmem_cache_alloc_trace(
549 kmalloc_caches[kmalloc_type(flags)][index],
553 return __kmalloc(size, flags);
557 * Determine size used for the nth kmalloc cache.
558 * return size or 0 if a kmalloc cache for that
559 * size does not exist
561 static __always_inline unsigned int kmalloc_size(unsigned int n)
567 if (n == 1 && KMALLOC_MIN_SIZE <= 32)
570 if (n == 2 && KMALLOC_MIN_SIZE <= 64)
576 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
579 if (__builtin_constant_p(size) &&
580 size <= KMALLOC_MAX_CACHE_SIZE) {
581 unsigned int i = kmalloc_index(size);
584 return ZERO_SIZE_PTR;
586 return kmem_cache_alloc_node_trace(
587 kmalloc_caches[kmalloc_type(flags)][i],
591 return __kmalloc_node(size, flags, node);
594 struct memcg_cache_array {
596 struct kmem_cache *entries[0];
600 * This is the main placeholder for memcg-related information in kmem caches.
601 * Both the root cache and the child caches will have it. For the root cache,
602 * this will hold a dynamically allocated array large enough to hold
603 * information about the currently limited memcgs in the system. To allow the
604 * array to be accessed without taking any locks, on relocation we free the old
605 * version only after a grace period.
607 * Root and child caches hold different metadata.
609 * @root_cache: Common to root and child caches. NULL for root, pointer to
610 * the root cache for children.
612 * The following fields are specific to root caches.
614 * @memcg_caches: kmemcg ID indexed table of child caches. This table is
615 * used to index child cachces during allocation and cleared
616 * early during shutdown.
618 * @root_caches_node: List node for slab_root_caches list.
620 * @children: List of all child caches. While the child caches are also
621 * reachable through @memcg_caches, a child cache remains on
622 * this list until it is actually destroyed.
624 * The following fields are specific to child caches.
626 * @memcg: Pointer to the memcg this cache belongs to.
628 * @children_node: List node for @root_cache->children list.
630 * @kmem_caches_node: List node for @memcg->kmem_caches list.
632 struct memcg_cache_params {
633 struct kmem_cache *root_cache;
636 struct memcg_cache_array __rcu *memcg_caches;
637 struct list_head __root_caches_node;
638 struct list_head children;
642 struct mem_cgroup *memcg;
643 struct list_head children_node;
644 struct list_head kmem_caches_node;
646 void (*deact_fn)(struct kmem_cache *);
648 struct rcu_head deact_rcu_head;
649 struct work_struct deact_work;
655 int memcg_update_all_caches(int num_memcgs);
658 * kmalloc_array - allocate memory for an array.
659 * @n: number of elements.
660 * @size: element size.
661 * @flags: the type of memory to allocate (see kmalloc).
663 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
667 if (unlikely(check_mul_overflow(n, size, &bytes)))
669 if (__builtin_constant_p(n) && __builtin_constant_p(size))
670 return kmalloc(bytes, flags);
671 return __kmalloc(bytes, flags);
675 * kcalloc - allocate memory for an array. The memory is set to zero.
676 * @n: number of elements.
677 * @size: element size.
678 * @flags: the type of memory to allocate (see kmalloc).
680 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
682 return kmalloc_array(n, size, flags | __GFP_ZERO);
686 * kmalloc_track_caller is a special version of kmalloc that records the
687 * calling function of the routine calling it for slab leak tracking instead
688 * of just the calling function (confusing, eh?).
689 * It's useful when the call to kmalloc comes from a widely-used standard
690 * allocator where we care about the real place the memory allocation
691 * request comes from.
693 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
694 #define kmalloc_track_caller(size, flags) \
695 __kmalloc_track_caller(size, flags, _RET_IP_)
697 static inline void *kmalloc_array_node(size_t n, size_t size, gfp_t flags,
702 if (unlikely(check_mul_overflow(n, size, &bytes)))
704 if (__builtin_constant_p(n) && __builtin_constant_p(size))
705 return kmalloc_node(bytes, flags, node);
706 return __kmalloc_node(bytes, flags, node);
709 static inline void *kcalloc_node(size_t n, size_t size, gfp_t flags, int node)
711 return kmalloc_array_node(n, size, flags | __GFP_ZERO, node);
716 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
717 #define kmalloc_node_track_caller(size, flags, node) \
718 __kmalloc_node_track_caller(size, flags, node, \
721 #else /* CONFIG_NUMA */
723 #define kmalloc_node_track_caller(size, flags, node) \
724 kmalloc_track_caller(size, flags)
726 #endif /* CONFIG_NUMA */
731 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
733 return kmem_cache_alloc(k, flags | __GFP_ZERO);
737 * kzalloc - allocate memory. The memory is set to zero.
738 * @size: how many bytes of memory are required.
739 * @flags: the type of memory to allocate (see kmalloc).
741 static inline void *kzalloc(size_t size, gfp_t flags)
743 return kmalloc(size, flags | __GFP_ZERO);
747 * kzalloc_node - allocate zeroed memory from a particular memory node.
748 * @size: how many bytes of memory are required.
749 * @flags: the type of memory to allocate (see kmalloc).
750 * @node: memory node from which to allocate
752 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
754 return kmalloc_node(size, flags | __GFP_ZERO, node);
757 unsigned int kmem_cache_size(struct kmem_cache *s);
758 void __init kmem_cache_init_late(void);
760 #if defined(CONFIG_SMP) && defined(CONFIG_SLAB)
761 int slab_prepare_cpu(unsigned int cpu);
762 int slab_dead_cpu(unsigned int cpu);
764 #define slab_prepare_cpu NULL
765 #define slab_dead_cpu NULL
768 #endif /* _LINUX_SLAB_H */