1 /*
2 * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
3 *
4 * (C) SGI 2006, Christoph Lameter
5 * Cleaned up and restructured to ease the addition of alternative
6 * implementations of SLAB allocators.
7 * (C) Linux Foundation 2008-2013
8 * Unified interface for all slab allocators
9 */
10
11 #ifndef _LINUX_SLAB_H
12 #define _LINUX_SLAB_H
13
14 #include <linux/gfp.h>
15 #include <linux/types.h>
16 #include <linux/workqueue.h>
17
18
19 /*
20 * Flags to pass to kmem_cache_create().
21 * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
22 */
23 #define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */
24 #define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
25 #define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
26 #define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
27 #define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
28 #define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
29 #define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
30 /*
31 * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS!
32 *
33 * This delays freeing the SLAB page by a grace period, it does _NOT_
34 * delay object freeing. This means that if you do kmem_cache_free()
35 * that memory location is free to be reused at any time. Thus it may
36 * be possible to see another object there in the same RCU grace period.
37 *
38 * This feature only ensures the memory location backing the object
39 * stays valid, the trick to using this is relying on an independent
40 * object validation pass. Something like:
41 *
42 * rcu_read_lock()
43 * again:
44 * obj = lockless_lookup(key);
45 * if (obj) {
46 * if (!try_get_ref(obj)) // might fail for free objects
47 * goto again;
48 *
49 * if (obj->key != key) { // not the object we expected
50 * put_ref(obj);
51 * goto again;
52 * }
53 * }
54 * rcu_read_unlock();
55 *
56 * This is useful if we need to approach a kernel structure obliquely,
57 * from its address obtained without the usual locking. We can lock
58 * the structure to stabilize it and check it's still at the given address,
59 * only if we can be sure that the memory has not been meanwhile reused
60 * for some other kind of object (which our subsystem's lock might corrupt).
61 *
62 * rcu_read_lock before reading the address, then rcu_read_unlock after
63 * taking the spinlock within the structure expected at that address.
64 */
65 #define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
66 #define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
67 #define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
68
69 /* Flag to prevent checks on free */
70 #ifdef CONFIG_DEBUG_OBJECTS
71 # define SLAB_DEBUG_OBJECTS 0x00400000UL
72 #else
73 # define SLAB_DEBUG_OBJECTS 0x00000000UL
74 #endif
75
76 #define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */
77
78 /* Don't track use of uninitialized memory */
79 #ifdef CONFIG_KMEMCHECK
80 # define SLAB_NOTRACK 0x01000000UL
81 #else
82 # define SLAB_NOTRACK 0x00000000UL
83 #endif
84 #ifdef CONFIG_FAILSLAB
85 # define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */
86 #else
87 # define SLAB_FAILSLAB 0x00000000UL
88 #endif
89
90 /* The following flags affect the page allocator grouping pages by mobility */
91 #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
92 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
93 /*
94 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
95 *
96 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
97 *
98 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
99 * Both make kfree a no-op.
100 */
101 #define ZERO_SIZE_PTR ((void *)16)
102
103 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
104 (unsigned long)ZERO_SIZE_PTR)
105
106 #include <linux/kmemleak.h>
107
108 struct mem_cgroup;
109 /*
110 * struct kmem_cache related prototypes
111 */
112 void __init kmem_cache_init(void);
113 int slab_is_available(void);
114
115 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
116 unsigned long,
117 void (*)(void *));
118 #ifdef CONFIG_MEMCG_KMEM
119 struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *,
120 struct kmem_cache *,
121 const char *);
122 #endif
123 void kmem_cache_destroy(struct kmem_cache *);
124 int kmem_cache_shrink(struct kmem_cache *);
125 void kmem_cache_free(struct kmem_cache *, void *);
126
127 /*
128 * Please use this macro to create slab caches. Simply specify the
129 * name of the structure and maybe some flags that are listed above.
130 *
131 * The alignment of the struct determines object alignment. If you
132 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
133 * then the objects will be properly aligned in SMP configurations.
134 */
135 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
136 sizeof(struct __struct), __alignof__(struct __struct),\
137 (__flags), NULL)
138
139 /*
140 * Common kmalloc functions provided by all allocators
141 */
142 void * __must_check __krealloc(const void *, size_t, gfp_t);
143 void * __must_check krealloc(const void *, size_t, gfp_t);
144 void kfree(const void *);
145 void kzfree(const void *);
146 size_t ksize(const void *);
147
148 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
149 const char *__check_heap_object(const void *ptr, unsigned long n,
150 struct page *page);
151 #else
__check_heap_object(const void * ptr,unsigned long n,struct page * page)152 static inline const char *__check_heap_object(const void *ptr,
153 unsigned long n,
154 struct page *page)
155 {
156 return NULL;
157 }
158 #endif
159
160 /*
161 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
162 * alignment larger than the alignment of a 64-bit integer.
163 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
164 */
165 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
166 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
167 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
168 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
169 #else
170 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
171 #endif
172
173 /*
174 * Kmalloc array related definitions
175 */
176
177 #ifdef CONFIG_SLAB
178 /*
179 * The largest kmalloc size supported by the SLAB allocators is
180 * 32 megabyte (2^25) or the maximum allocatable page order if that is
181 * less than 32 MB.
182 *
183 * WARNING: Its not easy to increase this value since the allocators have
184 * to do various tricks to work around compiler limitations in order to
185 * ensure proper constant folding.
186 */
187 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
188 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
189 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
190 #ifndef KMALLOC_SHIFT_LOW
191 #define KMALLOC_SHIFT_LOW 5
192 #endif
193 #endif
194
195 #ifdef CONFIG_SLUB
196 /*
197 * SLUB directly allocates requests fitting in to an order-1 page
198 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
199 */
200 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
201 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
202 #ifndef KMALLOC_SHIFT_LOW
203 #define KMALLOC_SHIFT_LOW 3
204 #endif
205 #endif
206
207 #ifdef CONFIG_SLOB
208 /*
209 * SLOB passes all requests larger than one page to the page allocator.
210 * No kmalloc array is necessary since objects of different sizes can
211 * be allocated from the same page.
212 */
213 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
214 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1)
215 #ifndef KMALLOC_SHIFT_LOW
216 #define KMALLOC_SHIFT_LOW 3
217 #endif
218 #endif
219
220 /* Maximum allocatable size */
221 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
222 /* Maximum size for which we actually use a slab cache */
223 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
224 /* Maximum order allocatable via the slab allocagtor */
225 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
226
227 /*
228 * Kmalloc subsystem.
229 */
230 #ifndef KMALLOC_MIN_SIZE
231 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
232 #endif
233
234 /*
235 * This restriction comes from byte sized index implementation.
236 * Page size is normally 2^12 bytes and, in this case, if we want to use
237 * byte sized index which can represent 2^8 entries, the size of the object
238 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
239 * If minimum size of kmalloc is less than 16, we use it as minimum object
240 * size and give up to use byte sized index.
241 */
242 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
243 (KMALLOC_MIN_SIZE) : 16)
244
245 #ifndef CONFIG_SLOB
246 extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
247 #ifdef CONFIG_ZONE_DMA
248 extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
249 #endif
250
251 /*
252 * Figure out which kmalloc slab an allocation of a certain size
253 * belongs to.
254 * 0 = zero alloc
255 * 1 = 65 .. 96 bytes
256 * 2 = 120 .. 192 bytes
257 * n = 2^(n-1) .. 2^n -1
258 */
kmalloc_index(size_t size)259 static __always_inline int kmalloc_index(size_t size)
260 {
261 if (!size)
262 return 0;
263
264 if (size <= KMALLOC_MIN_SIZE)
265 return KMALLOC_SHIFT_LOW;
266
267 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
268 return 1;
269 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
270 return 2;
271 if (size <= 8) return 3;
272 if (size <= 16) return 4;
273 if (size <= 32) return 5;
274 if (size <= 64) return 6;
275 if (size <= 128) return 7;
276 if (size <= 256) return 8;
277 if (size <= 512) return 9;
278 if (size <= 1024) return 10;
279 if (size <= 2 * 1024) return 11;
280 if (size <= 4 * 1024) return 12;
281 if (size <= 8 * 1024) return 13;
282 if (size <= 16 * 1024) return 14;
283 if (size <= 32 * 1024) return 15;
284 if (size <= 64 * 1024) return 16;
285 if (size <= 128 * 1024) return 17;
286 if (size <= 256 * 1024) return 18;
287 if (size <= 512 * 1024) return 19;
288 if (size <= 1024 * 1024) return 20;
289 if (size <= 2 * 1024 * 1024) return 21;
290 if (size <= 4 * 1024 * 1024) return 22;
291 if (size <= 8 * 1024 * 1024) return 23;
292 if (size <= 16 * 1024 * 1024) return 24;
293 if (size <= 32 * 1024 * 1024) return 25;
294 if (size <= 64 * 1024 * 1024) return 26;
295 BUG();
296
297 /* Will never be reached. Needed because the compiler may complain */
298 return -1;
299 }
300 #endif /* !CONFIG_SLOB */
301
302 void *__kmalloc(size_t size, gfp_t flags);
303 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags);
304
305 #ifdef CONFIG_NUMA
306 void *__kmalloc_node(size_t size, gfp_t flags, int node);
307 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
308 #else
__kmalloc_node(size_t size,gfp_t flags,int node)309 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
310 {
311 return __kmalloc(size, flags);
312 }
313
kmem_cache_alloc_node(struct kmem_cache * s,gfp_t flags,int node)314 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
315 {
316 return kmem_cache_alloc(s, flags);
317 }
318 #endif
319
320 #ifdef CONFIG_TRACING
321 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t);
322
323 #ifdef CONFIG_NUMA
324 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
325 gfp_t gfpflags,
326 int node, size_t size);
327 #else
328 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)329 kmem_cache_alloc_node_trace(struct kmem_cache *s,
330 gfp_t gfpflags,
331 int node, size_t size)
332 {
333 return kmem_cache_alloc_trace(s, gfpflags, size);
334 }
335 #endif /* CONFIG_NUMA */
336
337 #else /* CONFIG_TRACING */
kmem_cache_alloc_trace(struct kmem_cache * s,gfp_t flags,size_t size)338 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
339 gfp_t flags, size_t size)
340 {
341 return kmem_cache_alloc(s, flags);
342 }
343
344 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)345 kmem_cache_alloc_node_trace(struct kmem_cache *s,
346 gfp_t gfpflags,
347 int node, size_t size)
348 {
349 return kmem_cache_alloc_node(s, gfpflags, node);
350 }
351 #endif /* CONFIG_TRACING */
352
353 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order);
354
355 #ifdef CONFIG_TRACING
356 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
357 #else
358 static __always_inline void *
kmalloc_order_trace(size_t size,gfp_t flags,unsigned int order)359 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
360 {
361 return kmalloc_order(size, flags, order);
362 }
363 #endif
364
kmalloc_large(size_t size,gfp_t flags)365 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
366 {
367 unsigned int order = get_order(size);
368 return kmalloc_order_trace(size, flags, order);
369 }
370
371 /**
372 * kmalloc - allocate memory
373 * @size: how many bytes of memory are required.
374 * @flags: the type of memory to allocate.
375 *
376 * kmalloc is the normal method of allocating memory
377 * for objects smaller than page size in the kernel.
378 *
379 * The @flags argument may be one of:
380 *
381 * %GFP_USER - Allocate memory on behalf of user. May sleep.
382 *
383 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
384 *
385 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
386 * For example, use this inside interrupt handlers.
387 *
388 * %GFP_HIGHUSER - Allocate pages from high memory.
389 *
390 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
391 *
392 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
393 *
394 * %GFP_NOWAIT - Allocation will not sleep.
395 *
396 * %__GFP_THISNODE - Allocate node-local memory only.
397 *
398 * %GFP_DMA - Allocation suitable for DMA.
399 * Should only be used for kmalloc() caches. Otherwise, use a
400 * slab created with SLAB_DMA.
401 *
402 * Also it is possible to set different flags by OR'ing
403 * in one or more of the following additional @flags:
404 *
405 * %__GFP_COLD - Request cache-cold pages instead of
406 * trying to return cache-warm pages.
407 *
408 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
409 *
410 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
411 * (think twice before using).
412 *
413 * %__GFP_NORETRY - If memory is not immediately available,
414 * then give up at once.
415 *
416 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
417 *
418 * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
419 *
420 * There are other flags available as well, but these are not intended
421 * for general use, and so are not documented here. For a full list of
422 * potential flags, always refer to linux/gfp.h.
423 */
kmalloc(size_t size,gfp_t flags)424 static __always_inline void *kmalloc(size_t size, gfp_t flags)
425 {
426 if (__builtin_constant_p(size)) {
427 if (size > KMALLOC_MAX_CACHE_SIZE)
428 return kmalloc_large(size, flags);
429 #ifndef CONFIG_SLOB
430 if (!(flags & GFP_DMA)) {
431 int index = kmalloc_index(size);
432
433 if (!index)
434 return ZERO_SIZE_PTR;
435
436 return kmem_cache_alloc_trace(kmalloc_caches[index],
437 flags, size);
438 }
439 #endif
440 }
441 return __kmalloc(size, flags);
442 }
443
444 /*
445 * Determine size used for the nth kmalloc cache.
446 * return size or 0 if a kmalloc cache for that
447 * size does not exist
448 */
kmalloc_size(int n)449 static __always_inline int kmalloc_size(int n)
450 {
451 #ifndef CONFIG_SLOB
452 if (n > 2)
453 return 1 << n;
454
455 if (n == 1 && KMALLOC_MIN_SIZE <= 32)
456 return 96;
457
458 if (n == 2 && KMALLOC_MIN_SIZE <= 64)
459 return 192;
460 #endif
461 return 0;
462 }
463
kmalloc_node(size_t size,gfp_t flags,int node)464 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
465 {
466 #ifndef CONFIG_SLOB
467 if (__builtin_constant_p(size) &&
468 size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
469 int i = kmalloc_index(size);
470
471 if (!i)
472 return ZERO_SIZE_PTR;
473
474 return kmem_cache_alloc_node_trace(kmalloc_caches[i],
475 flags, node, size);
476 }
477 #endif
478 return __kmalloc_node(size, flags, node);
479 }
480
481 /*
482 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
483 * Intended for arches that get misalignment faults even for 64 bit integer
484 * aligned buffers.
485 */
486 #ifndef ARCH_SLAB_MINALIGN
487 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
488 #endif
489 /*
490 * This is the main placeholder for memcg-related information in kmem caches.
491 * struct kmem_cache will hold a pointer to it, so the memory cost while
492 * disabled is 1 pointer. The runtime cost while enabled, gets bigger than it
493 * would otherwise be if that would be bundled in kmem_cache: we'll need an
494 * extra pointer chase. But the trade off clearly lays in favor of not
495 * penalizing non-users.
496 *
497 * Both the root cache and the child caches will have it. For the root cache,
498 * this will hold a dynamically allocated array large enough to hold
499 * information about the currently limited memcgs in the system. To allow the
500 * array to be accessed without taking any locks, on relocation we free the old
501 * version only after a grace period.
502 *
503 * Child caches will hold extra metadata needed for its operation. Fields are:
504 *
505 * @memcg: pointer to the memcg this cache belongs to
506 * @list: list_head for the list of all caches in this memcg
507 * @root_cache: pointer to the global, root cache, this cache was derived from
508 * @nr_pages: number of pages that belongs to this cache.
509 */
510 struct memcg_cache_params {
511 bool is_root_cache;
512 union {
513 struct {
514 struct rcu_head rcu_head;
515 struct kmem_cache *memcg_caches[0];
516 };
517 struct {
518 struct mem_cgroup *memcg;
519 struct list_head list;
520 struct kmem_cache *root_cache;
521 atomic_t nr_pages;
522 };
523 };
524 };
525
526 int memcg_update_all_caches(int num_memcgs);
527
528 struct seq_file;
529 int cache_show(struct kmem_cache *s, struct seq_file *m);
530 void print_slabinfo_header(struct seq_file *m);
531
532 /**
533 * kmalloc_array - allocate memory for an array.
534 * @n: number of elements.
535 * @size: element size.
536 * @flags: the type of memory to allocate (see kmalloc).
537 */
kmalloc_array(size_t n,size_t size,gfp_t flags)538 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
539 {
540 if (size != 0 && n > SIZE_MAX / size)
541 return NULL;
542 return __kmalloc(n * size, flags);
543 }
544
545 /**
546 * kcalloc - allocate memory for an array. The memory is set to zero.
547 * @n: number of elements.
548 * @size: element size.
549 * @flags: the type of memory to allocate (see kmalloc).
550 */
kcalloc(size_t n,size_t size,gfp_t flags)551 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
552 {
553 return kmalloc_array(n, size, flags | __GFP_ZERO);
554 }
555
556 /*
557 * kmalloc_track_caller is a special version of kmalloc that records the
558 * calling function of the routine calling it for slab leak tracking instead
559 * of just the calling function (confusing, eh?).
560 * It's useful when the call to kmalloc comes from a widely-used standard
561 * allocator where we care about the real place the memory allocation
562 * request comes from.
563 */
564 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
565 #define kmalloc_track_caller(size, flags) \
566 __kmalloc_track_caller(size, flags, _RET_IP_)
567
568 #ifdef CONFIG_NUMA
569 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
570 #define kmalloc_node_track_caller(size, flags, node) \
571 __kmalloc_node_track_caller(size, flags, node, \
572 _RET_IP_)
573
574 #else /* CONFIG_NUMA */
575
576 #define kmalloc_node_track_caller(size, flags, node) \
577 kmalloc_track_caller(size, flags)
578
579 #endif /* CONFIG_NUMA */
580
581 /*
582 * Shortcuts
583 */
kmem_cache_zalloc(struct kmem_cache * k,gfp_t flags)584 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
585 {
586 return kmem_cache_alloc(k, flags | __GFP_ZERO);
587 }
588
589 /**
590 * kzalloc - allocate memory. The memory is set to zero.
591 * @size: how many bytes of memory are required.
592 * @flags: the type of memory to allocate (see kmalloc).
593 */
kzalloc(size_t size,gfp_t flags)594 static inline void *kzalloc(size_t size, gfp_t flags)
595 {
596 return kmalloc(size, flags | __GFP_ZERO);
597 }
598
599 /**
600 * kzalloc_node - allocate zeroed memory from a particular memory node.
601 * @size: how many bytes of memory are required.
602 * @flags: the type of memory to allocate (see kmalloc).
603 * @node: memory node from which to allocate
604 */
kzalloc_node(size_t size,gfp_t flags,int node)605 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
606 {
607 return kmalloc_node(size, flags | __GFP_ZERO, node);
608 }
609
610 unsigned int kmem_cache_size(struct kmem_cache *s);
611 void __init kmem_cache_init_late(void);
612
613 #endif /* _LINUX_SLAB_H */
614