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_DEBUG_SLAB is set.
22 */
23 #define SLAB_CONSISTENCY_CHECKS 0x00000100UL /* DEBUG: Perform (expensive) checks on alloc/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 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
90 # define SLAB_ACCOUNT 0x04000000UL /* Account to memcg */
91 #else
92 # define SLAB_ACCOUNT 0x00000000UL
93 #endif
94
95 #ifdef CONFIG_KASAN
96 #define SLAB_KASAN 0x08000000UL
97 #else
98 #define SLAB_KASAN 0x00000000UL
99 #endif
100
101 /* The following flags affect the page allocator grouping pages by mobility */
102 #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
103 #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
104 /*
105 * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
106 *
107 * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
108 *
109 * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
110 * Both make kfree a no-op.
111 */
112 #define ZERO_SIZE_PTR ((void *)16)
113
114 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
115 (unsigned long)ZERO_SIZE_PTR)
116
117 #include <linux/kmemleak.h>
118 #include <linux/kasan.h>
119
120 struct mem_cgroup;
121 /*
122 * struct kmem_cache related prototypes
123 */
124 void __init kmem_cache_init(void);
125 bool slab_is_available(void);
126
127 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
128 unsigned long,
129 void (*)(void *));
130 void kmem_cache_destroy(struct kmem_cache *);
131 int kmem_cache_shrink(struct kmem_cache *);
132
133 void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
134 void memcg_deactivate_kmem_caches(struct mem_cgroup *);
135 void memcg_destroy_kmem_caches(struct mem_cgroup *);
136
137 /*
138 * Please use this macro to create slab caches. Simply specify the
139 * name of the structure and maybe some flags that are listed above.
140 *
141 * The alignment of the struct determines object alignment. If you
142 * f.e. add ____cacheline_aligned_in_smp to the struct declaration
143 * then the objects will be properly aligned in SMP configurations.
144 */
145 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
146 sizeof(struct __struct), __alignof__(struct __struct),\
147 (__flags), NULL)
148
149 /*
150 * Common kmalloc functions provided by all allocators
151 */
152 void * __must_check __krealloc(const void *, size_t, gfp_t);
153 void * __must_check krealloc(const void *, size_t, gfp_t);
154 void kfree(const void *);
155 void kzfree(const void *);
156 size_t ksize(const void *);
157
158 /*
159 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
160 * alignment larger than the alignment of a 64-bit integer.
161 * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
162 */
163 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
164 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
165 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
166 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
167 #else
168 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
169 #endif
170
171 /*
172 * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
173 * Intended for arches that get misalignment faults even for 64 bit integer
174 * aligned buffers.
175 */
176 #ifndef ARCH_SLAB_MINALIGN
177 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
178 #endif
179
180 /*
181 * kmalloc and friends return ARCH_KMALLOC_MINALIGN aligned
182 * pointers. kmem_cache_alloc and friends return ARCH_SLAB_MINALIGN
183 * aligned pointers.
184 */
185 #define __assume_kmalloc_alignment __assume_aligned(ARCH_KMALLOC_MINALIGN)
186 #define __assume_slab_alignment __assume_aligned(ARCH_SLAB_MINALIGN)
187 #define __assume_page_alignment __assume_aligned(PAGE_SIZE)
188
189 /*
190 * Kmalloc array related definitions
191 */
192
193 #ifdef CONFIG_SLAB
194 /*
195 * The largest kmalloc size supported by the SLAB allocators is
196 * 32 megabyte (2^25) or the maximum allocatable page order if that is
197 * less than 32 MB.
198 *
199 * WARNING: Its not easy to increase this value since the allocators have
200 * to do various tricks to work around compiler limitations in order to
201 * ensure proper constant folding.
202 */
203 #define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
204 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
205 #define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
206 #ifndef KMALLOC_SHIFT_LOW
207 #define KMALLOC_SHIFT_LOW 5
208 #endif
209 #endif
210
211 #ifdef CONFIG_SLUB
212 /*
213 * SLUB directly allocates requests fitting in to an order-1 page
214 * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
215 */
216 #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
217 #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
218 #ifndef KMALLOC_SHIFT_LOW
219 #define KMALLOC_SHIFT_LOW 3
220 #endif
221 #endif
222
223 #ifdef CONFIG_SLOB
224 /*
225 * SLOB passes all requests larger than one page to the page allocator.
226 * No kmalloc array is necessary since objects of different sizes can
227 * be allocated from the same page.
228 */
229 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT
230 #define KMALLOC_SHIFT_MAX 30
231 #ifndef KMALLOC_SHIFT_LOW
232 #define KMALLOC_SHIFT_LOW 3
233 #endif
234 #endif
235
236 /* Maximum allocatable size */
237 #define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
238 /* Maximum size for which we actually use a slab cache */
239 #define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
240 /* Maximum order allocatable via the slab allocagtor */
241 #define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
242
243 /*
244 * Kmalloc subsystem.
245 */
246 #ifndef KMALLOC_MIN_SIZE
247 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
248 #endif
249
250 /*
251 * This restriction comes from byte sized index implementation.
252 * Page size is normally 2^12 bytes and, in this case, if we want to use
253 * byte sized index which can represent 2^8 entries, the size of the object
254 * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
255 * If minimum size of kmalloc is less than 16, we use it as minimum object
256 * size and give up to use byte sized index.
257 */
258 #define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
259 (KMALLOC_MIN_SIZE) : 16)
260
261 #ifndef CONFIG_SLOB
262 extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
263 #ifdef CONFIG_ZONE_DMA
264 extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
265 #endif
266
267 /*
268 * Figure out which kmalloc slab an allocation of a certain size
269 * belongs to.
270 * 0 = zero alloc
271 * 1 = 65 .. 96 bytes
272 * 2 = 129 .. 192 bytes
273 * n = 2^(n-1)+1 .. 2^n
274 */
275 static __always_inline int kmalloc_index(size_t size)
276 {
277 if (!size)
278 return 0;
279
280 if (size <= KMALLOC_MIN_SIZE)
281 return KMALLOC_SHIFT_LOW;
282
283 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
284 return 1;
285 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
286 return 2;
287 if (size <= 8) return 3;
288 if (size <= 16) return 4;
289 if (size <= 32) return 5;
290 if (size <= 64) return 6;
291 if (size <= 128) return 7;
292 if (size <= 256) return 8;
293 if (size <= 512) return 9;
294 if (size <= 1024) return 10;
295 if (size <= 2 * 1024) return 11;
296 if (size <= 4 * 1024) return 12;
297 if (size <= 8 * 1024) return 13;
298 if (size <= 16 * 1024) return 14;
299 if (size <= 32 * 1024) return 15;
300 if (size <= 64 * 1024) return 16;
301 if (size <= 128 * 1024) return 17;
302 if (size <= 256 * 1024) return 18;
303 if (size <= 512 * 1024) return 19;
304 if (size <= 1024 * 1024) return 20;
305 if (size <= 2 * 1024 * 1024) return 21;
306 if (size <= 4 * 1024 * 1024) return 22;
307 if (size <= 8 * 1024 * 1024) return 23;
308 if (size <= 16 * 1024 * 1024) return 24;
309 if (size <= 32 * 1024 * 1024) return 25;
310 if (size <= 64 * 1024 * 1024) return 26;
311 BUG();
312
313 /* Will never be reached. Needed because the compiler may complain */
314 return -1;
315 }
316 #endif /* !CONFIG_SLOB */
317
318 void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment;
319 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags) __assume_slab_alignment;
320 void kmem_cache_free(struct kmem_cache *, void *);
321
322 /*
323 * Bulk allocation and freeing operations. These are accelerated in an
324 * allocator specific way to avoid taking locks repeatedly or building
325 * metadata structures unnecessarily.
326 *
327 * Note that interrupts must be enabled when calling these functions.
328 */
329 void kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
330 int kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
331
332 /*
333 * Caller must not use kfree_bulk() on memory not originally allocated
334 * by kmalloc(), because the SLOB allocator cannot handle this.
335 */
336 static __always_inline void kfree_bulk(size_t size, void **p)
337 {
338 kmem_cache_free_bulk(NULL, size, p);
339 }
340
341 #ifdef CONFIG_NUMA
342 void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment;
343 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node) __assume_slab_alignment;
344 #else
345 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
346 {
347 return __kmalloc(size, flags);
348 }
349
350 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
351 {
352 return kmem_cache_alloc(s, flags);
353 }
354 #endif
355
356 #ifdef CONFIG_TRACING
357 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t) __assume_slab_alignment;
358
359 #ifdef CONFIG_NUMA
360 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
361 gfp_t gfpflags,
362 int node, size_t size) __assume_slab_alignment;
363 #else
364 static __always_inline void *
365 kmem_cache_alloc_node_trace(struct kmem_cache *s,
366 gfp_t gfpflags,
367 int node, size_t size)
368 {
369 return kmem_cache_alloc_trace(s, gfpflags, size);
370 }
371 #endif /* CONFIG_NUMA */
372
373 #else /* CONFIG_TRACING */
374 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
375 gfp_t flags, size_t size)
376 {
377 void *ret = kmem_cache_alloc(s, flags);
378
379 kasan_kmalloc(s, ret, size, flags);
380 return ret;
381 }
382
383 static __always_inline void *
384 kmem_cache_alloc_node_trace(struct kmem_cache *s,
385 gfp_t gfpflags,
386 int node, size_t size)
387 {
388 void *ret = kmem_cache_alloc_node(s, gfpflags, node);
389
390 kasan_kmalloc(s, ret, size, gfpflags);
391 return ret;
392 }
393 #endif /* CONFIG_TRACING */
394
395 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment;
396
397 #ifdef CONFIG_TRACING
398 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) __assume_page_alignment;
399 #else
400 static __always_inline void *
401 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
402 {
403 return kmalloc_order(size, flags, order);
404 }
405 #endif
406
407 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
408 {
409 unsigned int order = get_order(size);
410 return kmalloc_order_trace(size, flags, order);
411 }
412
413 /**
414 * kmalloc - allocate memory
415 * @size: how many bytes of memory are required.
416 * @flags: the type of memory to allocate.
417 *
418 * kmalloc is the normal method of allocating memory
419 * for objects smaller than page size in the kernel.
420 *
421 * The @flags argument may be one of:
422 *
423 * %GFP_USER - Allocate memory on behalf of user. May sleep.
424 *
425 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
426 *
427 * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
428 * For example, use this inside interrupt handlers.
429 *
430 * %GFP_HIGHUSER - Allocate pages from high memory.
431 *
432 * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
433 *
434 * %GFP_NOFS - Do not make any fs calls while trying to get memory.
435 *
436 * %GFP_NOWAIT - Allocation will not sleep.
437 *
438 * %__GFP_THISNODE - Allocate node-local memory only.
439 *
440 * %GFP_DMA - Allocation suitable for DMA.
441 * Should only be used for kmalloc() caches. Otherwise, use a
442 * slab created with SLAB_DMA.
443 *
444 * Also it is possible to set different flags by OR'ing
445 * in one or more of the following additional @flags:
446 *
447 * %__GFP_COLD - Request cache-cold pages instead of
448 * trying to return cache-warm pages.
449 *
450 * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
451 *
452 * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
453 * (think twice before using).
454 *
455 * %__GFP_NORETRY - If memory is not immediately available,
456 * then give up at once.
457 *
458 * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
459 *
460 * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
461 *
462 * There are other flags available as well, but these are not intended
463 * for general use, and so are not documented here. For a full list of
464 * potential flags, always refer to linux/gfp.h.
465 */
466 static __always_inline void *kmalloc(size_t size, gfp_t flags)
467 {
468 if (__builtin_constant_p(size)) {
469 if (size > KMALLOC_MAX_CACHE_SIZE)
470 return kmalloc_large(size, flags);
471 #ifndef CONFIG_SLOB
472 if (!(flags & GFP_DMA)) {
473 int index = kmalloc_index(size);
474
475 if (!index)
476 return ZERO_SIZE_PTR;
477
478 return kmem_cache_alloc_trace(kmalloc_caches[index],
479 flags, size);
480 }
481 #endif
482 }
483 return __kmalloc(size, flags);
484 }
485
486 /*
487 * Determine size used for the nth kmalloc cache.
488 * return size or 0 if a kmalloc cache for that
489 * size does not exist
490 */
491 static __always_inline int kmalloc_size(int n)
492 {
493 #ifndef CONFIG_SLOB
494 if (n > 2)
495 return 1 << n;
496
497 if (n == 1 && KMALLOC_MIN_SIZE <= 32)
498 return 96;
499
500 if (n == 2 && KMALLOC_MIN_SIZE <= 64)
501 return 192;
502 #endif
503 return 0;
504 }
505
506 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
507 {
508 #ifndef CONFIG_SLOB
509 if (__builtin_constant_p(size) &&
510 size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
511 int i = kmalloc_index(size);
512
513 if (!i)
514 return ZERO_SIZE_PTR;
515
516 return kmem_cache_alloc_node_trace(kmalloc_caches[i],
517 flags, node, size);
518 }
519 #endif
520 return __kmalloc_node(size, flags, node);
521 }
522
523 struct memcg_cache_array {
524 struct rcu_head rcu;
525 struct kmem_cache *entries[0];
526 };
527
528 /*
529 * This is the main placeholder for memcg-related information in kmem caches.
530 * Both the root cache and the child caches will have it. For the root cache,
531 * this will hold a dynamically allocated array large enough to hold
532 * information about the currently limited memcgs in the system. To allow the
533 * array to be accessed without taking any locks, on relocation we free the old
534 * version only after a grace period.
535 *
536 * Child caches will hold extra metadata needed for its operation. Fields are:
537 *
538 * @memcg: pointer to the memcg this cache belongs to
539 * @root_cache: pointer to the global, root cache, this cache was derived from
540 *
541 * Both root and child caches of the same kind are linked into a list chained
542 * through @list.
543 */
544 struct memcg_cache_params {
545 bool is_root_cache;
546 struct list_head list;
547 union {
548 struct memcg_cache_array __rcu *memcg_caches;
549 struct {
550 struct mem_cgroup *memcg;
551 struct kmem_cache *root_cache;
552 };
553 };
554 };
555
556 int memcg_update_all_caches(int num_memcgs);
557
558 /**
559 * kmalloc_array - allocate memory for an array.
560 * @n: number of elements.
561 * @size: element size.
562 * @flags: the type of memory to allocate (see kmalloc).
563 */
564 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
565 {
566 if (size != 0 && n > SIZE_MAX / size)
567 return NULL;
568 return __kmalloc(n * size, flags);
569 }
570
571 /**
572 * kcalloc - allocate memory for an array. The memory is set to zero.
573 * @n: number of elements.
574 * @size: element size.
575 * @flags: the type of memory to allocate (see kmalloc).
576 */
577 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
578 {
579 return kmalloc_array(n, size, flags | __GFP_ZERO);
580 }
581
582 /*
583 * kmalloc_track_caller is a special version of kmalloc that records the
584 * calling function of the routine calling it for slab leak tracking instead
585 * of just the calling function (confusing, eh?).
586 * It's useful when the call to kmalloc comes from a widely-used standard
587 * allocator where we care about the real place the memory allocation
588 * request comes from.
589 */
590 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
591 #define kmalloc_track_caller(size, flags) \
592 __kmalloc_track_caller(size, flags, _RET_IP_)
593
594 #ifdef CONFIG_NUMA
595 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
596 #define kmalloc_node_track_caller(size, flags, node) \
597 __kmalloc_node_track_caller(size, flags, node, \
598 _RET_IP_)
599
600 #else /* CONFIG_NUMA */
601
602 #define kmalloc_node_track_caller(size, flags, node) \
603 kmalloc_track_caller(size, flags)
604
605 #endif /* CONFIG_NUMA */
606
607 /*
608 * Shortcuts
609 */
610 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
611 {
612 return kmem_cache_alloc(k, flags | __GFP_ZERO);
613 }
614
615 /**
616 * kzalloc - allocate memory. The memory is set to zero.
617 * @size: how many bytes of memory are required.
618 * @flags: the type of memory to allocate (see kmalloc).
619 */
620 static inline void *kzalloc(size_t size, gfp_t flags)
621 {
622 return kmalloc(size, flags | __GFP_ZERO);
623 }
624
625 /**
626 * kzalloc_node - allocate zeroed memory from a particular memory node.
627 * @size: how many bytes of memory are required.
628 * @flags: the type of memory to allocate (see kmalloc).
629 * @node: memory node from which to allocate
630 */
631 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
632 {
633 return kmalloc_node(size, flags | __GFP_ZERO, node);
634 }
635
636 unsigned int kmem_cache_size(struct kmem_cache *s);
637 void __init kmem_cache_init_late(void);
638
639 #endif /* _LINUX_SLAB_H */
640
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