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Linux/include/linux/slab.h

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

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