File: /Users/paulross/dev/linux/linux-3.13/include/linux/slab.h

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       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: struct kmem_cache *
     119: kmem_cache_create_memcg(struct mem_cgroup *, const char *, size_t, size_t,
     120:             unsigned long, void (*)(void *), struct kmem_cache *);
     121: void kmem_cache_destroy(struct kmem_cache *);
     122: int kmem_cache_shrink(struct kmem_cache *);
     123: void kmem_cache_free(struct kmem_cache *, void *);
     124: 
     125: /*
     126:  * Please use this macro to create slab caches. Simply specify the
     127:  * name of the structure and maybe some flags that are listed above.
     128:  *
     129:  * The alignment of the struct determines object alignment. If you
     130:  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
     131:  * then the objects will be properly aligned in SMP configurations.
     132:  */
     133: #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
        sizeof(struct __struct), __alignof__(struct __struct),\
        (__flags), NULL)
     136: 
     137: /*
     138:  * Common kmalloc functions provided by all allocators
     139:  */
     140: void * __must_check __krealloc(const void *, size_t, gfp_t);
     141: void * __must_check krealloc(const void *, size_t, gfp_t);
     142: void kfree(const void *);
     143: void kzfree(const void *);
     144: size_t ksize(const void *);
     145: 
     146: /*
     147:  * Some archs want to perform DMA into kmalloc caches and need a guaranteed
     148:  * alignment larger than the alignment of a 64-bit integer.
     149:  * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
     150:  */
     151: #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
     152: #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
     153: #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
     154: #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
     155: #else
     156: #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
     157: #endif
     158: 
     159: #ifdef CONFIG_SLOB
     160: /*
     161:  * Common fields provided in kmem_cache by all slab allocators
     162:  * This struct is either used directly by the allocator (SLOB)
     163:  * or the allocator must include definitions for all fields
     164:  * provided in kmem_cache_common in their definition of kmem_cache.
     165:  *
     166:  * Once we can do anonymous structs (C11 standard) we could put a
     167:  * anonymous struct definition in these allocators so that the
     168:  * separate allocations in the kmem_cache structure of SLAB and
     169:  * SLUB is no longer needed.
     170:  */
     171: struct kmem_cache {
     172:     unsigned int object_size;/* The original size of the object */
     173:     unsigned int size;    /* The aligned/padded/added on size  */
     174:     unsigned int align;    /* Alignment as calculated */
     175:     unsigned long flags;    /* Active flags on the slab */
     176:     const char *name;    /* Slab name for sysfs */
     177:     int refcount;        /* Use counter */
     178:     void (*ctor)(void *);    /* Called on object slot creation */
     179:     struct list_head list;    /* List of all slab caches on the system */
     180: };
     181: 
     182: #endif /* CONFIG_SLOB */
     183: 
     184: /*
     185:  * Kmalloc array related definitions
     186:  */
     187: 
     188: #ifdef CONFIG_SLAB
     189: /*
     190:  * The largest kmalloc size supported by the SLAB allocators is
     191:  * 32 megabyte (2^25) or the maximum allocatable page order if that is
     192:  * less than 32 MB.
     193:  *
     194:  * WARNING: Its not easy to increase this value since the allocators have
     195:  * to do various tricks to work around compiler limitations in order to
     196:  * ensure proper constant folding.
     197:  */
     198: #define KMALLOC_SHIFT_HIGH    ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
     199:                 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
     200: #define KMALLOC_SHIFT_MAX    KMALLOC_SHIFT_HIGH
     201: #ifndef KMALLOC_SHIFT_LOW
     202: #define KMALLOC_SHIFT_LOW    5
     203: #endif
     204: #endif
     205: 
     206: #ifdef CONFIG_SLUB
     207: /*
     208:  * SLUB allocates up to order 2 pages directly and otherwise
     209:  * passes the request to the page allocator.
     210:  */
     211: #define KMALLOC_SHIFT_HIGH    (PAGE_SHIFT + 1)
     212: #define KMALLOC_SHIFT_MAX    (MAX_ORDER + PAGE_SHIFT)
     213: #ifndef KMALLOC_SHIFT_LOW
     214: #define KMALLOC_SHIFT_LOW    3
     215: #endif
     216: #endif
     217: 
     218: #ifdef CONFIG_SLOB
     219: /*
     220:  * SLOB passes all page size and larger requests to the page allocator.
     221:  * No kmalloc array is necessary since objects of different sizes can
     222:  * be allocated from the same page.
     223:  */
     224: #define KMALLOC_SHIFT_MAX    30
     225: #define KMALLOC_SHIFT_HIGH    PAGE_SHIFT
     226: #ifndef KMALLOC_SHIFT_LOW
     227: #define KMALLOC_SHIFT_LOW    3
     228: #endif
     229: #endif
     230: 
     231: /* Maximum allocatable size */
     232: #define KMALLOC_MAX_SIZE    (1UL << KMALLOC_SHIFT_MAX)
     233: /* Maximum size for which we actually use a slab cache */
     234: #define KMALLOC_MAX_CACHE_SIZE    (1UL << KMALLOC_SHIFT_HIGH)
     235: /* Maximum order allocatable via the slab allocagtor */
     236: #define KMALLOC_MAX_ORDER    (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
     237: 
     238: /*
     239:  * Kmalloc subsystem.
     240:  */
     241: #ifndef KMALLOC_MIN_SIZE
     242: #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
     243: #endif
     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:  */
     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
     309: static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
     310: {
     311:     return __kmalloc(size, flags);
     312: }
     313: 
     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 *
     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 */
     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 *
     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: #ifdef CONFIG_SLAB
     354: #include <linux/slab_def.h>
     355: #endif
     356: 
     357: #ifdef CONFIG_SLUB
     358: #include <linux/slub_def.h>
     359: #endif
     360: 
     361: static __always_inline void *
     362: kmalloc_order(size_t size, gfp_t flags, unsigned int order)
     363: {
     364:     void *ret;
     365: 
     366:     flags |= (__GFP_COMP | __GFP_KMEMCG);
     367:     ret = (void *) __get_free_pages(flags, order);
     368:     kmemleak_alloc(ret, size, 1, flags);
     369:     return ret;
     370: }
     371: 
     372: #ifdef CONFIG_TRACING
     373: extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
     374: #else
     375: static __always_inline void *
     376: kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
     377: {
     378:     return kmalloc_order(size, flags, order);
     379: }
     380: #endif
     381: 
     382: static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
     383: {
     384:     unsigned int order = get_order(size);
     385:     return kmalloc_order_trace(size, flags, order);
     386: }
     387: 
     388: /**
     389:  * kmalloc - allocate memory
     390:  * @size: how many bytes of memory are required.
     391:  * @flags: the type of memory to allocate.
     392:  *
     393:  * kmalloc is the normal method of allocating memory
     394:  * for objects smaller than page size in the kernel.
     395:  *
     396:  * The @flags argument may be one of:
     397:  *
     398:  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
     399:  *
     400:  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
     401:  *
     402:  * %GFP_ATOMIC - Allocation will not sleep.  May use emergency pools.
     403:  *   For example, use this inside interrupt handlers.
     404:  *
     405:  * %GFP_HIGHUSER - Allocate pages from high memory.
     406:  *
     407:  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
     408:  *
     409:  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
     410:  *
     411:  * %GFP_NOWAIT - Allocation will not sleep.
     412:  *
     413:  * %GFP_THISNODE - Allocate node-local memory only.
     414:  *
     415:  * %GFP_DMA - Allocation suitable for DMA.
     416:  *   Should only be used for kmalloc() caches. Otherwise, use a
     417:  *   slab created with SLAB_DMA.
     418:  *
     419:  * Also it is possible to set different flags by OR'ing
     420:  * in one or more of the following additional @flags:
     421:  *
     422:  * %__GFP_COLD - Request cache-cold pages instead of
     423:  *   trying to return cache-warm pages.
     424:  *
     425:  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
     426:  *
     427:  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
     428:  *   (think twice before using).
     429:  *
     430:  * %__GFP_NORETRY - If memory is not immediately available,
     431:  *   then give up at once.
     432:  *
     433:  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
     434:  *
     435:  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
     436:  *
     437:  * There are other flags available as well, but these are not intended
     438:  * for general use, and so are not documented here. For a full list of
     439:  * potential flags, always refer to linux/gfp.h.
     440:  */
     441: static __always_inline void *kmalloc(size_t size, gfp_t flags)
     442: {
     443:     if (__builtin_constant_p(size)) {
     444:         if (size > KMALLOC_MAX_CACHE_SIZE)
     445:             return kmalloc_large(size, flags);
     446: #ifndef CONFIG_SLOB
     447:         if (!(flags & GFP_DMA)) {
     448:             int index = kmalloc_index(size);
     449: 
     450:             if (!index)
     451:                 return ZERO_SIZE_PTR;
     452: 
     453:             return kmem_cache_alloc_trace(kmalloc_caches[index],
     454:                     flags, size);
     455:         }
     456: #endif
     457:     }
     458:     return __kmalloc(size, flags);
     459: }
     460: 
     461: /*
     462:  * Determine size used for the nth kmalloc cache.
     463:  * return size or 0 if a kmalloc cache for that
     464:  * size does not exist
     465:  */
     466: static __always_inline int kmalloc_size(int n)
     467: {
     468: #ifndef CONFIG_SLOB
     469:     if (n > 2)
     470:         return 1 << n;
     471: 
     472:     if (n == 1 && KMALLOC_MIN_SIZE <= 32)
     473:         return 96;
     474: 
     475:     if (n == 2 && KMALLOC_MIN_SIZE <= 64)
     476:         return 192;
     477: #endif
     478:     return 0;
     479: }
     480: 
     481: static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
     482: {
     483: #ifndef CONFIG_SLOB
     484:     if (__builtin_constant_p(size) &&
     485:         size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
     486:         int i = kmalloc_index(size);
     487: 
     488:         if (!i)
     489:             return ZERO_SIZE_PTR;
     490: 
     491:         return kmem_cache_alloc_node_trace(kmalloc_caches[i],
     492:                         flags, node, size);
     493:     }
     494: #endif
     495:     return __kmalloc_node(size, flags, node);
     496: }
     497: 
     498: /*
     499:  * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
     500:  * Intended for arches that get misalignment faults even for 64 bit integer
     501:  * aligned buffers.
     502:  */
     503: #ifndef ARCH_SLAB_MINALIGN
     504: #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
     505: #endif
     506: /*
     507:  * This is the main placeholder for memcg-related information in kmem caches.
     508:  * struct kmem_cache will hold a pointer to it, so the memory cost while
     509:  * disabled is 1 pointer. The runtime cost while enabled, gets bigger than it
     510:  * would otherwise be if that would be bundled in kmem_cache: we'll need an
     511:  * extra pointer chase. But the trade off clearly lays in favor of not
     512:  * penalizing non-users.
     513:  *
     514:  * Both the root cache and the child caches will have it. For the root cache,
     515:  * this will hold a dynamically allocated array large enough to hold
     516:  * information about the currently limited memcgs in the system.
     517:  *
     518:  * Child caches will hold extra metadata needed for its operation. Fields are:
     519:  *
     520:  * @memcg: pointer to the memcg this cache belongs to
     521:  * @list: list_head for the list of all caches in this memcg
     522:  * @root_cache: pointer to the global, root cache, this cache was derived from
     523:  * @dead: set to true after the memcg dies; the cache may still be around.
     524:  * @nr_pages: number of pages that belongs to this cache.
     525:  * @destroy: worker to be called whenever we are ready, or believe we may be
     526:  *           ready, to destroy this cache.
     527:  */
     528: struct memcg_cache_params {
     529:     bool is_root_cache;
     530:     union {
     531:         struct kmem_cache *memcg_caches[0];
     532:         struct {
     533:             struct mem_cgroup *memcg;
     534:             struct list_head list;
     535:             struct kmem_cache *root_cache;
     536:             bool dead;
     537:             atomic_t nr_pages;
     538:             struct work_struct destroy;
     539:         };
     540:     };
     541: };
     542: 
     543: int memcg_update_all_caches(int num_memcgs);
     544: 
     545: struct seq_file;
     546: int cache_show(struct kmem_cache *s, struct seq_file *m);
     547: void print_slabinfo_header(struct seq_file *m);
     548: 
     549: /**
     550:  * kmalloc_array - allocate memory for an array.
     551:  * @n: number of elements.
     552:  * @size: element size.
     553:  * @flags: the type of memory to allocate (see kmalloc).
     554:  */
     555: static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
     556: {
     557:     if (size != 0 && n > SIZE_MAX / size)
     558:         return NULL;
     559:     return __kmalloc(n * size, flags);
     560: }
     561: 
     562: /**
     563:  * kcalloc - allocate memory for an array. The memory is set to zero.
     564:  * @n: number of elements.
     565:  * @size: element size.
     566:  * @flags: the type of memory to allocate (see kmalloc).
     567:  */
     568: static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
     569: {
     570:     return kmalloc_array(n, size, flags | __GFP_ZERO);
     571: }
     572: 
     573: /*
     574:  * kmalloc_track_caller is a special version of kmalloc that records the
     575:  * calling function of the routine calling it for slab leak tracking instead
     576:  * of just the calling function (confusing, eh?).
     577:  * It's useful when the call to kmalloc comes from a widely-used standard
     578:  * allocator where we care about the real place the memory allocation
     579:  * request comes from.
     580:  */
     581: #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \
     582:     (defined(CONFIG_SLAB) && defined(CONFIG_TRACING)) || \
     583:     (defined(CONFIG_SLOB) && defined(CONFIG_TRACING))
     584: extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
     585: #define kmalloc_track_caller(size, flags) \
     586:     __kmalloc_track_caller(size, flags, _RET_IP_)
     587: #else
     588: #define kmalloc_track_caller(size, flags) \
     589:     __kmalloc(size, flags)
     590: #endif /* DEBUG_SLAB */
     591: 
     592: #ifdef CONFIG_NUMA
     593: /*
     594:  * kmalloc_node_track_caller is a special version of kmalloc_node that
     595:  * records the calling function of the routine calling it for slab leak
     596:  * tracking instead of just the calling function (confusing, eh?).
     597:  * It's useful when the call to kmalloc_node comes from a widely-used
     598:  * standard allocator where we care about the real place the memory
     599:  * allocation request comes from.
     600:  */
     601: #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \
     602:     (defined(CONFIG_SLAB) && defined(CONFIG_TRACING)) || \
     603:     (defined(CONFIG_SLOB) && defined(CONFIG_TRACING))
     604: extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
     605: #define kmalloc_node_track_caller(size, flags, node) \
     606:     __kmalloc_node_track_caller(size, flags, node, \
     607:             _RET_IP_)
     608: #else
     609: #define kmalloc_node_track_caller(size, flags, node) \
     610:     __kmalloc_node(size, flags, node)
     611: #endif
     612: 
     613: #else /* CONFIG_NUMA */
     614: 
     615: #define kmalloc_node_track_caller(size, flags, node) \
     616:     kmalloc_track_caller(size, flags)
     617: 
     618: #endif /* CONFIG_NUMA */
     619: 
     620: /*
     621:  * Shortcuts
     622:  */
     623: static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
     624: {
     625:     return kmem_cache_alloc(k, flags | __GFP_ZERO);
     626: }
     627: 
     628: /**
     629:  * kzalloc - allocate memory. The memory is set to zero.
     630:  * @size: how many bytes of memory are required.
     631:  * @flags: the type of memory to allocate (see kmalloc).
     632:  */
     633: static inline void *kzalloc(size_t size, gfp_t flags)
     634: {
     635:     return kmalloc(size, flags | __GFP_ZERO);
     636: }
     637: 
     638: /**
     639:  * kzalloc_node - allocate zeroed memory from a particular memory node.
     640:  * @size: how many bytes of memory are required.
     641:  * @flags: the type of memory to allocate (see kmalloc).
     642:  * @node: memory node from which to allocate
     643:  */
     644: static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
     645: {
     646:     return kmalloc_node(size, flags | __GFP_ZERO, node);
     647: }
     648: 
     649: /*
     650:  * Determine the size of a slab object
     651:  */
     652: static inline unsigned int kmem_cache_size(struct kmem_cache *s)
     653: {
     654:     return s->object_size;
     655: }
     656: 
     657: void __init kmem_cache_init_late(void);
     658: 
     659: #endif    /* _LINUX_SLAB_H */
     660: