include/linux/slab.h

   1 /*
   2  * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
   3  *
   4  * (C) SGI 2006, Christoph Lameter <clameter@sgi.com>
   5  *      Cleaned up and restructured to ease the addition of alternative
   6  *      implementations of SLAB allocators.
   7  */
   8
   9 #ifndef _LINUX_SLAB_H
  10 #define _LINUX_SLAB_H
  11
  12 #ifdef __KERNEL__
  13
  14 #include <linux/gfp.h>
  15 #include <linux/types.h>
  16
  17 typedef struct kmem_cache kmem_cache_t __deprecated;
  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_RECLAIM_ACCOUNT    0x00020000UL    /* Objects are reclaimable */
  30 #define SLAB_PANIC              0x00040000UL    /* Panic if kmem_cache_create() fails */
  31 #define SLAB_DESTROY_BY_RCU     0x00080000UL    /* Defer freeing slabs to RCU */
  32 #define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
  33 #define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
  34
  35 /*
  36  * struct kmem_cache related prototypes
  37  */
  38 void __init kmem_cache_init(void);
  39 int slab_is_available(void);
  40
  41 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
  42                         unsigned long,
  43                         void (*)(void *, struct kmem_cache *, unsigned long),
  44                         void (*)(void *, struct kmem_cache *, unsigned long));
  45 void kmem_cache_destroy(struct kmem_cache *);
  46 int kmem_cache_shrink(struct kmem_cache *);
  47 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
  48 void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
  49 void kmem_cache_free(struct kmem_cache *, void *);
  50 unsigned int kmem_cache_size(struct kmem_cache *);
  51 const char *kmem_cache_name(struct kmem_cache *);
  52 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
  53
  54 /*
  55  * Please use this macro to create slab caches. Simply specify the
  56  * name of the structure and maybe some flags that are listed above.
  57  *
  58  * The alignment of the struct determines object alignment. If you
  59  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
  60  * then the objects will be properly aligned in SMP configurations.
  61  */
  62 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
  63                 sizeof(struct __struct), __alignof__(struct __struct),\
  64                 (__flags), NULL, NULL)
  65
  66 #ifdef CONFIG_NUMA
  67 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
  68 #else
  69 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
  70                                         gfp_t flags, int node)
  71 {
  72         return kmem_cache_alloc(cachep, flags);
  73 }
  74 #endif
  75
  76 /*
  77  * Common kmalloc functions provided by all allocators
  78  */
  79 void *__kmalloc(size_t, gfp_t);
  80 void *__kzalloc(size_t, gfp_t);
  81 void * __must_check krealloc(const void *, size_t, gfp_t);
  82 void kfree(const void *);
  83 size_t ksize(const void *);
  84
  85 /**
  86  * kcalloc - allocate memory for an array. The memory is set to zero.
  87  * @n: number of elements.
  88  * @size: element size.
  89  * @flags: the type of memory to allocate.
  90  */
  91 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
  92 {
  93         if (n != 0 && size > ULONG_MAX / n)
  94                 return NULL;
  95         return __kzalloc(n * size, flags);
  96 }
  97
  98 /*
  99  * Allocator specific definitions. These are mainly used to establish optimized
 100  * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting
 101  * the appropriate general cache at compile time.
 102  */
 103
 104 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB)
 105 #ifdef CONFIG_SLUB
 106 #include <linux/slub_def.h>
 107 #else
 108 #include <linux/slab_def.h>
 109 #endif /* !CONFIG_SLUB */
 110 #else
 111
 112 /*
 113  * Fallback definitions for an allocator not wanting to provide
 114  * its own optimized kmalloc definitions (like SLOB).
 115  */
 116
 117 /**
 118  * kmalloc - allocate memory
 119  * @size: how many bytes of memory are required.
 120  * @flags: the type of memory to allocate.
 121  *
 122  * kmalloc is the normal method of allocating memory
 123  * in the kernel.
 124  *
 125  * The @flags argument may be one of:
 126  *
 127  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 128  *
 129  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 130  *
 131  * %GFP_ATOMIC - Allocation will not sleep.
 132  *   For example, use this inside interrupt handlers.
 133  *
 134  * %GFP_HIGHUSER - Allocate pages from high memory.
 135  *
 136  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
 137  *
 138  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
 139  *
 140  * Also it is possible to set different flags by OR'ing
 141  * in one or more of the following additional @flags:
 142  *
 143  * %__GFP_COLD - Request cache-cold pages instead of
 144  *   trying to return cache-warm pages.
 145  *
 146  * %__GFP_DMA - Request memory from the DMA-capable zone.
 147  *
 148  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
 149  *
 150  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
 151  *
 152  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
 153  *   (think twice before using).
 154  *
 155  * %__GFP_NORETRY - If memory is not immediately available,
 156  *   then give up at once.
 157  *
 158  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
 159  *
 160  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
 161  */
 162 static inline void *kmalloc(size_t size, gfp_t flags)
 163 {
 164         return __kmalloc(size, flags);
 165 }
 166
 167 /**
 168  * kzalloc - allocate memory. The memory is set to zero.
 169  * @size: how many bytes of memory are required.
 170  * @flags: the type of memory to allocate (see kmalloc).
 171  */
 172 static inline void *kzalloc(size_t size, gfp_t flags)
 173 {
 174         return __kzalloc(size, flags);
 175 }
 176 #endif
 177
 178 #ifndef CONFIG_NUMA
 179 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 180 {
 181         return kmalloc(size, flags);
 182 }
 183
 184 static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
 185 {
 186         return __kmalloc(size, flags);
 187 }
 188 #endif /* !CONFIG_NUMA */
 189
 190 /*
 191  * kmalloc_track_caller is a special version of kmalloc that records the
 192  * calling function of the routine calling it for slab leak tracking instead
 193  * of just the calling function (confusing, eh?).
 194  * It's useful when the call to kmalloc comes from a widely-used standard
 195  * allocator where we care about the real place the memory allocation
 196  * request comes from.
 197  */
 198 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
 199 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
 200 #define kmalloc_track_caller(size, flags) \
 201         __kmalloc_track_caller(size, flags, __builtin_return_address(0))
 202 #else
 203 #define kmalloc_track_caller(size, flags) \
 204         __kmalloc(size, flags)
 205 #endif /* DEBUG_SLAB */
 206
 207 #ifdef CONFIG_NUMA
 208 /*
 209  * kmalloc_node_track_caller is a special version of kmalloc_node that
 210  * records the calling function of the routine calling it for slab leak
 211  * tracking instead of just the calling function (confusing, eh?).
 212  * It's useful when the call to kmalloc_node comes from a widely-used
 213  * standard allocator where we care about the real place the memory
 214  * allocation request comes from.
 215  */
 216 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
 217 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
 218 #define kmalloc_node_track_caller(size, flags, node) \
 219         __kmalloc_node_track_caller(size, flags, node, \
 220                         __builtin_return_address(0))
 221 #else
 222 #define kmalloc_node_track_caller(size, flags, node) \
 223         __kmalloc_node(size, flags, node)
 224 #endif
 225
 226 #else /* CONFIG_NUMA */
 227
 228 #define kmalloc_node_track_caller(size, flags, node) \
 229         kmalloc_track_caller(size, flags)
 230
 231 #endif /* DEBUG_SLAB */
 232
 233 #endif  /* __KERNEL__ */
 234 #endif  /* _LINUX_SLAB_H */
 235