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_DEBUG_INITIAL      0x00000200UL    /* DEBUG: Call constructor (as verifier) */
  25 #define SLAB_RED_ZONE           0x00000400UL    /* DEBUG: Red zone objs in a cache */
  26 #define SLAB_POISON             0x00000800UL    /* DEBUG: Poison objects */
  27 #define SLAB_HWCACHE_ALIGN      0x00002000UL    /* Align objs on cache lines */
  28 #define SLAB_CACHE_DMA          0x00004000UL    /* Use GFP_DMA memory */
  29 #define SLAB_MUST_HWCACHE_ALIGN 0x00008000UL    /* Force alignment even if debuggin is active */
  30 #define SLAB_STORE_USER         0x00010000UL    /* DEBUG: Store the last owner for bug hunting */
  31 #define SLAB_RECLAIM_ACCOUNT    0x00020000UL    /* Objects are reclaimable */
  32 #define SLAB_PANIC              0x00040000UL    /* Panic if kmem_cache_create() fails */
  33 #define SLAB_DESTROY_BY_RCU     0x00080000UL    /* Defer freeing slabs to RCU */
  34 #define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
  35
  36 /* Flags passed to a constructor functions */
  37 #define SLAB_CTOR_CONSTRUCTOR   0x001UL         /* If not set, then deconstructor */
  38 #define SLAB_CTOR_ATOMIC        0x002UL         /* Tell constructor it can't sleep */
  39 #define SLAB_CTOR_VERIFY        0x004UL         /* Tell constructor it's a verify call */
  40
  41 /*
  42  * struct kmem_cache related prototypes
  43  */
  44 void __init kmem_cache_init(void);
  45 extern int slab_is_available(void);
  46
  47 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
  48                         unsigned long,
  49                         void (*)(void *, struct kmem_cache *, unsigned long),
  50                         void (*)(void *, struct kmem_cache *, unsigned long));
  51 void kmem_cache_destroy(struct kmem_cache *);
  52 int kmem_cache_shrink(struct kmem_cache *);
  53 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
  54 void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
  55 void kmem_cache_free(struct kmem_cache *, void *);
  56 unsigned int kmem_cache_size(struct kmem_cache *);
  57 const char *kmem_cache_name(struct kmem_cache *);
  58 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
  59
  60 #ifdef CONFIG_NUMA
  61 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
  62 #else
  63 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
  64                                         gfp_t flags, int node)
  65 {
  66         return kmem_cache_alloc(cachep, flags);
  67 }
  68 #endif
  69
  70 /*
  71  * Common kmalloc functions provided by all allocators
  72  */
  73 void *__kmalloc(size_t, gfp_t);
  74 void *__kzalloc(size_t, gfp_t);
  75 void * __must_check krealloc(const void *, size_t, gfp_t);
  76 void kfree(const void *);
  77 size_t ksize(const void *);
  78
  79 /**
  80  * kcalloc - allocate memory for an array. The memory is set to zero.
  81  * @n: number of elements.
  82  * @size: element size.
  83  * @flags: the type of memory to allocate.
  84  */
  85 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
  86 {
  87         if (n != 0 && size > ULONG_MAX / n)
  88                 return NULL;
  89         return __kzalloc(n * size, flags);
  90 }
  91
  92 /*
  93  * Allocator specific definitions. These are mainly used to establish optimized
  94  * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting
  95  * the appropriate general cache at compile time.
  96  */
  97
  98 #ifdef CONFIG_SLAB
  99 #include <linux/slab_def.h>
 100 #else
 101 /*
 102  * Fallback definitions for an allocator not wanting to provide
 103  * its own optimized kmalloc definitions (like SLOB).
 104  */
 105
 106 /**
 107  * kmalloc - allocate memory
 108  * @size: how many bytes of memory are required.
 109  * @flags: the type of memory to allocate.
 110  *
 111  * kmalloc is the normal method of allocating memory
 112  * in the kernel.
 113  *
 114  * The @flags argument may be one of:
 115  *
 116  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 117  *
 118  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 119  *
 120  * %GFP_ATOMIC - Allocation will not sleep.
 121  *   For example, use this inside interrupt handlers.
 122  *
 123  * %GFP_HIGHUSER - Allocate pages from high memory.
 124  *
 125  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
 126  *
 127  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
 128  *
 129  * Also it is possible to set different flags by OR'ing
 130  * in one or more of the following additional @flags:
 131  *
 132  * %__GFP_COLD - Request cache-cold pages instead of
 133  *   trying to return cache-warm pages.
 134  *
 135  * %__GFP_DMA - Request memory from the DMA-capable zone.
 136  *
 137  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
 138  *
 139  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
 140  *
 141  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
 142  *   (think twice before using).
 143  *
 144  * %__GFP_NORETRY - If memory is not immediately available,
 145  *   then give up at once.
 146  *
 147  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
 148  *
 149  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
 150  */
 151 static inline void *kmalloc(size_t size, gfp_t flags)
 152 {
 153         return __kmalloc(size, flags);
 154 }
 155
 156 /**
 157  * kzalloc - allocate memory. The memory is set to zero.
 158  * @size: how many bytes of memory are required.
 159  * @flags: the type of memory to allocate (see kmalloc).
 160  */
 161 static inline void *kzalloc(size_t size, gfp_t flags)
 162 {
 163         return __kzalloc(size, flags);
 164 }
 165 #endif
 166
 167 #ifndef CONFIG_NUMA
 168 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 169 {
 170         return kmalloc(size, flags);
 171 }
 172
 173 static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
 174 {
 175         return __kmalloc(size, flags);
 176 }
 177 #endif /* !CONFIG_NUMA */
 178
 179 /*
 180  * kmalloc_track_caller is a special version of kmalloc that records the
 181  * calling function of the routine calling it for slab leak tracking instead
 182  * of just the calling function (confusing, eh?).
 183  * It's useful when the call to kmalloc comes from a widely-used standard
 184  * allocator where we care about the real place the memory allocation
 185  * request comes from.
 186  */
 187 #ifdef CONFIG_DEBUG_SLAB
 188 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
 189 #define kmalloc_track_caller(size, flags) \
 190         __kmalloc_track_caller(size, flags, __builtin_return_address(0))
 191 #else
 192 #define kmalloc_track_caller(size, flags) \
 193         __kmalloc(size, flags)
 194 #endif /* DEBUG_SLAB */
 195
 196 #ifdef CONFIG_NUMA
 197 /*
 198  * kmalloc_node_track_caller is a special version of kmalloc_node that
 199  * records the calling function of the routine calling it for slab leak
 200  * tracking instead of just the calling function (confusing, eh?).
 201  * It's useful when the call to kmalloc_node comes from a widely-used
 202  * standard allocator where we care about the real place the memory
 203  * allocation request comes from.
 204  */
 205 #ifdef CONFIG_DEBUG_SLAB
 206 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
 207 #define kmalloc_node_track_caller(size, flags, node) \
 208         __kmalloc_node_track_caller(size, flags, node, \
 209                         __builtin_return_address(0))
 210 #else
 211 #define kmalloc_node_track_caller(size, flags, node) \
 212         __kmalloc_node(size, flags, node)
 213 #endif
 214
 215 #else /* CONFIG_NUMA */
 216
 217 #define kmalloc_node_track_caller(size, flags, node) \
 218         kmalloc_track_caller(size, flags)
 219
 220 #endif /* DEBUG_SLAB */
 221
 222 #endif  /* __KERNEL__ */
 223 #endif  /* _LINUX_SLAB_H */
 224