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, 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 kfree(const void *);
  76 unsigned int ksize(const void *);
  77
  78 /**
  79  * kcalloc - allocate memory for an array. The memory is set to zero.
  80  * @n: number of elements.
  81  * @size: element size.
  82  * @flags: the type of memory to allocate.
  83  */
  84 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
  85 {
  86         if (n != 0 && size > ULONG_MAX / n)
  87                 return NULL;
  88         return __kzalloc(n * size, flags);
  89 }
  90
  91 /*
  92  * Allocator specific definitions. These are mainly used to establish optimized
  93  * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting
  94  * the appropriate general cache at compile time.
  95  */
  96 #ifdef CONFIG_SLAB
  97 #include <linux/slab_def.h>
  98 #else
  99
 100 /*
 101  * Fallback definitions for an allocator not wanting to provide
 102  * its own optimized kmalloc definitions (like SLOB).
 103  */
 104
 105 #if defined(CONFIG_NUMA) || defined(CONFIG_DEBUG_SLAB)
 106 #error "SLAB fallback definitions not usable for NUMA or Slab debug"
 107 #endif
 108
 109 /**
 110  * kmalloc - allocate memory
 111  * @size: how many bytes of memory are required.
 112  * @flags: the type of memory to allocate.
 113  *
 114  * kmalloc is the normal method of allocating memory
 115  * in the kernel.
 116  *
 117  * The @flags argument may be one of:
 118  *
 119  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 120  *
 121  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 122  *
 123  * %GFP_ATOMIC - Allocation will not sleep.
 124  *   For example, use this inside interrupt handlers.
 125  *
 126  * %GFP_HIGHUSER - Allocate pages from high memory.
 127  *
 128  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
 129  *
 130  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
 131  *
 132  * Also it is possible to set different flags by OR'ing
 133  * in one or more of the following additional @flags:
 134  *
 135  * %__GFP_COLD - Request cache-cold pages instead of
 136  *   trying to return cache-warm pages.
 137  *
 138  * %__GFP_DMA - Request memory from the DMA-capable zone.
 139  *
 140  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
 141  *
 142  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
 143  *
 144  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
 145  *   (think twice before using).
 146  *
 147  * %__GFP_NORETRY - If memory is not immediately available,
 148  *   then give up at once.
 149  *
 150  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
 151  *
 152  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
 153  */
 154 void *kmalloc(size_t size, gfp_t flags)
 155 {
 156         return __kmalloc(size, flags);
 157 }
 158
 159 /**
 160  * kzalloc - allocate memory. The memory is set to zero.
 161  * @size: how many bytes of memory are required.
 162  * @flags: the type of memory to allocate (see kmalloc).
 163  */
 164 void *kzalloc(size_t size, gfp_t flags)
 165 {
 166         return __kzalloc(size, flags);
 167 }
 168 #endif
 169
 170 /*
 171  * kmalloc_track_caller is a special version of kmalloc that records the
 172  * calling function of the routine calling it for slab leak tracking instead
 173  * of just the calling function (confusing, eh?).
 174  * It's useful when the call to kmalloc comes from a widely-used standard
 175  * allocator where we care about the real place the memory allocation
 176  * request comes from.
 177  */
 178 #ifdef CONFIG_DEBUG_SLAB
 179 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
 180 #define kmalloc_track_caller(size, flags) \
 181         __kmalloc_track_caller(size, flags, __builtin_return_address(0))
 182 #else
 183 #define kmalloc_track_caller(size, flags) \
 184         __kmalloc(size, flags)
 185 #endif /* DEBUG_SLAB */
 186
 187 #ifdef CONFIG_NUMA
 188 /*
 189  * kmalloc_node_track_caller is a special version of kmalloc_node that
 190  * records the calling function of the routine calling it for slab leak
 191  * tracking instead of just the calling function (confusing, eh?).
 192  * It's useful when the call to kmalloc_node comes from a widely-used
 193  * standard allocator where we care about the real place the memory
 194  * allocation request comes from.
 195  */
 196 #ifdef CONFIG_DEBUG_SLAB
 197 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
 198 #define kmalloc_node_track_caller(size, flags, node) \
 199         __kmalloc_node_track_caller(size, flags, node, \
 200                         __builtin_return_address(0))
 201 #else
 202 #define kmalloc_node_track_caller(size, flags, node) \
 203         __kmalloc_node(size, flags, node)
 204 #endif
 205
 206 #else /* CONFIG_NUMA */
 207
 208 #define kmalloc_node_track_caller(size, flags, node) \
 209         kmalloc_track_caller(size, flags)
 210
 211 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 212 {
 213         return kmalloc(size, flags);
 214 }
 215
 216 #endif /* !CONFIG_NUMA */
 217 #endif  /* __KERNEL__ */
 218 #endif  /* _LINUX_SLAB_H */
 219