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 /* Flags passed to a constructor functions */
  36 #define SLAB_CTOR_CONSTRUCTOR   0x001UL         /* If not set, then deconstructor */
  37
  38 /*
  39  * struct kmem_cache related prototypes
  40  */
  41 void __init kmem_cache_init(void);
  42 int slab_is_available(void);
  43
  44 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
  45                         unsigned long,
  46                         void (*)(void *, struct kmem_cache *, unsigned long),
  47                         void (*)(void *, struct kmem_cache *, unsigned long));
  48 void kmem_cache_destroy(struct kmem_cache *);
  49 int kmem_cache_shrink(struct kmem_cache *);
  50 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
  51 void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
  52 void kmem_cache_free(struct kmem_cache *, void *);
  53 unsigned int kmem_cache_size(struct kmem_cache *);
  54 const char *kmem_cache_name(struct kmem_cache *);
  55 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr);
  56
  57 /*
  58  * Please use this macro to create slab caches. Simply specify the
  59  * name of the structure and maybe some flags that are listed above.
  60  *
  61  * The alignment of the struct determines object alignment. If you
  62  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
  63  * then the objects will be properly aligned in SMP configurations.
  64  */
  65 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
  66                 sizeof(struct __struct), __alignof__(struct __struct),\
  67                 (__flags), NULL, NULL)
  68
  69 #ifdef CONFIG_NUMA
  70 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
  71 #else
  72 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
  73                                         gfp_t flags, int node)
  74 {
  75         return kmem_cache_alloc(cachep, flags);
  76 }
  77 #endif
  78
  79 /*
  80  * Common kmalloc functions provided by all allocators
  81  */
  82 void *__kmalloc(size_t, gfp_t);
  83 void *__kzalloc(size_t, gfp_t);
  84 void * __must_check krealloc(const void *, size_t, gfp_t);
  85 void kfree(const void *);
  86 size_t ksize(const void *);
  87
  88 /**
  89  * kcalloc - allocate memory for an array. The memory is set to zero.
  90  * @n: number of elements.
  91  * @size: element size.
  92  * @flags: the type of memory to allocate.
  93  */
  94 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
  95 {
  96         if (n != 0 && size > ULONG_MAX / n)
  97                 return NULL;
  98         return __kzalloc(n * size, flags);
  99 }
 100
 101 /*
 102  * Allocator specific definitions. These are mainly used to establish optimized
 103  * ways to convert kmalloc() calls to kmem_cache_alloc() invocations by selecting
 104  * the appropriate general cache at compile time.
 105  */
 106
 107 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB)
 108 #ifdef CONFIG_SLUB
 109 #include <linux/slub_def.h>
 110 #else
 111 #include <linux/slab_def.h>
 112 #endif /* !CONFIG_SLUB */
 113 #else
 114
 115 /*
 116  * Fallback definitions for an allocator not wanting to provide
 117  * its own optimized kmalloc definitions (like SLOB).
 118  */
 119
 120 /**
 121  * kmalloc - allocate memory
 122  * @size: how many bytes of memory are required.
 123  * @flags: the type of memory to allocate.
 124  *
 125  * kmalloc is the normal method of allocating memory
 126  * in the kernel.
 127  *
 128  * The @flags argument may be one of:
 129  *
 130  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
 131  *
 132  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
 133  *
 134  * %GFP_ATOMIC - Allocation will not sleep.
 135  *   For example, use this inside interrupt handlers.
 136  *
 137  * %GFP_HIGHUSER - Allocate pages from high memory.
 138  *
 139  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
 140  *
 141  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
 142  *
 143  * Also it is possible to set different flags by OR'ing
 144  * in one or more of the following additional @flags:
 145  *
 146  * %__GFP_COLD - Request cache-cold pages instead of
 147  *   trying to return cache-warm pages.
 148  *
 149  * %__GFP_DMA - Request memory from the DMA-capable zone.
 150  *
 151  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
 152  *
 153  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
 154  *
 155  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
 156  *   (think twice before using).
 157  *
 158  * %__GFP_NORETRY - If memory is not immediately available,
 159  *   then give up at once.
 160  *
 161  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
 162  *
 163  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
 164  */
 165 static inline void *kmalloc(size_t size, gfp_t flags)
 166 {
 167         return __kmalloc(size, flags);
 168 }
 169
 170 /**
 171  * kzalloc - allocate memory. The memory is set to zero.
 172  * @size: how many bytes of memory are required.
 173  * @flags: the type of memory to allocate (see kmalloc).
 174  */
 175 static inline void *kzalloc(size_t size, gfp_t flags)
 176 {
 177         return __kzalloc(size, flags);
 178 }
 179 #endif
 180
 181 #ifndef CONFIG_NUMA
 182 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 183 {
 184         return kmalloc(size, flags);
 185 }
 186
 187 static inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
 188 {
 189         return __kmalloc(size, flags);
 190 }
 191 #endif /* !CONFIG_NUMA */
 192
 193 /*
 194  * kmalloc_track_caller is a special version of kmalloc that records the
 195  * calling function of the routine calling it for slab leak tracking instead
 196  * of just the calling function (confusing, eh?).
 197  * It's useful when the call to kmalloc comes from a widely-used standard
 198  * allocator where we care about the real place the memory allocation
 199  * request comes from.
 200  */
 201 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
 202 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
 203 #define kmalloc_track_caller(size, flags) \
 204         __kmalloc_track_caller(size, flags, __builtin_return_address(0))
 205 #else
 206 #define kmalloc_track_caller(size, flags) \
 207         __kmalloc(size, flags)
 208 #endif /* DEBUG_SLAB */
 209
 210 #ifdef CONFIG_NUMA
 211 /*
 212  * kmalloc_node_track_caller is a special version of kmalloc_node that
 213  * records the calling function of the routine calling it for slab leak
 214  * tracking instead of just the calling function (confusing, eh?).
 215  * It's useful when the call to kmalloc_node comes from a widely-used
 216  * standard allocator where we care about the real place the memory
 217  * allocation request comes from.
 218  */
 219 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB)
 220 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
 221 #define kmalloc_node_track_caller(size, flags, node) \
 222         __kmalloc_node_track_caller(size, flags, node, \
 223                         __builtin_return_address(0))
 224 #else
 225 #define kmalloc_node_track_caller(size, flags, node) \
 226         __kmalloc_node(size, flags, node)
 227 #endif
 228
 229 #else /* CONFIG_NUMA */
 230
 231 #define kmalloc_node_track_caller(size, flags, node) \
 232         kmalloc_track_caller(size, flags)
 233
 234 #endif /* DEBUG_SLAB */
 235
 236 extern const struct seq_operations slabinfo_op;
 237 ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
 238
 239 #endif  /* __KERNEL__ */
 240 #endif  /* _LINUX_SLAB_H */
 241