include/linux/slab_def.h

   1 #ifndef _LINUX_SLAB_DEF_H
   2 #define _LINUX_SLAB_DEF_H
   3
   4 /*
   5  * Definitions unique to the original Linux SLAB allocator.
   6  *
   7  * What we provide here is a way to optimize the frequent kmalloc
   8  * calls in the kernel by selecting the appropriate general cache
   9  * if kmalloc was called with a size that can be established at
  10  * compile time.
  11  */
  12
  13 #include <linux/init.h>
  14 #include <asm/page.h>           /* kmalloc_sizes.h needs PAGE_SIZE */
  15 #include <asm/cache.h>          /* kmalloc_sizes.h needs L1_CACHE_BYTES */
  16 #include <linux/compiler.h>
  17
  18 /*
  19  * struct kmem_cache
  20  *
  21  * manages a cache.
  22  */
  23
  24 struct kmem_cache {
  25 /* 1) Cache tunables. Protected by cache_chain_mutex */
  26         unsigned int batchcount;
  27         unsigned int limit;
  28         unsigned int shared;
  29
  30         unsigned int size;
  31         u32 reciprocal_buffer_size;
  32 /* 2) touched by every alloc & free from the backend */
  33
  34         unsigned int flags;             /* constant flags */
  35         unsigned int num;               /* # of objs per slab */
  36
  37 /* 3) cache_grow/shrink */
  38         /* order of pgs per slab (2^n) */
  39         unsigned int gfporder;
  40
  41         /* force GFP flags, e.g. GFP_DMA */
  42         gfp_t allocflags;
  43
  44         size_t colour;                  /* cache colouring range */
  45         unsigned int colour_off;        /* colour offset */
  46         struct kmem_cache *slabp_cache;
  47         unsigned int slab_size;
  48
  49         /* constructor func */
  50         void (*ctor)(void *obj);
  51
  52 /* 4) cache creation/removal */
  53         const char *name;
  54         struct list_head list;
  55         int refcount;
  56         int object_size;
  57         int align;
  58
  59 /* 5) statistics */
  60 #ifdef CONFIG_DEBUG_SLAB
  61         unsigned long num_active;
  62         unsigned long num_allocations;
  63         unsigned long high_mark;
  64         unsigned long grown;
  65         unsigned long reaped;
  66         unsigned long errors;
  67         unsigned long max_freeable;
  68         unsigned long node_allocs;
  69         unsigned long node_frees;
  70         unsigned long node_overflow;
  71         atomic_t allochit;
  72         atomic_t allocmiss;
  73         atomic_t freehit;
  74         atomic_t freemiss;
  75
  76         /*
  77          * If debugging is enabled, then the allocator can add additional
  78          * fields and/or padding to every object. size contains the total
  79          * object size including these internal fields, the following two
  80          * variables contain the offset to the user object and its size.
  81          */
  82         int obj_offset;
  83 #endif /* CONFIG_DEBUG_SLAB */
  84
  85 /* 6) per-cpu/per-node data, touched during every alloc/free */
  86         /*
  87          * We put array[] at the end of kmem_cache, because we want to size
  88          * this array to nr_cpu_ids slots instead of NR_CPUS
  89          * (see kmem_cache_init())
  90          * We still use [NR_CPUS] and not [1] or [0] because cache_cache
  91          * is statically defined, so we reserve the max number of cpus.
  92          *
  93          * We also need to guarantee that the list is able to accomodate a
  94          * pointer for each node since "nodelists" uses the remainder of
  95          * available pointers.
  96          */
  97         struct kmem_list3 **nodelists;
  98         struct array_cache *array[NR_CPUS + MAX_NUMNODES];
  99         /*
 100          * Do not add fields after array[]
 101          */
 102 };
 103
 104 /* Size description struct for general caches. */
 105 struct cache_sizes {
 106         size_t                  cs_size;
 107         struct kmem_cache       *cs_cachep;
 108 #ifdef CONFIG_ZONE_DMA
 109         struct kmem_cache       *cs_dmacachep;
 110 #endif
 111 };
 112 extern struct cache_sizes malloc_sizes[];
 113
 114 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 115 void *__kmalloc(size_t size, gfp_t flags);
 116
 117 #ifdef CONFIG_TRACING
 118 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t);
 119 #else
 120 static __always_inline void *
 121 kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
 122 {
 123         return kmem_cache_alloc(cachep, flags);
 124 }
 125 #endif
 126
 127 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 128 {
 129         struct kmem_cache *cachep;
 130         void *ret;
 131
 132         if (__builtin_constant_p(size)) {
 133                 int i = 0;
 134
 135                 if (!size)
 136                         return ZERO_SIZE_PTR;
 137
 138 #define CACHE(x) \
 139                 if (size <= x) \
 140                         goto found; \
 141                 else \
 142                         i++;
 143 #include <linux/kmalloc_sizes.h>
 144 #undef CACHE
 145                 return NULL;
 146 found:
 147 #ifdef CONFIG_ZONE_DMA
 148                 if (flags & GFP_DMA)
 149                         cachep = malloc_sizes[i].cs_dmacachep;
 150                 else
 151 #endif
 152                         cachep = malloc_sizes[i].cs_cachep;
 153
 154                 ret = kmem_cache_alloc_trace(cachep, flags, size);
 155
 156                 return ret;
 157         }
 158         return __kmalloc(size, flags);
 159 }
 160
 161 #ifdef CONFIG_NUMA
 162 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
 163 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 164
 165 #ifdef CONFIG_TRACING
 166 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
 167                                          gfp_t flags,
 168                                          int nodeid,
 169                                          size_t size);
 170 #else
 171 static __always_inline void *
 172 kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
 173                             gfp_t flags,
 174                             int nodeid,
 175                             size_t size)
 176 {
 177         return kmem_cache_alloc_node(cachep, flags, nodeid);
 178 }
 179 #endif
 180
 181 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 182 {
 183         struct kmem_cache *cachep;
 184
 185         if (__builtin_constant_p(size)) {
 186                 int i = 0;
 187
 188                 if (!size)
 189                         return ZERO_SIZE_PTR;
 190
 191 #define CACHE(x) \
 192                 if (size <= x) \
 193                         goto found; \
 194                 else \
 195                         i++;
 196 #include <linux/kmalloc_sizes.h>
 197 #undef CACHE
 198                 return NULL;
 199 found:
 200 #ifdef CONFIG_ZONE_DMA
 201                 if (flags & GFP_DMA)
 202                         cachep = malloc_sizes[i].cs_dmacachep;
 203                 else
 204 #endif
 205                         cachep = malloc_sizes[i].cs_cachep;
 206
 207                 return kmem_cache_alloc_node_trace(cachep, flags, node, size);
 208         }
 209         return __kmalloc_node(size, flags, node);
 210 }
 211
 212 #endif  /* CONFIG_NUMA */
 213
 214 #endif  /* _LINUX_SLAB_DEF_H */