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         struct kmem_list3 **nodelists;
  94         struct array_cache *array[NR_CPUS];
  95         /*
  96          * Do not add fields after array[]
  97          */
  98 };
  99
 100 /* Size description struct for general caches. */
 101 struct cache_sizes {
 102         size_t                  cs_size;
 103         struct kmem_cache       *cs_cachep;
 104 #ifdef CONFIG_ZONE_DMA
 105         struct kmem_cache       *cs_dmacachep;
 106 #endif
 107 };
 108 extern struct cache_sizes malloc_sizes[];
 109
 110 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 111 void *__kmalloc(size_t size, gfp_t flags);
 112
 113 #ifdef CONFIG_TRACING
 114 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t);
 115 #else
 116 static __always_inline void *
 117 kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
 118 {
 119         return kmem_cache_alloc(cachep, flags);
 120 }
 121 #endif
 122
 123 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 124 {
 125         struct kmem_cache *cachep;
 126         void *ret;
 127
 128         if (__builtin_constant_p(size)) {
 129                 int i = 0;
 130
 131                 if (!size)
 132                         return ZERO_SIZE_PTR;
 133
 134 #define CACHE(x) \
 135                 if (size <= x) \
 136                         goto found; \
 137                 else \
 138                         i++;
 139 #include <linux/kmalloc_sizes.h>
 140 #undef CACHE
 141                 return NULL;
 142 found:
 143 #ifdef CONFIG_ZONE_DMA
 144                 if (flags & GFP_DMA)
 145                         cachep = malloc_sizes[i].cs_dmacachep;
 146                 else
 147 #endif
 148                         cachep = malloc_sizes[i].cs_cachep;
 149
 150                 ret = kmem_cache_alloc_trace(cachep, flags, size);
 151
 152                 return ret;
 153         }
 154         return __kmalloc(size, flags);
 155 }
 156
 157 #ifdef CONFIG_NUMA
 158 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
 159 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 160
 161 #ifdef CONFIG_TRACING
 162 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
 163                                          gfp_t flags,
 164                                          int nodeid,
 165                                          size_t size);
 166 #else
 167 static __always_inline void *
 168 kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
 169                             gfp_t flags,
 170                             int nodeid,
 171                             size_t size)
 172 {
 173         return kmem_cache_alloc_node(cachep, flags, nodeid);
 174 }
 175 #endif
 176
 177 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 178 {
 179         struct kmem_cache *cachep;
 180
 181         if (__builtin_constant_p(size)) {
 182                 int i = 0;
 183
 184                 if (!size)
 185                         return ZERO_SIZE_PTR;
 186
 187 #define CACHE(x) \
 188                 if (size <= x) \
 189                         goto found; \
 190                 else \
 191                         i++;
 192 #include <linux/kmalloc_sizes.h>
 193 #undef CACHE
 194                 return NULL;
 195 found:
 196 #ifdef CONFIG_ZONE_DMA
 197                 if (flags & GFP_DMA)
 198                         cachep = malloc_sizes[i].cs_dmacachep;
 199                 else
 200 #endif
 201                         cachep = malloc_sizes[i].cs_cachep;
 202
 203                 return kmem_cache_alloc_node_trace(cachep, flags, node, size);
 204         }
 205         return __kmalloc_node(size, flags, node);
 206 }
 207
 208 #endif  /* CONFIG_NUMA */
 209
 210 #endif  /* _LINUX_SLAB_DEF_H */