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 buffer_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 gfpflags;
  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         unsigned int dflags;            /* dynamic flags */
  49
  50         /* constructor func */
  51         void (*ctor)(void *obj);
  52
  53 /* 4) cache creation/removal */
  54         const char *name;
  55         struct list_head next;
  56
  57 /* 5) statistics */
  58 #ifdef CONFIG_DEBUG_SLAB
  59         unsigned long num_active;
  60         unsigned long num_allocations;
  61         unsigned long high_mark;
  62         unsigned long grown;
  63         unsigned long reaped;
  64         unsigned long errors;
  65         unsigned long max_freeable;
  66         unsigned long node_allocs;
  67         unsigned long node_frees;
  68         unsigned long node_overflow;
  69         atomic_t allochit;
  70         atomic_t allocmiss;
  71         atomic_t freehit;
  72         atomic_t freemiss;
  73
  74         /*
  75          * If debugging is enabled, then the allocator can add additional
  76          * fields and/or padding to every object. buffer_size contains the total
  77          * object size including these internal fields, the following two
  78          * variables contain the offset to the user object and its size.
  79          */
  80         int obj_offset;
  81         int obj_size;
  82 #endif /* CONFIG_DEBUG_SLAB */
  83
  84 /* 6) per-cpu/per-node data, touched during every alloc/free */
  85         /*
  86          * We put array[] at the end of kmem_cache, because we want to size
  87          * this array to nr_cpu_ids slots instead of NR_CPUS
  88          * (see kmem_cache_init())
  89          * We still use [NR_CPUS] and not [1] or [0] because cache_cache
  90          * is statically defined, so we reserve the max number of cpus.
  91          */
  92         struct kmem_list3 **nodelists;
  93         struct array_cache *array[NR_CPUS];
  94         /*
  95          * Do not add fields after array[]
  96          */
  97 };
  98
  99 /* Size description struct for general caches. */
 100 struct cache_sizes {
 101         size_t                  cs_size;
 102         struct kmem_cache       *cs_cachep;
 103 #ifdef CONFIG_ZONE_DMA
 104         struct kmem_cache       *cs_dmacachep;
 105 #endif
 106 };
 107 extern struct cache_sizes malloc_sizes[];
 108
 109 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 110 void *__kmalloc(size_t size, gfp_t flags);
 111
 112 #ifdef CONFIG_TRACING
 113 extern void *kmem_cache_alloc_trace(size_t size,
 114                                     struct kmem_cache *cachep, gfp_t flags);
 115 extern size_t slab_buffer_size(struct kmem_cache *cachep);
 116 #else
 117 static __always_inline void *
 118 kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags)
 119 {
 120         return kmem_cache_alloc(cachep, flags);
 121 }
 122 static inline size_t slab_buffer_size(struct kmem_cache *cachep)
 123 {
 124         return 0;
 125 }
 126 #endif
 127
 128 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 129 {
 130         struct kmem_cache *cachep;
 131         void *ret;
 132
 133         if (__builtin_constant_p(size)) {
 134                 int i = 0;
 135
 136                 if (!size)
 137                         return ZERO_SIZE_PTR;
 138
 139 #define CACHE(x) \
 140                 if (size <= x) \
 141                         goto found; \
 142                 else \
 143                         i++;
 144 #include <linux/kmalloc_sizes.h>
 145 #undef CACHE
 146                 return NULL;
 147 found:
 148 #ifdef CONFIG_ZONE_DMA
 149                 if (flags & GFP_DMA)
 150                         cachep = malloc_sizes[i].cs_dmacachep;
 151                 else
 152 #endif
 153                         cachep = malloc_sizes[i].cs_cachep;
 154
 155                 ret = kmem_cache_alloc_trace(size, cachep, flags);
 156
 157                 return ret;
 158         }
 159         return __kmalloc(size, flags);
 160 }
 161
 162 #ifdef CONFIG_NUMA
 163 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
 164 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 165
 166 #ifdef CONFIG_TRACING
 167 extern void *kmem_cache_alloc_node_trace(size_t size,
 168                                          struct kmem_cache *cachep,
 169                                          gfp_t flags,
 170                                          int nodeid);
 171 #else
 172 static __always_inline void *
 173 kmem_cache_alloc_node_trace(size_t size,
 174                             struct kmem_cache *cachep,
 175                             gfp_t flags,
 176                             int nodeid)
 177 {
 178         return kmem_cache_alloc_node(cachep, flags, nodeid);
 179 }
 180 #endif
 181
 182 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 183 {
 184         struct kmem_cache *cachep;
 185
 186         if (__builtin_constant_p(size)) {
 187                 int i = 0;
 188
 189                 if (!size)
 190                         return ZERO_SIZE_PTR;
 191
 192 #define CACHE(x) \
 193                 if (size <= x) \
 194                         goto found; \
 195                 else \
 196                         i++;
 197 #include <linux/kmalloc_sizes.h>
 198 #undef CACHE
 199                 return NULL;
 200 found:
 201 #ifdef CONFIG_ZONE_DMA
 202                 if (flags & GFP_DMA)
 203                         cachep = malloc_sizes[i].cs_dmacachep;
 204                 else
 205 #endif
 206                         cachep = malloc_sizes[i].cs_cachep;
 207
 208                 return kmem_cache_alloc_node_trace(size, cachep, flags, node);
 209         }
 210         return __kmalloc_node(size, flags, node);
 211 }
 212
 213 #endif  /* CONFIG_NUMA */
 214
 215 #endif  /* _LINUX_SLAB_DEF_H */