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         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 list;
  56         int refcount;
  57         int object_size;
  58         int align;
  59
  60 /* 5) statistics */
  61 #ifdef CONFIG_DEBUG_SLAB
  62         unsigned long num_active;
  63         unsigned long num_allocations;
  64         unsigned long high_mark;
  65         unsigned long grown;
  66         unsigned long reaped;
  67         unsigned long errors;
  68         unsigned long max_freeable;
  69         unsigned long node_allocs;
  70         unsigned long node_frees;
  71         unsigned long node_overflow;
  72         atomic_t allochit;
  73         atomic_t allocmiss;
  74         atomic_t freehit;
  75         atomic_t freemiss;
  76
  77         /*
  78          * If debugging is enabled, then the allocator can add additional
  79          * fields and/or padding to every object. size contains the total
  80          * object size including these internal fields, the following two
  81          * variables contain the offset to the user object and its size.
  82          */
  83         int obj_offset;
  84 #endif /* CONFIG_DEBUG_SLAB */
  85
  86 /* 6) per-cpu/per-node data, touched during every alloc/free */
  87         /*
  88          * We put array[] at the end of kmem_cache, because we want to size
  89          * this array to nr_cpu_ids slots instead of NR_CPUS
  90          * (see kmem_cache_init())
  91          * We still use [NR_CPUS] and not [1] or [0] because cache_cache
  92          * is statically defined, so we reserve the max number of cpus.
  93          */
  94         struct kmem_list3 **nodelists;
  95         struct array_cache *array[NR_CPUS];
  96         /*
  97          * Do not add fields after array[]
  98          */
  99 };
 100
 101 /* Size description struct for general caches. */
 102 struct cache_sizes {
 103         size_t                  cs_size;
 104         struct kmem_cache       *cs_cachep;
 105 #ifdef CONFIG_ZONE_DMA
 106         struct kmem_cache       *cs_dmacachep;
 107 #endif
 108 };
 109 extern struct cache_sizes malloc_sizes[];
 110
 111 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 112 void *__kmalloc(size_t size, gfp_t flags);
 113
 114 #ifdef CONFIG_TRACING
 115 extern void *kmem_cache_alloc_trace(size_t size,
 116                                     struct kmem_cache *cachep, gfp_t flags);
 117 extern size_t slab_buffer_size(struct kmem_cache *cachep);
 118 #else
 119 static __always_inline void *
 120 kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags)
 121 {
 122         return kmem_cache_alloc(cachep, flags);
 123 }
 124 static inline size_t slab_buffer_size(struct kmem_cache *cachep)
 125 {
 126         return 0;
 127 }
 128 #endif
 129
 130 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 131 {
 132         struct kmem_cache *cachep;
 133         void *ret;
 134
 135         if (__builtin_constant_p(size)) {
 136                 int i = 0;
 137
 138                 if (!size)
 139                         return ZERO_SIZE_PTR;
 140
 141 #define CACHE(x) \
 142                 if (size <= x) \
 143                         goto found; \
 144                 else \
 145                         i++;
 146 #include <linux/kmalloc_sizes.h>
 147 #undef CACHE
 148                 return NULL;
 149 found:
 150 #ifdef CONFIG_ZONE_DMA
 151                 if (flags & GFP_DMA)
 152                         cachep = malloc_sizes[i].cs_dmacachep;
 153                 else
 154 #endif
 155                         cachep = malloc_sizes[i].cs_cachep;
 156
 157                 ret = kmem_cache_alloc_trace(size, cachep, flags);
 158
 159                 return ret;
 160         }
 161         return __kmalloc(size, flags);
 162 }
 163
 164 #ifdef CONFIG_NUMA
 165 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
 166 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 167
 168 #ifdef CONFIG_TRACING
 169 extern void *kmem_cache_alloc_node_trace(size_t size,
 170                                          struct kmem_cache *cachep,
 171                                          gfp_t flags,
 172                                          int nodeid);
 173 #else
 174 static __always_inline void *
 175 kmem_cache_alloc_node_trace(size_t size,
 176                             struct kmem_cache *cachep,
 177                             gfp_t flags,
 178                             int nodeid)
 179 {
 180         return kmem_cache_alloc_node(cachep, flags, nodeid);
 181 }
 182 #endif
 183
 184 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 185 {
 186         struct kmem_cache *cachep;
 187
 188         if (__builtin_constant_p(size)) {
 189                 int i = 0;
 190
 191                 if (!size)
 192                         return ZERO_SIZE_PTR;
 193
 194 #define CACHE(x) \
 195                 if (size <= x) \
 196                         goto found; \
 197                 else \
 198                         i++;
 199 #include <linux/kmalloc_sizes.h>
 200 #undef CACHE
 201                 return NULL;
 202 found:
 203 #ifdef CONFIG_ZONE_DMA
 204                 if (flags & GFP_DMA)
 205                         cachep = malloc_sizes[i].cs_dmacachep;
 206                 else
 207 #endif
 208                         cachep = malloc_sizes[i].cs_cachep;
 209
 210                 return kmem_cache_alloc_node_trace(size, cachep, flags, node);
 211         }
 212         return __kmalloc_node(size, flags, node);
 213 }
 214
 215 #endif  /* CONFIG_NUMA */
 216
 217 #endif  /* _LINUX_SLAB_DEF_H */