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 #include <linux/kmemtrace.h>
  18
  19 /*
  20  * struct kmem_cache
  21  *
  22  * manages a cache.
  23  */
  24
  25 struct kmem_cache {
  26 /* 1) per-cpu data, touched during every alloc/free */
  27         struct array_cache *array[NR_CPUS];
  28 /* 2) Cache tunables. Protected by cache_chain_mutex */
  29         unsigned int batchcount;
  30         unsigned int limit;
  31         unsigned int shared;
  32
  33         unsigned int buffer_size;
  34         u32 reciprocal_buffer_size;
  35 /* 3) touched by every alloc & free from the backend */
  36
  37         unsigned int flags;             /* constant flags */
  38         unsigned int num;               /* # of objs per slab */
  39
  40 /* 4) cache_grow/shrink */
  41         /* order of pgs per slab (2^n) */
  42         unsigned int gfporder;
  43
  44         /* force GFP flags, e.g. GFP_DMA */
  45         gfp_t gfpflags;
  46
  47         size_t colour;                  /* cache colouring range */
  48         unsigned int colour_off;        /* colour offset */
  49         struct kmem_cache *slabp_cache;
  50         unsigned int slab_size;
  51         unsigned int dflags;            /* dynamic flags */
  52
  53         /* constructor func */
  54         void (*ctor)(void *obj);
  55
  56 /* 5) cache creation/removal */
  57         const char *name;
  58         struct list_head next;
  59
  60 /* 6) 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. buffer_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         int obj_size;
  85 #endif /* CONFIG_DEBUG_SLAB */
  86
  87         /*
  88          * We put nodelists[] at the end of kmem_cache, because we want to size
  89          * this array to nr_node_ids slots instead of MAX_NUMNODES
  90          * (see kmem_cache_init())
  91          * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
  92          * is statically defined, so we reserve the max number of nodes.
  93          */
  94         struct kmem_list3 *nodelists[MAX_NUMNODES];
  95         /*
  96          * Do not add fields after nodelists[]
  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_notrace(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_notrace(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_notrace(cachep, flags);
 156
 157                 trace_kmalloc(_THIS_IP_, ret,
 158                               size, slab_buffer_size(cachep), flags);
 159
 160                 return ret;
 161         }
 162         return __kmalloc(size, flags);
 163 }
 164
 165 #ifdef CONFIG_NUMA
 166 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
 167 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 168
 169 #ifdef CONFIG_TRACING
 170 extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *cachep,
 171                                            gfp_t flags,
 172                                            int nodeid);
 173 #else
 174 static __always_inline void *
 175 kmem_cache_alloc_node_notrace(struct kmem_cache *cachep,
 176                               gfp_t flags,
 177                               int nodeid)
 178 {
 179         return kmem_cache_alloc_node(cachep, flags, nodeid);
 180 }
 181 #endif
 182
 183 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 184 {
 185         struct kmem_cache *cachep;
 186         void *ret;
 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                 ret = kmem_cache_alloc_node_notrace(cachep, flags, node);
 211
 212                 trace_kmalloc_node(_THIS_IP_, ret,
 213                                    size, slab_buffer_size(cachep),
 214                                    flags, node);
 215
 216                 return ret;
 217         }
 218         return __kmalloc_node(size, flags, node);
 219 }
 220
 221 #endif  /* CONFIG_NUMA */
 222
 223 #endif  /* _LINUX_SLAB_DEF_H */