include/linux/slab_def.h

   1 #ifndef _LINUX_SLAB_DEF_H
   2 #define _LINUX_SLAB_DEF_H
   3
   4 #include <linux/reciprocal_div.h>
   5
   6 /*
   7  * Definitions unique to the original Linux SLAB allocator.
   8  */
   9
  10 struct kmem_cache {
  11         struct array_cache __percpu *cpu_cache;
  12
  13 /* 1) Cache tunables. Protected by slab_mutex */
  14         unsigned int batchcount;
  15         unsigned int limit;
  16         unsigned int shared;
  17
  18         unsigned int size;
  19         struct reciprocal_value reciprocal_buffer_size;
  20 /* 2) touched by every alloc & free from the backend */
  21
  22         unsigned int flags;             /* constant flags */
  23         unsigned int num;               /* # of objs per slab */
  24
  25 /* 3) cache_grow/shrink */
  26         /* order of pgs per slab (2^n) */
  27         unsigned int gfporder;
  28
  29         /* force GFP flags, e.g. GFP_DMA */
  30         gfp_t allocflags;
  31
  32         size_t colour;                  /* cache colouring range */
  33         unsigned int colour_off;        /* colour offset */
  34         struct kmem_cache *freelist_cache;
  35         unsigned int freelist_size;
  36
  37         /* constructor func */
  38         void (*ctor)(void *obj);
  39
  40 /* 4) cache creation/removal */
  41         const char *name;
  42         struct list_head list;
  43         int refcount;
  44         int object_size;
  45         int align;
  46
  47 /* 5) statistics */
  48 #ifdef CONFIG_DEBUG_SLAB
  49         unsigned long num_active;
  50         unsigned long num_allocations;
  51         unsigned long high_mark;
  52         unsigned long grown;
  53         unsigned long reaped;
  54         unsigned long errors;
  55         unsigned long max_freeable;
  56         unsigned long node_allocs;
  57         unsigned long node_frees;
  58         unsigned long node_overflow;
  59         atomic_t allochit;
  60         atomic_t allocmiss;
  61         atomic_t freehit;
  62         atomic_t freemiss;
  63 #ifdef CONFIG_DEBUG_SLAB_LEAK
  64         atomic_t store_user_clean;
  65 #endif
  66
  67         /*
  68          * If debugging is enabled, then the allocator can add additional
  69          * fields and/or padding to every object. size contains the total
  70          * object size including these internal fields, the following two
  71          * variables contain the offset to the user object and its size.
  72          */
  73         int obj_offset;
  74 #endif /* CONFIG_DEBUG_SLAB */
  75
  76 #ifdef CONFIG_MEMCG
  77         struct memcg_cache_params memcg_params;
  78 #endif
  79 #ifdef CONFIG_KASAN
  80         struct kasan_cache kasan_info;
  81 #endif
  82
  83 #ifdef CONFIG_SLAB_FREELIST_RANDOM
  84         unsigned int *random_seq;
  85 #endif
  86
  87         struct kmem_cache_node *node[MAX_NUMNODES];
  88 };
  89
  90 static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
  91                                 void *x)
  92 {
  93         void *object = x - (x - page->s_mem) % cache->size;
  94         void *last_object = page->s_mem + (cache->num - 1) * cache->size;
  95
  96         if (unlikely(object > last_object))
  97                 return last_object;
  98         else
  99                 return object;
 100 }
 101
 102 #endif  /* _LINUX_SLAB_DEF_H */