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
   8 struct kmem_cache {
   9 /* 1) Cache tunables. Protected by slab_mutex */
  10         unsigned int batchcount;
  11         unsigned int limit;
  12         unsigned int shared;
  13
  14         unsigned int size;
  15         u32 reciprocal_buffer_size;
  16 /* 2) touched by every alloc & free from the backend */
  17
  18         unsigned int flags;             /* constant flags */
  19         unsigned int num;               /* # of objs per slab */
  20
  21 /* 3) cache_grow/shrink */
  22         /* order of pgs per slab (2^n) */
  23         unsigned int gfporder;
  24
  25         /* force GFP flags, e.g. GFP_DMA */
  26         gfp_t allocflags;
  27
  28         size_t colour;                  /* cache colouring range */
  29         unsigned int colour_off;        /* colour offset */
  30         struct kmem_cache *freelist_cache;
  31         unsigned int freelist_size;
  32
  33         /* constructor func */
  34         void (*ctor)(void *obj);
  35
  36 /* 4) cache creation/removal */
  37         const char *name;
  38         struct list_head list;
  39         int refcount;
  40         int object_size;
  41         int align;
  42
  43 /* 5) statistics */
  44 #ifdef CONFIG_DEBUG_SLAB
  45         unsigned long num_active;
  46         unsigned long num_allocations;
  47         unsigned long high_mark;
  48         unsigned long grown;
  49         unsigned long reaped;
  50         unsigned long errors;
  51         unsigned long max_freeable;
  52         unsigned long node_allocs;
  53         unsigned long node_frees;
  54         unsigned long node_overflow;
  55         atomic_t allochit;
  56         atomic_t allocmiss;
  57         atomic_t freehit;
  58         atomic_t freemiss;
  59
  60         /*
  61          * If debugging is enabled, then the allocator can add additional
  62          * fields and/or padding to every object. size contains the total
  63          * object size including these internal fields, the following two
  64          * variables contain the offset to the user object and its size.
  65          */
  66         int obj_offset;
  67 #endif /* CONFIG_DEBUG_SLAB */
  68 #ifdef CONFIG_MEMCG_KMEM
  69         struct memcg_cache_params *memcg_params;
  70 #endif
  71
  72 /* 6) per-cpu/per-node data, touched during every alloc/free */
  73         /*
  74          * We put array[] at the end of kmem_cache, because we want to size
  75          * this array to nr_cpu_ids slots instead of NR_CPUS
  76          * (see kmem_cache_init())
  77          * We still use [NR_CPUS] and not [1] or [0] because cache_cache
  78          * is statically defined, so we reserve the max number of cpus.
  79          *
  80          * We also need to guarantee that the list is able to accomodate a
  81          * pointer for each node since "nodelists" uses the remainder of
  82          * available pointers.
  83          */
  84         struct kmem_cache_node **node;
  85         struct array_cache *array[NR_CPUS + MAX_NUMNODES];
  86         /*
  87          * Do not add fields after array[]
  88          */
  89 };
  90
  91 #endif  /* _LINUX_SLAB_DEF_H */