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 /* 1) Cache tunables. Protected by slab_mutex */
  12         unsigned int batchcount;
  13         unsigned int limit;
  14         unsigned int shared;
  15
  16         unsigned int size;
  17         struct reciprocal_value reciprocal_buffer_size;
  18 /* 2) touched by every alloc & free from the backend */
  19
  20         unsigned int flags;             /* constant flags */
  21         unsigned int num;               /* # of objs per slab */
  22
  23 /* 3) cache_grow/shrink */
  24         /* order of pgs per slab (2^n) */
  25         unsigned int gfporder;
  26
  27         /* force GFP flags, e.g. GFP_DMA */
  28         gfp_t allocflags;
  29
  30         size_t colour;                  /* cache colouring range */
  31         unsigned int colour_off;        /* colour offset */
  32         struct kmem_cache *freelist_cache;
  33         unsigned int freelist_size;
  34
  35         /* constructor func */
  36         void (*ctor)(void *obj);
  37
  38 /* 4) cache creation/removal */
  39         const char *name;
  40         struct list_head list;
  41         int refcount;
  42         int object_size;
  43         int align;
  44
  45 /* 5) statistics */
  46 #ifdef CONFIG_DEBUG_SLAB
  47         unsigned long num_active;
  48         unsigned long num_allocations;
  49         unsigned long high_mark;
  50         unsigned long grown;
  51         unsigned long reaped;
  52         unsigned long errors;
  53         unsigned long max_freeable;
  54         unsigned long node_allocs;
  55         unsigned long node_frees;
  56         unsigned long node_overflow;
  57         atomic_t allochit;
  58         atomic_t allocmiss;
  59         atomic_t freehit;
  60         atomic_t freemiss;
  61
  62         /*
  63          * If debugging is enabled, then the allocator can add additional
  64          * fields and/or padding to every object. size contains the total
  65          * object size including these internal fields, the following two
  66          * variables contain the offset to the user object and its size.
  67          */
  68         int obj_offset;
  69 #endif /* CONFIG_DEBUG_SLAB */
  70 #ifdef CONFIG_MEMCG_KMEM
  71         struct memcg_cache_params *memcg_params;
  72 #endif
  73
  74 /* 6) per-cpu/per-node data, touched during every alloc/free */
  75         /*
  76          * We put array[] at the end of kmem_cache, because we want to size
  77          * this array to nr_cpu_ids slots instead of NR_CPUS
  78          * (see kmem_cache_init())
  79          * We still use [NR_CPUS] and not [1] or [0] because cache_cache
  80          * is statically defined, so we reserve the max number of cpus.
  81          *
  82          * We also need to guarantee that the list is able to accomodate a
  83          * pointer for each node since "nodelists" uses the remainder of
  84          * available pointers.
  85          */
  86         struct kmem_cache_node **node;
  87         struct array_cache *array[NR_CPUS + MAX_NUMNODES];
  88         /*
  89          * Do not add fields after array[]
  90          */
  91 };
  92
  93 #endif  /* _LINUX_SLAB_DEF_H */