include/linux/slab_def.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_SLAB_DEF_H
   3 #define _LINUX_SLAB_DEF_H
   4
   5 #include <linux/reciprocal_div.h>
   6
   7 /*
   8  * Definitions unique to the original Linux SLAB allocator.
   9  */
  10
  11 struct kmem_cache {
  12         struct array_cache __percpu *cpu_cache;
  13
  14 /* 1) Cache tunables. Protected by slab_mutex */
  15         unsigned int batchcount;
  16         unsigned int limit;
  17         unsigned int shared;
  18
  19         unsigned int size;
  20         struct reciprocal_value reciprocal_buffer_size;
  21 /* 2) touched by every alloc & free from the backend */
  22
  23         slab_flags_t flags;             /* constant flags */
  24         unsigned int num;               /* # of objs per slab */
  25
  26 /* 3) cache_grow/shrink */
  27         /* order of pgs per slab (2^n) */
  28         unsigned int gfporder;
  29
  30         /* force GFP flags, e.g. GFP_DMA */
  31         gfp_t allocflags;
  32
  33         size_t colour;                  /* cache colouring range */
  34         unsigned int colour_off;        /* colour offset */
  35         struct kmem_cache *freelist_cache;
  36         unsigned int freelist_size;
  37
  38         /* constructor func */
  39         void (*ctor)(void *obj);
  40
  41 /* 4) cache creation/removal */
  42         const char *name;
  43         struct list_head list;
  44         int refcount;
  45         int object_size;
  46         int align;
  47
  48 /* 5) statistics */
  49 #ifdef CONFIG_DEBUG_SLAB
  50         unsigned long num_active;
  51         unsigned long num_allocations;
  52         unsigned long high_mark;
  53         unsigned long grown;
  54         unsigned long reaped;
  55         unsigned long errors;
  56         unsigned long max_freeable;
  57         unsigned long node_allocs;
  58         unsigned long node_frees;
  59         unsigned long node_overflow;
  60         atomic_t allochit;
  61         atomic_t allocmiss;
  62         atomic_t freehit;
  63         atomic_t freemiss;
  64 #ifdef CONFIG_DEBUG_SLAB_LEAK
  65         atomic_t store_user_clean;
  66 #endif
  67
  68         /*
  69          * If debugging is enabled, then the allocator can add additional
  70          * fields and/or padding to every object. size contains the total
  71          * object size including these internal fields, the following two
  72          * variables contain the offset to the user object and its size.
  73          */
  74         int obj_offset;
  75 #endif /* CONFIG_DEBUG_SLAB */
  76
  77 #ifdef CONFIG_MEMCG
  78         struct memcg_cache_params memcg_params;
  79 #endif
  80 #ifdef CONFIG_KASAN
  81         struct kasan_cache kasan_info;
  82 #endif
  83
  84 #ifdef CONFIG_SLAB_FREELIST_RANDOM
  85         unsigned int *random_seq;
  86 #endif
  87
  88         struct kmem_cache_node *node[MAX_NUMNODES];
  89 };
  90
  91 static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
  92                                 void *x)
  93 {
  94         void *object = x - (x - page->s_mem) % cache->size;
  95         void *last_object = page->s_mem + (cache->num - 1) * cache->size;
  96
  97         if (unlikely(object > last_object))
  98                 return last_object;
  99         else
 100                 return object;
 101 }
 102
 103 #endif  /* _LINUX_SLAB_DEF_H */