LXR linux/include/linux/slub

   1#ifndef _LINUX_SLUB_DEF_H
   2#define _LINUX_SLUB_DEF_H
   3
   4/*
   5 * SLUB : A Slab allocator without object queues.
   6 *
   7 * (C) 2007 SGI, Christoph Lameter
   8 */
   9#include <linux/kobject.h>
  10
  11enum stat_item {
  12        ALLOC_FASTPATH,         /* Allocation from cpu slab */
  13        ALLOC_SLOWPATH,         /* Allocation by getting a new cpu slab */
  14        FREE_FASTPATH,          /* Free to cpu slab */
  15        FREE_SLOWPATH,          /* Freeing not to cpu slab */
  16        FREE_FROZEN,            /* Freeing to frozen slab */
  17        FREE_ADD_PARTIAL,       /* Freeing moves slab to partial list */
  18        FREE_REMOVE_PARTIAL,    /* Freeing removes last object */
  19        ALLOC_FROM_PARTIAL,     /* Cpu slab acquired from node partial list */
  20        ALLOC_SLAB,             /* Cpu slab acquired from page allocator */
  21        ALLOC_REFILL,           /* Refill cpu slab from slab freelist */
  22        ALLOC_NODE_MISMATCH,    /* Switching cpu slab */
  23        FREE_SLAB,              /* Slab freed to the page allocator */
  24        CPUSLAB_FLUSH,          /* Abandoning of the cpu slab */
  25        DEACTIVATE_FULL,        /* Cpu slab was full when deactivated */
  26        DEACTIVATE_EMPTY,       /* Cpu slab was empty when deactivated */
  27        DEACTIVATE_TO_HEAD,     /* Cpu slab was moved to the head of partials */
  28        DEACTIVATE_TO_TAIL,     /* Cpu slab was moved to the tail of partials */
  29        DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
  30        DEACTIVATE_BYPASS,      /* Implicit deactivation */
  31        ORDER_FALLBACK,         /* Number of times fallback was necessary */
  32        CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
  33        CMPXCHG_DOUBLE_FAIL,    /* Number of times that cmpxchg double did not match */
  34        CPU_PARTIAL_ALLOC,      /* Used cpu partial on alloc */
  35        CPU_PARTIAL_FREE,       /* Refill cpu partial on free */
  36        CPU_PARTIAL_NODE,       /* Refill cpu partial from node partial */
  37        CPU_PARTIAL_DRAIN,      /* Drain cpu partial to node partial */
  38        NR_SLUB_STAT_ITEMS };
  39
  40struct kmem_cache_cpu {
  41        void **freelist;        /* Pointer to next available object */
  42        unsigned long tid;      /* Globally unique transaction id */
  43        struct page *page;      /* The slab from which we are allocating */
  44        struct page *partial;   /* Partially allocated frozen slabs */
  45#ifdef CONFIG_SLUB_STATS
  46        unsigned stat[NR_SLUB_STAT_ITEMS];
  47#endif
  48};
  49
  50/*
  51 * Word size structure that can be atomically updated or read and that
  52 * contains both the order and the number of objects that a slab of the
  53 * given order would contain.
  54 */
  55struct kmem_cache_order_objects {
  56        unsigned long x;
  57};
  58
  59/*
  60 * Slab cache management.
  61 */
  62struct kmem_cache {
  63        struct kmem_cache_cpu __percpu *cpu_slab;
  64        /* Used for retriving partial slabs etc */
  65        unsigned long flags;
  66        unsigned long min_partial;
  67        int size;               /* The size of an object including meta data */
  68        int object_size;        /* The size of an object without meta data */
  69        int offset;             /* Free pointer offset. */
  70        int cpu_partial;        /* Number of per cpu partial objects to keep around */
  71        struct kmem_cache_order_objects oo;
  72
  73        /* Allocation and freeing of slabs */
  74        struct kmem_cache_order_objects max;
  75        struct kmem_cache_order_objects min;
  76        gfp_t allocflags;       /* gfp flags to use on each alloc */
  77        int refcount;           /* Refcount for slab cache destroy */
  78        void (*ctor)(void *);
  79        int inuse;              /* Offset to metadata */
  80        int align;              /* Alignment */
  81        int reserved;           /* Reserved bytes at the end of slabs */
  82        const char *name;       /* Name (only for display!) */
  83        struct list_head list;  /* List of slab caches */
  84        int red_left_pad;       /* Left redzone padding size */
  85#ifdef CONFIG_SYSFS
  86        struct kobject kobj;    /* For sysfs */
  87#endif
  88#ifdef CONFIG_MEMCG
  89        struct memcg_cache_params memcg_params;
  90        int max_attr_size; /* for propagation, maximum size of a stored attr */
  91#ifdef CONFIG_SYSFS
  92        struct kset *memcg_kset;
  93#endif
  94#endif
  95
  96#ifdef CONFIG_NUMA
  97        /*
  98         * Defragmentation by allocating from a remote node.
  99         */
 100        int remote_node_defrag_ratio;
 101#endif
 102        struct kmem_cache_node *node[MAX_NUMNODES];
 103};
 104
 105#ifdef CONFIG_SYSFS
 106#define SLAB_SUPPORTS_SYSFS
 107void sysfs_slab_remove(struct kmem_cache *);
 108#else
 109static inline void sysfs_slab_remove(struct kmem_cache *s)
 110{
 111}
 112#endif
 113
 114
 115/**
 116 * virt_to_obj - returns address of the beginning of object.
 117 * @s: object's kmem_cache
 118 * @slab_page: address of slab page
 119 * @x: address within object memory range
 120 *
 121 * Returns address of the beginning of object
 122 */
 123static inline void *virt_to_obj(struct kmem_cache *s,
 124                                const void *slab_page,
 125                                const void *x)
 126{
 127        return (void *)x - ((x - slab_page) % s->size);
 128}
 129
 130void object_err(struct kmem_cache *s, struct page *page,
 131                u8 *object, char *reason);
 132
 133static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
 134                                void *x) {
 135        void *object = x - (x - page_address(page)) % cache->size;
 136        void *last_object = page_address(page) +
 137                (page->objects - 1) * cache->size;
 138        if (unlikely(object > last_object))
 139                return last_object;
 140        else
 141                return object;
 142}
 143
 144#endif /* _LINUX_SLUB_DEF_H */
 145