include/linux/slub_def.h

   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
  11 enum 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
  40 struct 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  */
  55 struct kmem_cache_order_objects {
  56         unsigned long x;
  57 };
  58
  59 /*
  60  * Slab cache management.
  61  */
  62 struct 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
 107 void sysfs_slab_remove(struct kmem_cache *);
 108 #else
 109 static 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  */
 123 static 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
 130 void object_err(struct kmem_cache *s, struct page *page,
 131                 u8 *object, char *reason);
 132
 133 static 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 */