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 #ifdef CONFIG_SLUB_CPU_PARTIAL
  45         struct page *partial;   /* Partially allocated frozen slabs */
  46 #endif
  47 #ifdef CONFIG_SLUB_STATS
  48         unsigned stat[NR_SLUB_STAT_ITEMS];
  49 #endif
  50 };
  51
  52 #ifdef CONFIG_SLUB_CPU_PARTIAL
  53 #define slub_percpu_partial(c)          ((c)->partial)
  54
  55 #define slub_set_percpu_partial(c, p)           \
  56 ({                                              \
  57         slub_percpu_partial(c) = (p)->next;     \
  58 })
  59
  60 #define slub_percpu_partial_read_once(c)     READ_ONCE(slub_percpu_partial(c))
  61 #else
  62 #define slub_percpu_partial(c)                  NULL
  63
  64 #define slub_set_percpu_partial(c, p)
  65
  66 #define slub_percpu_partial_read_once(c)        NULL
  67 #endif // CONFIG_SLUB_CPU_PARTIAL
  68
  69 /*
  70  * Word size structure that can be atomically updated or read and that
  71  * contains both the order and the number of objects that a slab of the
  72  * given order would contain.
  73  */
  74 struct kmem_cache_order_objects {
  75         unsigned long x;
  76 };
  77
  78 /*
  79  * Slab cache management.
  80  */
  81 struct kmem_cache {
  82         struct kmem_cache_cpu __percpu *cpu_slab;
  83         /* Used for retriving partial slabs etc */
  84         unsigned long flags;
  85         unsigned long min_partial;
  86         int size;               /* The size of an object including meta data */
  87         int object_size;        /* The size of an object without meta data */
  88         int offset;             /* Free pointer offset. */
  89 #ifdef CONFIG_SLUB_CPU_PARTIAL
  90         int cpu_partial;        /* Number of per cpu partial objects to keep around */
  91 #endif
  92         struct kmem_cache_order_objects oo;
  93
  94         /* Allocation and freeing of slabs */
  95         struct kmem_cache_order_objects max;
  96         struct kmem_cache_order_objects min;
  97         gfp_t allocflags;       /* gfp flags to use on each alloc */
  98         int refcount;           /* Refcount for slab cache destroy */
  99         void (*ctor)(void *);
 100         int inuse;              /* Offset to metadata */
 101         int align;              /* Alignment */
 102         int reserved;           /* Reserved bytes at the end of slabs */
 103         int red_left_pad;       /* Left redzone padding size */
 104         const char *name;       /* Name (only for display!) */
 105         struct list_head list;  /* List of slab caches */
 106 #ifdef CONFIG_SYSFS
 107         struct kobject kobj;    /* For sysfs */
 108         struct work_struct kobj_remove_work;
 109 #endif
 110 #ifdef CONFIG_MEMCG
 111         struct memcg_cache_params memcg_params;
 112         int max_attr_size; /* for propagation, maximum size of a stored attr */
 113 #ifdef CONFIG_SYSFS
 114         struct kset *memcg_kset;
 115 #endif
 116 #endif
 117
 118 #ifdef CONFIG_NUMA
 119         /*
 120          * Defragmentation by allocating from a remote node.
 121          */
 122         int remote_node_defrag_ratio;
 123 #endif
 124
 125 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 126         unsigned int *random_seq;
 127 #endif
 128
 129 #ifdef CONFIG_KASAN
 130         struct kasan_cache kasan_info;
 131 #endif
 132
 133         struct kmem_cache_node *node[MAX_NUMNODES];
 134 };
 135
 136 #ifdef CONFIG_SLUB_CPU_PARTIAL
 137 #define slub_cpu_partial(s)             ((s)->cpu_partial)
 138 #define slub_set_cpu_partial(s, n)              \
 139 ({                                              \
 140         slub_cpu_partial(s) = (n);              \
 141 })
 142 #else
 143 #define slub_cpu_partial(s)             (0)
 144 #define slub_set_cpu_partial(s, n)
 145 #endif // CONFIG_SLUB_CPU_PARTIAL
 146
 147 #ifdef CONFIG_SYSFS
 148 #define SLAB_SUPPORTS_SYSFS
 149 void sysfs_slab_release(struct kmem_cache *);
 150 #else
 151 static inline void sysfs_slab_release(struct kmem_cache *s)
 152 {
 153 }
 154 #endif
 155
 156 void object_err(struct kmem_cache *s, struct page *page,
 157                 u8 *object, char *reason);
 158
 159 void *fixup_red_left(struct kmem_cache *s, void *p);
 160
 161 static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
 162                                 void *x) {
 163         void *object = x - (x - page_address(page)) % cache->size;
 164         void *last_object = page_address(page) +
 165                 (page->objects - 1) * cache->size;
 166         void *result = (unlikely(object > last_object)) ? last_object : object;
 167
 168         result = fixup_red_left(cache, result);
 169         return result;
 170 }
 171
 172 #endif /* _LINUX_SLUB_DEF_H */