include/linux/slub_def.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_SLUB_DEF_H
   3 #define _LINUX_SLUB_DEF_H
   4
   5 /*
   6  * SLUB : A Slab allocator without object queues.
   7  *
   8  * (C) 2007 SGI, Christoph Lameter
   9  */
  10 #include <linux/kobject.h>
  11
  12 enum stat_item {
  13         ALLOC_FASTPATH,         /* Allocation from cpu slab */
  14         ALLOC_SLOWPATH,         /* Allocation by getting a new cpu slab */
  15         FREE_FASTPATH,          /* Free to cpu slab */
  16         FREE_SLOWPATH,          /* Freeing not to cpu slab */
  17         FREE_FROZEN,            /* Freeing to frozen slab */
  18         FREE_ADD_PARTIAL,       /* Freeing moves slab to partial list */
  19         FREE_REMOVE_PARTIAL,    /* Freeing removes last object */
  20         ALLOC_FROM_PARTIAL,     /* Cpu slab acquired from node partial list */
  21         ALLOC_SLAB,             /* Cpu slab acquired from page allocator */
  22         ALLOC_REFILL,           /* Refill cpu slab from slab freelist */
  23         ALLOC_NODE_MISMATCH,    /* Switching cpu slab */
  24         FREE_SLAB,              /* Slab freed to the page allocator */
  25         CPUSLAB_FLUSH,          /* Abandoning of the cpu slab */
  26         DEACTIVATE_FULL,        /* Cpu slab was full when deactivated */
  27         DEACTIVATE_EMPTY,       /* Cpu slab was empty when deactivated */
  28         DEACTIVATE_TO_HEAD,     /* Cpu slab was moved to the head of partials */
  29         DEACTIVATE_TO_TAIL,     /* Cpu slab was moved to the tail of partials */
  30         DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
  31         DEACTIVATE_BYPASS,      /* Implicit deactivation */
  32         ORDER_FALLBACK,         /* Number of times fallback was necessary */
  33         CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
  34         CMPXCHG_DOUBLE_FAIL,    /* Number of times that cmpxchg double did not match */
  35         CPU_PARTIAL_ALLOC,      /* Used cpu partial on alloc */
  36         CPU_PARTIAL_FREE,       /* Refill cpu partial on free */
  37         CPU_PARTIAL_NODE,       /* Refill cpu partial from node partial */
  38         CPU_PARTIAL_DRAIN,      /* Drain cpu partial to node partial */
  39         NR_SLUB_STAT_ITEMS };
  40
  41 struct kmem_cache_cpu {
  42         void **freelist;        /* Pointer to next available object */
  43         unsigned long tid;      /* Globally unique transaction id */
  44         struct page *page;      /* The slab from which we are allocating */
  45 #ifdef CONFIG_SLUB_CPU_PARTIAL
  46         struct page *partial;   /* Partially allocated frozen slabs */
  47 #endif
  48 #ifdef CONFIG_SLUB_STATS
  49         unsigned stat[NR_SLUB_STAT_ITEMS];
  50 #endif
  51 };
  52
  53 #ifdef CONFIG_SLUB_CPU_PARTIAL
  54 #define slub_percpu_partial(c)          ((c)->partial)
  55
  56 #define slub_set_percpu_partial(c, p)           \
  57 ({                                              \
  58         slub_percpu_partial(c) = (p)->next;     \
  59 })
  60
  61 #define slub_percpu_partial_read_once(c)     READ_ONCE(slub_percpu_partial(c))
  62 #else
  63 #define slub_percpu_partial(c)                  NULL
  64
  65 #define slub_set_percpu_partial(c, p)
  66
  67 #define slub_percpu_partial_read_once(c)        NULL
  68 #endif // CONFIG_SLUB_CPU_PARTIAL
  69
  70 /*
  71  * Word size structure that can be atomically updated or read and that
  72  * contains both the order and the number of objects that a slab of the
  73  * given order would contain.
  74  */
  75 struct kmem_cache_order_objects {
  76         unsigned long x;
  77 };
  78
  79 /*
  80  * Slab cache management.
  81  */
  82 struct kmem_cache {
  83         struct kmem_cache_cpu __percpu *cpu_slab;
  84         /* Used for retriving partial slabs etc */
  85         slab_flags_t flags;
  86         unsigned long min_partial;
  87         int size;               /* The size of an object including meta data */
  88         int object_size;        /* The size of an object without meta data */
  89         int offset;             /* Free pointer offset. */
  90 #ifdef CONFIG_SLUB_CPU_PARTIAL
  91         int cpu_partial;        /* Number of per cpu partial objects to keep around */
  92 #endif
  93         struct kmem_cache_order_objects oo;
  94
  95         /* Allocation and freeing of slabs */
  96         struct kmem_cache_order_objects max;
  97         struct kmem_cache_order_objects min;
  98         gfp_t allocflags;       /* gfp flags to use on each alloc */
  99         int refcount;           /* Refcount for slab cache destroy */
 100         void (*ctor)(void *);
 101         int inuse;              /* Offset to metadata */
 102         int align;              /* Alignment */
 103         int reserved;           /* Reserved bytes at the end of slabs */
 104         int red_left_pad;       /* Left redzone padding size */
 105         const char *name;       /* Name (only for display!) */
 106         struct list_head list;  /* List of slab caches */
 107 #ifdef CONFIG_SYSFS
 108         struct kobject kobj;    /* For sysfs */
 109         struct work_struct kobj_remove_work;
 110 #endif
 111 #ifdef CONFIG_MEMCG
 112         struct memcg_cache_params memcg_params;
 113         int max_attr_size; /* for propagation, maximum size of a stored attr */
 114 #ifdef CONFIG_SYSFS
 115         struct kset *memcg_kset;
 116 #endif
 117 #endif
 118
 119 #ifdef CONFIG_SLAB_FREELIST_HARDENED
 120         unsigned long random;
 121 #endif
 122
 123 #ifdef CONFIG_NUMA
 124         /*
 125          * Defragmentation by allocating from a remote node.
 126          */
 127         int remote_node_defrag_ratio;
 128 #endif
 129
 130 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 131         unsigned int *random_seq;
 132 #endif
 133
 134 #ifdef CONFIG_KASAN
 135         struct kasan_cache kasan_info;
 136 #endif
 137
 138         size_t useroffset;              /* Usercopy region offset */
 139         size_t usersize;                /* Usercopy region size */
 140
 141         struct kmem_cache_node *node[MAX_NUMNODES];
 142 };
 143
 144 #ifdef CONFIG_SLUB_CPU_PARTIAL
 145 #define slub_cpu_partial(s)             ((s)->cpu_partial)
 146 #define slub_set_cpu_partial(s, n)              \
 147 ({                                              \
 148         slub_cpu_partial(s) = (n);              \
 149 })
 150 #else
 151 #define slub_cpu_partial(s)             (0)
 152 #define slub_set_cpu_partial(s, n)
 153 #endif // CONFIG_SLUB_CPU_PARTIAL
 154
 155 #ifdef CONFIG_SYSFS
 156 #define SLAB_SUPPORTS_SYSFS
 157 void sysfs_slab_release(struct kmem_cache *);
 158 #else
 159 static inline void sysfs_slab_release(struct kmem_cache *s)
 160 {
 161 }
 162 #endif
 163
 164 void object_err(struct kmem_cache *s, struct page *page,
 165                 u8 *object, char *reason);
 166
 167 void *fixup_red_left(struct kmem_cache *s, void *p);
 168
 169 static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
 170                                 void *x) {
 171         void *object = x - (x - page_address(page)) % cache->size;
 172         void *last_object = page_address(page) +
 173                 (page->objects - 1) * cache->size;
 174         void *result = (unlikely(object > last_object)) ? last_object : object;
 175
 176         result = fixup_red_left(cache, result);
 177         return result;
 178 }
 179
 180 #endif /* _LINUX_SLUB_DEF_H */