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 <clameter@sgi.com>
   8  */
   9 #include <linux/types.h>
  10 #include <linux/gfp.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/kobject.h>
  13
  14 enum stat_item {
  15         ALLOC_FASTPATH,         /* Allocation from cpu slab */
  16         ALLOC_SLOWPATH,         /* Allocation by getting a new cpu slab */
  17         FREE_FASTPATH,          /* Free to cpu slub */
  18         FREE_SLOWPATH,          /* Freeing not to cpu slab */
  19         FREE_FROZEN,            /* Freeing to frozen slab */
  20         FREE_ADD_PARTIAL,       /* Freeing moves slab to partial list */
  21         FREE_REMOVE_PARTIAL,    /* Freeing removes last object */
  22         ALLOC_FROM_PARTIAL,     /* Cpu slab acquired from partial list */
  23         ALLOC_SLAB,             /* Cpu slab acquired from page allocator */
  24         ALLOC_REFILL,           /* Refill cpu slab from slab freelist */
  25         FREE_SLAB,              /* Slab freed to the page allocator */
  26         CPUSLAB_FLUSH,          /* Abandoning of the cpu slab */
  27         DEACTIVATE_FULL,        /* Cpu slab was full when deactivated */
  28         DEACTIVATE_EMPTY,       /* Cpu slab was empty when deactivated */
  29         DEACTIVATE_TO_HEAD,     /* Cpu slab was moved to the head of partials */
  30         DEACTIVATE_TO_TAIL,     /* Cpu slab was moved to the tail of partials */
  31         DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
  32         NR_SLUB_STAT_ITEMS };
  33
  34 struct kmem_cache_cpu {
  35         void **freelist;        /* Pointer to first free per cpu object */
  36         struct page *page;      /* The slab from which we are allocating */
  37         int node;               /* The node of the page (or -1 for debug) */
  38         unsigned int offset;    /* Freepointer offset (in word units) */
  39         unsigned int objsize;   /* Size of an object (from kmem_cache) */
  40 #ifdef CONFIG_SLUB_STATS
  41         unsigned stat[NR_SLUB_STAT_ITEMS];
  42 #endif
  43 };
  44
  45 struct kmem_cache_node {
  46         spinlock_t list_lock;   /* Protect partial list and nr_partial */
  47         unsigned long nr_partial;
  48         atomic_long_t nr_slabs;
  49         struct list_head partial;
  50 #ifdef CONFIG_SLUB_DEBUG
  51         struct list_head full;
  52 #endif
  53 };
  54
  55 /*
  56  * Slab cache management.
  57  */
  58 struct kmem_cache {
  59         /* Used for retriving partial slabs etc */
  60         unsigned long flags;
  61         int size;               /* The size of an object including meta data */
  62         int objsize;            /* The size of an object without meta data */
  63         int offset;             /* Free pointer offset. */
  64         int order;
  65
  66         /*
  67          * Avoid an extra cache line for UP, SMP and for the node local to
  68          * struct kmem_cache.
  69          */
  70         struct kmem_cache_node local_node;
  71
  72         /* Allocation and freeing of slabs */
  73         int objects;            /* Number of objects in slab */
  74         int refcount;           /* Refcount for slab cache destroy */
  75         void (*ctor)(struct kmem_cache *, void *);
  76         int inuse;              /* Offset to metadata */
  77         int align;              /* Alignment */
  78         const char *name;       /* Name (only for display!) */
  79         struct list_head list;  /* List of slab caches */
  80 #ifdef CONFIG_SLUB_DEBUG
  81         struct kobject kobj;    /* For sysfs */
  82 #endif
  83
  84 #ifdef CONFIG_NUMA
  85         /*
  86          * Defragmentation by allocating from a remote node.
  87          */
  88         int remote_node_defrag_ratio;
  89         struct kmem_cache_node *node[MAX_NUMNODES];
  90 #endif
  91 #ifdef CONFIG_SMP
  92         struct kmem_cache_cpu *cpu_slab[NR_CPUS];
  93 #else
  94         struct kmem_cache_cpu cpu_slab;
  95 #endif
  96 };
  97
  98 /*
  99  * Kmalloc subsystem.
 100  */
 101 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
 102 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
 103 #else
 104 #define KMALLOC_MIN_SIZE 8
 105 #endif
 106
 107 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
 108
 109 /*
 110  * We keep the general caches in an array of slab caches that are used for
 111  * 2^x bytes of allocations.
 112  */
 113 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT];
 114
 115 /*
 116  * Sorry that the following has to be that ugly but some versions of GCC
 117  * have trouble with constant propagation and loops.
 118  */
 119 static __always_inline int kmalloc_index(size_t size)
 120 {
 121         if (!size)
 122                 return 0;
 123
 124         if (size <= KMALLOC_MIN_SIZE)
 125                 return KMALLOC_SHIFT_LOW;
 126
 127         if (size > 64 && size <= 96)
 128                 return 1;
 129         if (size > 128 && size <= 192)
 130                 return 2;
 131         if (size <=          8) return 3;
 132         if (size <=         16) return 4;
 133         if (size <=         32) return 5;
 134         if (size <=         64) return 6;
 135         if (size <=        128) return 7;
 136         if (size <=        256) return 8;
 137         if (size <=        512) return 9;
 138         if (size <=       1024) return 10;
 139         if (size <=   2 * 1024) return 11;
 140 /*
 141  * The following is only needed to support architectures with a larger page
 142  * size than 4k.
 143  */
 144         if (size <=   4 * 1024) return 12;
 145         if (size <=   8 * 1024) return 13;
 146         if (size <=  16 * 1024) return 14;
 147         if (size <=  32 * 1024) return 15;
 148         if (size <=  64 * 1024) return 16;
 149         if (size <= 128 * 1024) return 17;
 150         if (size <= 256 * 1024) return 18;
 151         if (size <= 512 * 1024) return 19;
 152         if (size <= 1024 * 1024) return 20;
 153         if (size <=  2 * 1024 * 1024) return 21;
 154         return -1;
 155
 156 /*
 157  * What we really wanted to do and cannot do because of compiler issues is:
 158  *      int i;
 159  *      for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
 160  *              if (size <= (1 << i))
 161  *                      return i;
 162  */
 163 }
 164
 165 /*
 166  * Find the slab cache for a given combination of allocation flags and size.
 167  *
 168  * This ought to end up with a global pointer to the right cache
 169  * in kmalloc_caches.
 170  */
 171 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
 172 {
 173         int index = kmalloc_index(size);
 174
 175         if (index == 0)
 176                 return NULL;
 177
 178         return &kmalloc_caches[index];
 179 }
 180
 181 #ifdef CONFIG_ZONE_DMA
 182 #define SLUB_DMA __GFP_DMA
 183 #else
 184 /* Disable DMA functionality */
 185 #define SLUB_DMA (__force gfp_t)0
 186 #endif
 187
 188 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 189 void *__kmalloc(size_t size, gfp_t flags);
 190
 191 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 192 {
 193         if (__builtin_constant_p(size)) {
 194                 if (size > PAGE_SIZE / 2)
 195                         return (void *)__get_free_pages(flags | __GFP_COMP,
 196                                                         get_order(size));
 197
 198                 if (!(flags & SLUB_DMA)) {
 199                         struct kmem_cache *s = kmalloc_slab(size);
 200
 201                         if (!s)
 202                                 return ZERO_SIZE_PTR;
 203
 204                         return kmem_cache_alloc(s, flags);
 205                 }
 206         }
 207         return __kmalloc(size, flags);
 208 }
 209
 210 #ifdef CONFIG_NUMA
 211 void *__kmalloc_node(size_t size, gfp_t flags, int node);
 212 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 213
 214 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 215 {
 216         if (__builtin_constant_p(size) &&
 217                 size <= PAGE_SIZE / 2 && !(flags & SLUB_DMA)) {
 218                         struct kmem_cache *s = kmalloc_slab(size);
 219
 220                 if (!s)
 221                         return ZERO_SIZE_PTR;
 222
 223                 return kmem_cache_alloc_node(s, flags, node);
 224         }
 225         return __kmalloc_node(size, flags, node);
 226 }
 227 #endif
 228
 229 #endif /* _LINUX_SLUB_DEF_H */