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 <<<<<<< HEAD:include/linux/slub_def.h
  65         int order;
  66 =======
  67         int order;              /* Current preferred allocation order */
  68 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:include/linux/slub_def.h
  69
  70         /*
  71          * Avoid an extra cache line for UP, SMP and for the node local to
  72          * struct kmem_cache.
  73          */
  74         struct kmem_cache_node local_node;
  75
  76         /* Allocation and freeing of slabs */
  77         int objects;            /* Number of objects in slab */
  78         gfp_t allocflags;       /* gfp flags to use on each alloc */
  79         int refcount;           /* Refcount for slab cache destroy */
  80         void (*ctor)(struct kmem_cache *, void *);
  81         int inuse;              /* Offset to metadata */
  82         int align;              /* Alignment */
  83         const char *name;       /* Name (only for display!) */
  84         struct list_head list;  /* List of slab caches */
  85 #ifdef CONFIG_SLUB_DEBUG
  86         struct kobject kobj;    /* For sysfs */
  87 #endif
  88
  89 #ifdef CONFIG_NUMA
  90         /*
  91          * Defragmentation by allocating from a remote node.
  92          */
  93         int remote_node_defrag_ratio;
  94         struct kmem_cache_node *node[MAX_NUMNODES];
  95 #endif
  96 #ifdef CONFIG_SMP
  97         struct kmem_cache_cpu *cpu_slab[NR_CPUS];
  98 #else
  99         struct kmem_cache_cpu cpu_slab;
 100 #endif
 101 };
 102
 103 /*
 104  * Kmalloc subsystem.
 105  */
 106 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
 107 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
 108 #else
 109 #define KMALLOC_MIN_SIZE 8
 110 #endif
 111
 112 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
 113
 114 /*
 115  * We keep the general caches in an array of slab caches that are used for
 116  * 2^x bytes of allocations.
 117  */
 118 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1];
 119
 120 /*
 121  * Sorry that the following has to be that ugly but some versions of GCC
 122  * have trouble with constant propagation and loops.
 123  */
 124 static __always_inline int kmalloc_index(size_t size)
 125 {
 126         if (!size)
 127                 return 0;
 128
 129         if (size <= KMALLOC_MIN_SIZE)
 130                 return KMALLOC_SHIFT_LOW;
 131
 132         if (size > 64 && size <= 96)
 133                 return 1;
 134         if (size > 128 && size <= 192)
 135                 return 2;
 136         if (size <=          8) return 3;
 137         if (size <=         16) return 4;
 138         if (size <=         32) return 5;
 139         if (size <=         64) return 6;
 140         if (size <=        128) return 7;
 141         if (size <=        256) return 8;
 142         if (size <=        512) return 9;
 143         if (size <=       1024) return 10;
 144         if (size <=   2 * 1024) return 11;
 145 <<<<<<< HEAD:include/linux/slub_def.h
 146 =======
 147         if (size <=   4 * 1024) return 12;
 148 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:include/linux/slub_def.h
 149 /*
 150  * The following is only needed to support architectures with a larger page
 151  * size than 4k.
 152  */
 153 <<<<<<< HEAD:include/linux/slub_def.h
 154         if (size <=   4 * 1024) return 12;
 155 =======
 156 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:include/linux/slub_def.h
 157         if (size <=   8 * 1024) return 13;
 158         if (size <=  16 * 1024) return 14;
 159         if (size <=  32 * 1024) return 15;
 160         if (size <=  64 * 1024) return 16;
 161         if (size <= 128 * 1024) return 17;
 162         if (size <= 256 * 1024) return 18;
 163         if (size <= 512 * 1024) return 19;
 164         if (size <= 1024 * 1024) return 20;
 165         if (size <=  2 * 1024 * 1024) return 21;
 166         return -1;
 167
 168 /*
 169  * What we really wanted to do and cannot do because of compiler issues is:
 170  *      int i;
 171  *      for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
 172  *              if (size <= (1 << i))
 173  *                      return i;
 174  */
 175 }
 176
 177 /*
 178  * Find the slab cache for a given combination of allocation flags and size.
 179  *
 180  * This ought to end up with a global pointer to the right cache
 181  * in kmalloc_caches.
 182  */
 183 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
 184 {
 185         int index = kmalloc_index(size);
 186
 187         if (index == 0)
 188                 return NULL;
 189
 190         return &kmalloc_caches[index];
 191 }
 192
 193 #ifdef CONFIG_ZONE_DMA
 194 #define SLUB_DMA __GFP_DMA
 195 #else
 196 /* Disable DMA functionality */
 197 #define SLUB_DMA (__force gfp_t)0
 198 #endif
 199
 200 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 201 void *__kmalloc(size_t size, gfp_t flags);
 202
 203 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
 204 {
 205         return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
 206 }
 207
 208 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 209 {
 210         if (__builtin_constant_p(size)) {
 211                 if (size > PAGE_SIZE)
 212                         return kmalloc_large(size, flags);
 213
 214                 if (!(flags & SLUB_DMA)) {
 215                         struct kmem_cache *s = kmalloc_slab(size);
 216
 217                         if (!s)
 218                                 return ZERO_SIZE_PTR;
 219
 220                         return kmem_cache_alloc(s, flags);
 221                 }
 222         }
 223         return __kmalloc(size, flags);
 224 }
 225
 226 #ifdef CONFIG_NUMA
 227 void *__kmalloc_node(size_t size, gfp_t flags, int node);
 228 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 229
 230 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 231 {
 232         if (__builtin_constant_p(size) &&
 233                 size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
 234                         struct kmem_cache *s = kmalloc_slab(size);
 235
 236                 if (!s)
 237                         return ZERO_SIZE_PTR;
 238
 239                 return kmem_cache_alloc_node(s, flags, node);
 240         }
 241         return __kmalloc_node(size, flags, node);
 242 }
 243 #endif
 244
 245 #endif /* _LINUX_SLUB_DEF_H */