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