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/types.h>
  10 #include <linux/gfp.h>
  11 #include <linux/workqueue.h>
  12 #include <linux/kobject.h>
  13 #include <trace/kmemtrace.h>
  14
  15 enum stat_item {
  16         ALLOC_FASTPATH,         /* Allocation from cpu slab */
  17         ALLOC_SLOWPATH,         /* Allocation by getting a new cpu slab */
  18         FREE_FASTPATH,          /* Free to cpu slub */
  19         FREE_SLOWPATH,          /* Freeing not to cpu slab */
  20         FREE_FROZEN,            /* Freeing to frozen slab */
  21         FREE_ADD_PARTIAL,       /* Freeing moves slab to partial list */
  22         FREE_REMOVE_PARTIAL,    /* Freeing removes last object */
  23         ALLOC_FROM_PARTIAL,     /* Cpu slab acquired from partial list */
  24         ALLOC_SLAB,             /* Cpu slab acquired from page allocator */
  25         ALLOC_REFILL,           /* Refill cpu slab from slab freelist */
  26         FREE_SLAB,              /* Slab freed to the page allocator */
  27         CPUSLAB_FLUSH,          /* Abandoning of the cpu slab */
  28         DEACTIVATE_FULL,        /* Cpu slab was full when deactivated */
  29         DEACTIVATE_EMPTY,       /* Cpu slab was empty when deactivated */
  30         DEACTIVATE_TO_HEAD,     /* Cpu slab was moved to the head of partials */
  31         DEACTIVATE_TO_TAIL,     /* Cpu slab was moved to the tail of partials */
  32         DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
  33         ORDER_FALLBACK,         /* Number of times fallback was necessary */
  34         NR_SLUB_STAT_ITEMS };
  35
  36 struct kmem_cache_cpu {
  37         void **freelist;        /* Pointer to first free per cpu object */
  38         struct page *page;      /* The slab from which we are allocating */
  39         int node;               /* The node of the page (or -1 for debug) */
  40         unsigned int offset;    /* Freepointer offset (in word units) */
  41         unsigned int objsize;   /* Size of an object (from kmem_cache) */
  42 #ifdef CONFIG_SLUB_STATS
  43         unsigned stat[NR_SLUB_STAT_ITEMS];
  44 #endif
  45 };
  46
  47 struct kmem_cache_node {
  48         spinlock_t list_lock;   /* Protect partial list and nr_partial */
  49         unsigned long nr_partial;
  50         unsigned long min_partial;
  51         struct list_head partial;
  52 #ifdef CONFIG_SLUB_DEBUG
  53         atomic_long_t nr_slabs;
  54         atomic_long_t total_objects;
  55         struct list_head full;
  56 #endif
  57 };
  58
  59 /*
  60  * Word size structure that can be atomically updated or read and that
  61  * contains both the order and the number of objects that a slab of the
  62  * given order would contain.
  63  */
  64 struct kmem_cache_order_objects {
  65         unsigned long x;
  66 };
  67
  68 /*
  69  * Slab cache management.
  70  */
  71 struct kmem_cache {
  72         /* Used for retriving partial slabs etc */
  73         unsigned long flags;
  74         int size;               /* The size of an object including meta data */
  75         int objsize;            /* The size of an object without meta data */
  76         int offset;             /* Free pointer offset. */
  77         struct kmem_cache_order_objects oo;
  78
  79         /*
  80          * Avoid an extra cache line for UP, SMP and for the node local to
  81          * struct kmem_cache.
  82          */
  83         struct kmem_cache_node local_node;
  84
  85         /* Allocation and freeing of slabs */
  86         struct kmem_cache_order_objects max;
  87         struct kmem_cache_order_objects min;
  88         gfp_t allocflags;       /* gfp flags to use on each alloc */
  89         int refcount;           /* Refcount for slab cache destroy */
  90         void (*ctor)(void *);
  91         int inuse;              /* Offset to metadata */
  92         int align;              /* Alignment */
  93         const char *name;       /* Name (only for display!) */
  94         struct list_head list;  /* List of slab caches */
  95 #ifdef CONFIG_SLUB_DEBUG
  96         struct kobject kobj;    /* For sysfs */
  97 #endif
  98
  99 #ifdef CONFIG_NUMA
 100         /*
 101          * Defragmentation by allocating from a remote node.
 102          */
 103         int remote_node_defrag_ratio;
 104         struct kmem_cache_node *node[MAX_NUMNODES];
 105 #endif
 106 #ifdef CONFIG_SMP
 107         struct kmem_cache_cpu *cpu_slab[NR_CPUS];
 108 #else
 109         struct kmem_cache_cpu cpu_slab;
 110 #endif
 111 };
 112
 113 /*
 114  * Kmalloc subsystem.
 115  */
 116 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
 117 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
 118 #else
 119 #define KMALLOC_MIN_SIZE 8
 120 #endif
 121
 122 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
 123
 124 /*
 125  * We keep the general caches in an array of slab caches that are used for
 126  * 2^x bytes of allocations.
 127  */
 128 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1];
 129
 130 /*
 131  * Sorry that the following has to be that ugly but some versions of GCC
 132  * have trouble with constant propagation and loops.
 133  */
 134 static __always_inline int kmalloc_index(size_t size)
 135 {
 136         if (!size)
 137                 return 0;
 138
 139         if (size <= KMALLOC_MIN_SIZE)
 140                 return KMALLOC_SHIFT_LOW;
 141
 142 #if KMALLOC_MIN_SIZE <= 64
 143         if (size > 64 && size <= 96)
 144                 return 1;
 145         if (size > 128 && size <= 192)
 146                 return 2;
 147 #endif
 148         if (size <=          8) return 3;
 149         if (size <=         16) return 4;
 150         if (size <=         32) return 5;
 151         if (size <=         64) return 6;
 152         if (size <=        128) return 7;
 153         if (size <=        256) return 8;
 154         if (size <=        512) return 9;
 155         if (size <=       1024) return 10;
 156         if (size <=   2 * 1024) return 11;
 157         if (size <=   4 * 1024) return 12;
 158 /*
 159  * The following is only needed to support architectures with a larger page
 160  * size than 4k.
 161  */
 162         if (size <=   8 * 1024) return 13;
 163         if (size <=  16 * 1024) return 14;
 164         if (size <=  32 * 1024) return 15;
 165         if (size <=  64 * 1024) return 16;
 166         if (size <= 128 * 1024) return 17;
 167         if (size <= 256 * 1024) return 18;
 168         if (size <= 512 * 1024) return 19;
 169         if (size <= 1024 * 1024) return 20;
 170         if (size <=  2 * 1024 * 1024) return 21;
 171         return -1;
 172
 173 /*
 174  * What we really wanted to do and cannot do because of compiler issues is:
 175  *      int i;
 176  *      for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
 177  *              if (size <= (1 << i))
 178  *                      return i;
 179  */
 180 }
 181
 182 /*
 183  * Find the slab cache for a given combination of allocation flags and size.
 184  *
 185  * This ought to end up with a global pointer to the right cache
 186  * in kmalloc_caches.
 187  */
 188 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
 189 {
 190         int index = kmalloc_index(size);
 191
 192         if (index == 0)
 193                 return NULL;
 194
 195         return &kmalloc_caches[index];
 196 }
 197
 198 #ifdef CONFIG_ZONE_DMA
 199 #define SLUB_DMA __GFP_DMA
 200 #else
 201 /* Disable DMA functionality */
 202 #define SLUB_DMA (__force gfp_t)0
 203 #endif
 204
 205 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 206 void *__kmalloc(size_t size, gfp_t flags);
 207
 208 #ifdef CONFIG_KMEMTRACE
 209 extern void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags);
 210 #else
 211 static __always_inline void *
 212 kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags)
 213 {
 214         return kmem_cache_alloc(s, gfpflags);
 215 }
 216 #endif
 217
 218 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
 219 {
 220         unsigned int order = get_order(size);
 221         void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
 222
 223         kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC, _THIS_IP_, ret,
 224                              size, PAGE_SIZE << order, flags);
 225
 226         return ret;
 227 }
 228
 229 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 230 {
 231         void *ret;
 232
 233         if (__builtin_constant_p(size)) {
 234                 if (size > PAGE_SIZE)
 235                         return kmalloc_large(size, flags);
 236
 237                 if (!(flags & SLUB_DMA)) {
 238                         struct kmem_cache *s = kmalloc_slab(size);
 239
 240                         if (!s)
 241                                 return ZERO_SIZE_PTR;
 242
 243                         ret = kmem_cache_alloc_notrace(s, flags);
 244
 245                         kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC,
 246                                              _THIS_IP_, ret,
 247                                              size, s->size, flags);
 248
 249                         return ret;
 250                 }
 251         }
 252         return __kmalloc(size, flags);
 253 }
 254
 255 #ifdef CONFIG_NUMA
 256 void *__kmalloc_node(size_t size, gfp_t flags, int node);
 257 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 258
 259 #ifdef CONFIG_KMEMTRACE
 260 extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *s,
 261                                            gfp_t gfpflags,
 262                                            int node);
 263 #else
 264 static __always_inline void *
 265 kmem_cache_alloc_node_notrace(struct kmem_cache *s,
 266                               gfp_t gfpflags,
 267                               int node)
 268 {
 269         return kmem_cache_alloc_node(s, gfpflags, node);
 270 }
 271 #endif
 272
 273 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 274 {
 275         void *ret;
 276
 277         if (__builtin_constant_p(size) &&
 278                 size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
 279                         struct kmem_cache *s = kmalloc_slab(size);
 280
 281                 if (!s)
 282                         return ZERO_SIZE_PTR;
 283
 284                 ret = kmem_cache_alloc_node_notrace(s, flags, node);
 285
 286                 kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC,
 287                                           _THIS_IP_, ret,
 288                                           size, s->size, flags, node);
 289
 290                 return ret;
 291         }
 292         return __kmalloc_node(size, flags, node);
 293 }
 294 #endif
 295
 296 #endif /* _LINUX_SLUB_DEF_H */