1 #ifndef _LINUX_SLUB_DEF_H
2 #define _LINUX_SLUB_DEF_H
5 * SLUB : A Slab allocator without object queues.
7 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
9 #include <linux/types.h>
10 #include <linux/gfp.h>
11 #include <linux/workqueue.h>
12 #include <linux/kobject.h>
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 */
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];
45 struct kmem_cache_node {
46 spinlock_t list_lock; /* Protect partial list and nr_partial */
47 unsigned long nr_partial;
48 struct list_head partial;
49 #ifdef CONFIG_SLUB_DEBUG
50 atomic_long_t nr_slabs;
51 struct list_head full;
56 * Word size structure that can be atomically updated or read and that
57 * contains both the order and the number of objects that a slab of the
58 * given order would contain.
60 struct kmem_cache_order_objects {
65 * Slab cache management.
68 /* Used for retriving partial slabs etc */
70 int size; /* The size of an object including meta data */
71 int objsize; /* The size of an object without meta data */
72 int offset; /* Free pointer offset. */
73 struct kmem_cache_order_objects oo;
76 * Avoid an extra cache line for UP, SMP and for the node local to
79 struct kmem_cache_node local_node;
81 /* Allocation and freeing of slabs */
82 gfp_t allocflags; /* gfp flags to use on each alloc */
83 int refcount; /* Refcount for slab cache destroy */
84 void (*ctor)(struct kmem_cache *, void *);
85 int inuse; /* Offset to metadata */
86 int align; /* Alignment */
87 const char *name; /* Name (only for display!) */
88 struct list_head list; /* List of slab caches */
89 #ifdef CONFIG_SLUB_DEBUG
90 struct kobject kobj; /* For sysfs */
95 * Defragmentation by allocating from a remote node.
97 int remote_node_defrag_ratio;
98 struct kmem_cache_node *node[MAX_NUMNODES];
101 struct kmem_cache_cpu *cpu_slab[NR_CPUS];
103 struct kmem_cache_cpu cpu_slab;
110 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
111 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
113 #define KMALLOC_MIN_SIZE 8
116 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
119 * We keep the general caches in an array of slab caches that are used for
120 * 2^x bytes of allocations.
122 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1];
125 * Sorry that the following has to be that ugly but some versions of GCC
126 * have trouble with constant propagation and loops.
128 static __always_inline int kmalloc_index(size_t size)
133 if (size <= KMALLOC_MIN_SIZE)
134 return KMALLOC_SHIFT_LOW;
136 if (size > 64 && size <= 96)
138 if (size > 128 && size <= 192)
140 if (size <= 8) return 3;
141 if (size <= 16) return 4;
142 if (size <= 32) return 5;
143 if (size <= 64) return 6;
144 if (size <= 128) return 7;
145 if (size <= 256) return 8;
146 if (size <= 512) return 9;
147 if (size <= 1024) return 10;
148 if (size <= 2 * 1024) return 11;
149 if (size <= 4 * 1024) return 12;
151 * The following is only needed to support architectures with a larger page
154 if (size <= 8 * 1024) return 13;
155 if (size <= 16 * 1024) return 14;
156 if (size <= 32 * 1024) return 15;
157 if (size <= 64 * 1024) return 16;
158 if (size <= 128 * 1024) return 17;
159 if (size <= 256 * 1024) return 18;
160 if (size <= 512 * 1024) return 19;
161 if (size <= 1024 * 1024) return 20;
162 if (size <= 2 * 1024 * 1024) return 21;
166 * What we really wanted to do and cannot do because of compiler issues is:
168 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
169 * if (size <= (1 << i))
175 * Find the slab cache for a given combination of allocation flags and size.
177 * This ought to end up with a global pointer to the right cache
180 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
182 int index = kmalloc_index(size);
187 return &kmalloc_caches[index];
190 #ifdef CONFIG_ZONE_DMA
191 #define SLUB_DMA __GFP_DMA
193 /* Disable DMA functionality */
194 #define SLUB_DMA (__force gfp_t)0
197 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
198 void *__kmalloc(size_t size, gfp_t flags);
200 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
202 return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
205 static __always_inline void *kmalloc(size_t size, gfp_t flags)
207 if (__builtin_constant_p(size)) {
208 if (size > PAGE_SIZE)
209 return kmalloc_large(size, flags);
211 if (!(flags & SLUB_DMA)) {
212 struct kmem_cache *s = kmalloc_slab(size);
215 return ZERO_SIZE_PTR;
217 return kmem_cache_alloc(s, flags);
220 return __kmalloc(size, flags);
224 void *__kmalloc_node(size_t size, gfp_t flags, int node);
225 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
227 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
229 if (__builtin_constant_p(size) &&
230 size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
231 struct kmem_cache *s = kmalloc_slab(size);
234 return ZERO_SIZE_PTR;
236 return kmem_cache_alloc_node(s, flags, node);
238 return __kmalloc_node(size, flags, node);
242 #endif /* _LINUX_SLUB_DEF_H */