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>
14 struct kmem_cache_cpu {
15 void **freelist; /* Pointer to first free per cpu object */
16 struct page *page; /* The slab from which we are allocating */
17 int node; /* The node of the page (or -1 for debug) */
18 unsigned int offset; /* Freepointer offset (in word units) */
19 unsigned int objsize; /* Size of an object (from kmem_cache) */
22 struct kmem_cache_node {
23 spinlock_t list_lock; /* Protect partial list and nr_partial */
24 unsigned long nr_partial;
25 atomic_long_t nr_slabs;
26 struct list_head partial;
27 #ifdef CONFIG_SLUB_DEBUG
28 struct list_head full;
33 * Slab cache management.
36 /* Used for retriving partial slabs etc */
38 int size; /* The size of an object including meta data */
39 int objsize; /* The size of an object without meta data */
40 int offset; /* Free pointer offset. */
44 * Avoid an extra cache line for UP, SMP and for the node local to
47 struct kmem_cache_node local_node;
49 /* Allocation and freeing of slabs */
50 int objects; /* Number of objects in slab */
51 int refcount; /* Refcount for slab cache destroy */
52 void (*ctor)(struct kmem_cache *, void *);
53 int inuse; /* Offset to metadata */
54 int align; /* Alignment */
55 const char *name; /* Name (only for display!) */
56 struct list_head list; /* List of slab caches */
57 #ifdef CONFIG_SLUB_DEBUG
58 struct kobject kobj; /* For sysfs */
63 * Defragmentation by allocating from a remote node.
65 int remote_node_defrag_ratio;
66 struct kmem_cache_node *node[MAX_NUMNODES];
69 struct kmem_cache_cpu *cpu_slab[NR_CPUS];
71 struct kmem_cache_cpu cpu_slab;
78 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
79 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
81 #define KMALLOC_MIN_SIZE 8
84 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
87 * We keep the general caches in an array of slab caches that are used for
88 * 2^x bytes of allocations.
90 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT];
93 * Sorry that the following has to be that ugly but some versions of GCC
94 * have trouble with constant propagation and loops.
96 static __always_inline int kmalloc_index(size_t size)
101 if (size <= KMALLOC_MIN_SIZE)
102 return KMALLOC_SHIFT_LOW;
104 if (size > 64 && size <= 96)
106 if (size > 128 && size <= 192)
108 if (size <= 8) return 3;
109 if (size <= 16) return 4;
110 if (size <= 32) return 5;
111 if (size <= 64) return 6;
112 if (size <= 128) return 7;
113 if (size <= 256) return 8;
114 if (size <= 512) return 9;
115 if (size <= 1024) return 10;
116 if (size <= 2 * 1024) return 11;
118 * The following is only needed to support architectures with a larger page
121 if (size <= 4 * 1024) return 12;
122 if (size <= 8 * 1024) return 13;
123 if (size <= 16 * 1024) return 14;
124 if (size <= 32 * 1024) return 15;
125 if (size <= 64 * 1024) return 16;
126 if (size <= 128 * 1024) return 17;
127 if (size <= 256 * 1024) return 18;
128 if (size <= 512 * 1024) return 19;
129 if (size <= 1024 * 1024) return 20;
130 if (size <= 2 * 1024 * 1024) return 21;
134 * What we really wanted to do and cannot do because of compiler issues is:
136 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
137 * if (size <= (1 << i))
143 * Find the slab cache for a given combination of allocation flags and size.
145 * This ought to end up with a global pointer to the right cache
148 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
150 int index = kmalloc_index(size);
155 return &kmalloc_caches[index];
158 #ifdef CONFIG_ZONE_DMA
159 #define SLUB_DMA __GFP_DMA
161 /* Disable DMA functionality */
162 #define SLUB_DMA (__force gfp_t)0
165 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
166 void *__kmalloc(size_t size, gfp_t flags);
168 static __always_inline void *kmalloc(size_t size, gfp_t flags)
170 if (__builtin_constant_p(size)) {
171 if (size > PAGE_SIZE / 2)
172 return (void *)__get_free_pages(flags | __GFP_COMP,
175 if (!(flags & SLUB_DMA)) {
176 struct kmem_cache *s = kmalloc_slab(size);
179 return ZERO_SIZE_PTR;
181 return kmem_cache_alloc(s, flags);
184 return __kmalloc(size, flags);
188 void *__kmalloc_node(size_t size, gfp_t flags, int node);
189 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
191 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
193 if (__builtin_constant_p(size) &&
194 size <= PAGE_SIZE / 2 && !(flags & SLUB_DMA)) {
195 struct kmem_cache *s = kmalloc_slab(size);
198 return ZERO_SIZE_PTR;
200 return kmem_cache_alloc_node(s, flags, node);
202 return __kmalloc_node(size, flags, node);
206 #endif /* _LINUX_SLUB_DEF_H */