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_node {
15 spinlock_t list_lock; /* Protect partial list and nr_partial */
16 unsigned long nr_partial;
17 atomic_long_t nr_slabs;
18 struct list_head partial;
19 #ifdef CONFIG_SLUB_DEBUG
20 struct list_head full;
25 * Slab cache management.
28 /* Used for retriving partial slabs etc */
30 int size; /* The size of an object including meta data */
31 int objsize; /* The size of an object without meta data */
32 int offset; /* Free pointer offset. */
36 * Avoid an extra cache line for UP, SMP and for the node local to
39 struct kmem_cache_node local_node;
41 /* Allocation and freeing of slabs */
42 int objects; /* Number of objects in slab */
43 int refcount; /* Refcount for slab cache destroy */
44 void (*ctor)(void *, struct kmem_cache *, unsigned long);
45 int inuse; /* Offset to metadata */
46 int align; /* Alignment */
47 const char *name; /* Name (only for display!) */
48 struct list_head list; /* List of slab caches */
49 #ifdef CONFIG_SLUB_DEBUG
50 struct kobject kobj; /* For sysfs */
55 struct kmem_cache_node *node[MAX_NUMNODES];
57 struct page *cpu_slab[NR_CPUS];
63 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
64 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
66 #define KMALLOC_MIN_SIZE 8
69 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
72 * We keep the general caches in an array of slab caches that are used for
73 * 2^x bytes of allocations.
75 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT];
78 * Sorry that the following has to be that ugly but some versions of GCC
79 * have trouble with constant propagation and loops.
81 static __always_inline int kmalloc_index(size_t size)
86 if (size <= KMALLOC_MIN_SIZE)
87 return KMALLOC_SHIFT_LOW;
89 if (size > 64 && size <= 96)
91 if (size > 128 && size <= 192)
93 if (size <= 8) return 3;
94 if (size <= 16) return 4;
95 if (size <= 32) return 5;
96 if (size <= 64) return 6;
97 if (size <= 128) return 7;
98 if (size <= 256) return 8;
99 if (size <= 512) return 9;
100 if (size <= 1024) return 10;
101 if (size <= 2 * 1024) return 11;
103 * The following is only needed to support architectures with a larger page
106 if (size <= 4 * 1024) return 12;
107 if (size <= 8 * 1024) return 13;
108 if (size <= 16 * 1024) return 14;
109 if (size <= 32 * 1024) return 15;
110 if (size <= 64 * 1024) return 16;
111 if (size <= 128 * 1024) return 17;
112 if (size <= 256 * 1024) return 18;
113 if (size <= 512 * 1024) return 19;
114 if (size <= 1024 * 1024) return 20;
115 if (size <= 2 * 1024 * 1024) return 21;
119 * What we really wanted to do and cannot do because of compiler issues is:
121 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
122 * if (size <= (1 << i))
128 * Find the slab cache for a given combination of allocation flags and size.
130 * This ought to end up with a global pointer to the right cache
133 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
135 int index = kmalloc_index(size);
140 return &kmalloc_caches[index];
143 #ifdef CONFIG_ZONE_DMA
144 #define SLUB_DMA __GFP_DMA
146 /* Disable DMA functionality */
147 #define SLUB_DMA (__force gfp_t)0
150 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
151 void *__kmalloc(size_t size, gfp_t flags);
153 static __always_inline void *kmalloc(size_t size, gfp_t flags)
155 if (__builtin_constant_p(size)) {
156 if (size > PAGE_SIZE / 2)
157 return (void *)__get_free_pages(flags | __GFP_COMP,
160 if (!(flags & SLUB_DMA)) {
161 struct kmem_cache *s = kmalloc_slab(size);
164 return ZERO_SIZE_PTR;
166 return kmem_cache_alloc(s, flags);
169 return __kmalloc(size, flags);
173 void *__kmalloc_node(size_t size, gfp_t flags, int node);
174 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
176 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
178 if (__builtin_constant_p(size) &&
179 size <= PAGE_SIZE / 2 && !(flags & SLUB_DMA)) {
180 struct kmem_cache *s = kmalloc_slab(size);
183 return ZERO_SIZE_PTR;
185 return kmem_cache_alloc_node(s, flags, node);
187 return __kmalloc_node(size, flags, node);
191 #endif /* _LINUX_SLUB_DEF_H */