slub_def.h 4.8 KB
Newer Older
C
Christoph Lameter 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13
#ifndef _LINUX_SLUB_DEF_H
#define _LINUX_SLUB_DEF_H

/*
 * SLUB : A Slab allocator without object queues.
 *
 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
 */
#include <linux/types.h>
#include <linux/gfp.h>
#include <linux/workqueue.h>
#include <linux/kobject.h>

14 15 16 17
struct kmem_cache_cpu {
	void **freelist;
	struct page *page;
	int node;
18
	unsigned int offset;
19 20 21
	/* Lots of wasted space */
} ____cacheline_aligned_in_smp;

C
Christoph Lameter 已提交
22 23 24 25 26
struct kmem_cache_node {
	spinlock_t list_lock;	/* Protect partial list and nr_partial */
	unsigned long nr_partial;
	atomic_long_t nr_slabs;
	struct list_head partial;
27
#ifdef CONFIG_SLUB_DEBUG
28
	struct list_head full;
29
#endif
C
Christoph Lameter 已提交
30 31 32 33 34 35 36 37 38 39 40
};

/*
 * Slab cache management.
 */
struct kmem_cache {
	/* Used for retriving partial slabs etc */
	unsigned long flags;
	int size;		/* The size of an object including meta data */
	int objsize;		/* The size of an object without meta data */
	int offset;		/* Free pointer offset. */
41
	int order;
C
Christoph Lameter 已提交
42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

	/*
	 * Avoid an extra cache line for UP, SMP and for the node local to
	 * struct kmem_cache.
	 */
	struct kmem_cache_node local_node;

	/* Allocation and freeing of slabs */
	int objects;		/* Number of objects in slab */
	int refcount;		/* Refcount for slab cache destroy */
	void (*ctor)(void *, struct kmem_cache *, unsigned long);
	int inuse;		/* Offset to metadata */
	int align;		/* Alignment */
	const char *name;	/* Name (only for display!) */
	struct list_head list;	/* List of slab caches */
57
#ifdef CONFIG_SLUB_DEBUG
C
Christoph Lameter 已提交
58
	struct kobject kobj;	/* For sysfs */
59
#endif
C
Christoph Lameter 已提交
60 61 62 63 64

#ifdef CONFIG_NUMA
	int defrag_ratio;
	struct kmem_cache_node *node[MAX_NUMNODES];
#endif
65
	struct kmem_cache_cpu cpu_slab[NR_CPUS];
C
Christoph Lameter 已提交
66 67 68 69 70
};

/*
 * Kmalloc subsystem.
 */
71 72 73 74 75 76 77
#if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
#else
#define KMALLOC_MIN_SIZE 8
#endif

#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
C
Christoph Lameter 已提交
78 79 80 81 82

/*
 * We keep the general caches in an array of slab caches that are used for
 * 2^x bytes of allocations.
 */
83
extern struct kmem_cache kmalloc_caches[PAGE_SHIFT];
C
Christoph Lameter 已提交
84 85 86 87 88

/*
 * Sorry that the following has to be that ugly but some versions of GCC
 * have trouble with constant propagation and loops.
 */
89
static __always_inline int kmalloc_index(size_t size)
C
Christoph Lameter 已提交
90
{
91 92
	if (!size)
		return 0;
93

94 95 96
	if (size <= KMALLOC_MIN_SIZE)
		return KMALLOC_SHIFT_LOW;

C
Christoph Lameter 已提交
97 98 99 100 101 102 103 104 105 106 107 108 109
	if (size > 64 && size <= 96)
		return 1;
	if (size > 128 && size <= 192)
		return 2;
	if (size <=          8) return 3;
	if (size <=         16) return 4;
	if (size <=         32) return 5;
	if (size <=         64) return 6;
	if (size <=        128) return 7;
	if (size <=        256) return 8;
	if (size <=        512) return 9;
	if (size <=       1024) return 10;
	if (size <=   2 * 1024) return 11;
110 111 112 113
/*
 * The following is only needed to support architectures with a larger page
 * size than 4k.
 */
C
Christoph Lameter 已提交
114 115 116 117 118 119 120
	if (size <=   4 * 1024) return 12;
	if (size <=   8 * 1024) return 13;
	if (size <=  16 * 1024) return 14;
	if (size <=  32 * 1024) return 15;
	if (size <=  64 * 1024) return 16;
	if (size <= 128 * 1024) return 17;
	if (size <= 256 * 1024) return 18;
121
	if (size <= 512 * 1024) return 19;
C
Christoph Lameter 已提交
122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
	if (size <= 1024 * 1024) return 20;
	if (size <=  2 * 1024 * 1024) return 21;
	return -1;

/*
 * What we really wanted to do and cannot do because of compiler issues is:
 *	int i;
 *	for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
 *		if (size <= (1 << i))
 *			return i;
 */
}

/*
 * Find the slab cache for a given combination of allocation flags and size.
 *
 * This ought to end up with a global pointer to the right cache
 * in kmalloc_caches.
 */
141
static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
C
Christoph Lameter 已提交
142 143 144 145 146 147 148 149 150 151 152 153 154
{
	int index = kmalloc_index(size);

	if (index == 0)
		return NULL;

	return &kmalloc_caches[index];
}

#ifdef CONFIG_ZONE_DMA
#define SLUB_DMA __GFP_DMA
#else
/* Disable DMA functionality */
A
Al Viro 已提交
155
#define SLUB_DMA (__force gfp_t)0
C
Christoph Lameter 已提交
156 157
#endif

P
Paul Mundt 已提交
158 159 160
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
void *__kmalloc(size_t size, gfp_t flags);

161
static __always_inline void *kmalloc(size_t size, gfp_t flags)
C
Christoph Lameter 已提交
162
{
163 164 165 166
	if (__builtin_constant_p(size)) {
		if (size > PAGE_SIZE / 2)
			return (void *)__get_free_pages(flags | __GFP_COMP,
							get_order(size));
C
Christoph Lameter 已提交
167

168 169 170 171 172
		if (!(flags & SLUB_DMA)) {
			struct kmem_cache *s = kmalloc_slab(size);

			if (!s)
				return ZERO_SIZE_PTR;
C
Christoph Lameter 已提交
173

174 175 176 177
			return kmem_cache_alloc(s, flags);
		}
	}
	return __kmalloc(size, flags);
C
Christoph Lameter 已提交
178 179 180
}

#ifdef CONFIG_NUMA
P
Paul Mundt 已提交
181 182
void *__kmalloc_node(size_t size, gfp_t flags, int node);
void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
C
Christoph Lameter 已提交
183

184
static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
C
Christoph Lameter 已提交
185
{
186 187 188
	if (__builtin_constant_p(size) &&
		size <= PAGE_SIZE / 2 && !(flags & SLUB_DMA)) {
			struct kmem_cache *s = kmalloc_slab(size);
C
Christoph Lameter 已提交
189 190

		if (!s)
191
			return ZERO_SIZE_PTR;
C
Christoph Lameter 已提交
192 193

		return kmem_cache_alloc_node(s, flags, node);
194 195
	}
	return __kmalloc_node(size, flags, node);
C
Christoph Lameter 已提交
196 197 198 199
}
#endif

#endif /* _LINUX_SLUB_DEF_H */