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 */