1 #ifndef _LINUX_SLUB_DEF_H
2 #define _LINUX_SLUB_DEF_H
3
4 /*
5 * SLUB : A Slab allocator without object queues.
6 *
7 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
8 */
9 #include <linux/types.h>
10 #include <linux/gfp.h>
11 #include <linux/workqueue.h>
12 #include <linux/kobject.h>
13
14 enum stat_item {
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 */
32 NR_SLUB_STAT_ITEMS };
33
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];
42 #endif
43 };
44
45 struct kmem_cache_node {
46 spinlock_t list_lock; /* Protect partial list and nr_partial */
47 unsigned long nr_partial;
48 atomic_long_t nr_slabs;
49 struct list_head partial;
50 #ifdef CONFIG_SLUB_DEBUG
51 struct list_head full;
52 #endif
53 };
54
55 /*
56 * Slab cache management.
57 */
58 struct kmem_cache {
59 /* Used for retriving partial slabs etc */
60 unsigned long flags;
61 int size; /* The size of an object including meta data */
62 int objsize; /* The size of an object without meta data */
63 int offset; /* Free pointer offset. */
64 int order; /* Current preferred allocation order */
65
66 /*
67 * Avoid an extra cache line for UP, SMP and for the node local to
68 * struct kmem_cache.
69 */
70 struct kmem_cache_node local_node;
71
72 /* Allocation and freeing of slabs */
73 int objects; /* Number of objects in slab */
74 gfp_t allocflags; /* gfp flags to use on each alloc */
75 int refcount; /* Refcount for slab cache destroy */
76 void (*ctor)(struct kmem_cache *, void *);
77 int inuse; /* Offset to metadata */
78 int align; /* Alignment */
79 const char *name; /* Name (only for display!) */
80 struct list_head list; /* List of slab caches */
81 #ifdef CONFIG_SLUB_DEBUG
82 struct kobject kobj; /* For sysfs */
83 #endif
84
85 #ifdef CONFIG_NUMA
86 /*
87 * Defragmentation by allocating from a remote node.
88 */
89 int remote_node_defrag_ratio;
90 struct kmem_cache_node *node[MAX_NUMNODES];
91 #endif
92 #ifdef CONFIG_SMP
93 struct kmem_cache_cpu *cpu_slab[NR_CPUS];
94 #else
95 struct kmem_cache_cpu cpu_slab;
96 #endif
97 };
98
99 /*
100 * Kmalloc subsystem.
101 */
102 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
103 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
104 #else
105 #define KMALLOC_MIN_SIZE 8
106 #endif
107
108 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
109
110 /*
111 * We keep the general caches in an array of slab caches that are used for
112 * 2^x bytes of allocations.
113 */
114 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1];
115
116 /*
117 * Sorry that the following has to be that ugly but some versions of GCC
118 * have trouble with constant propagation and loops.
119 */
120 static __always_inline int kmalloc_index(size_t size)
121 {
122 if (!size)
123 return 0;
124
125 if (size <= KMALLOC_MIN_SIZE)
126 return KMALLOC_SHIFT_LOW;
127
128 if (size > 64 && size <= 96)
129 return 1;
130 if (size > 128 && size <= 192)
131 return 2;
132 if (size <= 8) return 3;
133 if (size <= 16) return 4;
134 if (size <= 32) return 5;
135 if (size <= 64) return 6;
136 if (size <= 128) return 7;
137 if (size <= 256) return 8;
138 if (size <= 512) return 9;
139 if (size <= 1024) return 10;
140 if (size <= 2 * 1024) return 11;
141 if (size <= 4 * 1024) return 12;
142 /*
143 * The following is only needed to support architectures with a larger page
144 * size than 4k.
145 */
146 if (size <= 8 * 1024) return 13;
147 if (size <= 16 * 1024) return 14;
148 if (size <= 32 * 1024) return 15;
149 if (size <= 64 * 1024) return 16;
150 if (size <= 128 * 1024) return 17;
151 if (size <= 256 * 1024) return 18;
152 if (size <= 512 * 1024) return 19;
153 if (size <= 1024 * 1024) return 20;
154 if (size <= 2 * 1024 * 1024) return 21;
155 return -1;
156
157 /*
158 * What we really wanted to do and cannot do because of compiler issues is:
159 * int i;
160 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
161 * if (size <= (1 << i))
162 * return i;
163 */
164 }
165
166 /*
167 * Find the slab cache for a given combination of allocation flags and size.
168 *
169 * This ought to end up with a global pointer to the right cache
170 * in kmalloc_caches.
171 */
172 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
173 {
174 int index = kmalloc_index(size);
175
176 if (index == 0)
177 return NULL;
178
179 return &kmalloc_caches[index];
180 }
181
182 #ifdef CONFIG_ZONE_DMA
183 #define SLUB_DMA __GFP_DMA
184 #else
185 /* Disable DMA functionality */
186 #define SLUB_DMA (__force gfp_t)0
187 #endif
188
189 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
190 void *__kmalloc(size_t size, gfp_t flags);
191
192 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
193 {
194 return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
195 }
196
197 static __always_inline void *kmalloc(size_t size, gfp_t flags)
198 {
199 if (__builtin_constant_p(size)) {
200 if (size > PAGE_SIZE)
201 return kmalloc_large(size, flags);
202
203 if (!(flags & SLUB_DMA)) {
204 struct kmem_cache *s = kmalloc_slab(size);
205
206 if (!s)
207 return ZERO_SIZE_PTR;
208
209 return kmem_cache_alloc(s, flags);
210 }
211 }
212 return __kmalloc(size, flags);
213 }
214
215 #ifdef CONFIG_NUMA
216 void *__kmalloc_node(size_t size, gfp_t flags, int node);
217 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
218
219 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
220 {
221 if (__builtin_constant_p(size) &&
222 size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
223 struct kmem_cache *s = kmalloc_slab(size);
224
225 if (!s)
226 return ZERO_SIZE_PTR;
227
228 return kmem_cache_alloc_node(s, flags, node);
229 }
230 return __kmalloc_node(size, flags, node);
231 }
232 #endif
233
234 #endif /* _LINUX_SLUB_DEF_H */
235
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