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
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 ORDER_FALLBACK, /* Number of times fallback was necessary */
33 NR_SLUB_STAT_ITEMS };
34
35 struct kmem_cache_cpu {
36 void **freelist; /* Pointer to first free per cpu object */
37 struct page *page; /* The slab from which we are allocating */
38 int node; /* The node of the page (or -1 for debug) */
39 unsigned int offset; /* Freepointer offset (in word units) */
40 unsigned int objsize; /* Size of an object (from kmem_cache) */
41 #ifdef CONFIG_SLUB_STATS
42 unsigned stat[NR_SLUB_STAT_ITEMS];
43 #endif
44 };
45
46 struct kmem_cache_node {
47 spinlock_t list_lock; /* Protect partial list and nr_partial */
48 unsigned long nr_partial;
49 unsigned long min_partial;
50 struct list_head partial;
51 #ifdef CONFIG_SLUB_DEBUG
52 atomic_long_t nr_slabs;
53 atomic_long_t total_objects;
54 struct list_head full;
55 #endif
56 };
57
58 /*
59 * Word size structure that can be atomically updated or read and that
60 * contains both the order and the number of objects that a slab of the
61 * given order would contain.
62 */
63 struct kmem_cache_order_objects {
64 unsigned long x;
65 };
66
67 /*
68 * Slab cache management.
69 */
70 struct kmem_cache {
71 /* Used for retriving partial slabs etc */
72 unsigned long flags;
73 int size; /* The size of an object including meta data */
74 int objsize; /* The size of an object without meta data */
75 int offset; /* Free pointer offset. */
76 struct kmem_cache_order_objects oo;
77
78 /*
79 * Avoid an extra cache line for UP, SMP and for the node local to
80 * struct kmem_cache.
81 */
82 struct kmem_cache_node local_node;
83
84 /* Allocation and freeing of slabs */
85 struct kmem_cache_order_objects max;
86 struct kmem_cache_order_objects min;
87 gfp_t allocflags; /* gfp flags to use on each alloc */
88 int refcount; /* Refcount for slab cache destroy */
89 void (*ctor)(void *);
90 int inuse; /* Offset to metadata */
91 int align; /* Alignment */
92 const char *name; /* Name (only for display!) */
93 struct list_head list; /* List of slab caches */
94 #ifdef CONFIG_SLUB_DEBUG
95 struct kobject kobj; /* For sysfs */
96 #endif
97
98 #ifdef CONFIG_NUMA
99 /*
100 * Defragmentation by allocating from a remote node.
101 */
102 int remote_node_defrag_ratio;
103 struct kmem_cache_node *node[MAX_NUMNODES];
104 #endif
105 #ifdef CONFIG_SMP
106 struct kmem_cache_cpu *cpu_slab[NR_CPUS];
107 #else
108 struct kmem_cache_cpu cpu_slab;
109 #endif
110 };
111
112 /*
113 * Kmalloc subsystem.
114 */
115 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
116 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
117 #else
118 #define KMALLOC_MIN_SIZE 8
119 #endif
120
121 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
122
123 /*
124 * We keep the general caches in an array of slab caches that are used for
125 * 2^x bytes of allocations.
126 */
127 extern struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1];
128
129 /*
130 * Sorry that the following has to be that ugly but some versions of GCC
131 * have trouble with constant propagation and loops.
132 */
kmalloc_index(size_t size)133 static __always_inline int kmalloc_index(size_t size)
134 {
135 if (!size)
136 return 0;
137
138 if (size <= KMALLOC_MIN_SIZE)
139 return KMALLOC_SHIFT_LOW;
140
141 #if KMALLOC_MIN_SIZE <= 64
142 if (size > 64 && size <= 96)
143 return 1;
144 if (size > 128 && size <= 192)
145 return 2;
146 #endif
147 if (size <= 8) return 3;
148 if (size <= 16) return 4;
149 if (size <= 32) return 5;
150 if (size <= 64) return 6;
151 if (size <= 128) return 7;
152 if (size <= 256) return 8;
153 if (size <= 512) return 9;
154 if (size <= 1024) return 10;
155 if (size <= 2 * 1024) return 11;
156 if (size <= 4 * 1024) return 12;
157 /*
158 * The following is only needed to support architectures with a larger page
159 * size than 4k.
160 */
161 if (size <= 8 * 1024) return 13;
162 if (size <= 16 * 1024) return 14;
163 if (size <= 32 * 1024) return 15;
164 if (size <= 64 * 1024) return 16;
165 if (size <= 128 * 1024) return 17;
166 if (size <= 256 * 1024) return 18;
167 if (size <= 512 * 1024) return 19;
168 if (size <= 1024 * 1024) return 20;
169 if (size <= 2 * 1024 * 1024) return 21;
170 return -1;
171
172 /*
173 * What we really wanted to do and cannot do because of compiler issues is:
174 * int i;
175 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
176 * if (size <= (1 << i))
177 * return i;
178 */
179 }
180
181 /*
182 * Find the slab cache for a given combination of allocation flags and size.
183 *
184 * This ought to end up with a global pointer to the right cache
185 * in kmalloc_caches.
186 */
kmalloc_slab(size_t size)187 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
188 {
189 int index = kmalloc_index(size);
190
191 if (index == 0)
192 return NULL;
193
194 return &kmalloc_caches[index];
195 }
196
197 #ifdef CONFIG_ZONE_DMA
198 #define SLUB_DMA __GFP_DMA
199 #else
200 /* Disable DMA functionality */
201 #define SLUB_DMA (__force gfp_t)0
202 #endif
203
204 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
205 void *__kmalloc(size_t size, gfp_t flags);
206
kmalloc_large(size_t size,gfp_t flags)207 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
208 {
209 return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
210 }
211
kmalloc(size_t size,gfp_t flags)212 static __always_inline void *kmalloc(size_t size, gfp_t flags)
213 {
214 if (__builtin_constant_p(size)) {
215 if (size > PAGE_SIZE)
216 return kmalloc_large(size, flags);
217
218 if (!(flags & SLUB_DMA)) {
219 struct kmem_cache *s = kmalloc_slab(size);
220
221 if (!s)
222 return ZERO_SIZE_PTR;
223
224 return kmem_cache_alloc(s, flags);
225 }
226 }
227 return __kmalloc(size, flags);
228 }
229
230 #ifdef CONFIG_NUMA
231 void *__kmalloc_node(size_t size, gfp_t flags, int node);
232 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
233
kmalloc_node(size_t size,gfp_t flags,int node)234 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
235 {
236 if (__builtin_constant_p(size) &&
237 size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
238 struct kmem_cache *s = kmalloc_slab(size);
239
240 if (!s)
241 return ZERO_SIZE_PTR;
242
243 return kmem_cache_alloc_node(s, flags, node);
244 }
245 return __kmalloc_node(size, flags, node);
246 }
247 #endif
248
249 #endif /* _LINUX_SLUB_DEF_H */
250