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 #include <linux/kmemtrace.h>
14 #include <linux/kmemleak.h>
15
16 enum stat_item {
17 ALLOC_FASTPATH, /* Allocation from cpu slab */
18 ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
19 FREE_FASTPATH, /* Free to cpu slub */
20 FREE_SLOWPATH, /* Freeing not to cpu slab */
21 FREE_FROZEN, /* Freeing to frozen slab */
22 FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
23 FREE_REMOVE_PARTIAL, /* Freeing removes last object */
24 ALLOC_FROM_PARTIAL, /* Cpu slab acquired from partial list */
25 ALLOC_SLAB, /* Cpu slab acquired from page allocator */
26 ALLOC_REFILL, /* Refill cpu slab from slab freelist */
27 FREE_SLAB, /* Slab freed to the page allocator */
28 CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
29 DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
30 DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
31 DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
32 DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
33 DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
34 ORDER_FALLBACK, /* Number of times fallback was necessary */
35 NR_SLUB_STAT_ITEMS };
36
37 struct kmem_cache_cpu {
38 void **freelist; /* Pointer to first free per cpu object */
39 struct page *page; /* The slab from which we are allocating */
40 int node; /* The node of the page (or -1 for debug) */
41 unsigned int offset; /* Freepointer offset (in word units) */
42 unsigned int objsize; /* Size of an object (from kmem_cache) */
43 #ifdef CONFIG_SLUB_STATS
44 unsigned stat[NR_SLUB_STAT_ITEMS];
45 #endif
46 };
47
48 struct kmem_cache_node {
49 spinlock_t list_lock; /* Protect partial list and nr_partial */
50 unsigned long nr_partial;
51 struct list_head partial;
52 #ifdef CONFIG_SLUB_DEBUG
53 atomic_long_t nr_slabs;
54 atomic_long_t total_objects;
55 struct list_head full;
56 #endif
57 };
58
59 /*
60 * Word size structure that can be atomically updated or read and that
61 * contains both the order and the number of objects that a slab of the
62 * given order would contain.
63 */
64 struct kmem_cache_order_objects {
65 unsigned long x;
66 };
67
68 /*
69 * Slab cache management.
70 */
71 struct kmem_cache {
72 /* Used for retriving partial slabs etc */
73 unsigned long flags;
74 int size; /* The size of an object including meta data */
75 int objsize; /* The size of an object without meta data */
76 int offset; /* Free pointer offset. */
77 struct kmem_cache_order_objects oo;
78
79 /*
80 * Avoid an extra cache line for UP, SMP and for the node local to
81 * struct kmem_cache.
82 */
83 struct kmem_cache_node local_node;
84
85 /* Allocation and freeing of slabs */
86 struct kmem_cache_order_objects max;
87 struct kmem_cache_order_objects min;
88 gfp_t allocflags; /* gfp flags to use on each alloc */
89 int refcount; /* Refcount for slab cache destroy */
90 void (*ctor)(void *);
91 int inuse; /* Offset to metadata */
92 int align; /* Alignment */
93 unsigned long min_partial;
94 const char *name; /* Name (only for display!) */
95 struct list_head list; /* List of slab caches */
96 #ifdef CONFIG_SLUB_DEBUG
97 struct kobject kobj; /* For sysfs */
98 #endif
99
100 #ifdef CONFIG_NUMA
101 /*
102 * Defragmentation by allocating from a remote node.
103 */
104 int remote_node_defrag_ratio;
105 struct kmem_cache_node *node[MAX_NUMNODES];
106 #endif
107 #ifdef CONFIG_SMP
108 struct kmem_cache_cpu *cpu_slab[NR_CPUS];
109 #else
110 struct kmem_cache_cpu cpu_slab;
111 #endif
112 };
113
114 /*
115 * Kmalloc subsystem.
116 */
117 #if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
118 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
119 #else
120 #define KMALLOC_MIN_SIZE 8
121 #endif
122
123 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
124
125 /*
126 * Maximum kmalloc object size handled by SLUB. Larger object allocations
127 * are passed through to the page allocator. The page allocator "fastpath"
128 * is relatively slow so we need this value sufficiently high so that
129 * performance critical objects are allocated through the SLUB fastpath.
130 *
131 * This should be dropped to PAGE_SIZE / 2 once the page allocator
132 * "fastpath" becomes competitive with the slab allocator fastpaths.
133 */
134 #define SLUB_MAX_SIZE (2 * PAGE_SIZE)
135
136 #define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
137
138 /*
139 * We keep the general caches in an array of slab caches that are used for
140 * 2^x bytes of allocations.
141 */
142 extern struct kmem_cache kmalloc_caches[SLUB_PAGE_SHIFT];
143
144 /*
145 * Sorry that the following has to be that ugly but some versions of GCC
146 * have trouble with constant propagation and loops.
147 */
148 static __always_inline int kmalloc_index(size_t size)
149 {
150 if (!size)
151 return 0;
152
153 if (size <= KMALLOC_MIN_SIZE)
154 return KMALLOC_SHIFT_LOW;
155
156 #if KMALLOC_MIN_SIZE <= 64
157 if (size > 64 && size <= 96)
158 return 1;
159 if (size > 128 && size <= 192)
160 return 2;
161 #endif
162 if (size <= 8) return 3;
163 if (size <= 16) return 4;
164 if (size <= 32) return 5;
165 if (size <= 64) return 6;
166 if (size <= 128) return 7;
167 if (size <= 256) return 8;
168 if (size <= 512) return 9;
169 if (size <= 1024) return 10;
170 if (size <= 2 * 1024) return 11;
171 if (size <= 4 * 1024) return 12;
172 /*
173 * The following is only needed to support architectures with a larger page
174 * size than 4k.
175 */
176 if (size <= 8 * 1024) return 13;
177 if (size <= 16 * 1024) return 14;
178 if (size <= 32 * 1024) return 15;
179 if (size <= 64 * 1024) return 16;
180 if (size <= 128 * 1024) return 17;
181 if (size <= 256 * 1024) return 18;
182 if (size <= 512 * 1024) return 19;
183 if (size <= 1024 * 1024) return 20;
184 if (size <= 2 * 1024 * 1024) return 21;
185 return -1;
186
187 /*
188 * What we really wanted to do and cannot do because of compiler issues is:
189 * int i;
190 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
191 * if (size <= (1 << i))
192 * return i;
193 */
194 }
195
196 /*
197 * Find the slab cache for a given combination of allocation flags and size.
198 *
199 * This ought to end up with a global pointer to the right cache
200 * in kmalloc_caches.
201 */
202 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
203 {
204 int index = kmalloc_index(size);
205
206 if (index == 0)
207 return NULL;
208
209 return &kmalloc_caches[index];
210 }
211
212 #ifdef CONFIG_ZONE_DMA
213 #define SLUB_DMA __GFP_DMA
214 #else
215 /* Disable DMA functionality */
216 #define SLUB_DMA (__force gfp_t)0
217 #endif
218
219 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
220 void *__kmalloc(size_t size, gfp_t flags);
221
222 #ifdef CONFIG_KMEMTRACE
223 extern void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags);
224 #else
225 static __always_inline void *
226 kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags)
227 {
228 return kmem_cache_alloc(s, gfpflags);
229 }
230 #endif
231
232 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
233 {
234 unsigned int order = get_order(size);
235 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
236
237 kmemleak_alloc(ret, size, 1, flags);
238 trace_kmalloc(_THIS_IP_, ret, size, PAGE_SIZE << order, flags);
239
240 return ret;
241 }
242
243 static __always_inline void *kmalloc(size_t size, gfp_t flags)
244 {
245 void *ret;
246
247 if (__builtin_constant_p(size)) {
248 if (size > SLUB_MAX_SIZE)
249 return kmalloc_large(size, flags);
250
251 if (!(flags & SLUB_DMA)) {
252 struct kmem_cache *s = kmalloc_slab(size);
253
254 if (!s)
255 return ZERO_SIZE_PTR;
256
257 ret = kmem_cache_alloc_notrace(s, flags);
258
259 trace_kmalloc(_THIS_IP_, ret, size, s->size, flags);
260
261 return ret;
262 }
263 }
264 return __kmalloc(size, flags);
265 }
266
267 #ifdef CONFIG_NUMA
268 void *__kmalloc_node(size_t size, gfp_t flags, int node);
269 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
270
271 #ifdef CONFIG_KMEMTRACE
272 extern void *kmem_cache_alloc_node_notrace(struct kmem_cache *s,
273 gfp_t gfpflags,
274 int node);
275 #else
276 static __always_inline void *
277 kmem_cache_alloc_node_notrace(struct kmem_cache *s,
278 gfp_t gfpflags,
279 int node)
280 {
281 return kmem_cache_alloc_node(s, gfpflags, node);
282 }
283 #endif
284
285 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
286 {
287 void *ret;
288
289 if (__builtin_constant_p(size) &&
290 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
291 struct kmem_cache *s = kmalloc_slab(size);
292
293 if (!s)
294 return ZERO_SIZE_PTR;
295
296 ret = kmem_cache_alloc_node_notrace(s, flags, node);
297
298 trace_kmalloc_node(_THIS_IP_, ret,
299 size, s->size, flags, node);
300
301 return ret;
302 }
303 return __kmalloc_node(size, flags, node);
304 }
305 #endif
306
307 void __init kmem_cache_init_late(void);
308
309 #endif /* _LINUX_SLUB_DEF_H */
310
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