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