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 ALLOC_NODE_MISMATCH, /* Switching cpu slab */
28 FREE_SLAB, /* Slab freed to the page allocator */
29 CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
30 DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
31 DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
32 DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
33 DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
34 DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
35 DEACTIVATE_BYPASS, /* Implicit deactivation */
36 ORDER_FALLBACK, /* Number of times fallback was necessary */
37 CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
38 CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
39 CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
40 CPU_PARTIAL_FREE, /* USed cpu partial on free */
41 NR_SLUB_STAT_ITEMS };
42
43 struct kmem_cache_cpu {
44 void **freelist; /* Pointer to next available object */
45 unsigned long tid; /* Globally unique transaction id */
46 struct page *page; /* The slab from which we are allocating */
47 struct page *partial; /* Partially allocated frozen slabs */
48 int node; /* The node of the page (or -1 for debug) */
49 #ifdef CONFIG_SLUB_STATS
50 unsigned stat[NR_SLUB_STAT_ITEMS];
51 #endif
52 };
53
54 struct kmem_cache_node {
55 spinlock_t list_lock; /* Protect partial list and nr_partial */
56 unsigned long nr_partial;
57 struct list_head partial;
58 #ifdef CONFIG_SLUB_DEBUG
59 atomic_long_t nr_slabs;
60 atomic_long_t total_objects;
61 struct list_head full;
62 #endif
63 };
64
65 /*
66 * Word size structure that can be atomically updated or read and that
67 * contains both the order and the number of objects that a slab of the
68 * given order would contain.
69 */
70 struct kmem_cache_order_objects {
71 unsigned long x;
72 };
73
74 /*
75 * Slab cache management.
76 */
77 struct kmem_cache {
78 struct kmem_cache_cpu __percpu *cpu_slab;
79 /* Used for retriving partial slabs etc */
80 unsigned long flags;
81 unsigned long min_partial;
82 int size; /* The size of an object including meta data */
83 int objsize; /* The size of an object without meta data */
84 int offset; /* Free pointer offset. */
85 int cpu_partial; /* Number of per cpu partial objects to keep around */
86 struct kmem_cache_order_objects oo;
87
88 /* Allocation and freeing of slabs */
89 struct kmem_cache_order_objects max;
90 struct kmem_cache_order_objects min;
91 gfp_t allocflags; /* gfp flags to use on each alloc */
92 int refcount; /* Refcount for slab cache destroy */
93 void (*ctor)(void *);
94 int inuse; /* Offset to metadata */
95 int align; /* Alignment */
96 int reserved; /* Reserved bytes at the end of slabs */
97 const char *name; /* Name (only for display!) */
98 struct list_head list; /* List of slab caches */
99 #ifdef CONFIG_SYSFS
100 struct kobject kobj; /* For sysfs */
101 #endif
102
103 #ifdef CONFIG_NUMA
104 /*
105 * Defragmentation by allocating from a remote node.
106 */
107 int remote_node_defrag_ratio;
108 #endif
109 struct kmem_cache_node *node[MAX_NUMNODES];
110 };
111
112 /*
113 * Kmalloc subsystem.
114 */
115 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
116 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
117 #else
118 #define KMALLOC_MIN_SIZE 8
119 #endif
120
121 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
122
123 /*
124 * Maximum kmalloc object size handled by SLUB. Larger object allocations
125 * are passed through to the page allocator. The page allocator "fastpath"
126 * is relatively slow so we need this value sufficiently high so that
127 * performance critical objects are allocated through the SLUB fastpath.
128 *
129 * This should be dropped to PAGE_SIZE / 2 once the page allocator
130 * "fastpath" becomes competitive with the slab allocator fastpaths.
131 */
132 #define SLUB_MAX_SIZE (2 * PAGE_SIZE)
133
134 #define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
135
136 #ifdef CONFIG_ZONE_DMA
137 #define SLUB_DMA __GFP_DMA
138 #else
139 /* Disable DMA functionality */
140 #define SLUB_DMA (__force gfp_t)0
141 #endif
142
143 /*
144 * We keep the general caches in an array of slab caches that are used for
145 * 2^x bytes of allocations.
146 */
147 extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
148
149 /*
150 * Sorry that the following has to be that ugly but some versions of GCC
151 * have trouble with constant propagation and loops.
152 */
kmalloc_index(size_t size)153 static __always_inline int kmalloc_index(size_t size)
154 {
155 if (!size)
156 return 0;
157
158 if (size <= KMALLOC_MIN_SIZE)
159 return KMALLOC_SHIFT_LOW;
160
161 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
162 return 1;
163 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
164 return 2;
165 if (size <= 8) return 3;
166 if (size <= 16) return 4;
167 if (size <= 32) return 5;
168 if (size <= 64) return 6;
169 if (size <= 128) return 7;
170 if (size <= 256) return 8;
171 if (size <= 512) return 9;
172 if (size <= 1024) return 10;
173 if (size <= 2 * 1024) return 11;
174 if (size <= 4 * 1024) return 12;
175 /*
176 * The following is only needed to support architectures with a larger page
177 * size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
178 * size we would have to go up to 128k.
179 */
180 if (size <= 8 * 1024) return 13;
181 if (size <= 16 * 1024) return 14;
182 if (size <= 32 * 1024) return 15;
183 if (size <= 64 * 1024) return 16;
184 if (size <= 128 * 1024) return 17;
185 if (size <= 256 * 1024) return 18;
186 if (size <= 512 * 1024) return 19;
187 if (size <= 1024 * 1024) return 20;
188 if (size <= 2 * 1024 * 1024) return 21;
189 BUG();
190 return -1; /* Will never be reached */
191
192 /*
193 * What we really wanted to do and cannot do because of compiler issues is:
194 * int i;
195 * for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
196 * if (size <= (1 << i))
197 * return i;
198 */
199 }
200
201 /*
202 * Find the slab cache for a given combination of allocation flags and size.
203 *
204 * This ought to end up with a global pointer to the right cache
205 * in kmalloc_caches.
206 */
kmalloc_slab(size_t size)207 static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
208 {
209 int index = kmalloc_index(size);
210
211 if (index == 0)
212 return NULL;
213
214 return kmalloc_caches[index];
215 }
216
217 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
218 void *__kmalloc(size_t size, gfp_t flags);
219
220 static __always_inline void *
kmalloc_order(size_t size,gfp_t flags,unsigned int order)221 kmalloc_order(size_t size, gfp_t flags, unsigned int order)
222 {
223 void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
224 kmemleak_alloc(ret, size, 1, flags);
225 return ret;
226 }
227
228 /**
229 * Calling this on allocated memory will check that the memory
230 * is expected to be in use, and print warnings if not.
231 */
232 #ifdef CONFIG_SLUB_DEBUG
233 extern bool verify_mem_not_deleted(const void *x);
234 #else
verify_mem_not_deleted(const void * x)235 static inline bool verify_mem_not_deleted(const void *x)
236 {
237 return true;
238 }
239 #endif
240
241 #ifdef CONFIG_TRACING
242 extern void *
243 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);
244 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
245 #else
246 static __always_inline void *
kmem_cache_alloc_trace(struct kmem_cache * s,gfp_t gfpflags,size_t size)247 kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
248 {
249 return kmem_cache_alloc(s, gfpflags);
250 }
251
252 static __always_inline void *
kmalloc_order_trace(size_t size,gfp_t flags,unsigned int order)253 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
254 {
255 return kmalloc_order(size, flags, order);
256 }
257 #endif
258
kmalloc_large(size_t size,gfp_t flags)259 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
260 {
261 unsigned int order = get_order(size);
262 return kmalloc_order_trace(size, flags, order);
263 }
264
kmalloc(size_t size,gfp_t flags)265 static __always_inline void *kmalloc(size_t size, gfp_t flags)
266 {
267 if (__builtin_constant_p(size)) {
268 if (size > SLUB_MAX_SIZE)
269 return kmalloc_large(size, flags);
270
271 if (!(flags & SLUB_DMA)) {
272 struct kmem_cache *s = kmalloc_slab(size);
273
274 if (!s)
275 return ZERO_SIZE_PTR;
276
277 return kmem_cache_alloc_trace(s, flags, size);
278 }
279 }
280 return __kmalloc(size, flags);
281 }
282
283 #ifdef CONFIG_NUMA
284 void *__kmalloc_node(size_t size, gfp_t flags, int node);
285 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
286
287 #ifdef CONFIG_TRACING
288 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
289 gfp_t gfpflags,
290 int node, size_t size);
291 #else
292 static __always_inline void *
kmem_cache_alloc_node_trace(struct kmem_cache * s,gfp_t gfpflags,int node,size_t size)293 kmem_cache_alloc_node_trace(struct kmem_cache *s,
294 gfp_t gfpflags,
295 int node, size_t size)
296 {
297 return kmem_cache_alloc_node(s, gfpflags, node);
298 }
299 #endif
300
kmalloc_node(size_t size,gfp_t flags,int node)301 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
302 {
303 if (__builtin_constant_p(size) &&
304 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
305 struct kmem_cache *s = kmalloc_slab(size);
306
307 if (!s)
308 return ZERO_SIZE_PTR;
309
310 return kmem_cache_alloc_node_trace(s, flags, node, size);
311 }
312 return __kmalloc_node(size, flags, node);
313 }
314 #endif
315
316 #endif /* _LINUX_SLUB_DEF_H */
317