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1#ifndef _LINUX_SLUB_DEF_H
2#define _LINUX_SLUB_DEF_H
3
4/*
5 * SLUB : A Slab allocator without object queues.
6 *
cde53535 7 * (C) 2007 SGI, Christoph Lameter
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8 */
9#include <linux/types.h>
10#include <linux/gfp.h>
11#include <linux/workqueue.h>
12#include <linux/kobject.h>
13
4a92379b 14#include <linux/kmemleak.h>
039ca4e7 15
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16enum 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 */
65c3376a 34 ORDER_FALLBACK, /* Number of times fallback was necessary */
4fdccdfb 35 CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
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36 NR_SLUB_STAT_ITEMS };
37
dfb4f096 38struct kmem_cache_cpu {
8a5ec0ba 39 void **freelist; /* Pointer to next available object */
8a5ec0ba 40 unsigned long tid; /* Globally unique transaction id */
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41 struct page *page; /* The slab from which we are allocating */
42 int node; /* The node of the page (or -1 for debug) */
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43#ifdef CONFIG_SLUB_STATS
44 unsigned stat[NR_SLUB_STAT_ITEMS];
45#endif
4c93c355 46};
dfb4f096 47
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48struct kmem_cache_node {
49 spinlock_t list_lock; /* Protect partial list and nr_partial */
50 unsigned long nr_partial;
81819f0f 51 struct list_head partial;
0c710013 52#ifdef CONFIG_SLUB_DEBUG
0f389ec6 53 atomic_long_t nr_slabs;
205ab99d 54 atomic_long_t total_objects;
643b1138 55 struct list_head full;
0c710013 56#endif
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57};
58
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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 */
64struct kmem_cache_order_objects {
65 unsigned long x;
66};
67
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68/*
69 * Slab cache management.
70 */
71struct kmem_cache {
1b5ad248 72 struct kmem_cache_cpu __percpu *cpu_slab;
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73 /* Used for retriving partial slabs etc */
74 unsigned long flags;
1a757fe5 75 unsigned long min_partial;
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76 int size; /* The size of an object including meta data */
77 int objsize; /* The size of an object without meta data */
78 int offset; /* Free pointer offset. */
834f3d11 79 struct kmem_cache_order_objects oo;
81819f0f 80
81819f0f 81 /* Allocation and freeing of slabs */
205ab99d 82 struct kmem_cache_order_objects max;
65c3376a 83 struct kmem_cache_order_objects min;
b7a49f0d 84 gfp_t allocflags; /* gfp flags to use on each alloc */
81819f0f 85 int refcount; /* Refcount for slab cache destroy */
51cc5068 86 void (*ctor)(void *);
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87 int inuse; /* Offset to metadata */
88 int align; /* Alignment */
ab9a0f19 89 int reserved; /* Reserved bytes at the end of slabs */
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90 const char *name; /* Name (only for display!) */
91 struct list_head list; /* List of slab caches */
ab4d5ed5 92#ifdef CONFIG_SYSFS
81819f0f 93 struct kobject kobj; /* For sysfs */
0c710013 94#endif
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95
96#ifdef CONFIG_NUMA
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97 /*
98 * Defragmentation by allocating from a remote node.
99 */
100 int remote_node_defrag_ratio;
81819f0f 101#endif
7340cc84 102 struct kmem_cache_node *node[MAX_NUMNODES];
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103};
104
105/*
106 * Kmalloc subsystem.
107 */
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108#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
109#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
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110#else
111#define KMALLOC_MIN_SIZE 8
112#endif
113
114#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
81819f0f 115
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116#ifdef ARCH_DMA_MINALIGN
117#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
118#else
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119#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
120#endif
121
122#ifndef ARCH_SLAB_MINALIGN
123#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
124#endif
125
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126/*
127 * Maximum kmalloc object size handled by SLUB. Larger object allocations
128 * are passed through to the page allocator. The page allocator "fastpath"
129 * is relatively slow so we need this value sufficiently high so that
130 * performance critical objects are allocated through the SLUB fastpath.
131 *
132 * This should be dropped to PAGE_SIZE / 2 once the page allocator
133 * "fastpath" becomes competitive with the slab allocator fastpaths.
134 */
51735a7c 135#define SLUB_MAX_SIZE (2 * PAGE_SIZE)
ffadd4d0 136
51735a7c 137#define SLUB_PAGE_SHIFT (PAGE_SHIFT + 2)
ffadd4d0 138
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139#ifdef CONFIG_ZONE_DMA
140#define SLUB_DMA __GFP_DMA
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141#else
142/* Disable DMA functionality */
143#define SLUB_DMA (__force gfp_t)0
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144#endif
145
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146/*
147 * We keep the general caches in an array of slab caches that are used for
148 * 2^x bytes of allocations.
149 */
51df1142 150extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
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151
152/*
153 * Sorry that the following has to be that ugly but some versions of GCC
154 * have trouble with constant propagation and loops.
155 */
aa137f9d 156static __always_inline int kmalloc_index(size_t size)
81819f0f 157{
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158 if (!size)
159 return 0;
614410d5 160
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161 if (size <= KMALLOC_MIN_SIZE)
162 return KMALLOC_SHIFT_LOW;
163
acdfcd04 164 if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
81819f0f 165 return 1;
acdfcd04 166 if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
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167 return 2;
168 if (size <= 8) return 3;
169 if (size <= 16) return 4;
170 if (size <= 32) return 5;
171 if (size <= 64) return 6;
172 if (size <= 128) return 7;
173 if (size <= 256) return 8;
174 if (size <= 512) return 9;
175 if (size <= 1024) return 10;
176 if (size <= 2 * 1024) return 11;
6446faa2 177 if (size <= 4 * 1024) return 12;
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178/*
179 * The following is only needed to support architectures with a larger page
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180 * size than 4k. We need to support 2 * PAGE_SIZE here. So for a 64k page
181 * size we would have to go up to 128k.
aadb4bc4 182 */
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183 if (size <= 8 * 1024) return 13;
184 if (size <= 16 * 1024) return 14;
185 if (size <= 32 * 1024) return 15;
186 if (size <= 64 * 1024) return 16;
187 if (size <= 128 * 1024) return 17;
188 if (size <= 256 * 1024) return 18;
aadb4bc4 189 if (size <= 512 * 1024) return 19;
81819f0f 190 if (size <= 1024 * 1024) return 20;
81819f0f 191 if (size <= 2 * 1024 * 1024) return 21;
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192 BUG();
193 return -1; /* Will never be reached */
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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 */
aa137f9d 210static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
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211{
212 int index = kmalloc_index(size);
213
214 if (index == 0)
215 return NULL;
216
51df1142 217 return kmalloc_caches[index];
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218}
219
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220void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
221void *__kmalloc(size_t size, gfp_t flags);
222
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223static __always_inline void *
224kmalloc_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
0f24f128 231#ifdef CONFIG_TRACING
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232extern void *
233kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size);
234extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
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235#else
236static __always_inline void *
4a92379b 237kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
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238{
239 return kmem_cache_alloc(s, gfpflags);
240}
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241
242static __always_inline void *
243kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
244{
245 return kmalloc_order(size, flags, order);
246}
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247#endif
248
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249static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
250{
5b882be4 251 unsigned int order = get_order(size);
4a92379b 252 return kmalloc_order_trace(size, flags, order);
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253}
254
aa137f9d 255static __always_inline void *kmalloc(size_t size, gfp_t flags)
81819f0f 256{
aadb4bc4 257 if (__builtin_constant_p(size)) {
ffadd4d0 258 if (size > SLUB_MAX_SIZE)
eada35ef 259 return kmalloc_large(size, flags);
81819f0f 260
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261 if (!(flags & SLUB_DMA)) {
262 struct kmem_cache *s = kmalloc_slab(size);
263
264 if (!s)
265 return ZERO_SIZE_PTR;
81819f0f 266
4a92379b 267 return kmem_cache_alloc_trace(s, flags, size);
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268 }
269 }
270 return __kmalloc(size, flags);
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271}
272
81819f0f 273#ifdef CONFIG_NUMA
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274void *__kmalloc_node(size_t size, gfp_t flags, int node);
275void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
81819f0f 276
0f24f128 277#ifdef CONFIG_TRACING
4a92379b 278extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
5b882be4 279 gfp_t gfpflags,
4a92379b 280 int node, size_t size);
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281#else
282static __always_inline void *
4a92379b 283kmem_cache_alloc_node_trace(struct kmem_cache *s,
5b882be4 284 gfp_t gfpflags,
4a92379b 285 int node, size_t size)
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286{
287 return kmem_cache_alloc_node(s, gfpflags, node);
288}
289#endif
290
aa137f9d 291static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
81819f0f 292{
aadb4bc4 293 if (__builtin_constant_p(size) &&
ffadd4d0 294 size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
aadb4bc4 295 struct kmem_cache *s = kmalloc_slab(size);
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296
297 if (!s)
272c1d21 298 return ZERO_SIZE_PTR;
81819f0f 299
4a92379b 300 return kmem_cache_alloc_node_trace(s, flags, node, size);
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301 }
302 return __kmalloc_node(size, flags, node);
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303}
304#endif
305
306#endif /* _LINUX_SLUB_DEF_H */