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1 #ifndef MM_SLAB_H
2 #define MM_SLAB_H
3 /*
4 * Internal slab definitions
5 */
6
7 #ifdef CONFIG_SLOB
8 /*
9 * Common fields provided in kmem_cache by all slab allocators
10 * This struct is either used directly by the allocator (SLOB)
11 * or the allocator must include definitions for all fields
12 * provided in kmem_cache_common in their definition of kmem_cache.
13 *
14 * Once we can do anonymous structs (C11 standard) we could put a
15 * anonymous struct definition in these allocators so that the
16 * separate allocations in the kmem_cache structure of SLAB and
17 * SLUB is no longer needed.
18 */
19 struct kmem_cache {
20 unsigned int object_size;/* The original size of the object */
21 unsigned int size; /* The aligned/padded/added on size */
22 unsigned int align; /* Alignment as calculated */
23 unsigned long flags; /* Active flags on the slab */
24 const char *name; /* Slab name for sysfs */
25 int refcount; /* Use counter */
26 void (*ctor)(void *); /* Called on object slot creation */
27 struct list_head list; /* List of all slab caches on the system */
28 };
29
30 #endif /* CONFIG_SLOB */
31
32 #ifdef CONFIG_SLAB
33 #include <linux/slab_def.h>
34 #endif
35
36 #ifdef CONFIG_SLUB
37 #include <linux/slub_def.h>
38 #endif
39
40 #include <linux/memcontrol.h>
41
42 /*
43 * State of the slab allocator.
44 *
45 * This is used to describe the states of the allocator during bootup.
46 * Allocators use this to gradually bootstrap themselves. Most allocators
47 * have the problem that the structures used for managing slab caches are
48 * allocated from slab caches themselves.
49 */
50 enum slab_state {
51 DOWN, /* No slab functionality yet */
52 PARTIAL, /* SLUB: kmem_cache_node available */
53 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
54 UP, /* Slab caches usable but not all extras yet */
55 FULL /* Everything is working */
56 };
57
58 extern enum slab_state slab_state;
59
60 /* The slab cache mutex protects the management structures during changes */
61 extern struct mutex slab_mutex;
62
63 /* The list of all slab caches on the system */
64 extern struct list_head slab_caches;
65
66 /* The slab cache that manages slab cache information */
67 extern struct kmem_cache *kmem_cache;
68
69 unsigned long calculate_alignment(unsigned long flags,
70 unsigned long align, unsigned long size);
71
72 #ifndef CONFIG_SLOB
73 /* Kmalloc array related functions */
74 void setup_kmalloc_cache_index_table(void);
75 void create_kmalloc_caches(unsigned long);
76
77 /* Find the kmalloc slab corresponding for a certain size */
78 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
79 #endif
80
81
82 /* Functions provided by the slab allocators */
83 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
84
85 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
86 unsigned long flags);
87 extern void create_boot_cache(struct kmem_cache *, const char *name,
88 size_t size, unsigned long flags);
89
90 int slab_unmergeable(struct kmem_cache *s);
91 struct kmem_cache *find_mergeable(size_t size, size_t align,
92 unsigned long flags, const char *name, void (*ctor)(void *));
93 #ifndef CONFIG_SLOB
94 struct kmem_cache *
95 __kmem_cache_alias(const char *name, size_t size, size_t align,
96 unsigned long flags, void (*ctor)(void *));
97
98 unsigned long kmem_cache_flags(unsigned long object_size,
99 unsigned long flags, const char *name,
100 void (*ctor)(void *));
101 #else
102 static inline struct kmem_cache *
103 __kmem_cache_alias(const char *name, size_t size, size_t align,
104 unsigned long flags, void (*ctor)(void *))
105 { return NULL; }
106
107 static inline unsigned long kmem_cache_flags(unsigned long object_size,
108 unsigned long flags, const char *name,
109 void (*ctor)(void *))
110 {
111 return flags;
112 }
113 #endif
114
115
116 /* Legal flag mask for kmem_cache_create(), for various configurations */
117 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
118 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
119
120 #if defined(CONFIG_DEBUG_SLAB)
121 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
122 #elif defined(CONFIG_SLUB_DEBUG)
123 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
124 SLAB_TRACE | SLAB_DEBUG_FREE)
125 #else
126 #define SLAB_DEBUG_FLAGS (0)
127 #endif
128
129 #if defined(CONFIG_SLAB)
130 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
131 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
132 #elif defined(CONFIG_SLUB)
133 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
134 SLAB_TEMPORARY | SLAB_NOTRACK)
135 #else
136 #define SLAB_CACHE_FLAGS (0)
137 #endif
138
139 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
140
141 int __kmem_cache_shutdown(struct kmem_cache *);
142 int __kmem_cache_shrink(struct kmem_cache *, bool);
143 void slab_kmem_cache_release(struct kmem_cache *);
144
145 struct seq_file;
146 struct file;
147
148 struct slabinfo {
149 unsigned long active_objs;
150 unsigned long num_objs;
151 unsigned long active_slabs;
152 unsigned long num_slabs;
153 unsigned long shared_avail;
154 unsigned int limit;
155 unsigned int batchcount;
156 unsigned int shared;
157 unsigned int objects_per_slab;
158 unsigned int cache_order;
159 };
160
161 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
162 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
163 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
164 size_t count, loff_t *ppos);
165
166 /*
167 * Generic implementation of bulk operations
168 * These are useful for situations in which the allocator cannot
169 * perform optimizations. In that case segments of the objecct listed
170 * may be allocated or freed using these operations.
171 */
172 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
173 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
174
175 #ifdef CONFIG_MEMCG_KMEM
176 /*
177 * Iterate over all memcg caches of the given root cache. The caller must hold
178 * slab_mutex.
179 */
180 #define for_each_memcg_cache(iter, root) \
181 list_for_each_entry(iter, &(root)->memcg_params.list, \
182 memcg_params.list)
183
184 static inline bool is_root_cache(struct kmem_cache *s)
185 {
186 return s->memcg_params.is_root_cache;
187 }
188
189 static inline bool slab_equal_or_root(struct kmem_cache *s,
190 struct kmem_cache *p)
191 {
192 return p == s || p == s->memcg_params.root_cache;
193 }
194
195 /*
196 * We use suffixes to the name in memcg because we can't have caches
197 * created in the system with the same name. But when we print them
198 * locally, better refer to them with the base name
199 */
200 static inline const char *cache_name(struct kmem_cache *s)
201 {
202 if (!is_root_cache(s))
203 s = s->memcg_params.root_cache;
204 return s->name;
205 }
206
207 /*
208 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
209 * That said the caller must assure the memcg's cache won't go away by either
210 * taking a css reference to the owner cgroup, or holding the slab_mutex.
211 */
212 static inline struct kmem_cache *
213 cache_from_memcg_idx(struct kmem_cache *s, int idx)
214 {
215 struct kmem_cache *cachep;
216 struct memcg_cache_array *arr;
217
218 rcu_read_lock();
219 arr = rcu_dereference(s->memcg_params.memcg_caches);
220
221 /*
222 * Make sure we will access the up-to-date value. The code updating
223 * memcg_caches issues a write barrier to match this (see
224 * memcg_create_kmem_cache()).
225 */
226 cachep = lockless_dereference(arr->entries[idx]);
227 rcu_read_unlock();
228
229 return cachep;
230 }
231
232 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
233 {
234 if (is_root_cache(s))
235 return s;
236 return s->memcg_params.root_cache;
237 }
238
239 static __always_inline int memcg_charge_slab(struct page *page,
240 gfp_t gfp, int order,
241 struct kmem_cache *s)
242 {
243 if (!memcg_kmem_enabled())
244 return 0;
245 if (is_root_cache(s))
246 return 0;
247 return __memcg_kmem_charge_memcg(page, gfp, order,
248 s->memcg_params.memcg);
249 }
250
251 extern void slab_init_memcg_params(struct kmem_cache *);
252
253 #else /* !CONFIG_MEMCG_KMEM */
254
255 #define for_each_memcg_cache(iter, root) \
256 for ((void)(iter), (void)(root); 0; )
257
258 static inline bool is_root_cache(struct kmem_cache *s)
259 {
260 return true;
261 }
262
263 static inline bool slab_equal_or_root(struct kmem_cache *s,
264 struct kmem_cache *p)
265 {
266 return true;
267 }
268
269 static inline const char *cache_name(struct kmem_cache *s)
270 {
271 return s->name;
272 }
273
274 static inline struct kmem_cache *
275 cache_from_memcg_idx(struct kmem_cache *s, int idx)
276 {
277 return NULL;
278 }
279
280 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
281 {
282 return s;
283 }
284
285 static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
286 struct kmem_cache *s)
287 {
288 return 0;
289 }
290
291 static inline void slab_init_memcg_params(struct kmem_cache *s)
292 {
293 }
294 #endif /* CONFIG_MEMCG_KMEM */
295
296 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
297 {
298 struct kmem_cache *cachep;
299 struct page *page;
300
301 /*
302 * When kmemcg is not being used, both assignments should return the
303 * same value. but we don't want to pay the assignment price in that
304 * case. If it is not compiled in, the compiler should be smart enough
305 * to not do even the assignment. In that case, slab_equal_or_root
306 * will also be a constant.
307 */
308 if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
309 return s;
310
311 page = virt_to_head_page(x);
312 cachep = page->slab_cache;
313 if (slab_equal_or_root(cachep, s))
314 return cachep;
315
316 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
317 __func__, s->name, cachep->name);
318 WARN_ON_ONCE(1);
319 return s;
320 }
321
322 #ifndef CONFIG_SLOB
323 /*
324 * The slab lists for all objects.
325 */
326 struct kmem_cache_node {
327 spinlock_t list_lock;
328
329 #ifdef CONFIG_SLAB
330 struct list_head slabs_partial; /* partial list first, better asm code */
331 struct list_head slabs_full;
332 struct list_head slabs_free;
333 unsigned long free_objects;
334 unsigned int free_limit;
335 unsigned int colour_next; /* Per-node cache coloring */
336 struct array_cache *shared; /* shared per node */
337 struct alien_cache **alien; /* on other nodes */
338 unsigned long next_reap; /* updated without locking */
339 int free_touched; /* updated without locking */
340 #endif
341
342 #ifdef CONFIG_SLUB
343 unsigned long nr_partial;
344 struct list_head partial;
345 #ifdef CONFIG_SLUB_DEBUG
346 atomic_long_t nr_slabs;
347 atomic_long_t total_objects;
348 struct list_head full;
349 #endif
350 #endif
351
352 };
353
354 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
355 {
356 return s->node[node];
357 }
358
359 /*
360 * Iterator over all nodes. The body will be executed for each node that has
361 * a kmem_cache_node structure allocated (which is true for all online nodes)
362 */
363 #define for_each_kmem_cache_node(__s, __node, __n) \
364 for (__node = 0; __node < nr_node_ids; __node++) \
365 if ((__n = get_node(__s, __node)))
366
367 #endif
368
369 void *slab_start(struct seq_file *m, loff_t *pos);
370 void *slab_next(struct seq_file *m, void *p, loff_t *pos);
371 void slab_stop(struct seq_file *m, void *p);
372 int memcg_slab_show(struct seq_file *m, void *p);
373
374 #endif /* MM_SLAB_H */