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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 *
__kmem_cache_alias(const char * name,size_t size,size_t align,unsigned long flags,void (* ctor)(void *))103 __kmem_cache_alias(const char *name, size_t size, size_t align,
104 		   unsigned long flags, void (*ctor)(void *))
105 { return NULL; }
106 
kmem_cache_flags(unsigned long object_size,unsigned long flags,const char * name,void (* ctor)(void *))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 (SLAB_NOLEAKTRACE)
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 
is_root_cache(struct kmem_cache * s)184 static inline bool is_root_cache(struct kmem_cache *s)
185 {
186 	return s->memcg_params.is_root_cache;
187 }
188 
slab_equal_or_root(struct kmem_cache * s,struct kmem_cache * p)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  */
cache_name(struct kmem_cache * s)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 *
cache_from_memcg_idx(struct kmem_cache * s,int idx)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 
memcg_root_cache(struct kmem_cache * s)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 
memcg_charge_slab(struct page * page,gfp_t gfp,int order,struct kmem_cache * s)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 
is_root_cache(struct kmem_cache * s)258 static inline bool is_root_cache(struct kmem_cache *s)
259 {
260 	return true;
261 }
262 
slab_equal_or_root(struct kmem_cache * s,struct kmem_cache * p)263 static inline bool slab_equal_or_root(struct kmem_cache *s,
264 				      struct kmem_cache *p)
265 {
266 	return true;
267 }
268 
cache_name(struct kmem_cache * s)269 static inline const char *cache_name(struct kmem_cache *s)
270 {
271 	return s->name;
272 }
273 
274 static inline struct kmem_cache *
cache_from_memcg_idx(struct kmem_cache * s,int idx)275 cache_from_memcg_idx(struct kmem_cache *s, int idx)
276 {
277 	return NULL;
278 }
279 
memcg_root_cache(struct kmem_cache * s)280 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
281 {
282 	return s;
283 }
284 
memcg_charge_slab(struct page * page,gfp_t gfp,int order,struct kmem_cache * s)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 
slab_init_memcg_params(struct kmem_cache * s)291 static inline void slab_init_memcg_params(struct kmem_cache *s)
292 {
293 }
294 #endif /* CONFIG_MEMCG_KMEM */
295 
cache_from_obj(struct kmem_cache * s,void * x)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 
get_node(struct kmem_cache * s,int node)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 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
375 
376 #endif /* MM_SLAB_H */
377