aboutsummaryrefslogtreecommitdiffstats
path: root/mm/slab.h
blob: 620ceeddbe1ad74cfa5fb7bc5e2fc2d13f7e3191 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
#ifndef MM_SLAB_H
#define MM_SLAB_H
/*
 * Internal slab definitions
 */

/*
 * State of the slab allocator.
 *
 * This is used to describe the states of the allocator during bootup.
 * Allocators use this to gradually bootstrap themselves. Most allocators
 * have the problem that the structures used for managing slab caches are
 * allocated from slab caches themselves.
 */
enum slab_state {
	DOWN,			/* No slab functionality yet */
	PARTIAL,		/* SLUB: kmem_cache_node available */
	PARTIAL_ARRAYCACHE,	/* SLAB: kmalloc size for arraycache available */
	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */
	UP,			/* Slab caches usable but not all extras yet */
	FULL			/* Everything is working */
};

extern enum slab_state slab_state;

/* The slab cache mutex protects the management structures during changes */
extern struct mutex slab_mutex;

/* The list of all slab caches on the system */
extern struct list_head slab_caches;

/* The slab cache that manages slab cache information */
extern struct kmem_cache *kmem_cache;

unsigned long calculate_alignment(unsigned long flags,
		unsigned long align, unsigned long size);

#ifndef CONFIG_SLOB
/* Kmalloc array related functions */
void create_kmalloc_caches(unsigned long);

/* Find the kmalloc slab corresponding for a certain size */
struct kmem_cache *kmalloc_slab(size_t, gfp_t);
#endif


/* Functions provided by the slab allocators */
extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);

extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
			unsigned long flags);
extern void create_boot_cache(struct kmem_cache *, const char *name,
			size_t size, unsigned long flags);

struct mem_cgroup;
#ifdef CONFIG_SLUB
struct kmem_cache *
__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
		   size_t align, unsigned long flags, void (*ctor)(void *));
#else
static inline struct kmem_cache *
__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
		   size_t align, unsigned long flags, void (*ctor)(void *))
{ return NULL; }
#endif


/* Legal flag mask for kmem_cache_create(), for various configurations */
#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
			 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )

#if defined(CONFIG_DEBUG_SLAB)
#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
#elif defined(CONFIG_SLUB_DEBUG)
#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
			  SLAB_TRACE | SLAB_DEBUG_FREE)
#else
#define SLAB_DEBUG_FLAGS (0)
#endif

#if defined(CONFIG_SLAB)
#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
#elif defined(CONFIG_SLUB)
#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
			  SLAB_TEMPORARY | SLAB_NOTRACK)
#else
#define SLAB_CACHE_FLAGS (0)
#endif

#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)

int __kmem_cache_shutdown(struct kmem_cache *);

struct seq_file;
struct file;

struct slabinfo {
	unsigned long active_objs;
	unsigned long num_objs;
	unsigned long active_slabs;
	unsigned long num_slabs;
	unsigned long shared_avail;
	unsigned int limit;
	unsigned int batchcount;
	unsigned int shared;
	unsigned int objects_per_slab;
	unsigned int cache_order;
};

void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
ssize_t slabinfo_write(struct file *file, const char __user *buffer,
		       size_t count, loff_t *ppos);

#ifdef CONFIG_MEMCG_KMEM
static inline bool is_root_cache(struct kmem_cache *s)
{
	return !s->memcg_params || s->memcg_params->is_root_cache;
}

static inline bool cache_match_memcg(struct kmem_cache *cachep,
				     struct mem_cgroup *memcg)
{
	return (is_root_cache(cachep) && !memcg) ||
				(cachep->memcg_params->memcg == memcg);
}

static inline void memcg_bind_pages(struct kmem_cache *s, int order)
{
	if (!is_root_cache(s))
		atomic_add(1 << order, &s->memcg_params->nr_pages);
}

static inline void memcg_release_pages(struct kmem_cache *s, int order)
{
	if (is_root_cache(s))
		return;

	if (atomic_sub_and_test((1 << order), &s->memcg_params->nr_pages))
		mem_cgroup_destroy_cache(s);
}

static inline bool slab_equal_or_root(struct kmem_cache *s,
					struct kmem_cache *p)
{
	return (p == s) ||
		(s->memcg_params && (p == s->memcg_params->root_cache));
}

/*
 * We use suffixes to the name in memcg because we can't have caches
 * created in the system with the same name. But when we print them
 * locally, better refer to them with the base name
 */
static inline const char *cache_name(struct kmem_cache *s)
{
	if (!is_root_cache(s))
		return s->memcg_params->root_cache->name;
	return s->name;
}

static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
{
	return s->memcg_params->memcg_caches[idx];
}

static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
{
	if (is_root_cache(s))
		return s;
	return s->memcg_params->root_cache;
}
#else
static inline bool is_root_cache(struct kmem_cache *s)
{
	return true;
}

static inline bool cache_match_memcg(struct kmem_cache *cachep,
				     struct mem_cgroup *memcg)
{
	return true;
}

static inline void memcg_bind_pages(struct kmem_cache *s, int order)
{
}

static inline void memcg_release_pages(struct kmem_cache *s, int order)
{
}

static inline bool slab_equal_or_root(struct kmem_cache *s,
				      struct kmem_cache *p)
{
	return true;
}

static inline const char *cache_name(struct kmem_cache *s)
{
	return s->name;
}

static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
{
	return NULL;
}

static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
{
	return s;
}
#endif

static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
{
	struct kmem_cache *cachep;
	struct page *page;

	/*
	 * When kmemcg is not being used, both assignments should return the
	 * same value. but we don't want to pay the assignment price in that
	 * case. If it is not compiled in, the compiler should be smart enough
	 * to not do even the assignment. In that case, slab_equal_or_root
	 * will also be a constant.
	 */
	if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
		return s;

	page = virt_to_head_page(x);
	cachep = page->slab_cache;
	if (slab_equal_or_root(cachep, s))
		return cachep;

	pr_err("%s: Wrong slab cache. %s but object is from %s\n",
		__FUNCTION__, cachep->name, s->name);
	WARN_ON_ONCE(1);
	return s;
}
#endif


/*
 * The slab lists for all objects.
 */
struct kmem_cache_node {
	spinlock_t list_lock;

#ifdef CONFIG_SLAB
	struct list_head slabs_partial;	/* partial list first, better asm code */
	struct list_head slabs_full;
	struct list_head slabs_free;
	unsigned long free_objects;
	unsigned int free_limit;
	unsigned int colour_next;	/* Per-node cache coloring */
	struct array_cache *shared;	/* shared per node */
	struct array_cache **alien;	/* on other nodes */
	unsigned long next_reap;	/* updated without locking */
	int free_touched;		/* updated without locking */
#endif

#ifdef CONFIG_SLUB
	unsigned long nr_partial;
	struct list_head partial;
#ifdef CONFIG_SLUB_DEBUG
	atomic_long_t nr_slabs;
	atomic_long_t total_objects;
	struct list_head full;
#endif
#endif

};

void *slab_next(struct seq_file *m, void *p, loff_t *pos);
void slab_stop(struct seq_file *m, void *p);