4 * Internal slab definitions
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.
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.
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 */
30 #endif /* CONFIG_SLOB */
33 #include <linux/slab_def.h>
37 #include <linux/slub_def.h>
40 #include <linux/memcontrol.h>
41 #include <linux/fault-inject.h>
42 #include <linux/kmemcheck.h>
43 #include <linux/kasan.h>
44 #include <linux/kmemleak.h>
45 #include <linux/random.h>
46 #include <linux/sched/mm.h>
49 * State of the slab allocator.
51 * This is used to describe the states of the allocator during bootup.
52 * Allocators use this to gradually bootstrap themselves. Most allocators
53 * have the problem that the structures used for managing slab caches are
54 * allocated from slab caches themselves.
57 DOWN
, /* No slab functionality yet */
58 PARTIAL
, /* SLUB: kmem_cache_node available */
59 PARTIAL_NODE
, /* SLAB: kmalloc size for node struct available */
60 UP
, /* Slab caches usable but not all extras yet */
61 FULL
/* Everything is working */
64 extern enum slab_state slab_state
;
66 /* The slab cache mutex protects the management structures during changes */
67 extern struct mutex slab_mutex
;
69 /* The list of all slab caches on the system */
70 extern struct list_head slab_caches
;
72 /* The slab cache that manages slab cache information */
73 extern struct kmem_cache
*kmem_cache
;
75 /* A table of kmalloc cache names and sizes */
76 extern const struct kmalloc_info_struct
{
81 unsigned long calculate_alignment(unsigned long flags
,
82 unsigned long align
, unsigned long size
);
85 /* Kmalloc array related functions */
86 void setup_kmalloc_cache_index_table(void);
87 void create_kmalloc_caches(unsigned long);
89 /* Find the kmalloc slab corresponding for a certain size */
90 struct kmem_cache
*kmalloc_slab(size_t, gfp_t
);
94 /* Functions provided by the slab allocators */
95 extern int __kmem_cache_create(struct kmem_cache
*, unsigned long flags
);
97 extern struct kmem_cache
*create_kmalloc_cache(const char *name
, size_t size
,
99 extern void create_boot_cache(struct kmem_cache
*, const char *name
,
100 size_t size
, unsigned long flags
);
102 int slab_unmergeable(struct kmem_cache
*s
);
103 struct kmem_cache
*find_mergeable(size_t size
, size_t align
,
104 unsigned long flags
, const char *name
, void (*ctor
)(void *));
107 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
108 unsigned long flags
, void (*ctor
)(void *));
110 unsigned long kmem_cache_flags(unsigned long object_size
,
111 unsigned long flags
, const char *name
,
112 void (*ctor
)(void *));
114 static inline struct kmem_cache
*
115 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
116 unsigned long flags
, void (*ctor
)(void *))
119 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
120 unsigned long flags
, const char *name
,
121 void (*ctor
)(void *))
128 /* Legal flag mask for kmem_cache_create(), for various configurations */
129 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
130 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
132 #if defined(CONFIG_DEBUG_SLAB)
133 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
134 #elif defined(CONFIG_SLUB_DEBUG)
135 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
136 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
138 #define SLAB_DEBUG_FLAGS (0)
141 #if defined(CONFIG_SLAB)
142 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
143 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
144 SLAB_NOTRACK | SLAB_ACCOUNT)
145 #elif defined(CONFIG_SLUB)
146 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
147 SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)
149 #define SLAB_CACHE_FLAGS (0)
152 /* Common flags available with current configuration */
153 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
155 /* Common flags permitted for kmem_cache_create */
156 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
161 SLAB_CONSISTENCY_CHECKS | \
164 SLAB_RECLAIM_ACCOUNT | \
169 int __kmem_cache_shutdown(struct kmem_cache
*);
170 void __kmem_cache_release(struct kmem_cache
*);
171 int __kmem_cache_shrink(struct kmem_cache
*);
172 void __kmemcg_cache_deactivate(struct kmem_cache
*s
);
173 void slab_kmem_cache_release(struct kmem_cache
*);
179 unsigned long active_objs
;
180 unsigned long num_objs
;
181 unsigned long active_slabs
;
182 unsigned long num_slabs
;
183 unsigned long shared_avail
;
185 unsigned int batchcount
;
187 unsigned int objects_per_slab
;
188 unsigned int cache_order
;
191 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
);
192 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
);
193 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
194 size_t count
, loff_t
*ppos
);
197 * Generic implementation of bulk operations
198 * These are useful for situations in which the allocator cannot
199 * perform optimizations. In that case segments of the object listed
200 * may be allocated or freed using these operations.
202 void __kmem_cache_free_bulk(struct kmem_cache
*, size_t, void **);
203 int __kmem_cache_alloc_bulk(struct kmem_cache
*, gfp_t
, size_t, void **);
205 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
207 /* List of all root caches. */
208 extern struct list_head slab_root_caches
;
209 #define root_caches_node memcg_params.__root_caches_node
212 * Iterate over all memcg caches of the given root cache. The caller must hold
215 #define for_each_memcg_cache(iter, root) \
216 list_for_each_entry(iter, &(root)->memcg_params.children, \
217 memcg_params.children_node)
219 static inline bool is_root_cache(struct kmem_cache
*s
)
221 return !s
->memcg_params
.root_cache
;
224 static inline bool slab_equal_or_root(struct kmem_cache
*s
,
225 struct kmem_cache
*p
)
227 return p
== s
|| p
== s
->memcg_params
.root_cache
;
231 * We use suffixes to the name in memcg because we can't have caches
232 * created in the system with the same name. But when we print them
233 * locally, better refer to them with the base name
235 static inline const char *cache_name(struct kmem_cache
*s
)
237 if (!is_root_cache(s
))
238 s
= s
->memcg_params
.root_cache
;
243 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
244 * That said the caller must assure the memcg's cache won't go away by either
245 * taking a css reference to the owner cgroup, or holding the slab_mutex.
247 static inline struct kmem_cache
*
248 cache_from_memcg_idx(struct kmem_cache
*s
, int idx
)
250 struct kmem_cache
*cachep
;
251 struct memcg_cache_array
*arr
;
254 arr
= rcu_dereference(s
->memcg_params
.memcg_caches
);
257 * Make sure we will access the up-to-date value. The code updating
258 * memcg_caches issues a write barrier to match this (see
259 * memcg_create_kmem_cache()).
261 cachep
= lockless_dereference(arr
->entries
[idx
]);
267 static inline struct kmem_cache
*memcg_root_cache(struct kmem_cache
*s
)
269 if (is_root_cache(s
))
271 return s
->memcg_params
.root_cache
;
274 static __always_inline
int memcg_charge_slab(struct page
*page
,
275 gfp_t gfp
, int order
,
276 struct kmem_cache
*s
)
278 if (!memcg_kmem_enabled())
280 if (is_root_cache(s
))
282 return memcg_kmem_charge_memcg(page
, gfp
, order
, s
->memcg_params
.memcg
);
285 static __always_inline
void memcg_uncharge_slab(struct page
*page
, int order
,
286 struct kmem_cache
*s
)
288 if (!memcg_kmem_enabled())
290 memcg_kmem_uncharge(page
, order
);
293 extern void slab_init_memcg_params(struct kmem_cache
*);
294 extern void memcg_link_cache(struct kmem_cache
*s
);
295 extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache
*s
,
296 void (*deact_fn
)(struct kmem_cache
*));
298 #else /* CONFIG_MEMCG && !CONFIG_SLOB */
300 /* If !memcg, all caches are root. */
301 #define slab_root_caches slab_caches
302 #define root_caches_node list
304 #define for_each_memcg_cache(iter, root) \
305 for ((void)(iter), (void)(root); 0; )
307 static inline bool is_root_cache(struct kmem_cache
*s
)
312 static inline bool slab_equal_or_root(struct kmem_cache
*s
,
313 struct kmem_cache
*p
)
318 static inline const char *cache_name(struct kmem_cache
*s
)
323 static inline struct kmem_cache
*
324 cache_from_memcg_idx(struct kmem_cache
*s
, int idx
)
329 static inline struct kmem_cache
*memcg_root_cache(struct kmem_cache
*s
)
334 static inline int memcg_charge_slab(struct page
*page
, gfp_t gfp
, int order
,
335 struct kmem_cache
*s
)
340 static inline void memcg_uncharge_slab(struct page
*page
, int order
,
341 struct kmem_cache
*s
)
345 static inline void slab_init_memcg_params(struct kmem_cache
*s
)
349 static inline void memcg_link_cache(struct kmem_cache
*s
)
353 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
355 static inline struct kmem_cache
*cache_from_obj(struct kmem_cache
*s
, void *x
)
357 struct kmem_cache
*cachep
;
361 * When kmemcg is not being used, both assignments should return the
362 * same value. but we don't want to pay the assignment price in that
363 * case. If it is not compiled in, the compiler should be smart enough
364 * to not do even the assignment. In that case, slab_equal_or_root
365 * will also be a constant.
367 if (!memcg_kmem_enabled() &&
368 !unlikely(s
->flags
& SLAB_CONSISTENCY_CHECKS
))
371 page
= virt_to_head_page(x
);
372 cachep
= page
->slab_cache
;
373 if (slab_equal_or_root(cachep
, s
))
376 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
377 __func__
, s
->name
, cachep
->name
);
382 static inline size_t slab_ksize(const struct kmem_cache
*s
)
385 return s
->object_size
;
387 #else /* CONFIG_SLUB */
388 # ifdef CONFIG_SLUB_DEBUG
390 * Debugging requires use of the padding between object
391 * and whatever may come after it.
393 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
394 return s
->object_size
;
396 if (s
->flags
& SLAB_KASAN
)
397 return s
->object_size
;
399 * If we have the need to store the freelist pointer
400 * back there or track user information then we can
401 * only use the space before that information.
403 if (s
->flags
& (SLAB_TYPESAFE_BY_RCU
| SLAB_STORE_USER
))
406 * Else we can use all the padding etc for the allocation
412 static inline struct kmem_cache
*slab_pre_alloc_hook(struct kmem_cache
*s
,
415 flags
&= gfp_allowed_mask
;
417 fs_reclaim_acquire(flags
);
418 fs_reclaim_release(flags
);
420 might_sleep_if(gfpflags_allow_blocking(flags
));
422 if (should_failslab(s
, flags
))
425 if (memcg_kmem_enabled() &&
426 ((flags
& __GFP_ACCOUNT
) || (s
->flags
& SLAB_ACCOUNT
)))
427 return memcg_kmem_get_cache(s
);
432 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
433 size_t size
, void **p
)
437 flags
&= gfp_allowed_mask
;
438 for (i
= 0; i
< size
; i
++) {
441 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
442 kmemleak_alloc_recursive(object
, s
->object_size
, 1,
444 kasan_slab_alloc(s
, object
, flags
);
447 if (memcg_kmem_enabled())
448 memcg_kmem_put_cache(s
);
453 * The slab lists for all objects.
455 struct kmem_cache_node
{
456 spinlock_t list_lock
;
459 struct list_head slabs_partial
; /* partial list first, better asm code */
460 struct list_head slabs_full
;
461 struct list_head slabs_free
;
462 unsigned long total_slabs
; /* length of all slab lists */
463 unsigned long free_slabs
; /* length of free slab list only */
464 unsigned long free_objects
;
465 unsigned int free_limit
;
466 unsigned int colour_next
; /* Per-node cache coloring */
467 struct array_cache
*shared
; /* shared per node */
468 struct alien_cache
**alien
; /* on other nodes */
469 unsigned long next_reap
; /* updated without locking */
470 int free_touched
; /* updated without locking */
474 unsigned long nr_partial
;
475 struct list_head partial
;
476 #ifdef CONFIG_SLUB_DEBUG
477 atomic_long_t nr_slabs
;
478 atomic_long_t total_objects
;
479 struct list_head full
;
485 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
487 return s
->node
[node
];
491 * Iterator over all nodes. The body will be executed for each node that has
492 * a kmem_cache_node structure allocated (which is true for all online nodes)
494 #define for_each_kmem_cache_node(__s, __node, __n) \
495 for (__node = 0; __node < nr_node_ids; __node++) \
496 if ((__n = get_node(__s, __node)))
500 void *slab_start(struct seq_file
*m
, loff_t
*pos
);
501 void *slab_next(struct seq_file
*m
, void *p
, loff_t
*pos
);
502 void slab_stop(struct seq_file
*m
, void *p
);
503 void *memcg_slab_start(struct seq_file
*m
, loff_t
*pos
);
504 void *memcg_slab_next(struct seq_file
*m
, void *p
, loff_t
*pos
);
505 void memcg_slab_stop(struct seq_file
*m
, void *p
);
506 int memcg_slab_show(struct seq_file
*m
, void *p
);
508 void ___cache_free(struct kmem_cache
*cache
, void *x
, unsigned long addr
);
510 #ifdef CONFIG_SLAB_FREELIST_RANDOM
511 int cache_random_seq_create(struct kmem_cache
*cachep
, unsigned int count
,
513 void cache_random_seq_destroy(struct kmem_cache
*cachep
);
515 static inline int cache_random_seq_create(struct kmem_cache
*cachep
,
516 unsigned int count
, gfp_t gfp
)
520 static inline void cache_random_seq_destroy(struct kmem_cache
*cachep
) { }
521 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
523 #endif /* MM_SLAB_H */