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>
48 * State of the slab allocator.
50 * This is used to describe the states of the allocator during bootup.
51 * Allocators use this to gradually bootstrap themselves. Most allocators
52 * have the problem that the structures used for managing slab caches are
53 * allocated from slab caches themselves.
56 DOWN
, /* No slab functionality yet */
57 PARTIAL
, /* SLUB: kmem_cache_node available */
58 PARTIAL_NODE
, /* SLAB: kmalloc size for node struct available */
59 UP
, /* Slab caches usable but not all extras yet */
60 FULL
/* Everything is working */
63 extern enum slab_state slab_state
;
65 /* The slab cache mutex protects the management structures during changes */
66 extern struct mutex slab_mutex
;
68 /* The list of all slab caches on the system */
69 extern struct list_head slab_caches
;
71 /* The slab cache that manages slab cache information */
72 extern struct kmem_cache
*kmem_cache
;
74 /* A table of kmalloc cache names and sizes */
75 extern const struct kmalloc_info_struct
{
80 unsigned long calculate_alignment(unsigned long flags
,
81 unsigned long align
, unsigned long size
);
84 /* Kmalloc array related functions */
85 void setup_kmalloc_cache_index_table(void);
86 void create_kmalloc_caches(unsigned long);
88 /* Find the kmalloc slab corresponding for a certain size */
89 struct kmem_cache
*kmalloc_slab(size_t, gfp_t
);
93 /* Functions provided by the slab allocators */
94 extern int __kmem_cache_create(struct kmem_cache
*, unsigned long flags
);
96 extern struct kmem_cache
*create_kmalloc_cache(const char *name
, size_t size
,
98 extern void create_boot_cache(struct kmem_cache
*, const char *name
,
99 size_t size
, unsigned long flags
);
101 int slab_unmergeable(struct kmem_cache
*s
);
102 struct kmem_cache
*find_mergeable(size_t size
, size_t align
,
103 unsigned long flags
, const char *name
, void (*ctor
)(void *));
106 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
107 unsigned long flags
, void (*ctor
)(void *));
109 unsigned long kmem_cache_flags(unsigned long object_size
,
110 unsigned long flags
, const char *name
,
111 void (*ctor
)(void *));
113 static inline struct kmem_cache
*
114 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
115 unsigned long flags
, void (*ctor
)(void *))
118 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
119 unsigned long flags
, const char *name
,
120 void (*ctor
)(void *))
127 /* Legal flag mask for kmem_cache_create(), for various configurations */
128 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
129 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
131 #if defined(CONFIG_DEBUG_SLAB)
132 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
133 #elif defined(CONFIG_SLUB_DEBUG)
134 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
135 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
137 #define SLAB_DEBUG_FLAGS (0)
140 #if defined(CONFIG_SLAB)
141 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
142 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
143 SLAB_NOTRACK | SLAB_ACCOUNT)
144 #elif defined(CONFIG_SLUB)
145 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
146 SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)
148 #define SLAB_CACHE_FLAGS (0)
151 /* Common flags available with current configuration */
152 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
154 /* Common flags permitted for kmem_cache_create */
155 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
160 SLAB_CONSISTENCY_CHECKS | \
163 SLAB_RECLAIM_ACCOUNT | \
168 int __kmem_cache_shutdown(struct kmem_cache
*);
169 void __kmem_cache_release(struct kmem_cache
*);
170 int __kmem_cache_shrink(struct kmem_cache
*, bool);
171 void slab_kmem_cache_release(struct kmem_cache
*);
177 unsigned long active_objs
;
178 unsigned long num_objs
;
179 unsigned long active_slabs
;
180 unsigned long num_slabs
;
181 unsigned long shared_avail
;
183 unsigned int batchcount
;
185 unsigned int objects_per_slab
;
186 unsigned int cache_order
;
189 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
);
190 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
);
191 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
192 size_t count
, loff_t
*ppos
);
195 * Generic implementation of bulk operations
196 * These are useful for situations in which the allocator cannot
197 * perform optimizations. In that case segments of the object listed
198 * may be allocated or freed using these operations.
200 void __kmem_cache_free_bulk(struct kmem_cache
*, size_t, void **);
201 int __kmem_cache_alloc_bulk(struct kmem_cache
*, gfp_t
, size_t, void **);
203 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
205 * Iterate over all memcg caches of the given root cache. The caller must hold
208 #define for_each_memcg_cache(iter, root) \
209 list_for_each_entry(iter, &(root)->memcg_params.children, \
210 memcg_params.children_node)
212 static inline bool is_root_cache(struct kmem_cache
*s
)
214 return !s
->memcg_params
.root_cache
;
217 static inline bool slab_equal_or_root(struct kmem_cache
*s
,
218 struct kmem_cache
*p
)
220 return p
== s
|| p
== s
->memcg_params
.root_cache
;
224 * We use suffixes to the name in memcg because we can't have caches
225 * created in the system with the same name. But when we print them
226 * locally, better refer to them with the base name
228 static inline const char *cache_name(struct kmem_cache
*s
)
230 if (!is_root_cache(s
))
231 s
= s
->memcg_params
.root_cache
;
236 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
237 * That said the caller must assure the memcg's cache won't go away by either
238 * taking a css reference to the owner cgroup, or holding the slab_mutex.
240 static inline struct kmem_cache
*
241 cache_from_memcg_idx(struct kmem_cache
*s
, int idx
)
243 struct kmem_cache
*cachep
;
244 struct memcg_cache_array
*arr
;
247 arr
= rcu_dereference(s
->memcg_params
.memcg_caches
);
250 * Make sure we will access the up-to-date value. The code updating
251 * memcg_caches issues a write barrier to match this (see
252 * memcg_create_kmem_cache()).
254 cachep
= lockless_dereference(arr
->entries
[idx
]);
260 static inline struct kmem_cache
*memcg_root_cache(struct kmem_cache
*s
)
262 if (is_root_cache(s
))
264 return s
->memcg_params
.root_cache
;
267 static __always_inline
int memcg_charge_slab(struct page
*page
,
268 gfp_t gfp
, int order
,
269 struct kmem_cache
*s
)
273 if (!memcg_kmem_enabled())
275 if (is_root_cache(s
))
278 ret
= memcg_kmem_charge_memcg(page
, gfp
, order
, s
->memcg_params
.memcg
);
282 memcg_kmem_update_page_stat(page
,
283 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
284 MEMCG_SLAB_RECLAIMABLE
: MEMCG_SLAB_UNRECLAIMABLE
,
289 static __always_inline
void memcg_uncharge_slab(struct page
*page
, int order
,
290 struct kmem_cache
*s
)
292 if (!memcg_kmem_enabled())
295 memcg_kmem_update_page_stat(page
,
296 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
297 MEMCG_SLAB_RECLAIMABLE
: MEMCG_SLAB_UNRECLAIMABLE
,
299 memcg_kmem_uncharge(page
, order
);
302 extern void slab_init_memcg_params(struct kmem_cache
*);
304 #else /* CONFIG_MEMCG && !CONFIG_SLOB */
306 #define for_each_memcg_cache(iter, root) \
307 for ((void)(iter), (void)(root); 0; )
309 static inline bool is_root_cache(struct kmem_cache
*s
)
314 static inline bool slab_equal_or_root(struct kmem_cache
*s
,
315 struct kmem_cache
*p
)
320 static inline const char *cache_name(struct kmem_cache
*s
)
325 static inline struct kmem_cache
*
326 cache_from_memcg_idx(struct kmem_cache
*s
, int idx
)
331 static inline struct kmem_cache
*memcg_root_cache(struct kmem_cache
*s
)
336 static inline int memcg_charge_slab(struct page
*page
, gfp_t gfp
, int order
,
337 struct kmem_cache
*s
)
342 static inline void memcg_uncharge_slab(struct page
*page
, int order
,
343 struct kmem_cache
*s
)
347 static inline void slab_init_memcg_params(struct kmem_cache
*s
)
350 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
352 static inline struct kmem_cache
*cache_from_obj(struct kmem_cache
*s
, void *x
)
354 struct kmem_cache
*cachep
;
358 * When kmemcg is not being used, both assignments should return the
359 * same value. but we don't want to pay the assignment price in that
360 * case. If it is not compiled in, the compiler should be smart enough
361 * to not do even the assignment. In that case, slab_equal_or_root
362 * will also be a constant.
364 if (!memcg_kmem_enabled() &&
365 !unlikely(s
->flags
& SLAB_CONSISTENCY_CHECKS
))
368 page
= virt_to_head_page(x
);
369 cachep
= page
->slab_cache
;
370 if (slab_equal_or_root(cachep
, s
))
373 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
374 __func__
, s
->name
, cachep
->name
);
379 static inline size_t slab_ksize(const struct kmem_cache
*s
)
382 return s
->object_size
;
384 #else /* CONFIG_SLUB */
385 # ifdef CONFIG_SLUB_DEBUG
387 * Debugging requires use of the padding between object
388 * and whatever may come after it.
390 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
391 return s
->object_size
;
393 if (s
->flags
& SLAB_KASAN
)
394 return s
->object_size
;
396 * If we have the need to store the freelist pointer
397 * back there or track user information then we can
398 * only use the space before that information.
400 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
403 * Else we can use all the padding etc for the allocation
409 static inline struct kmem_cache
*slab_pre_alloc_hook(struct kmem_cache
*s
,
412 flags
&= gfp_allowed_mask
;
413 lockdep_trace_alloc(flags
);
414 might_sleep_if(gfpflags_allow_blocking(flags
));
416 if (should_failslab(s
, flags
))
419 if (memcg_kmem_enabled() &&
420 ((flags
& __GFP_ACCOUNT
) || (s
->flags
& SLAB_ACCOUNT
)))
421 return memcg_kmem_get_cache(s
);
426 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
427 size_t size
, void **p
)
431 flags
&= gfp_allowed_mask
;
432 for (i
= 0; i
< size
; i
++) {
435 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
436 kmemleak_alloc_recursive(object
, s
->object_size
, 1,
438 kasan_slab_alloc(s
, object
, flags
);
441 if (memcg_kmem_enabled())
442 memcg_kmem_put_cache(s
);
447 * The slab lists for all objects.
449 struct kmem_cache_node
{
450 spinlock_t list_lock
;
453 struct list_head slabs_partial
; /* partial list first, better asm code */
454 struct list_head slabs_full
;
455 struct list_head slabs_free
;
456 unsigned long total_slabs
; /* length of all slab lists */
457 unsigned long free_slabs
; /* length of free slab list only */
458 unsigned long free_objects
;
459 unsigned int free_limit
;
460 unsigned int colour_next
; /* Per-node cache coloring */
461 struct array_cache
*shared
; /* shared per node */
462 struct alien_cache
**alien
; /* on other nodes */
463 unsigned long next_reap
; /* updated without locking */
464 int free_touched
; /* updated without locking */
468 unsigned long nr_partial
;
469 struct list_head partial
;
470 #ifdef CONFIG_SLUB_DEBUG
471 atomic_long_t nr_slabs
;
472 atomic_long_t total_objects
;
473 struct list_head full
;
479 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
481 return s
->node
[node
];
485 * Iterator over all nodes. The body will be executed for each node that has
486 * a kmem_cache_node structure allocated (which is true for all online nodes)
488 #define for_each_kmem_cache_node(__s, __node, __n) \
489 for (__node = 0; __node < nr_node_ids; __node++) \
490 if ((__n = get_node(__s, __node)))
494 void *slab_start(struct seq_file
*m
, loff_t
*pos
);
495 void *slab_next(struct seq_file
*m
, void *p
, loff_t
*pos
);
496 void slab_stop(struct seq_file
*m
, void *p
);
497 void *memcg_slab_start(struct seq_file
*m
, loff_t
*pos
);
498 void *memcg_slab_next(struct seq_file
*m
, void *p
, loff_t
*pos
);
499 void memcg_slab_stop(struct seq_file
*m
, void *p
);
500 int memcg_slab_show(struct seq_file
*m
, void *p
);
502 void ___cache_free(struct kmem_cache
*cache
, void *x
, unsigned long addr
);
504 #ifdef CONFIG_SLAB_FREELIST_RANDOM
505 int cache_random_seq_create(struct kmem_cache
*cachep
, unsigned int count
,
507 void cache_random_seq_destroy(struct kmem_cache
*cachep
);
509 static inline int cache_random_seq_create(struct kmem_cache
*cachep
,
510 unsigned int count
, gfp_t gfp
)
514 static inline void cache_random_seq_destroy(struct kmem_cache
*cachep
) { }
515 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
517 #endif /* MM_SLAB_H */