1 /* SPDX-License-Identifier: GPL-2.0 */
5 * Internal slab definitions
10 * Common fields provided in kmem_cache by all slab allocators
11 * This struct is either used directly by the allocator (SLOB)
12 * or the allocator must include definitions for all fields
13 * provided in kmem_cache_common in their definition of kmem_cache.
15 * Once we can do anonymous structs (C11 standard) we could put a
16 * anonymous struct definition in these allocators so that the
17 * separate allocations in the kmem_cache structure of SLAB and
18 * SLUB is no longer needed.
21 unsigned int object_size;/* The original size of the object */
22 unsigned int size; /* The aligned/padded/added on size */
23 unsigned int align; /* Alignment as calculated */
24 slab_flags_t flags; /* Active flags on the slab */
25 const char *name; /* Slab name for sysfs */
26 int refcount; /* Use counter */
27 void (*ctor)(void *); /* Called on object slot creation */
28 struct list_head list; /* List of all slab caches on the system */
31 #endif /* CONFIG_SLOB */
34 #include <linux/slab_def.h>
38 #include <linux/slub_def.h>
41 #include <linux/memcontrol.h>
42 #include <linux/fault-inject.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(slab_flags_t 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(slab_flags_t);
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 int __kmem_cache_create(struct kmem_cache *, slab_flags_t 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, slab_flags_t flags);
102 int slab_unmergeable(struct kmem_cache *s);
103 struct kmem_cache *find_mergeable(size_t size, size_t align,
104 slab_flags_t flags, const char *name, void (*ctor)(void *));
107 __kmem_cache_alias(const char *name, size_t size, size_t align,
108 slab_flags_t flags, void (*ctor)(void *));
110 slab_flags_t kmem_cache_flags(unsigned long object_size,
111 slab_flags_t 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 slab_flags_t flags, void (*ctor)(void *))
119 static inline slab_flags_t kmem_cache_flags(unsigned long object_size,
120 slab_flags_t 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 | \
145 #elif defined(CONFIG_SLUB)
146 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
147 SLAB_TEMPORARY | 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 | \
168 int __kmem_cache_shutdown(struct kmem_cache *);
169 void __kmem_cache_release(struct kmem_cache *);
170 int __kmem_cache_shrink(struct kmem_cache *);
171 void __kmemcg_cache_deactivate(struct kmem_cache *s);
172 void slab_kmem_cache_release(struct kmem_cache *);
178 unsigned long active_objs;
179 unsigned long num_objs;
180 unsigned long active_slabs;
181 unsigned long num_slabs;
182 unsigned long shared_avail;
184 unsigned int batchcount;
186 unsigned int objects_per_slab;
187 unsigned int cache_order;
190 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
191 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
192 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
193 size_t count, loff_t *ppos);
196 * Generic implementation of bulk operations
197 * These are useful for situations in which the allocator cannot
198 * perform optimizations. In that case segments of the object listed
199 * may be allocated or freed using these operations.
201 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
202 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
204 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
206 /* List of all root caches. */
207 extern struct list_head slab_root_caches;
208 #define root_caches_node memcg_params.__root_caches_node
211 * Iterate over all memcg caches of the given root cache. The caller must hold
214 #define for_each_memcg_cache(iter, root) \
215 list_for_each_entry(iter, &(root)->memcg_params.children, \
216 memcg_params.children_node)
218 static inline bool is_root_cache(struct kmem_cache *s)
220 return !s->memcg_params.root_cache;
223 static inline bool slab_equal_or_root(struct kmem_cache *s,
224 struct kmem_cache *p)
226 return p == s || p == s->memcg_params.root_cache;
230 * We use suffixes to the name in memcg because we can't have caches
231 * created in the system with the same name. But when we print them
232 * locally, better refer to them with the base name
234 static inline const char *cache_name(struct kmem_cache *s)
236 if (!is_root_cache(s))
237 s = s->memcg_params.root_cache;
242 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
243 * That said the caller must assure the memcg's cache won't go away by either
244 * taking a css reference to the owner cgroup, or holding the slab_mutex.
246 static inline struct kmem_cache *
247 cache_from_memcg_idx(struct kmem_cache *s, int idx)
249 struct kmem_cache *cachep;
250 struct memcg_cache_array *arr;
253 arr = rcu_dereference(s->memcg_params.memcg_caches);
256 * Make sure we will access the up-to-date value. The code updating
257 * memcg_caches issues a write barrier to match this (see
258 * memcg_create_kmem_cache()).
260 cachep = READ_ONCE(arr->entries[idx]);
266 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
268 if (is_root_cache(s))
270 return s->memcg_params.root_cache;
273 static __always_inline int memcg_charge_slab(struct page *page,
274 gfp_t gfp, int order,
275 struct kmem_cache *s)
277 if (!memcg_kmem_enabled())
279 if (is_root_cache(s))
281 return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
284 static __always_inline void memcg_uncharge_slab(struct page *page, int order,
285 struct kmem_cache *s)
287 if (!memcg_kmem_enabled())
289 memcg_kmem_uncharge(page, order);
292 extern void slab_init_memcg_params(struct kmem_cache *);
293 extern void memcg_link_cache(struct kmem_cache *s);
294 extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
295 void (*deact_fn)(struct kmem_cache *));
297 #else /* CONFIG_MEMCG && !CONFIG_SLOB */
299 /* If !memcg, all caches are root. */
300 #define slab_root_caches slab_caches
301 #define root_caches_node list
303 #define for_each_memcg_cache(iter, root) \
304 for ((void)(iter), (void)(root); 0; )
306 static inline bool is_root_cache(struct kmem_cache *s)
311 static inline bool slab_equal_or_root(struct kmem_cache *s,
312 struct kmem_cache *p)
317 static inline const char *cache_name(struct kmem_cache *s)
322 static inline struct kmem_cache *
323 cache_from_memcg_idx(struct kmem_cache *s, int idx)
328 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
333 static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
334 struct kmem_cache *s)
339 static inline void memcg_uncharge_slab(struct page *page, int order,
340 struct kmem_cache *s)
344 static inline void slab_init_memcg_params(struct kmem_cache *s)
348 static inline void memcg_link_cache(struct kmem_cache *s)
352 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
354 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
356 struct kmem_cache *cachep;
360 * When kmemcg is not being used, both assignments should return the
361 * same value. but we don't want to pay the assignment price in that
362 * case. If it is not compiled in, the compiler should be smart enough
363 * to not do even the assignment. In that case, slab_equal_or_root
364 * will also be a constant.
366 if (!memcg_kmem_enabled() &&
367 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
370 page = virt_to_head_page(x);
371 cachep = page->slab_cache;
372 if (slab_equal_or_root(cachep, s))
375 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
376 __func__, s->name, cachep->name);
381 static inline size_t slab_ksize(const struct kmem_cache *s)
384 return s->object_size;
386 #else /* CONFIG_SLUB */
387 # ifdef CONFIG_SLUB_DEBUG
389 * Debugging requires use of the padding between object
390 * and whatever may come after it.
392 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
393 return s->object_size;
395 if (s->flags & SLAB_KASAN)
396 return s->object_size;
398 * If we have the need to store the freelist pointer
399 * back there or track user information then we can
400 * only use the space before that information.
402 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
405 * Else we can use all the padding etc for the allocation
411 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
414 flags &= gfp_allowed_mask;
416 fs_reclaim_acquire(flags);
417 fs_reclaim_release(flags);
419 might_sleep_if(gfpflags_allow_blocking(flags));
421 if (should_failslab(s, flags))
424 if (memcg_kmem_enabled() &&
425 ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
426 return memcg_kmem_get_cache(s);
431 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
432 size_t size, void **p)
436 flags &= gfp_allowed_mask;
437 for (i = 0; i < size; i++) {
440 kmemleak_alloc_recursive(object, s->object_size, 1,
442 kasan_slab_alloc(s, object, flags);
445 if (memcg_kmem_enabled())
446 memcg_kmem_put_cache(s);
451 * The slab lists for all objects.
453 struct kmem_cache_node {
454 spinlock_t list_lock;
457 struct list_head slabs_partial; /* partial list first, better asm code */
458 struct list_head slabs_full;
459 struct list_head slabs_free;
460 unsigned long total_slabs; /* length of all slab lists */
461 unsigned long free_slabs; /* length of free slab list only */
462 unsigned long free_objects;
463 unsigned int free_limit;
464 unsigned int colour_next; /* Per-node cache coloring */
465 struct array_cache *shared; /* shared per node */
466 struct alien_cache **alien; /* on other nodes */
467 unsigned long next_reap; /* updated without locking */
468 int free_touched; /* updated without locking */
472 unsigned long nr_partial;
473 struct list_head partial;
474 #ifdef CONFIG_SLUB_DEBUG
475 atomic_long_t nr_slabs;
476 atomic_long_t total_objects;
477 struct list_head full;
483 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
485 return s->node[node];
489 * Iterator over all nodes. The body will be executed for each node that has
490 * a kmem_cache_node structure allocated (which is true for all online nodes)
492 #define for_each_kmem_cache_node(__s, __node, __n) \
493 for (__node = 0; __node < nr_node_ids; __node++) \
494 if ((__n = get_node(__s, __node)))
498 void *slab_start(struct seq_file *m, loff_t *pos);
499 void *slab_next(struct seq_file *m, void *p, loff_t *pos);
500 void slab_stop(struct seq_file *m, void *p);
501 void *memcg_slab_start(struct seq_file *m, loff_t *pos);
502 void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
503 void memcg_slab_stop(struct seq_file *m, void *p);
504 int memcg_slab_show(struct seq_file *m, void *p);
506 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
507 void dump_unreclaimable_slab(void);
509 static inline void dump_unreclaimable_slab(void)
514 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
516 #ifdef CONFIG_SLAB_FREELIST_RANDOM
517 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
519 void cache_random_seq_destroy(struct kmem_cache *cachep);
521 static inline int cache_random_seq_create(struct kmem_cache *cachep,
522 unsigned int count, gfp_t gfp)
526 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
527 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
529 #endif /* MM_SLAB_H */