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>
43 * State of the slab allocator.
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.
51 DOWN, /* No slab functionality yet */
52 PARTIAL, /* SLUB: kmem_cache_node available */
53 PARTIAL_ARRAYCACHE, /* SLAB: kmalloc size for arraycache available */
54 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
55 UP, /* Slab caches usable but not all extras yet */
56 FULL /* Everything is working */
59 extern enum slab_state slab_state;
61 /* The slab cache mutex protects the management structures during changes */
62 extern struct mutex slab_mutex;
64 /* The list of all slab caches on the system */
65 extern struct list_head slab_caches;
67 /* The slab cache that manages slab cache information */
68 extern struct kmem_cache *kmem_cache;
70 unsigned long calculate_alignment(unsigned long flags,
71 unsigned long align, unsigned long size);
74 /* Kmalloc array related functions */
75 void create_kmalloc_caches(unsigned long);
77 /* Find the kmalloc slab corresponding for a certain size */
78 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
82 /* Functions provided by the slab allocators */
83 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
85 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
87 extern void create_boot_cache(struct kmem_cache *, const char *name,
88 size_t size, unsigned long flags);
93 __kmem_cache_alias(const char *name, size_t size, size_t align,
94 unsigned long flags, void (*ctor)(void *));
96 static inline struct kmem_cache *
97 __kmem_cache_alias(const char *name, size_t size, size_t align,
98 unsigned long flags, void (*ctor)(void *))
103 /* Legal flag mask for kmem_cache_create(), for various configurations */
104 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
105 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
107 #if defined(CONFIG_DEBUG_SLAB)
108 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
109 #elif defined(CONFIG_SLUB_DEBUG)
110 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
111 SLAB_TRACE | SLAB_DEBUG_FREE)
113 #define SLAB_DEBUG_FLAGS (0)
116 #if defined(CONFIG_SLAB)
117 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
118 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
119 #elif defined(CONFIG_SLUB)
120 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
121 SLAB_TEMPORARY | SLAB_NOTRACK)
123 #define SLAB_CACHE_FLAGS (0)
126 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
128 int __kmem_cache_shutdown(struct kmem_cache *);
129 int __kmem_cache_shrink(struct kmem_cache *);
130 void slab_kmem_cache_release(struct kmem_cache *);
136 unsigned long active_objs;
137 unsigned long num_objs;
138 unsigned long active_slabs;
139 unsigned long num_slabs;
140 unsigned long shared_avail;
142 unsigned int batchcount;
144 unsigned int objects_per_slab;
145 unsigned int cache_order;
148 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
149 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
150 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
151 size_t count, loff_t *ppos);
153 #ifdef CONFIG_MEMCG_KMEM
154 static inline bool is_root_cache(struct kmem_cache *s)
156 return !s->memcg_params || s->memcg_params->is_root_cache;
159 static inline bool slab_equal_or_root(struct kmem_cache *s,
160 struct kmem_cache *p)
163 (s->memcg_params && (p == s->memcg_params->root_cache));
167 * We use suffixes to the name in memcg because we can't have caches
168 * created in the system with the same name. But when we print them
169 * locally, better refer to them with the base name
171 static inline const char *cache_name(struct kmem_cache *s)
173 if (!is_root_cache(s))
174 return s->memcg_params->root_cache->name;
179 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
180 * That said the caller must assure the memcg's cache won't go away. Since once
181 * created a memcg's cache is destroyed only along with the root cache, it is
182 * true if we are going to allocate from the cache or hold a reference to the
183 * root cache by other means. Otherwise, we should hold either the slab_mutex
184 * or the memcg's slab_caches_mutex while calling this function and accessing
185 * the returned value.
187 static inline struct kmem_cache *
188 cache_from_memcg_idx(struct kmem_cache *s, int idx)
190 struct kmem_cache *cachep;
191 struct memcg_cache_params *params;
193 if (!s->memcg_params)
197 params = rcu_dereference(s->memcg_params);
198 cachep = params->memcg_caches[idx];
202 * Make sure we will access the up-to-date value. The code updating
203 * memcg_caches issues a write barrier to match this (see
204 * memcg_register_cache()).
206 smp_read_barrier_depends();
210 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
212 if (is_root_cache(s))
214 return s->memcg_params->root_cache;
217 static __always_inline int memcg_charge_slab(struct kmem_cache *s,
218 gfp_t gfp, int order)
220 if (!memcg_kmem_enabled())
222 if (is_root_cache(s))
224 return __memcg_charge_slab(s, gfp, order);
227 static __always_inline void memcg_uncharge_slab(struct kmem_cache *s, int order)
229 if (!memcg_kmem_enabled())
231 if (is_root_cache(s))
233 __memcg_uncharge_slab(s, order);
236 static inline bool is_root_cache(struct kmem_cache *s)
241 static inline bool slab_equal_or_root(struct kmem_cache *s,
242 struct kmem_cache *p)
247 static inline const char *cache_name(struct kmem_cache *s)
252 static inline struct kmem_cache *
253 cache_from_memcg_idx(struct kmem_cache *s, int idx)
258 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
263 static inline int memcg_charge_slab(struct kmem_cache *s, gfp_t gfp, int order)
268 static inline void memcg_uncharge_slab(struct kmem_cache *s, int order)
273 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
275 struct kmem_cache *cachep;
279 * When kmemcg is not being used, both assignments should return the
280 * same value. but we don't want to pay the assignment price in that
281 * case. If it is not compiled in, the compiler should be smart enough
282 * to not do even the assignment. In that case, slab_equal_or_root
283 * will also be a constant.
285 if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
288 page = virt_to_head_page(x);
289 cachep = page->slab_cache;
290 if (slab_equal_or_root(cachep, s))
293 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
294 __func__, cachep->name, s->name);
301 * The slab lists for all objects.
303 struct kmem_cache_node {
304 spinlock_t list_lock;
307 struct list_head slabs_partial; /* partial list first, better asm code */
308 struct list_head slabs_full;
309 struct list_head slabs_free;
310 unsigned long free_objects;
311 unsigned int free_limit;
312 unsigned int colour_next; /* Per-node cache coloring */
313 struct array_cache *shared; /* shared per node */
314 struct alien_cache **alien; /* on other nodes */
315 unsigned long next_reap; /* updated without locking */
316 int free_touched; /* updated without locking */
320 unsigned long nr_partial;
321 struct list_head partial;
322 #ifdef CONFIG_SLUB_DEBUG
323 atomic_long_t nr_slabs;
324 atomic_long_t total_objects;
325 struct list_head full;
331 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
333 return s->node[node];
337 * Iterator over all nodes. The body will be executed for each node that has
338 * a kmem_cache_node structure allocated (which is true for all online nodes)
340 #define for_each_kmem_cache_node(__s, __node, __n) \
341 for (__node = 0; __node < nr_node_ids; __node++) \
342 if ((__n = get_node(__s, __node)))
346 void *slab_next(struct seq_file *m, void *p, loff_t *pos);
347 void slab_stop(struct seq_file *m, void *p);
349 #endif /* MM_SLAB_H */