1 #ifndef MM_SLAB_H 2 #define MM_SLAB_H 3 /* 4 * Internal slab definitions 5 */ 6 7 /* 8 * State of the slab allocator. 9 * 10 * This is used to describe the states of the allocator during bootup. 11 * Allocators use this to gradually bootstrap themselves. Most allocators 12 * have the problem that the structures used for managing slab caches are 13 * allocated from slab caches themselves. 14 */ 15 enum slab_state { 16 DOWN, /* No slab functionality yet */ 17 PARTIAL, /* SLUB: kmem_cache_node available */ 18 PARTIAL_ARRAYCACHE, /* SLAB: kmalloc size for arraycache available */ 19 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */ 20 UP, /* Slab caches usable but not all extras yet */ 21 FULL /* Everything is working */ 22 }; 23 24 extern enum slab_state slab_state; 25 26 /* The slab cache mutex protects the management structures during changes */ 27 extern struct mutex slab_mutex; 28 29 /* The list of all slab caches on the system */ 30 extern struct list_head slab_caches; 31 32 /* The slab cache that manages slab cache information */ 33 extern struct kmem_cache *kmem_cache; 34 35 unsigned long calculate_alignment(unsigned long flags, 36 unsigned long align, unsigned long size); 37 38 #ifndef CONFIG_SLOB 39 /* Kmalloc array related functions */ 40 void create_kmalloc_caches(unsigned long); 41 42 /* Find the kmalloc slab corresponding for a certain size */ 43 struct kmem_cache *kmalloc_slab(size_t, gfp_t); 44 #endif 45 46 47 /* Functions provided by the slab allocators */ 48 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags); 49 50 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size, 51 unsigned long flags); 52 extern void create_boot_cache(struct kmem_cache *, const char *name, 53 size_t size, unsigned long flags); 54 55 struct mem_cgroup; 56 #ifdef CONFIG_SLUB 57 struct kmem_cache * 58 __kmem_cache_alias(const char *name, size_t size, size_t align, 59 unsigned long flags, void (*ctor)(void *)); 60 #else 61 static inline struct kmem_cache * 62 __kmem_cache_alias(const char *name, size_t size, size_t align, 63 unsigned long flags, void (*ctor)(void *)) 64 { return NULL; } 65 #endif 66 67 68 /* Legal flag mask for kmem_cache_create(), for various configurations */ 69 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \ 70 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS ) 71 72 #if defined(CONFIG_DEBUG_SLAB) 73 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) 74 #elif defined(CONFIG_SLUB_DEBUG) 75 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ 76 SLAB_TRACE | SLAB_DEBUG_FREE) 77 #else 78 #define SLAB_DEBUG_FLAGS (0) 79 #endif 80 81 #if defined(CONFIG_SLAB) 82 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ 83 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK) 84 #elif defined(CONFIG_SLUB) 85 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ 86 SLAB_TEMPORARY | SLAB_NOTRACK) 87 #else 88 #define SLAB_CACHE_FLAGS (0) 89 #endif 90 91 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) 92 93 int __kmem_cache_shutdown(struct kmem_cache *); 94 void slab_kmem_cache_release(struct kmem_cache *); 95 96 struct seq_file; 97 struct file; 98 99 struct slabinfo { 100 unsigned long active_objs; 101 unsigned long num_objs; 102 unsigned long active_slabs; 103 unsigned long num_slabs; 104 unsigned long shared_avail; 105 unsigned int limit; 106 unsigned int batchcount; 107 unsigned int shared; 108 unsigned int objects_per_slab; 109 unsigned int cache_order; 110 }; 111 112 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); 113 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); 114 ssize_t slabinfo_write(struct file *file, const char __user *buffer, 115 size_t count, loff_t *ppos); 116 117 #ifdef CONFIG_MEMCG_KMEM 118 static inline bool is_root_cache(struct kmem_cache *s) 119 { 120 return !s->memcg_params || s->memcg_params->is_root_cache; 121 } 122 123 static inline void memcg_bind_pages(struct kmem_cache *s, int order) 124 { 125 if (!is_root_cache(s)) 126 atomic_add(1 << order, &s->memcg_params->nr_pages); 127 } 128 129 static inline void memcg_release_pages(struct kmem_cache *s, int order) 130 { 131 if (is_root_cache(s)) 132 return; 133 134 if (atomic_sub_and_test((1 << order), &s->memcg_params->nr_pages)) 135 mem_cgroup_destroy_cache(s); 136 } 137 138 static inline bool slab_equal_or_root(struct kmem_cache *s, 139 struct kmem_cache *p) 140 { 141 return (p == s) || 142 (s->memcg_params && (p == s->memcg_params->root_cache)); 143 } 144 145 /* 146 * We use suffixes to the name in memcg because we can't have caches 147 * created in the system with the same name. But when we print them 148 * locally, better refer to them with the base name 149 */ 150 static inline const char *cache_name(struct kmem_cache *s) 151 { 152 if (!is_root_cache(s)) 153 return s->memcg_params->root_cache->name; 154 return s->name; 155 } 156 157 /* 158 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches. 159 * That said the caller must assure the memcg's cache won't go away. Since once 160 * created a memcg's cache is destroyed only along with the root cache, it is 161 * true if we are going to allocate from the cache or hold a reference to the 162 * root cache by other means. Otherwise, we should hold either the slab_mutex 163 * or the memcg's slab_caches_mutex while calling this function and accessing 164 * the returned value. 165 */ 166 static inline struct kmem_cache * 167 cache_from_memcg_idx(struct kmem_cache *s, int idx) 168 { 169 struct kmem_cache *cachep; 170 struct memcg_cache_params *params; 171 172 if (!s->memcg_params) 173 return NULL; 174 175 rcu_read_lock(); 176 params = rcu_dereference(s->memcg_params); 177 cachep = params->memcg_caches[idx]; 178 rcu_read_unlock(); 179 180 /* 181 * Make sure we will access the up-to-date value. The code updating 182 * memcg_caches issues a write barrier to match this (see 183 * memcg_register_cache()). 184 */ 185 smp_read_barrier_depends(); 186 return cachep; 187 } 188 189 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) 190 { 191 if (is_root_cache(s)) 192 return s; 193 return s->memcg_params->root_cache; 194 } 195 #else 196 static inline bool is_root_cache(struct kmem_cache *s) 197 { 198 return true; 199 } 200 201 static inline void memcg_bind_pages(struct kmem_cache *s, int order) 202 { 203 } 204 205 static inline void memcg_release_pages(struct kmem_cache *s, int order) 206 { 207 } 208 209 static inline bool slab_equal_or_root(struct kmem_cache *s, 210 struct kmem_cache *p) 211 { 212 return true; 213 } 214 215 static inline const char *cache_name(struct kmem_cache *s) 216 { 217 return s->name; 218 } 219 220 static inline struct kmem_cache * 221 cache_from_memcg_idx(struct kmem_cache *s, int idx) 222 { 223 return NULL; 224 } 225 226 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) 227 { 228 return s; 229 } 230 #endif 231 232 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 233 { 234 struct kmem_cache *cachep; 235 struct page *page; 236 237 /* 238 * When kmemcg is not being used, both assignments should return the 239 * same value. but we don't want to pay the assignment price in that 240 * case. If it is not compiled in, the compiler should be smart enough 241 * to not do even the assignment. In that case, slab_equal_or_root 242 * will also be a constant. 243 */ 244 if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE)) 245 return s; 246 247 page = virt_to_head_page(x); 248 cachep = page->slab_cache; 249 if (slab_equal_or_root(cachep, s)) 250 return cachep; 251 252 pr_err("%s: Wrong slab cache. %s but object is from %s\n", 253 __FUNCTION__, cachep->name, s->name); 254 WARN_ON_ONCE(1); 255 return s; 256 } 257 #endif 258 259 260 /* 261 * The slab lists for all objects. 262 */ 263 struct kmem_cache_node { 264 spinlock_t list_lock; 265 266 #ifdef CONFIG_SLAB 267 struct list_head slabs_partial; /* partial list first, better asm code */ 268 struct list_head slabs_full; 269 struct list_head slabs_free; 270 unsigned long free_objects; 271 unsigned int free_limit; 272 unsigned int colour_next; /* Per-node cache coloring */ 273 struct array_cache *shared; /* shared per node */ 274 struct array_cache **alien; /* on other nodes */ 275 unsigned long next_reap; /* updated without locking */ 276 int free_touched; /* updated without locking */ 277 #endif 278 279 #ifdef CONFIG_SLUB 280 unsigned long nr_partial; 281 struct list_head partial; 282 #ifdef CONFIG_SLUB_DEBUG 283 atomic_long_t nr_slabs; 284 atomic_long_t total_objects; 285 struct list_head full; 286 #endif 287 #endif 288 289 }; 290 291 void *slab_next(struct seq_file *m, void *p, loff_t *pos); 292 void slab_stop(struct seq_file *m, void *p); 293