1 #ifndef MM_SLAB_H 2 #define MM_SLAB_H 3 /* 4 * Internal slab definitions 5 */ 6 7 #ifdef CONFIG_SLOB 8 /* 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. 13 * 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. 18 */ 19 struct kmem_cache { 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 */ 28 }; 29 30 #endif /* CONFIG_SLOB */ 31 32 #ifdef CONFIG_SLAB 33 #include <linux/slab_def.h> 34 #endif 35 36 #ifdef CONFIG_SLUB 37 #include <linux/slub_def.h> 38 #endif 39 40 #include <linux/memcontrol.h> 41 42 /* 43 * State of the slab allocator. 44 * 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. 49 */ 50 enum slab_state { 51 DOWN, /* No slab functionality yet */ 52 PARTIAL, /* SLUB: kmem_cache_node available */ 53 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */ 54 UP, /* Slab caches usable but not all extras yet */ 55 FULL /* Everything is working */ 56 }; 57 58 extern enum slab_state slab_state; 59 60 /* The slab cache mutex protects the management structures during changes */ 61 extern struct mutex slab_mutex; 62 63 /* The list of all slab caches on the system */ 64 extern struct list_head slab_caches; 65 66 /* The slab cache that manages slab cache information */ 67 extern struct kmem_cache *kmem_cache; 68 69 unsigned long calculate_alignment(unsigned long flags, 70 unsigned long align, unsigned long size); 71 72 #ifndef CONFIG_SLOB 73 /* Kmalloc array related functions */ 74 void setup_kmalloc_cache_index_table(void); 75 void create_kmalloc_caches(unsigned long); 76 77 /* Find the kmalloc slab corresponding for a certain size */ 78 struct kmem_cache *kmalloc_slab(size_t, gfp_t); 79 #endif 80 81 82 /* Functions provided by the slab allocators */ 83 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags); 84 85 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size, 86 unsigned long flags); 87 extern void create_boot_cache(struct kmem_cache *, const char *name, 88 size_t size, unsigned long flags); 89 90 int slab_unmergeable(struct kmem_cache *s); 91 struct kmem_cache *find_mergeable(size_t size, size_t align, 92 unsigned long flags, const char *name, void (*ctor)(void *)); 93 #ifndef CONFIG_SLOB 94 struct kmem_cache * 95 __kmem_cache_alias(const char *name, size_t size, size_t align, 96 unsigned long flags, void (*ctor)(void *)); 97 98 unsigned long kmem_cache_flags(unsigned long object_size, 99 unsigned long flags, const char *name, 100 void (*ctor)(void *)); 101 #else 102 static inline struct kmem_cache * 103 __kmem_cache_alias(const char *name, size_t size, size_t align, 104 unsigned long flags, void (*ctor)(void *)) 105 { return NULL; } 106 107 static inline unsigned long kmem_cache_flags(unsigned long object_size, 108 unsigned long flags, const char *name, 109 void (*ctor)(void *)) 110 { 111 return flags; 112 } 113 #endif 114 115 116 /* Legal flag mask for kmem_cache_create(), for various configurations */ 117 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \ 118 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS ) 119 120 #if defined(CONFIG_DEBUG_SLAB) 121 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) 122 #elif defined(CONFIG_SLUB_DEBUG) 123 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ 124 SLAB_TRACE | SLAB_DEBUG_FREE) 125 #else 126 #define SLAB_DEBUG_FLAGS (0) 127 #endif 128 129 #if defined(CONFIG_SLAB) 130 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ 131 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \ 132 SLAB_NOTRACK | SLAB_ACCOUNT) 133 #elif defined(CONFIG_SLUB) 134 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ 135 SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT) 136 #else 137 #define SLAB_CACHE_FLAGS (0) 138 #endif 139 140 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) 141 142 int __kmem_cache_shutdown(struct kmem_cache *); 143 int __kmem_cache_shrink(struct kmem_cache *, bool); 144 void slab_kmem_cache_release(struct kmem_cache *); 145 146 struct seq_file; 147 struct file; 148 149 struct slabinfo { 150 unsigned long active_objs; 151 unsigned long num_objs; 152 unsigned long active_slabs; 153 unsigned long num_slabs; 154 unsigned long shared_avail; 155 unsigned int limit; 156 unsigned int batchcount; 157 unsigned int shared; 158 unsigned int objects_per_slab; 159 unsigned int cache_order; 160 }; 161 162 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); 163 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); 164 ssize_t slabinfo_write(struct file *file, const char __user *buffer, 165 size_t count, loff_t *ppos); 166 167 /* 168 * Generic implementation of bulk operations 169 * These are useful for situations in which the allocator cannot 170 * perform optimizations. In that case segments of the objecct listed 171 * may be allocated or freed using these operations. 172 */ 173 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 174 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 175 176 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) 177 /* 178 * Iterate over all memcg caches of the given root cache. The caller must hold 179 * slab_mutex. 180 */ 181 #define for_each_memcg_cache(iter, root) \ 182 list_for_each_entry(iter, &(root)->memcg_params.list, \ 183 memcg_params.list) 184 185 static inline bool is_root_cache(struct kmem_cache *s) 186 { 187 return s->memcg_params.is_root_cache; 188 } 189 190 static inline bool slab_equal_or_root(struct kmem_cache *s, 191 struct kmem_cache *p) 192 { 193 return p == s || p == s->memcg_params.root_cache; 194 } 195 196 /* 197 * We use suffixes to the name in memcg because we can't have caches 198 * created in the system with the same name. But when we print them 199 * locally, better refer to them with the base name 200 */ 201 static inline const char *cache_name(struct kmem_cache *s) 202 { 203 if (!is_root_cache(s)) 204 s = s->memcg_params.root_cache; 205 return s->name; 206 } 207 208 /* 209 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches. 210 * That said the caller must assure the memcg's cache won't go away by either 211 * taking a css reference to the owner cgroup, or holding the slab_mutex. 212 */ 213 static inline struct kmem_cache * 214 cache_from_memcg_idx(struct kmem_cache *s, int idx) 215 { 216 struct kmem_cache *cachep; 217 struct memcg_cache_array *arr; 218 219 rcu_read_lock(); 220 arr = rcu_dereference(s->memcg_params.memcg_caches); 221 222 /* 223 * Make sure we will access the up-to-date value. The code updating 224 * memcg_caches issues a write barrier to match this (see 225 * memcg_create_kmem_cache()). 226 */ 227 cachep = lockless_dereference(arr->entries[idx]); 228 rcu_read_unlock(); 229 230 return cachep; 231 } 232 233 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) 234 { 235 if (is_root_cache(s)) 236 return s; 237 return s->memcg_params.root_cache; 238 } 239 240 static __always_inline int memcg_charge_slab(struct page *page, 241 gfp_t gfp, int order, 242 struct kmem_cache *s) 243 { 244 if (!memcg_kmem_enabled()) 245 return 0; 246 if (is_root_cache(s)) 247 return 0; 248 return __memcg_kmem_charge_memcg(page, gfp, order, 249 s->memcg_params.memcg); 250 } 251 252 extern void slab_init_memcg_params(struct kmem_cache *); 253 254 #else /* CONFIG_MEMCG && !CONFIG_SLOB */ 255 256 #define for_each_memcg_cache(iter, root) \ 257 for ((void)(iter), (void)(root); 0; ) 258 259 static inline bool is_root_cache(struct kmem_cache *s) 260 { 261 return true; 262 } 263 264 static inline bool slab_equal_or_root(struct kmem_cache *s, 265 struct kmem_cache *p) 266 { 267 return true; 268 } 269 270 static inline const char *cache_name(struct kmem_cache *s) 271 { 272 return s->name; 273 } 274 275 static inline struct kmem_cache * 276 cache_from_memcg_idx(struct kmem_cache *s, int idx) 277 { 278 return NULL; 279 } 280 281 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) 282 { 283 return s; 284 } 285 286 static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order, 287 struct kmem_cache *s) 288 { 289 return 0; 290 } 291 292 static inline void slab_init_memcg_params(struct kmem_cache *s) 293 { 294 } 295 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ 296 297 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 298 { 299 struct kmem_cache *cachep; 300 struct page *page; 301 302 /* 303 * When kmemcg is not being used, both assignments should return the 304 * same value. but we don't want to pay the assignment price in that 305 * case. If it is not compiled in, the compiler should be smart enough 306 * to not do even the assignment. In that case, slab_equal_or_root 307 * will also be a constant. 308 */ 309 if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE)) 310 return s; 311 312 page = virt_to_head_page(x); 313 cachep = page->slab_cache; 314 if (slab_equal_or_root(cachep, s)) 315 return cachep; 316 317 pr_err("%s: Wrong slab cache. %s but object is from %s\n", 318 __func__, s->name, cachep->name); 319 WARN_ON_ONCE(1); 320 return s; 321 } 322 323 #ifndef CONFIG_SLOB 324 /* 325 * The slab lists for all objects. 326 */ 327 struct kmem_cache_node { 328 spinlock_t list_lock; 329 330 #ifdef CONFIG_SLAB 331 struct list_head slabs_partial; /* partial list first, better asm code */ 332 struct list_head slabs_full; 333 struct list_head slabs_free; 334 unsigned long free_objects; 335 unsigned int free_limit; 336 unsigned int colour_next; /* Per-node cache coloring */ 337 struct array_cache *shared; /* shared per node */ 338 struct alien_cache **alien; /* on other nodes */ 339 unsigned long next_reap; /* updated without locking */ 340 int free_touched; /* updated without locking */ 341 #endif 342 343 #ifdef CONFIG_SLUB 344 unsigned long nr_partial; 345 struct list_head partial; 346 #ifdef CONFIG_SLUB_DEBUG 347 atomic_long_t nr_slabs; 348 atomic_long_t total_objects; 349 struct list_head full; 350 #endif 351 #endif 352 353 }; 354 355 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 356 { 357 return s->node[node]; 358 } 359 360 /* 361 * Iterator over all nodes. The body will be executed for each node that has 362 * a kmem_cache_node structure allocated (which is true for all online nodes) 363 */ 364 #define for_each_kmem_cache_node(__s, __node, __n) \ 365 for (__node = 0; __node < nr_node_ids; __node++) \ 366 if ((__n = get_node(__s, __node))) 367 368 #endif 369 370 void *slab_start(struct seq_file *m, loff_t *pos); 371 void *slab_next(struct seq_file *m, void *p, loff_t *pos); 372 void slab_stop(struct seq_file *m, void *p); 373 int memcg_slab_show(struct seq_file *m, void *p); 374 375 #endif /* MM_SLAB_H */ 376