mm/slab.h

   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_L3,             /* SLAB: kmalloc size for l3 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 /* Functions provided by the slab allocators */
  39 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
  40
  41 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
  42                         unsigned long flags);
  43 extern void create_boot_cache(struct kmem_cache *, const char *name,
  44                         size_t size, unsigned long flags);
  45
  46 struct mem_cgroup;
  47 #ifdef CONFIG_SLUB
  48 struct kmem_cache *
  49 __kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
  50                    size_t align, unsigned long flags, void (*ctor)(void *));
  51 #else
  52 static inline struct kmem_cache *
  53 __kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
  54                    size_t align, unsigned long flags, void (*ctor)(void *))
  55 { return NULL; }
  56 #endif
  57
  58
  59 /* Legal flag mask for kmem_cache_create(), for various configurations */
  60 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
  61                          SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
  62
  63 #if defined(CONFIG_DEBUG_SLAB)
  64 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
  65 #elif defined(CONFIG_SLUB_DEBUG)
  66 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
  67                           SLAB_TRACE | SLAB_DEBUG_FREE)
  68 #else
  69 #define SLAB_DEBUG_FLAGS (0)
  70 #endif
  71
  72 #if defined(CONFIG_SLAB)
  73 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
  74                           SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
  75 #elif defined(CONFIG_SLUB)
  76 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
  77                           SLAB_TEMPORARY | SLAB_NOTRACK)
  78 #else
  79 #define SLAB_CACHE_FLAGS (0)
  80 #endif
  81
  82 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
  83
  84 int __kmem_cache_shutdown(struct kmem_cache *);
  85
  86 struct seq_file;
  87 struct file;
  88
  89 struct slabinfo {
  90         unsigned long active_objs;
  91         unsigned long num_objs;
  92         unsigned long active_slabs;
  93         unsigned long num_slabs;
  94         unsigned long shared_avail;
  95         unsigned int limit;
  96         unsigned int batchcount;
  97         unsigned int shared;
  98         unsigned int objects_per_slab;
  99         unsigned int cache_order;
 100 };
 101
 102 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
 103 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
 104 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 105                        size_t count, loff_t *ppos);
 106
 107 #ifdef CONFIG_MEMCG_KMEM
 108 static inline bool is_root_cache(struct kmem_cache *s)
 109 {
 110         return !s->memcg_params || s->memcg_params->is_root_cache;
 111 }
 112
 113 static inline bool cache_match_memcg(struct kmem_cache *cachep,
 114                                      struct mem_cgroup *memcg)
 115 {
 116         return (is_root_cache(cachep) && !memcg) ||
 117                                 (cachep->memcg_params->memcg == memcg);
 118 }
 119
 120 static inline void memcg_bind_pages(struct kmem_cache *s, int order)
 121 {
 122         if (!is_root_cache(s))
 123                 atomic_add(1 << order, &s->memcg_params->nr_pages);
 124 }
 125
 126 static inline void memcg_release_pages(struct kmem_cache *s, int order)
 127 {
 128         if (is_root_cache(s))
 129                 return;
 130
 131         if (atomic_sub_and_test((1 << order), &s->memcg_params->nr_pages))
 132                 mem_cgroup_destroy_cache(s);
 133 }
 134
 135 static inline bool slab_equal_or_root(struct kmem_cache *s,
 136                                         struct kmem_cache *p)
 137 {
 138         return (p == s) ||
 139                 (s->memcg_params && (p == s->memcg_params->root_cache));
 140 }
 141
 142 /*
 143  * We use suffixes to the name in memcg because we can't have caches
 144  * created in the system with the same name. But when we print them
 145  * locally, better refer to them with the base name
 146  */
 147 static inline const char *cache_name(struct kmem_cache *s)
 148 {
 149         if (!is_root_cache(s))
 150                 return s->memcg_params->root_cache->name;
 151         return s->name;
 152 }
 153
 154 static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
 155 {
 156         return s->memcg_params->memcg_caches[idx];
 157 }
 158
 159 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
 160 {
 161         if (is_root_cache(s))
 162                 return s;
 163         return s->memcg_params->root_cache;
 164 }
 165 #else
 166 static inline bool is_root_cache(struct kmem_cache *s)
 167 {
 168         return true;
 169 }
 170
 171 static inline bool cache_match_memcg(struct kmem_cache *cachep,
 172                                      struct mem_cgroup *memcg)
 173 {
 174         return true;
 175 }
 176
 177 static inline void memcg_bind_pages(struct kmem_cache *s, int order)
 178 {
 179 }
 180
 181 static inline void memcg_release_pages(struct kmem_cache *s, int order)
 182 {
 183 }
 184
 185 static inline bool slab_equal_or_root(struct kmem_cache *s,
 186                                       struct kmem_cache *p)
 187 {
 188         return true;
 189 }
 190
 191 static inline const char *cache_name(struct kmem_cache *s)
 192 {
 193         return s->name;
 194 }
 195
 196 static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
 197 {
 198         return NULL;
 199 }
 200
 201 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
 202 {
 203         return s;
 204 }
 205 #endif
 206
 207 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 208 {
 209         struct kmem_cache *cachep;
 210         struct page *page;
 211
 212         /*
 213          * When kmemcg is not being used, both assignments should return the
 214          * same value. but we don't want to pay the assignment price in that
 215          * case. If it is not compiled in, the compiler should be smart enough
 216          * to not do even the assignment. In that case, slab_equal_or_root
 217          * will also be a constant.
 218          */
 219         if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
 220                 return s;
 221
 222         page = virt_to_head_page(x);
 223         cachep = page->slab_cache;
 224         if (slab_equal_or_root(cachep, s))
 225                 return cachep;
 226
 227         pr_err("%s: Wrong slab cache. %s but object is from %s\n",
 228                 __FUNCTION__, cachep->name, s->name);
 229         WARN_ON_ONCE(1);
 230         return s;
 231 }
 232 #endif