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 #ifndef CONFIG_SLOB
  39 /* Kmalloc array related functions */
  40 void create_kmalloc_caches(unsigned long);
  41 #endif
  42
  43
  44 /* Functions provided by the slab allocators */
  45 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
  46
  47 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
  48                         unsigned long flags);
  49 extern void create_boot_cache(struct kmem_cache *, const char *name,
  50                         size_t size, unsigned long flags);
  51
  52 struct mem_cgroup;
  53 #ifdef CONFIG_SLUB
  54 struct kmem_cache *
  55 __kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
  56                    size_t align, unsigned long flags, void (*ctor)(void *));
  57 #else
  58 static inline struct kmem_cache *
  59 __kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
  60                    size_t align, unsigned long flags, void (*ctor)(void *))
  61 { return NULL; }
  62 #endif
  63
  64
  65 /* Legal flag mask for kmem_cache_create(), for various configurations */
  66 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
  67                          SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
  68
  69 #if defined(CONFIG_DEBUG_SLAB)
  70 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
  71 #elif defined(CONFIG_SLUB_DEBUG)
  72 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
  73                           SLAB_TRACE | SLAB_DEBUG_FREE)
  74 #else
  75 #define SLAB_DEBUG_FLAGS (0)
  76 #endif
  77
  78 #if defined(CONFIG_SLAB)
  79 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
  80                           SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
  81 #elif defined(CONFIG_SLUB)
  82 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
  83                           SLAB_TEMPORARY | SLAB_NOTRACK)
  84 #else
  85 #define SLAB_CACHE_FLAGS (0)
  86 #endif
  87
  88 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
  89
  90 int __kmem_cache_shutdown(struct kmem_cache *);
  91
  92 struct seq_file;
  93 struct file;
  94
  95 struct slabinfo {
  96         unsigned long active_objs;
  97         unsigned long num_objs;
  98         unsigned long active_slabs;
  99         unsigned long num_slabs;
 100         unsigned long shared_avail;
 101         unsigned int limit;
 102         unsigned int batchcount;
 103         unsigned int shared;
 104         unsigned int objects_per_slab;
 105         unsigned int cache_order;
 106 };
 107
 108 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
 109 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
 110 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 111                        size_t count, loff_t *ppos);
 112
 113 #ifdef CONFIG_MEMCG_KMEM
 114 static inline bool is_root_cache(struct kmem_cache *s)
 115 {
 116         return !s->memcg_params || s->memcg_params->is_root_cache;
 117 }
 118
 119 static inline bool cache_match_memcg(struct kmem_cache *cachep,
 120                                      struct mem_cgroup *memcg)
 121 {
 122         return (is_root_cache(cachep) && !memcg) ||
 123                                 (cachep->memcg_params->memcg == memcg);
 124 }
 125
 126 static inline void memcg_bind_pages(struct kmem_cache *s, int order)
 127 {
 128         if (!is_root_cache(s))
 129                 atomic_add(1 << order, &s->memcg_params->nr_pages);
 130 }
 131
 132 static inline void memcg_release_pages(struct kmem_cache *s, int order)
 133 {
 134         if (is_root_cache(s))
 135                 return;
 136
 137         if (atomic_sub_and_test((1 << order), &s->memcg_params->nr_pages))
 138                 mem_cgroup_destroy_cache(s);
 139 }
 140
 141 static inline bool slab_equal_or_root(struct kmem_cache *s,
 142                                         struct kmem_cache *p)
 143 {
 144         return (p == s) ||
 145                 (s->memcg_params && (p == s->memcg_params->root_cache));
 146 }
 147
 148 /*
 149  * We use suffixes to the name in memcg because we can't have caches
 150  * created in the system with the same name. But when we print them
 151  * locally, better refer to them with the base name
 152  */
 153 static inline const char *cache_name(struct kmem_cache *s)
 154 {
 155         if (!is_root_cache(s))
 156                 return s->memcg_params->root_cache->name;
 157         return s->name;
 158 }
 159
 160 static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
 161 {
 162         return s->memcg_params->memcg_caches[idx];
 163 }
 164
 165 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
 166 {
 167         if (is_root_cache(s))
 168                 return s;
 169         return s->memcg_params->root_cache;
 170 }
 171 #else
 172 static inline bool is_root_cache(struct kmem_cache *s)
 173 {
 174         return true;
 175 }
 176
 177 static inline bool cache_match_memcg(struct kmem_cache *cachep,
 178                                      struct mem_cgroup *memcg)
 179 {
 180         return true;
 181 }
 182
 183 static inline void memcg_bind_pages(struct kmem_cache *s, int order)
 184 {
 185 }
 186
 187 static inline void memcg_release_pages(struct kmem_cache *s, int order)
 188 {
 189 }
 190
 191 static inline bool slab_equal_or_root(struct kmem_cache *s,
 192                                       struct kmem_cache *p)
 193 {
 194         return true;
 195 }
 196
 197 static inline const char *cache_name(struct kmem_cache *s)
 198 {
 199         return s->name;
 200 }
 201
 202 static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
 203 {
 204         return NULL;
 205 }
 206
 207 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
 208 {
 209         return s;
 210 }
 211 #endif
 212
 213 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 214 {
 215         struct kmem_cache *cachep;
 216         struct page *page;
 217
 218         /*
 219          * When kmemcg is not being used, both assignments should return the
 220          * same value. but we don't want to pay the assignment price in that
 221          * case. If it is not compiled in, the compiler should be smart enough
 222          * to not do even the assignment. In that case, slab_equal_or_root
 223          * will also be a constant.
 224          */
 225         if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
 226                 return s;
 227
 228         page = virt_to_head_page(x);
 229         cachep = page->slab_cache;
 230         if (slab_equal_or_root(cachep, s))
 231                 return cachep;
 232
 233         pr_err("%s: Wrong slab cache. %s but object is from %s\n",
 234                 __FUNCTION__, cachep->name, s->name);
 235         WARN_ON_ONCE(1);
 236         return s;
 237 }
 238 #endif