include/linux/page_cgroup.h

   1 #ifndef __LINUX_PAGE_CGROUP_H
   2 #define __LINUX_PAGE_CGROUP_H
   3
   4 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
   5 #include <linux/bit_spinlock.h>
   6 /*
   7  * Page Cgroup can be considered as an extended mem_map.
   8  * A page_cgroup page is associated with every page descriptor. The
   9  * page_cgroup helps us identify information about the cgroup
  10  * All page cgroups are allocated at boot or memory hotplug event,
  11  * then the page cgroup for pfn always exists.
  12  */
  13 struct page_cgroup {
  14         unsigned long flags;
  15         struct mem_cgroup *mem_cgroup;
  16         struct page *page;
  17         struct list_head lru;           /* per cgroup LRU list */
  18 };
  19
  20 void __init pgdat_page_cgroup_init(struct pglist_data *pgdat);
  21 void __init page_cgroup_init(void);
  22 struct page_cgroup *lookup_page_cgroup(struct page *page);
  23
  24 enum {
  25         /* flags for mem_cgroup */
  26         PCG_LOCK,  /* page cgroup is locked */
  27         PCG_CACHE, /* charged as cache */
  28         PCG_USED, /* this object is in use. */
  29         /* flags for LRU placement */
  30         PCG_ACTIVE, /* page is active in this cgroup */
  31         PCG_FILE, /* page is file system backed */
  32         PCG_UNEVICTABLE, /* page is unevictableable */
  33 };
  34
  35 #define TESTPCGFLAG(uname, lname)                       \
  36 static inline int PageCgroup##uname(struct page_cgroup *pc)     \
  37         { return test_bit(PCG_##lname, &pc->flags); }
  38
  39 #define SETPCGFLAG(uname, lname)                        \
  40 static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
  41         { set_bit(PCG_##lname, &pc->flags);  }
  42
  43 #define CLEARPCGFLAG(uname, lname)                      \
  44 static inline void ClearPageCgroup##uname(struct page_cgroup *pc)       \
  45         { clear_bit(PCG_##lname, &pc->flags);  }
  46
  47 /* Cache flag is set only once (at allocation) */
  48 TESTPCGFLAG(Cache, CACHE)
  49
  50 TESTPCGFLAG(Used, USED)
  51 CLEARPCGFLAG(Used, USED)
  52
  53 /* LRU management flags (from global-lru definition) */
  54 TESTPCGFLAG(File, FILE)
  55 SETPCGFLAG(File, FILE)
  56 CLEARPCGFLAG(File, FILE)
  57
  58 TESTPCGFLAG(Active, ACTIVE)
  59 SETPCGFLAG(Active, ACTIVE)
  60 CLEARPCGFLAG(Active, ACTIVE)
  61
  62 TESTPCGFLAG(Unevictable, UNEVICTABLE)
  63 SETPCGFLAG(Unevictable, UNEVICTABLE)
  64 CLEARPCGFLAG(Unevictable, UNEVICTABLE)
  65
  66 static inline int page_cgroup_nid(struct page_cgroup *pc)
  67 {
  68         return page_to_nid(pc->page);
  69 }
  70
  71 static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
  72 {
  73         return page_zonenum(pc->page);
  74 }
  75
  76 static inline void lock_page_cgroup(struct page_cgroup *pc)
  77 {
  78         bit_spin_lock(PCG_LOCK, &pc->flags);
  79 }
  80
  81 static inline int trylock_page_cgroup(struct page_cgroup *pc)
  82 {
  83         return bit_spin_trylock(PCG_LOCK, &pc->flags);
  84 }
  85
  86 static inline void unlock_page_cgroup(struct page_cgroup *pc)
  87 {
  88         bit_spin_unlock(PCG_LOCK, &pc->flags);
  89 }
  90
  91 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
  92 struct page_cgroup;
  93
  94 static inline void pgdat_page_cgroup_init(struct pglist_data *pgdat)
  95 {
  96 }
  97
  98 static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
  99 {
 100         return NULL;
 101 }
 102
 103 static inline void page_cgroup_init(void)
 104 {
 105 }
 106
 107 #endif
 108 #endif