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 __meminit 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 };
  30
  31 #define TESTPCGFLAG(uname, lname)                       \
  32 static inline int PageCgroup##uname(struct page_cgroup *pc)     \
  33         { return test_bit(PCG_##lname, &pc->flags); }
  34
  35 #define SETPCGFLAG(uname, lname)                        \
  36 static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
  37         { set_bit(PCG_##lname, &pc->flags);  }
  38
  39 #define CLEARPCGFLAG(uname, lname)                      \
  40 static inline void ClearPageCgroup##uname(struct page_cgroup *pc)       \
  41         { clear_bit(PCG_##lname, &pc->flags);  }
  42
  43 /* Cache flag is set only once (at allocation) */
  44 TESTPCGFLAG(Cache, CACHE)
  45
  46 TESTPCGFLAG(Used, USED)
  47 CLEARPCGFLAG(Used, USED)
  48
  49 static inline int page_cgroup_nid(struct page_cgroup *pc)
  50 {
  51         return page_to_nid(pc->page);
  52 }
  53
  54 static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
  55 {
  56         return page_zonenum(pc->page);
  57 }
  58
  59 static inline void lock_page_cgroup(struct page_cgroup *pc)
  60 {
  61         bit_spin_lock(PCG_LOCK, &pc->flags);
  62 }
  63
  64 static inline int trylock_page_cgroup(struct page_cgroup *pc)
  65 {
  66         return bit_spin_trylock(PCG_LOCK, &pc->flags);
  67 }
  68
  69 static inline void unlock_page_cgroup(struct page_cgroup *pc)
  70 {
  71         bit_spin_unlock(PCG_LOCK, &pc->flags);
  72 }
  73
  74 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
  75 struct page_cgroup;
  76
  77 static inline void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
  78 {
  79 }
  80
  81 static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
  82 {
  83         return NULL;
  84 }
  85
  86 static inline void page_cgroup_init(void)
  87 {
  88 }
  89
  90 #endif
  91
  92 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
  93 #include <linux/swap.h>
  94 extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
  95 extern unsigned short lookup_swap_cgroup(swp_entry_t ent);
  96 extern int swap_cgroup_swapon(int type, unsigned long max_pages);
  97 extern void swap_cgroup_swapoff(int type);
  98 #else
  99 #include <linux/swap.h>
 100
 101 static inline
 102 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
 103 {
 104         return 0;
 105 }
 106
 107 static inline
 108 unsigned short lookup_swap_cgroup(swp_entry_t ent)
 109 {
 110         return 0;
 111 }
 112
 113 static inline int
 114 swap_cgroup_swapon(int type, unsigned long max_pages)
 115 {
 116         return 0;
 117 }
 118
 119 static inline void swap_cgroup_swapoff(int type)
 120 {
 121         return;
 122 }
 123
 124 #endif
 125 #endif