include/linux/page_cgroup.h

   1 #ifndef __LINUX_PAGE_CGROUP_H
   2 #define __LINUX_PAGE_CGROUP_H
   3
   4 enum {
   5         /* flags for mem_cgroup */
   6         PCG_USED = 0x01,        /* This page is charged to a memcg */
   7         PCG_MEM = 0x02,         /* This page holds a memory charge */
   8         PCG_MEMSW = 0x04,       /* This page holds a memory+swap charge */
   9 };
  10
  11 struct pglist_data;
  12
  13 #ifdef CONFIG_MEMCG
  14 struct mem_cgroup;
  15
  16 /*
  17  * Page Cgroup can be considered as an extended mem_map.
  18  * A page_cgroup page is associated with every page descriptor. The
  19  * page_cgroup helps us identify information about the cgroup
  20  * All page cgroups are allocated at boot or memory hotplug event,
  21  * then the page cgroup for pfn always exists.
  22  */
  23 struct page_cgroup {
  24         unsigned long flags;
  25         struct mem_cgroup *mem_cgroup;
  26 };
  27
  28 extern void pgdat_page_cgroup_init(struct pglist_data *pgdat);
  29
  30 #ifdef CONFIG_SPARSEMEM
  31 static inline void page_cgroup_init_flatmem(void)
  32 {
  33 }
  34 extern void page_cgroup_init(void);
  35 #else
  36 extern void page_cgroup_init_flatmem(void);
  37 static inline void page_cgroup_init(void)
  38 {
  39 }
  40 #endif
  41
  42 struct page_cgroup *lookup_page_cgroup(struct page *page);
  43
  44 static inline int PageCgroupUsed(struct page_cgroup *pc)
  45 {
  46         return !!(pc->flags & PCG_USED);
  47 }
  48 #else /* !CONFIG_MEMCG */
  49 struct page_cgroup;
  50
  51 static inline void pgdat_page_cgroup_init(struct pglist_data *pgdat)
  52 {
  53 }
  54
  55 static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
  56 {
  57         return NULL;
  58 }
  59
  60 static inline void page_cgroup_init(void)
  61 {
  62 }
  63
  64 static inline void page_cgroup_init_flatmem(void)
  65 {
  66 }
  67 #endif /* CONFIG_MEMCG */
  68
  69 #include <linux/swap.h>
  70
  71 #ifdef CONFIG_MEMCG_SWAP
  72 extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
  73                                         unsigned short old, unsigned short new);
  74 extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
  75 extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent);
  76 extern int swap_cgroup_swapon(int type, unsigned long max_pages);
  77 extern void swap_cgroup_swapoff(int type);
  78 #else
  79
  80 static inline
  81 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
  82 {
  83         return 0;
  84 }
  85
  86 static inline
  87 unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
  88 {
  89         return 0;
  90 }
  91
  92 static inline int
  93 swap_cgroup_swapon(int type, unsigned long max_pages)
  94 {
  95         return 0;
  96 }
  97
  98 static inline void swap_cgroup_swapoff(int type)
  99 {
 100         return;
 101 }
 102
 103 #endif /* CONFIG_MEMCG_SWAP */
 104
 105 #endif /* __LINUX_PAGE_CGROUP_H */