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_LOCK,  /* Lock for pc->mem_cgroup and following bits. */
   7         PCG_CACHE, /* charged as cache */
   8         PCG_USED, /* this object is in use. */
   9         PCG_MIGRATION, /* under page migration */
  10         /* flags for mem_cgroup and file and I/O status */
  11         PCG_MOVE_LOCK, /* For race between move_account v.s. following bits */
  12         PCG_FILE_MAPPED, /* page is accounted as "mapped" */
  13         /* No lock in page_cgroup */
  14         PCG_ACCT_LRU, /* page has been accounted for (under lru_lock) */
  15         __NR_PCG_FLAGS,
  16 };
  17
  18 #ifndef __GENERATING_BOUNDS_H
  19 #include <generated/bounds.h>
  20
  21 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
  22 #include <linux/bit_spinlock.h>
  23
  24 /*
  25  * Page Cgroup can be considered as an extended mem_map.
  26  * A page_cgroup page is associated with every page descriptor. The
  27  * page_cgroup helps us identify information about the cgroup
  28  * All page cgroups are allocated at boot or memory hotplug event,
  29  * then the page cgroup for pfn always exists.
  30  */
  31 struct page_cgroup {
  32         unsigned long flags;
  33         struct mem_cgroup *mem_cgroup;
  34         struct list_head lru;           /* per cgroup LRU list */
  35 };
  36
  37 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
  38
  39 #ifdef CONFIG_SPARSEMEM
  40 static inline void __init page_cgroup_init_flatmem(void)
  41 {
  42 }
  43 extern void __init page_cgroup_init(void);
  44 #else
  45 void __init page_cgroup_init_flatmem(void);
  46 static inline void __init page_cgroup_init(void)
  47 {
  48 }
  49 #endif
  50
  51 struct page_cgroup *lookup_page_cgroup(struct page *page);
  52 struct page *lookup_cgroup_page(struct page_cgroup *pc);
  53
  54 #define TESTPCGFLAG(uname, lname)                       \
  55 static inline int PageCgroup##uname(struct page_cgroup *pc)     \
  56         { return test_bit(PCG_##lname, &pc->flags); }
  57
  58 #define SETPCGFLAG(uname, lname)                        \
  59 static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
  60         { set_bit(PCG_##lname, &pc->flags);  }
  61
  62 #define CLEARPCGFLAG(uname, lname)                      \
  63 static inline void ClearPageCgroup##uname(struct page_cgroup *pc)       \
  64         { clear_bit(PCG_##lname, &pc->flags);  }
  65
  66 #define TESTCLEARPCGFLAG(uname, lname)                  \
  67 static inline int TestClearPageCgroup##uname(struct page_cgroup *pc)    \
  68         { return test_and_clear_bit(PCG_##lname, &pc->flags);  }
  69
  70 /* Cache flag is set only once (at allocation) */
  71 TESTPCGFLAG(Cache, CACHE)
  72 CLEARPCGFLAG(Cache, CACHE)
  73 SETPCGFLAG(Cache, CACHE)
  74
  75 TESTPCGFLAG(Used, USED)
  76 CLEARPCGFLAG(Used, USED)
  77 SETPCGFLAG(Used, USED)
  78
  79 SETPCGFLAG(AcctLRU, ACCT_LRU)
  80 CLEARPCGFLAG(AcctLRU, ACCT_LRU)
  81 TESTPCGFLAG(AcctLRU, ACCT_LRU)
  82 TESTCLEARPCGFLAG(AcctLRU, ACCT_LRU)
  83
  84
  85 SETPCGFLAG(FileMapped, FILE_MAPPED)
  86 CLEARPCGFLAG(FileMapped, FILE_MAPPED)
  87 TESTPCGFLAG(FileMapped, FILE_MAPPED)
  88
  89 SETPCGFLAG(Migration, MIGRATION)
  90 CLEARPCGFLAG(Migration, MIGRATION)
  91 TESTPCGFLAG(Migration, MIGRATION)
  92
  93 static inline void lock_page_cgroup(struct page_cgroup *pc)
  94 {
  95         /*
  96          * Don't take this lock in IRQ context.
  97          * This lock is for pc->mem_cgroup, USED, CACHE, MIGRATION
  98          */
  99         bit_spin_lock(PCG_LOCK, &pc->flags);
 100 }
 101
 102 static inline void unlock_page_cgroup(struct page_cgroup *pc)
 103 {
 104         bit_spin_unlock(PCG_LOCK, &pc->flags);
 105 }
 106
 107 static inline void move_lock_page_cgroup(struct page_cgroup *pc,
 108         unsigned long *flags)
 109 {
 110         /*
 111          * We know updates to pc->flags of page cache's stats are from both of
 112          * usual context or IRQ context. Disable IRQ to avoid deadlock.
 113          */
 114         local_irq_save(*flags);
 115         bit_spin_lock(PCG_MOVE_LOCK, &pc->flags);
 116 }
 117
 118 static inline void move_unlock_page_cgroup(struct page_cgroup *pc,
 119         unsigned long *flags)
 120 {
 121         bit_spin_unlock(PCG_MOVE_LOCK, &pc->flags);
 122         local_irq_restore(*flags);
 123 }
 124
 125 #ifdef CONFIG_SPARSEMEM
 126 #define PCG_ARRAYID_WIDTH       SECTIONS_SHIFT
 127 #else
 128 #define PCG_ARRAYID_WIDTH       NODES_SHIFT
 129 #endif
 130
 131 #if (PCG_ARRAYID_WIDTH > BITS_PER_LONG - NR_PCG_FLAGS)
 132 #error Not enough space left in pc->flags to store page_cgroup array IDs
 133 #endif
 134
 135 /* pc->flags: ARRAY-ID | FLAGS */
 136
 137 #define PCG_ARRAYID_MASK        ((1UL << PCG_ARRAYID_WIDTH) - 1)
 138
 139 #define PCG_ARRAYID_OFFSET      (BITS_PER_LONG - PCG_ARRAYID_WIDTH)
 140 /*
 141  * Zero the shift count for non-existent fields, to prevent compiler
 142  * warnings and ensure references are optimized away.
 143  */
 144 #define PCG_ARRAYID_SHIFT       (PCG_ARRAYID_OFFSET * (PCG_ARRAYID_WIDTH != 0))
 145
 146 static inline void set_page_cgroup_array_id(struct page_cgroup *pc,
 147                                             unsigned long id)
 148 {
 149         pc->flags &= ~(PCG_ARRAYID_MASK << PCG_ARRAYID_SHIFT);
 150         pc->flags |= (id & PCG_ARRAYID_MASK) << PCG_ARRAYID_SHIFT;
 151 }
 152
 153 static inline unsigned long page_cgroup_array_id(struct page_cgroup *pc)
 154 {
 155         return (pc->flags >> PCG_ARRAYID_SHIFT) & PCG_ARRAYID_MASK;
 156 }
 157
 158 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 159 struct page_cgroup;
 160
 161 static inline void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
 162 {
 163 }
 164
 165 static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
 166 {
 167         return NULL;
 168 }
 169
 170 static inline void page_cgroup_init(void)
 171 {
 172 }
 173
 174 static inline void __init page_cgroup_init_flatmem(void)
 175 {
 176 }
 177
 178 #endif /* CONFIG_CGROUP_MEM_RES_CTLR */
 179
 180 #include <linux/swap.h>
 181
 182 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 183 extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
 184                                         unsigned short old, unsigned short new);
 185 extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
 186 extern unsigned short lookup_swap_cgroup(swp_entry_t ent);
 187 extern int swap_cgroup_swapon(int type, unsigned long max_pages);
 188 extern void swap_cgroup_swapoff(int type);
 189 #else
 190
 191 static inline
 192 unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
 193 {
 194         return 0;
 195 }
 196
 197 static inline
 198 unsigned short lookup_swap_cgroup(swp_entry_t ent)
 199 {
 200         return 0;
 201 }
 202
 203 static inline int
 204 swap_cgroup_swapon(int type, unsigned long max_pages)
 205 {
 206         return 0;
 207 }
 208
 209 static inline void swap_cgroup_swapoff(int type)
 210 {
 211         return;
 212 }
 213
 214 #endif /* CONFIG_CGROUP_MEM_RES_CTLR_SWAP */
 215
 216 #endif /* !__GENERATING_BOUNDS_H */
 217
 218 #endif /* __LINUX_PAGE_CGROUP_H */