include/linux/migrate.h

   1 #ifndef _LINUX_MIGRATE_H
   2 #define _LINUX_MIGRATE_H
   3
   4 #include <linux/mm.h>
   5 #include <linux/mempolicy.h>
   6
   7 typedef struct page *new_page_t(struct page *, unsigned long private, int **);
   8
   9 /*
  10  * MIGRATE_ASYNC means never block
  11  * MIGRATE_SYNC_LIGHT in the current implementation means to allow blocking
  12  *      on most operations but not ->writepage as the potential stall time
  13  *      is too significant
  14  * MIGRATE_SYNC will block when migrating pages
  15  */
  16 enum migrate_mode {
  17         MIGRATE_ASYNC,
  18         MIGRATE_SYNC_LIGHT,
  19         MIGRATE_SYNC,
  20 };
  21
  22 #ifdef CONFIG_MIGRATION
  23 #define PAGE_MIGRATION 1
  24
  25 extern void putback_lru_pages(struct list_head *l);
  26 extern int migrate_page(struct address_space *,
  27                         struct page *, struct page *, enum migrate_mode);
  28 extern int migrate_pages(struct list_head *l, new_page_t x,
  29                         unsigned long private, bool offlining,
  30                         enum migrate_mode mode);
  31 extern int migrate_huge_pages(struct list_head *l, new_page_t x,
  32                         unsigned long private, bool offlining,
  33                         enum migrate_mode mode);
  34
  35 extern int fail_migrate_page(struct address_space *,
  36                         struct page *, struct page *);
  37
  38 extern int migrate_prep(void);
  39 extern int migrate_prep_local(void);
  40 extern int migrate_vmas(struct mm_struct *mm,
  41                 const nodemask_t *from, const nodemask_t *to,
  42                 unsigned long flags);
  43 extern void migrate_page_copy(struct page *newpage, struct page *page);
  44 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  45                                   struct page *newpage, struct page *page);
  46 #else
  47 #define PAGE_MIGRATION 0
  48
  49 static inline void putback_lru_pages(struct list_head *l) {}
  50 static inline int migrate_pages(struct list_head *l, new_page_t x,
  51                 unsigned long private, bool offlining,
  52                 enum migrate_mode mode) { return -ENOSYS; }
  53 static inline int migrate_huge_pages(struct list_head *l, new_page_t x,
  54                 unsigned long private, bool offlining,
  55                 enum migrate_mode mode) { return -ENOSYS; }
  56
  57 static inline int migrate_prep(void) { return -ENOSYS; }
  58 static inline int migrate_prep_local(void) { return -ENOSYS; }
  59
  60 static inline int migrate_vmas(struct mm_struct *mm,
  61                 const nodemask_t *from, const nodemask_t *to,
  62                 unsigned long flags)
  63 {
  64         return -ENOSYS;
  65 }
  66
  67 static inline void migrate_page_copy(struct page *newpage,
  68                                      struct page *page) {}
  69
  70 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  71                                   struct page *newpage, struct page *page)
  72 {
  73         return -ENOSYS;
  74 }
  75
  76 /* Possible settings for the migrate_page() method in address_operations */
  77 #define migrate_page NULL
  78 #define fail_migrate_page NULL
  79
  80 #endif /* CONFIG_MIGRATION */
  81 #endif /* _LINUX_MIGRATE_H */