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 #include <linux/migrate_mode.h>
   7
   8 typedef struct page *new_page_t(struct page *page, unsigned long private,
   9                                 int **reason);
  10 typedef void free_page_t(struct page *page, unsigned long private);
  11
  12 /*
  13  * Return values from addresss_space_operations.migratepage():
  14  * - negative errno on page migration failure;
  15  * - zero on page migration success;
  16  */
  17 #define MIGRATEPAGE_SUCCESS             0
  18
  19 enum migrate_reason {
  20         MR_COMPACTION,
  21         MR_MEMORY_FAILURE,
  22         MR_MEMORY_HOTPLUG,
  23         MR_SYSCALL,             /* also applies to cpusets */
  24         MR_MEMPOLICY_MBIND,
  25         MR_NUMA_MISPLACED,
  26         MR_CMA
  27 };
  28
  29 #ifdef CONFIG_MIGRATION
  30
  31 extern void putback_movable_pages(struct list_head *l);
  32 extern int migrate_page(struct address_space *,
  33                         struct page *, struct page *, enum migrate_mode);
  34 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  35                 unsigned long private, enum migrate_mode mode, int reason);
  36
  37 extern int migrate_prep(void);
  38 extern int migrate_prep_local(void);
  39 extern void migrate_page_copy(struct page *newpage, struct page *page);
  40 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  41                                   struct page *newpage, struct page *page);
  42 extern int migrate_page_move_mapping(struct address_space *mapping,
  43                 struct page *newpage, struct page *page,
  44                 struct buffer_head *head, enum migrate_mode mode,
  45                 int extra_count);
  46 #else
  47
  48 static inline void putback_movable_pages(struct list_head *l) {}
  49 static inline int migrate_pages(struct list_head *l, new_page_t new,
  50                 free_page_t free, unsigned long private, enum migrate_mode mode,
  51                 int reason)
  52         { return -ENOSYS; }
  53
  54 static inline int migrate_prep(void) { return -ENOSYS; }
  55 static inline int migrate_prep_local(void) { return -ENOSYS; }
  56
  57 static inline void migrate_page_copy(struct page *newpage,
  58                                      struct page *page) {}
  59
  60 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  61                                   struct page *newpage, struct page *page)
  62 {
  63         return -ENOSYS;
  64 }
  65
  66 #endif /* CONFIG_MIGRATION */
  67
  68 #ifdef CONFIG_NUMA_BALANCING
  69 extern bool pmd_trans_migrating(pmd_t pmd);
  70 extern int migrate_misplaced_page(struct page *page,
  71                                   struct vm_area_struct *vma, int node);
  72 extern bool migrate_ratelimited(int node);
  73 #else
  74 static inline bool pmd_trans_migrating(pmd_t pmd)
  75 {
  76         return false;
  77 }
  78 static inline int migrate_misplaced_page(struct page *page,
  79                                          struct vm_area_struct *vma, int node)
  80 {
  81         return -EAGAIN; /* can't migrate now */
  82 }
  83 static inline bool migrate_ratelimited(int node)
  84 {
  85         return false;
  86 }
  87 #endif /* CONFIG_NUMA_BALANCING */
  88
  89 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
  90 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
  91                         struct vm_area_struct *vma,
  92                         pmd_t *pmd, pmd_t entry,
  93                         unsigned long address,
  94                         struct page *page, int node);
  95 #else
  96 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
  97                         struct vm_area_struct *vma,
  98                         pmd_t *pmd, pmd_t entry,
  99                         unsigned long address,
 100                         struct page *page, int node)
 101 {
 102         return -EAGAIN;
 103 }
 104 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
 105
 106 #endif /* _LINUX_MIGRATE_H */