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         MR_TYPES
  28 };
  29
  30 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
  31 extern char *migrate_reason_names[MR_TYPES];
  32
  33 #ifdef CONFIG_MIGRATION
  34
  35 extern void putback_movable_pages(struct list_head *l);
  36 extern int migrate_page(struct address_space *,
  37                         struct page *, struct page *, enum migrate_mode);
  38 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  39                 unsigned long private, enum migrate_mode mode, int reason);
  40 extern bool isolate_movable_page(struct page *page, isolate_mode_t mode);
  41 extern void putback_movable_page(struct page *page);
  42
  43 extern int migrate_prep(void);
  44 extern int migrate_prep_local(void);
  45 extern void migrate_page_copy(struct page *newpage, struct page *page);
  46 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  47                                   struct page *newpage, struct page *page);
  48 extern int migrate_page_move_mapping(struct address_space *mapping,
  49                 struct page *newpage, struct page *page,
  50                 struct buffer_head *head, enum migrate_mode mode,
  51                 int extra_count);
  52 #else
  53
  54 static inline void putback_movable_pages(struct list_head *l) {}
  55 static inline int migrate_pages(struct list_head *l, new_page_t new,
  56                 free_page_t free, unsigned long private, enum migrate_mode mode,
  57                 int reason)
  58         { return -ENOSYS; }
  59
  60 static inline int migrate_prep(void) { return -ENOSYS; }
  61 static inline int migrate_prep_local(void) { return -ENOSYS; }
  62
  63 static inline void migrate_page_copy(struct page *newpage,
  64                                      struct page *page) {}
  65
  66 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  67                                   struct page *newpage, struct page *page)
  68 {
  69         return -ENOSYS;
  70 }
  71
  72 #endif /* CONFIG_MIGRATION */
  73
  74 #ifdef CONFIG_NUMA_BALANCING
  75 extern bool pmd_trans_migrating(pmd_t pmd);
  76 extern int migrate_misplaced_page(struct page *page,
  77                                   struct vm_area_struct *vma, int node);
  78 #else
  79 static inline bool pmd_trans_migrating(pmd_t pmd)
  80 {
  81         return false;
  82 }
  83 static inline int migrate_misplaced_page(struct page *page,
  84                                          struct vm_area_struct *vma, int node)
  85 {
  86         return -EAGAIN; /* can't migrate now */
  87 }
  88 #endif /* CONFIG_NUMA_BALANCING */
  89
  90 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
  91 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
  92                         struct vm_area_struct *vma,
  93                         pmd_t *pmd, pmd_t entry,
  94                         unsigned long address,
  95                         struct page *page, int node);
  96 #else
  97 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
  98                         struct vm_area_struct *vma,
  99                         pmd_t *pmd, pmd_t entry,
 100                         unsigned long address,
 101                         struct page *page, int node)
 102 {
 103         return -EAGAIN;
 104 }
 105 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
 106
 107 #endif /* _LINUX_MIGRATE_H */