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 *mapping,
  37                         struct page *newpage, struct page *page,
  38                         enum migrate_mode mode);
  39 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  40                 unsigned long private, enum migrate_mode mode, int reason);
  41 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
  42 extern void putback_movable_page(struct page *page);
  43
  44 extern int migrate_prep(void);
  45 extern int migrate_prep_local(void);
  46 extern void migrate_page_copy(struct page *newpage, struct page *page);
  47 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  48                                   struct page *newpage, struct page *page);
  49 extern int migrate_page_move_mapping(struct address_space *mapping,
  50                 struct page *newpage, struct page *page,
  51                 struct buffer_head *head, enum migrate_mode mode,
  52                 int extra_count);
  53 #else
  54
  55 static inline void putback_movable_pages(struct list_head *l) {}
  56 static inline int migrate_pages(struct list_head *l, new_page_t new,
  57                 free_page_t free, unsigned long private, enum migrate_mode mode,
  58                 int reason)
  59         { return -ENOSYS; }
  60 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
  61         { return -EBUSY; }
  62
  63 static inline int migrate_prep(void) { return -ENOSYS; }
  64 static inline int migrate_prep_local(void) { return -ENOSYS; }
  65
  66 static inline void migrate_page_copy(struct page *newpage,
  67                                      struct page *page) {}
  68
  69 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  70                                   struct page *newpage, struct page *page)
  71 {
  72         return -ENOSYS;
  73 }
  74
  75 #endif /* CONFIG_MIGRATION */
  76
  77 #ifdef CONFIG_COMPACTION
  78 extern int PageMovable(struct page *page);
  79 extern void __SetPageMovable(struct page *page, struct address_space *mapping);
  80 extern void __ClearPageMovable(struct page *page);
  81 #else
  82 static inline int PageMovable(struct page *page) { return 0; };
  83 static inline void __SetPageMovable(struct page *page,
  84                                 struct address_space *mapping)
  85 {
  86 }
  87 static inline void __ClearPageMovable(struct page *page)
  88 {
  89 }
  90 #endif
  91
  92 #ifdef CONFIG_NUMA_BALANCING
  93 extern bool pmd_trans_migrating(pmd_t pmd);
  94 extern int migrate_misplaced_page(struct page *page,
  95                                   struct vm_area_struct *vma, int node);
  96 #else
  97 static inline bool pmd_trans_migrating(pmd_t pmd)
  98 {
  99         return false;
 100 }
 101 static inline int migrate_misplaced_page(struct page *page,
 102                                          struct vm_area_struct *vma, int node)
 103 {
 104         return -EAGAIN; /* can't migrate now */
 105 }
 106 #endif /* CONFIG_NUMA_BALANCING */
 107
 108 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 109 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 110                         struct vm_area_struct *vma,
 111                         pmd_t *pmd, pmd_t entry,
 112                         unsigned long address,
 113                         struct page *page, int node);
 114 #else
 115 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 116                         struct vm_area_struct *vma,
 117                         pmd_t *pmd, pmd_t entry,
 118                         unsigned long address,
 119                         struct page *page, int node)
 120 {
 121         return -EAGAIN;
 122 }
 123 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
 124
 125 #endif /* _LINUX_MIGRATE_H */