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 int migrate_vmas(struct mm_struct *mm,
  40                 const nodemask_t *from, const nodemask_t *to,
  41                 unsigned long flags);
  42 extern void migrate_page_copy(struct page *newpage, struct page *page);
  43 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  44                                   struct page *newpage, struct page *page);
  45 extern int migrate_page_move_mapping(struct address_space *mapping,
  46                 struct page *newpage, struct page *page,
  47                 struct buffer_head *head, enum migrate_mode mode,
  48                 int extra_count);
  49 #else
  50
  51 static inline void putback_movable_pages(struct list_head *l) {}
  52 static inline int migrate_pages(struct list_head *l, new_page_t new,
  53                 free_page_t free, unsigned long private, enum migrate_mode mode,
  54                 int reason)
  55         { 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 #endif /* CONFIG_MIGRATION */
  77
  78 #ifdef CONFIG_NUMA_BALANCING
  79 extern bool pmd_trans_migrating(pmd_t pmd);
  80 extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
  81 extern int migrate_misplaced_page(struct page *page,
  82                                   struct vm_area_struct *vma, int node);
  83 extern bool migrate_ratelimited(int node);
  84 #else
  85 static inline bool pmd_trans_migrating(pmd_t pmd)
  86 {
  87         return false;
  88 }
  89 static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
  90 {
  91 }
  92 static inline int migrate_misplaced_page(struct page *page,
  93                                          struct vm_area_struct *vma, int node)
  94 {
  95         return -EAGAIN; /* can't migrate now */
  96 }
  97 static inline bool migrate_ratelimited(int node)
  98 {
  99         return false;
 100 }
 101 #endif /* CONFIG_NUMA_BALANCING */
 102
 103 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 104 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 105                         struct vm_area_struct *vma,
 106                         pmd_t *pmd, pmd_t entry,
 107                         unsigned long address,
 108                         struct page *page, int node);
 109 #else
 110 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 111                         struct vm_area_struct *vma,
 112                         pmd_t *pmd, pmd_t entry,
 113                         unsigned long address,
 114                         struct page *page, int node)
 115 {
 116         return -EAGAIN;
 117 }
 118 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
 119
 120 #endif /* _LINUX_MIGRATE_H */