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 #include <linux/hugetlb.h>
   8
   9 typedef struct page *new_page_t(struct page *page, unsigned long private,
  10                                 int **reason);
  11 typedef void free_page_t(struct page *page, unsigned long private);
  12
  13 /*
  14  * Return values from addresss_space_operations.migratepage():
  15  * - negative errno on page migration failure;
  16  * - zero on page migration success;
  17  */
  18 #define MIGRATEPAGE_SUCCESS             0
  19
  20 enum migrate_reason {
  21         MR_COMPACTION,
  22         MR_MEMORY_FAILURE,
  23         MR_MEMORY_HOTPLUG,
  24         MR_SYSCALL,             /* also applies to cpusets */
  25         MR_MEMPOLICY_MBIND,
  26         MR_NUMA_MISPLACED,
  27         MR_CMA,
  28         MR_TYPES
  29 };
  30
  31 /* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
  32 extern char *migrate_reason_names[MR_TYPES];
  33
  34 static inline struct page *new_page_nodemask(struct page *page,
  35                                 int preferred_nid, nodemask_t *nodemask)
  36 {
  37         gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
  38
  39         if (PageHuge(page))
  40                 return alloc_huge_page_nodemask(page_hstate(compound_head(page)),
  41                                 preferred_nid, nodemask);
  42
  43         if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
  44                 gfp_mask |= __GFP_HIGHMEM;
  45
  46         return __alloc_pages_nodemask(gfp_mask, 0, preferred_nid, nodemask);
  47 }
  48
  49 #ifdef CONFIG_MIGRATION
  50
  51 extern void putback_movable_pages(struct list_head *l);
  52 extern int migrate_page(struct address_space *mapping,
  53                         struct page *newpage, struct page *page,
  54                         enum migrate_mode mode);
  55 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
  56                 unsigned long private, enum migrate_mode mode, int reason);
  57 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
  58 extern void putback_movable_page(struct page *page);
  59
  60 extern int migrate_prep(void);
  61 extern int migrate_prep_local(void);
  62 extern void migrate_page_copy(struct page *newpage, struct page *page);
  63 extern int migrate_huge_page_move_mapping(struct address_space *mapping,
  64                                   struct page *newpage, struct page *page);
  65 extern int migrate_page_move_mapping(struct address_space *mapping,
  66                 struct page *newpage, struct page *page,
  67                 struct buffer_head *head, enum migrate_mode mode,
  68                 int extra_count);
  69 #else
  70
  71 static inline void putback_movable_pages(struct list_head *l) {}
  72 static inline int migrate_pages(struct list_head *l, new_page_t new,
  73                 free_page_t free, unsigned long private, enum migrate_mode mode,
  74                 int reason)
  75         { return -ENOSYS; }
  76 static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
  77         { return -EBUSY; }
  78
  79 static inline int migrate_prep(void) { return -ENOSYS; }
  80 static inline int migrate_prep_local(void) { return -ENOSYS; }
  81
  82 static inline void migrate_page_copy(struct page *newpage,
  83                                      struct page *page) {}
  84
  85 static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
  86                                   struct page *newpage, struct page *page)
  87 {
  88         return -ENOSYS;
  89 }
  90
  91 #endif /* CONFIG_MIGRATION */
  92
  93 #ifdef CONFIG_COMPACTION
  94 extern int PageMovable(struct page *page);
  95 extern void __SetPageMovable(struct page *page, struct address_space *mapping);
  96 extern void __ClearPageMovable(struct page *page);
  97 #else
  98 static inline int PageMovable(struct page *page) { return 0; };
  99 static inline void __SetPageMovable(struct page *page,
 100                                 struct address_space *mapping)
 101 {
 102 }
 103 static inline void __ClearPageMovable(struct page *page)
 104 {
 105 }
 106 #endif
 107
 108 #ifdef CONFIG_NUMA_BALANCING
 109 extern bool pmd_trans_migrating(pmd_t pmd);
 110 extern int migrate_misplaced_page(struct page *page,
 111                                   struct vm_area_struct *vma, int node);
 112 #else
 113 static inline bool pmd_trans_migrating(pmd_t pmd)
 114 {
 115         return false;
 116 }
 117 static inline int migrate_misplaced_page(struct page *page,
 118                                          struct vm_area_struct *vma, int node)
 119 {
 120         return -EAGAIN; /* can't migrate now */
 121 }
 122 #endif /* CONFIG_NUMA_BALANCING */
 123
 124 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
 125 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 126                         struct vm_area_struct *vma,
 127                         pmd_t *pmd, pmd_t entry,
 128                         unsigned long address,
 129                         struct page *page, int node);
 130 #else
 131 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
 132                         struct vm_area_struct *vma,
 133                         pmd_t *pmd, pmd_t entry,
 134                         unsigned long address,
 135                         struct page *page, int node)
 136 {
 137         return -EAGAIN;
 138 }
 139 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
 140
 141 #endif /* _LINUX_MIGRATE_H */