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 *, unsigned long private, int **); 9 10 /* 11 * Return values from addresss_space_operations.migratepage(): 12 * - negative errno on page migration failure; 13 * - zero on page migration success; 14 * 15 * The balloon page migration introduces this special case where a 'distinct' 16 * return code is used to flag a successful page migration to unmap_and_move(). 17 * This approach is necessary because page migration can race against balloon 18 * deflation procedure, and for such case we could introduce a nasty page leak 19 * if a successfully migrated balloon page gets released concurrently with 20 * migration's unmap_and_move() wrap-up steps. 21 */ 22 #define MIGRATEPAGE_SUCCESS 0 23 #define MIGRATEPAGE_BALLOON_SUCCESS 1 /* special ret code for balloon page 24 * sucessful migration case. 25 */ 26 27 #ifdef CONFIG_MIGRATION 28 29 extern void putback_lru_pages(struct list_head *l); 30 extern void putback_movable_pages(struct list_head *l); 31 extern int migrate_page(struct address_space *, 32 struct page *, struct page *, enum migrate_mode); 33 extern int migrate_pages(struct list_head *l, new_page_t x, 34 unsigned long private, bool offlining, 35 enum migrate_mode mode); 36 extern int migrate_huge_page(struct page *, new_page_t x, 37 unsigned long private, bool offlining, 38 enum migrate_mode mode); 39 40 extern int fail_migrate_page(struct address_space *, 41 struct page *, struct page *); 42 43 extern int migrate_prep(void); 44 extern int migrate_prep_local(void); 45 extern int migrate_vmas(struct mm_struct *mm, 46 const nodemask_t *from, const nodemask_t *to, 47 unsigned long flags); 48 extern void migrate_page_copy(struct page *newpage, struct page *page); 49 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 50 struct page *newpage, struct page *page); 51 #else 52 53 static inline void putback_lru_pages(struct list_head *l) {} 54 static inline void putback_movable_pages(struct list_head *l) {} 55 static inline int migrate_pages(struct list_head *l, new_page_t x, 56 unsigned long private, bool offlining, 57 enum migrate_mode mode) { return -ENOSYS; } 58 static inline int migrate_huge_page(struct page *page, new_page_t x, 59 unsigned long private, bool offlining, 60 enum migrate_mode mode) { return -ENOSYS; } 61 62 static inline int migrate_prep(void) { return -ENOSYS; } 63 static inline int migrate_prep_local(void) { return -ENOSYS; } 64 65 static inline int migrate_vmas(struct mm_struct *mm, 66 const nodemask_t *from, const nodemask_t *to, 67 unsigned long flags) 68 { 69 return -ENOSYS; 70 } 71 72 static inline void migrate_page_copy(struct page *newpage, 73 struct page *page) {} 74 75 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 76 struct page *newpage, struct page *page) 77 { 78 return -ENOSYS; 79 } 80 81 /* Possible settings for the migrate_page() method in address_operations */ 82 #define migrate_page NULL 83 #define fail_migrate_page NULL 84 85 #endif /* CONFIG_MIGRATION */ 86 #endif /* _LINUX_MIGRATE_H */ 87