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 enum migrate_reason { 27 MR_COMPACTION, 28 MR_MEMORY_FAILURE, 29 MR_MEMORY_HOTPLUG, 30 MR_SYSCALL, /* also applies to cpusets */ 31 MR_MEMPOLICY_MBIND, 32 MR_NUMA_MISPLACED, 33 MR_CMA 34 }; 35 36 #ifdef CONFIG_MIGRATION 37 38 extern void putback_lru_pages(struct list_head *l); 39 extern void putback_movable_pages(struct list_head *l); 40 extern int migrate_page(struct address_space *, 41 struct page *, struct page *, enum migrate_mode); 42 extern int migrate_pages(struct list_head *l, new_page_t x, 43 unsigned long private, bool offlining, 44 enum migrate_mode mode, int reason); 45 extern int migrate_huge_page(struct page *, new_page_t x, 46 unsigned long private, bool offlining, 47 enum migrate_mode mode); 48 49 extern int fail_migrate_page(struct address_space *, 50 struct page *, struct page *); 51 52 extern int migrate_prep(void); 53 extern int migrate_prep_local(void); 54 extern int migrate_vmas(struct mm_struct *mm, 55 const nodemask_t *from, const nodemask_t *to, 56 unsigned long flags); 57 extern void migrate_page_copy(struct page *newpage, struct page *page); 58 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 59 struct page *newpage, struct page *page); 60 #else 61 62 static inline void putback_lru_pages(struct list_head *l) {} 63 static inline void putback_movable_pages(struct list_head *l) {} 64 static inline int migrate_pages(struct list_head *l, new_page_t x, 65 unsigned long private, bool offlining, 66 enum migrate_mode mode, int reason) { return -ENOSYS; } 67 static inline int migrate_huge_page(struct page *page, new_page_t x, 68 unsigned long private, bool offlining, 69 enum migrate_mode mode) { return -ENOSYS; } 70 71 static inline int migrate_prep(void) { return -ENOSYS; } 72 static inline int migrate_prep_local(void) { return -ENOSYS; } 73 74 static inline int migrate_vmas(struct mm_struct *mm, 75 const nodemask_t *from, const nodemask_t *to, 76 unsigned long flags) 77 { 78 return -ENOSYS; 79 } 80 81 static inline void migrate_page_copy(struct page *newpage, 82 struct page *page) {} 83 84 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 85 struct page *newpage, struct page *page) 86 { 87 return -ENOSYS; 88 } 89 90 /* Possible settings for the migrate_page() method in address_operations */ 91 #define migrate_page NULL 92 #define fail_migrate_page NULL 93 94 #endif /* CONFIG_MIGRATION */ 95 96 #ifdef CONFIG_NUMA_BALANCING 97 extern int migrate_misplaced_page(struct page *page, int node); 98 extern int migrate_misplaced_page(struct page *page, int node); 99 extern bool migrate_ratelimited(int node); 100 #else 101 static inline int migrate_misplaced_page(struct page *page, int node) 102 { 103 return -EAGAIN; /* can't migrate now */ 104 } 105 static inline bool migrate_ratelimited(int node) 106 { 107 return false; 108 } 109 #endif /* CONFIG_NUMA_BALANCING */ 110 111 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 112 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm, 113 struct vm_area_struct *vma, 114 pmd_t *pmd, pmd_t entry, 115 unsigned long address, 116 struct page *page, int node); 117 #else 118 static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm, 119 struct vm_area_struct *vma, 120 pmd_t *pmd, pmd_t entry, 121 unsigned long address, 122 struct page *page, int node) 123 { 124 return -EAGAIN; 125 } 126 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/ 127 128 #endif /* _LINUX_MIGRATE_H */ 129