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, enum migrate_mode mode, int reason); 44 45 extern int fail_migrate_page(struct address_space *, 46 struct page *, struct page *); 47 48 extern int migrate_prep(void); 49 extern int migrate_prep_local(void); 50 extern int migrate_vmas(struct mm_struct *mm, 51 const nodemask_t *from, const nodemask_t *to, 52 unsigned long flags); 53 extern void migrate_page_copy(struct page *newpage, struct page *page); 54 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 55 struct page *newpage, struct page *page); 56 extern int migrate_page_move_mapping(struct address_space *mapping, 57 struct page *newpage, struct page *page, 58 struct buffer_head *head, enum migrate_mode mode, 59 int extra_count); 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, enum migrate_mode mode, int reason) 66 { return -ENOSYS; } 67 68 static inline int migrate_prep(void) { return -ENOSYS; } 69 static inline int migrate_prep_local(void) { return -ENOSYS; } 70 71 static inline int migrate_vmas(struct mm_struct *mm, 72 const nodemask_t *from, const nodemask_t *to, 73 unsigned long flags) 74 { 75 return -ENOSYS; 76 } 77 78 static inline void migrate_page_copy(struct page *newpage, 79 struct page *page) {} 80 81 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 82 struct page *newpage, struct page *page) 83 { 84 return -ENOSYS; 85 } 86 87 /* Possible settings for the migrate_page() method in address_operations */ 88 #define migrate_page NULL 89 #define fail_migrate_page NULL 90 91 #endif /* CONFIG_MIGRATION */ 92 93 #ifdef CONFIG_NUMA_BALANCING 94 extern bool pmd_trans_migrating(pmd_t pmd); 95 extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd); 96 extern int migrate_misplaced_page(struct page *page, 97 struct vm_area_struct *vma, int node); 98 extern bool migrate_ratelimited(int node); 99 #else 100 static inline bool pmd_trans_migrating(pmd_t pmd) 101 { 102 return false; 103 } 104 static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd) 105 { 106 } 107 static inline int migrate_misplaced_page(struct page *page, 108 struct vm_area_struct *vma, int node) 109 { 110 return -EAGAIN; /* can't migrate now */ 111 } 112 static inline bool migrate_ratelimited(int node) 113 { 114 return false; 115 } 116 #endif /* CONFIG_NUMA_BALANCING */ 117 118 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 119 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm, 120 struct vm_area_struct *vma, 121 pmd_t *pmd, pmd_t entry, 122 unsigned long address, 123 struct page *page, int node); 124 #else 125 static inline 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 { 131 return -EAGAIN; 132 } 133 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/ 134 135 #endif /* _LINUX_MIGRATE_H */ 136