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_movable_pages(struct list_head *l); 39 extern int migrate_page(struct address_space *, 40 struct page *, struct page *, enum migrate_mode); 41 extern int migrate_pages(struct list_head *l, new_page_t x, 42 unsigned long private, enum migrate_mode mode, int reason); 43 44 extern int migrate_prep(void); 45 extern int migrate_prep_local(void); 46 extern int migrate_vmas(struct mm_struct *mm, 47 const nodemask_t *from, const nodemask_t *to, 48 unsigned long flags); 49 extern void migrate_page_copy(struct page *newpage, struct page *page); 50 extern int migrate_huge_page_move_mapping(struct address_space *mapping, 51 struct page *newpage, struct page *page); 52 extern int migrate_page_move_mapping(struct address_space *mapping, 53 struct page *newpage, struct page *page, 54 struct buffer_head *head, enum migrate_mode mode, 55 int extra_count); 56 #else 57 58 static inline void putback_movable_pages(struct list_head *l) {} 59 static inline int migrate_pages(struct list_head *l, new_page_t x, 60 unsigned long private, enum migrate_mode mode, int reason) 61 { return -ENOSYS; } 62 63 static inline int migrate_prep(void) { return -ENOSYS; } 64 static inline int migrate_prep_local(void) { return -ENOSYS; } 65 66 static inline int migrate_vmas(struct mm_struct *mm, 67 const nodemask_t *from, const nodemask_t *to, 68 unsigned long flags) 69 { 70 return -ENOSYS; 71 } 72 73 static inline void migrate_page_copy(struct page *newpage, 74 struct page *page) {} 75 76 static inline int migrate_huge_page_move_mapping(struct address_space *mapping, 77 struct page *newpage, struct page *page) 78 { 79 return -ENOSYS; 80 } 81 82 /* Possible settings for the migrate_page() method in address_operations */ 83 #define migrate_page NULL 84 85 #endif /* CONFIG_MIGRATION */ 86 87 #ifdef CONFIG_NUMA_BALANCING 88 extern bool pmd_trans_migrating(pmd_t pmd); 89 extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd); 90 extern int migrate_misplaced_page(struct page *page, 91 struct vm_area_struct *vma, int node); 92 extern bool migrate_ratelimited(int node); 93 #else 94 static inline bool pmd_trans_migrating(pmd_t pmd) 95 { 96 return false; 97 } 98 static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd) 99 { 100 } 101 static inline int migrate_misplaced_page(struct page *page, 102 struct vm_area_struct *vma, int node) 103 { 104 return -EAGAIN; /* can't migrate now */ 105 } 106 static inline bool migrate_ratelimited(int node) 107 { 108 return false; 109 } 110 #endif /* CONFIG_NUMA_BALANCING */ 111 112 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 113 extern int migrate_misplaced_transhuge_page(struct mm_struct *mm, 114 struct vm_area_struct *vma, 115 pmd_t *pmd, pmd_t entry, 116 unsigned long address, 117 struct page *page, int node); 118 #else 119 static inline 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 { 125 return -EAGAIN; 126 } 127 #endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/ 128 129 #endif /* _LINUX_MIGRATE_H */ 130