Linux kernel mirror (for testing)
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linux
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
8typedef 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 */
26enum 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
38extern void putback_lru_pages(struct list_head *l);
39extern void putback_movable_pages(struct list_head *l);
40extern int migrate_page(struct address_space *,
41 struct page *, struct page *, enum migrate_mode);
42extern int migrate_pages(struct list_head *l, new_page_t x,
43 unsigned long private, bool offlining,
44 enum migrate_mode mode, int reason);
45extern int migrate_huge_page(struct page *, new_page_t x,
46 unsigned long private, bool offlining,
47 enum migrate_mode mode);
48
49extern int fail_migrate_page(struct address_space *,
50 struct page *, struct page *);
51
52extern int migrate_prep(void);
53extern int migrate_prep_local(void);
54extern int migrate_vmas(struct mm_struct *mm,
55 const nodemask_t *from, const nodemask_t *to,
56 unsigned long flags);
57extern void migrate_page_copy(struct page *newpage, struct page *page);
58extern int migrate_huge_page_move_mapping(struct address_space *mapping,
59 struct page *newpage, struct page *page);
60#else
61
62static inline void putback_lru_pages(struct list_head *l) {}
63static inline void putback_movable_pages(struct list_head *l) {}
64static 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; }
67static 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
71static inline int migrate_prep(void) { return -ENOSYS; }
72static inline int migrate_prep_local(void) { return -ENOSYS; }
73
74static 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
81static inline void migrate_page_copy(struct page *newpage,
82 struct page *page) {}
83
84static 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
97extern int migrate_misplaced_page(struct page *page, int node);
98extern int migrate_misplaced_page(struct page *page, int node);
99extern bool migrate_ratelimited(int node);
100#else
101static inline int migrate_misplaced_page(struct page *page, int node)
102{
103 return -EAGAIN; /* can't migrate now */
104}
105static 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)
112extern 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
118static 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 */