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