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 int extra_count);
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, enum migrate_mode mode, int reason)
66 { return -ENOSYS; }
67
68static inline int migrate_prep(void) { return -ENOSYS; }
69static inline int migrate_prep_local(void) { return -ENOSYS; }
70
71static 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
78static inline void migrate_page_copy(struct page *newpage,
79 struct page *page) {}
80
81static 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
94extern bool pmd_trans_migrating(pmd_t pmd);
95extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
96extern int migrate_misplaced_page(struct page *page,
97 struct vm_area_struct *vma, int node);
98extern bool migrate_ratelimited(int node);
99#else
100static inline bool pmd_trans_migrating(pmd_t pmd)
101{
102 return false;
103}
104static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
105{
106}
107static 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}
112static 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)
119extern 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
125static 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 */