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_movable_pages(struct list_head *l);
39extern int migrate_page(struct address_space *,
40 struct page *, struct page *, enum migrate_mode);
41extern int migrate_pages(struct list_head *l, new_page_t x,
42 unsigned long private, enum migrate_mode mode, int reason);
43
44extern int migrate_prep(void);
45extern int migrate_prep_local(void);
46extern int migrate_vmas(struct mm_struct *mm,
47 const nodemask_t *from, const nodemask_t *to,
48 unsigned long flags);
49extern void migrate_page_copy(struct page *newpage, struct page *page);
50extern int migrate_huge_page_move_mapping(struct address_space *mapping,
51 struct page *newpage, struct page *page);
52extern 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
58static inline void putback_movable_pages(struct list_head *l) {}
59static 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
63static inline int migrate_prep(void) { return -ENOSYS; }
64static inline int migrate_prep_local(void) { return -ENOSYS; }
65
66static 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
73static inline void migrate_page_copy(struct page *newpage,
74 struct page *page) {}
75
76static 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
88extern bool pmd_trans_migrating(pmd_t pmd);
89extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
90extern int migrate_misplaced_page(struct page *page,
91 struct vm_area_struct *vma, int node);
92extern bool migrate_ratelimited(int node);
93#else
94static inline bool pmd_trans_migrating(pmd_t pmd)
95{
96 return false;
97}
98static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
99{
100}
101static 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}
106static 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)
113extern 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
119static 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 */