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 *page, unsigned long private,
9 int **reason);
10typedef void free_page_t(struct page *page, unsigned long private);
11
12/*
13 * Return values from addresss_space_operations.migratepage():
14 * - negative errno on page migration failure;
15 * - zero on page migration success;
16 *
17 * The balloon page migration introduces this special case where a 'distinct'
18 * return code is used to flag a successful page migration to unmap_and_move().
19 * This approach is necessary because page migration can race against balloon
20 * deflation procedure, and for such case we could introduce a nasty page leak
21 * if a successfully migrated balloon page gets released concurrently with
22 * migration's unmap_and_move() wrap-up steps.
23 */
24#define MIGRATEPAGE_SUCCESS 0
25#define MIGRATEPAGE_BALLOON_SUCCESS 1 /* special ret code for balloon page
26 * sucessful migration case.
27 */
28enum migrate_reason {
29 MR_COMPACTION,
30 MR_MEMORY_FAILURE,
31 MR_MEMORY_HOTPLUG,
32 MR_SYSCALL, /* also applies to cpusets */
33 MR_MEMPOLICY_MBIND,
34 MR_NUMA_MISPLACED,
35 MR_CMA
36};
37
38#ifdef CONFIG_MIGRATION
39
40extern void putback_movable_pages(struct list_head *l);
41extern int migrate_page(struct address_space *,
42 struct page *, struct page *, enum migrate_mode);
43extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
44 unsigned long private, enum migrate_mode mode, int reason);
45
46extern int migrate_prep(void);
47extern int migrate_prep_local(void);
48extern int migrate_vmas(struct mm_struct *mm,
49 const nodemask_t *from, const nodemask_t *to,
50 unsigned long flags);
51extern void migrate_page_copy(struct page *newpage, struct page *page);
52extern int migrate_huge_page_move_mapping(struct address_space *mapping,
53 struct page *newpage, struct page *page);
54extern int migrate_page_move_mapping(struct address_space *mapping,
55 struct page *newpage, struct page *page,
56 struct buffer_head *head, enum migrate_mode mode,
57 int extra_count);
58#else
59
60static inline void putback_movable_pages(struct list_head *l) {}
61static inline int migrate_pages(struct list_head *l, new_page_t new,
62 free_page_t free, unsigned long private, enum migrate_mode mode,
63 int reason)
64 { return -ENOSYS; }
65
66static inline int migrate_prep(void) { return -ENOSYS; }
67static inline int migrate_prep_local(void) { return -ENOSYS; }
68
69static inline int migrate_vmas(struct mm_struct *mm,
70 const nodemask_t *from, const nodemask_t *to,
71 unsigned long flags)
72{
73 return -ENOSYS;
74}
75
76static inline void migrate_page_copy(struct page *newpage,
77 struct page *page) {}
78
79static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
80 struct page *newpage, struct page *page)
81{
82 return -ENOSYS;
83}
84
85/* Possible settings for the migrate_page() method in address_operations */
86#define migrate_page NULL
87
88#endif /* CONFIG_MIGRATION */
89
90#ifdef CONFIG_NUMA_BALANCING
91extern bool pmd_trans_migrating(pmd_t pmd);
92extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
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 bool pmd_trans_migrating(pmd_t pmd)
98{
99 return false;
100}
101static inline void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd)
102{
103}
104static inline int migrate_misplaced_page(struct page *page,
105 struct vm_area_struct *vma, int node)
106{
107 return -EAGAIN; /* can't migrate now */
108}
109static inline bool migrate_ratelimited(int node)
110{
111 return false;
112}
113#endif /* CONFIG_NUMA_BALANCING */
114
115#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
116extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
117 struct vm_area_struct *vma,
118 pmd_t *pmd, pmd_t entry,
119 unsigned long address,
120 struct page *page, int node);
121#else
122static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
123 struct vm_area_struct *vma,
124 pmd_t *pmd, pmd_t entry,
125 unsigned long address,
126 struct page *page, int node)
127{
128 return -EAGAIN;
129}
130#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
131
132#endif /* _LINUX_MIGRATE_H */