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Christoph Lameterb20a3502006-03-22 00:09:12 -08001#ifndef _LINUX_MIGRATE_H
2#define _LINUX_MIGRATE_H
3
Christoph Lameterb20a3502006-03-22 00:09:12 -08004#include <linux/mm.h>
Christoph Lameter906e0be2007-05-06 14:50:20 -07005#include <linux/mempolicy.h>
Andrew Morton6536e312012-01-20 14:33:53 -08006#include <linux/migrate_mode.h>
Christoph Lameterb20a3502006-03-22 00:09:12 -08007
Christoph Lameter742755a2006-06-23 02:03:55 -07008typedef struct page *new_page_t(struct page *, unsigned long private, int **);
Christoph Lameter95a402c2006-06-23 02:03:53 -07009
Rafael Aquini78bd5202012-12-11 16:02:31 -080010/*
11 * Return values from addresss_space_operations.migratepage():
12 * - negative errno on page migration failure;
13 * - zero on page migration success;
Rafael Aquini18468d92012-12-11 16:02:38 -080014 *
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.
Rafael Aquini78bd5202012-12-11 16:02:31 -080021 */
22#define MIGRATEPAGE_SUCCESS 0
Rafael Aquini18468d92012-12-11 16:02:38 -080023#define MIGRATEPAGE_BALLOON_SUCCESS 1 /* special ret code for balloon page
24 * sucessful migration case.
25 */
Mel Gorman7b2a2d42012-10-19 14:07:31 +010026enum migrate_reason {
27 MR_COMPACTION,
28 MR_MEMORY_FAILURE,
29 MR_MEMORY_HOTPLUG,
30 MR_SYSCALL, /* also applies to cpusets */
31 MR_MEMPOLICY_MBIND,
Peter Zijlstra7039e1d2012-10-25 14:16:34 +020032 MR_NUMA_MISPLACED,
Mel Gorman7b2a2d42012-10-19 14:07:31 +010033 MR_CMA
34};
Rafael Aquini78bd5202012-12-11 16:02:31 -080035
Christoph Lameter906e0be2007-05-06 14:50:20 -070036#ifdef CONFIG_MIGRATION
KOSAKI Motohiro64cdd542009-01-06 14:39:16 -080037
Rafael Aquini5733c7d2012-12-11 16:02:47 -080038extern void putback_movable_pages(struct list_head *l);
Christoph Lameter2d1db3b2006-06-23 02:03:33 -070039extern int migrate_page(struct address_space *,
Mel Gormana6bc32b2012-01-12 17:19:43 -080040 struct page *, struct page *, enum migrate_mode);
Hugh Dickins62b61f62009-12-14 17:59:33 -080041extern int migrate_pages(struct list_head *l, new_page_t x,
Hugh Dickins9c620e22013-02-22 16:35:14 -080042 unsigned long private, enum migrate_mode mode, int reason);
Christoph Lameter95a402c2006-06-23 02:03:53 -070043
Christoph Lameterb20a3502006-03-22 00:09:12 -080044extern int migrate_prep(void);
Mel Gorman748446b2010-05-24 14:32:27 -070045extern int migrate_prep_local(void);
Christoph Lameter7b2259b2006-06-25 05:46:48 -070046extern int migrate_vmas(struct mm_struct *mm,
47 const nodemask_t *from, const nodemask_t *to,
48 unsigned long flags);
Naoya Horiguchi290408d2010-09-08 10:19:35 +090049extern 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);
Gu Zheng36bc08c2013-07-16 17:56:16 +080052extern int migrate_page_move_mapping(struct address_space *mapping,
53 struct page *newpage, struct page *page,
Benjamin LaHaise8e321fe2013-12-21 17:56:08 -050054 struct buffer_head *head, enum migrate_mode mode,
55 int extra_count);
Christoph Lameterb20a3502006-03-22 00:09:12 -080056#else
KOSAKI Motohiro64cdd542009-01-06 14:39:16 -080057
Rafael Aquini5733c7d2012-12-11 16:02:47 -080058static inline void putback_movable_pages(struct list_head *l) {}
Christoph Lameter95a402c2006-06-23 02:03:53 -070059static inline int migrate_pages(struct list_head *l, new_page_t x,
Hugh Dickins9c620e22013-02-22 16:35:14 -080060 unsigned long private, enum migrate_mode mode, int reason)
61 { return -ENOSYS; }
Christoph Lameter9bf9e892006-03-31 02:29:56 -080062
Christoph Lameterb20a3502006-03-22 00:09:12 -080063static inline int migrate_prep(void) { return -ENOSYS; }
Mel Gorman748446b2010-05-24 14:32:27 -070064static inline int migrate_prep_local(void) { return -ENOSYS; }
Christoph Lameterb20a3502006-03-22 00:09:12 -080065
Christoph Lameter7b2259b2006-06-25 05:46:48 -070066static 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
Naoya Horiguchi290408d2010-09-08 10:19:35 +090073static inline void migrate_page_copy(struct page *newpage,
74 struct page *page) {}
75
Naoya Horiguchi6f39ce02010-09-30 11:54:51 +090076static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
Naoya Horiguchi290408d2010-09-08 10:19:35 +090077 struct page *newpage, struct page *page)
78{
79 return -ENOSYS;
80}
81
Christoph Lameterb20a3502006-03-22 00:09:12 -080082/* Possible settings for the migrate_page() method in address_operations */
83#define migrate_page NULL
Christoph Lameterb20a3502006-03-22 00:09:12 -080084
85#endif /* CONFIG_MIGRATION */
Peter Zijlstra7039e1d2012-10-25 14:16:34 +020086
87#ifdef CONFIG_NUMA_BALANCING
Mel Gormande466bd2013-12-18 17:08:42 -080088extern bool pmd_trans_migrating(pmd_t pmd);
89extern void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd);
Mel Gorman1bc115d2013-10-07 11:29:05 +010090extern int migrate_misplaced_page(struct page *page,
91 struct vm_area_struct *vma, int node);
Mel Gormane14808b2012-11-19 10:59:15 +000092extern bool migrate_ratelimited(int node);
Peter Zijlstra7039e1d2012-10-25 14:16:34 +020093#else
Mel Gormande466bd2013-12-18 17:08:42 -080094static 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}
Mel Gorman1bc115d2013-10-07 11:29:05 +0100101static inline int migrate_misplaced_page(struct page *page,
102 struct vm_area_struct *vma, int node)
Peter Zijlstra7039e1d2012-10-25 14:16:34 +0200103{
104 return -EAGAIN; /* can't migrate now */
105}
Mel Gormane14808b2012-11-19 10:59:15 +0000106static inline bool migrate_ratelimited(int node)
107{
108 return false;
109}
Mel Gorman220018d2012-12-05 09:32:56 +0000110#endif /* CONFIG_NUMA_BALANCING */
Mel Gormanb32967f2012-11-19 12:35:47 +0000111
Mel Gorman220018d2012-12-05 09:32:56 +0000112#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
Mel Gormanb32967f2012-11-19 12:35:47 +0000119static 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}
Mel Gorman220018d2012-12-05 09:32:56 +0000127#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/
Peter Zijlstra7039e1d2012-10-25 14:16:34 +0200128
Christoph Lameterb20a3502006-03-22 00:09:12 -0800129#endif /* _LINUX_MIGRATE_H */