summaryrefslogtreecommitdiff
path: root/include/linux/migrate.h
blob: 3e546cbf03ddf6f7c5ea61e7e33c820bfbc781dd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MIGRATE_H
#define _LINUX_MIGRATE_H

#include <linux/mm.h>
#include <linux/mempolicy.h>
#include <linux/migrate_mode.h>
#include <linux/hugetlb.h>

typedef struct page *new_page_t(struct page *page, unsigned long private);
typedef void free_page_t(struct page *page, unsigned long private);

/*
 * Return values from addresss_space_operations.migratepage():
 * - negative errno on page migration failure;
 * - zero on page migration success;
 */
#define MIGRATEPAGE_SUCCESS		0

enum migrate_reason {
	MR_COMPACTION,
	MR_MEMORY_FAILURE,
	MR_MEMORY_HOTPLUG,
	MR_SYSCALL,		/* also applies to cpusets */
	MR_MEMPOLICY_MBIND,
	MR_NUMA_MISPLACED,
	MR_CONTIG_RANGE,
	MR_TYPES
};

/* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
extern const char *migrate_reason_names[MR_TYPES];

static inline struct page *new_page_nodemask(struct page *page,
				int preferred_nid, nodemask_t *nodemask)
{
	gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL;
	unsigned int order = 0;
	struct page *new_page = NULL;

	if (PageHuge(page))
		return alloc_huge_page_nodemask(page_hstate(compound_head(page)),
				preferred_nid, nodemask);

	if (PageTransHuge(page)) {
		gfp_mask |= GFP_TRANSHUGE;
		order = HPAGE_PMD_ORDER;
	}

	if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
		gfp_mask |= __GFP_HIGHMEM;

	new_page = __alloc_pages_nodemask(gfp_mask, order,
				preferred_nid, nodemask);

	if (new_page && PageTransHuge(new_page))
		prep_transhuge_page(new_page);

	return new_page;
}

#ifdef CONFIG_MIGRATION

extern void putback_movable_pages(struct list_head *l);
extern int migrate_page(struct address_space *mapping,
			struct page *newpage, struct page *page,
			enum migrate_mode mode);
extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
		unsigned long private, enum migrate_mode mode, int reason);
extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
extern void putback_movable_page(struct page *page);

extern int migrate_prep(void);
extern int migrate_prep_local(void);
extern void migrate_page_states(struct page *newpage, struct page *page);
extern void migrate_page_copy(struct page *newpage, struct page *page);
extern int migrate_huge_page_move_mapping(struct address_space *mapping,
				  struct page *newpage, struct page *page);
extern int migrate_page_move_mapping(struct address_space *mapping,
		struct page *newpage, struct page *page, int extra_count);
#else

static inline void putback_movable_pages(struct list_head *l) {}
static inline int migrate_pages(struct list_head *l, new_page_t new,
		free_page_t free, unsigned long private, enum migrate_mode mode,
		int reason)
	{ return -ENOSYS; }
static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
	{ return -EBUSY; }

static inline int migrate_prep(void) { return -ENOSYS; }
static inline int migrate_prep_local(void) { return -ENOSYS; }

static inline void migrate_page_states(struct page *newpage, struct page *page)
{
}

static inline void migrate_page_copy(struct page *newpage,
				     struct page *page) {}

static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
				  struct page *newpage, struct page *page)
{
	return -ENOSYS;
}

#endif /* CONFIG_MIGRATION */

#ifdef CONFIG_COMPACTION
extern int PageMovable(struct page *page);
extern void __SetPageMovable(struct page *page, struct address_space *mapping);
extern void __ClearPageMovable(struct page *page);
#else
static inline int PageMovable(struct page *page) { return 0; };
static inline void __SetPageMovable(struct page *page,
				struct address_space *mapping)
{
}
static inline void __ClearPageMovable(struct page *page)
{
}
#endif

#ifdef CONFIG_NUMA_BALANCING
extern bool pmd_trans_migrating(pmd_t pmd);
extern int migrate_misplaced_page(struct page *page,
				  struct vm_area_struct *vma, int node);
#else
static inline bool pmd_trans_migrating(pmd_t pmd)
{
	return false;
}
static inline int migrate_misplaced_page(struct page *page,
					 struct vm_area_struct *vma, int node)
{
	return -EAGAIN; /* can't migrate now */
}
#endif /* CONFIG_NUMA_BALANCING */

#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
extern int migrate_misplaced_transhuge_page(struct mm_struct *mm,
			struct vm_area_struct *vma,
			pmd_t *pmd, pmd_t entry,
			unsigned long address,
			struct page *page, int node);
#else
static inline int migrate_misplaced_transhuge_page(struct mm_struct *mm,
			struct vm_area_struct *vma,
			pmd_t *pmd, pmd_t entry,
			unsigned long address,
			struct page *page, int node)
{
	return -EAGAIN;
}
#endif /* CONFIG_NUMA_BALANCING && CONFIG_TRANSPARENT_HUGEPAGE*/


#ifdef CONFIG_MIGRATION

/*
 * Watch out for PAE architecture, which has an unsigned long, and might not
 * have enough bits to store all physical address and flags. So far we have
 * enough room for all our flags.
 */
#define MIGRATE_PFN_VALID	(1UL << 0)
#define MIGRATE_PFN_MIGRATE	(1UL << 1)
#define MIGRATE_PFN_LOCKED	(1UL << 2)
#define MIGRATE_PFN_WRITE	(1UL << 3)
#define MIGRATE_PFN_SHIFT	6

static inline struct page *migrate_pfn_to_page(unsigned long mpfn)
{
	if (!(mpfn & MIGRATE_PFN_VALID))
		return NULL;
	return pfn_to_page(mpfn >> MIGRATE_PFN_SHIFT);
}

static inline unsigned long migrate_pfn(unsigned long pfn)
{
	return (pfn << MIGRATE_PFN_SHIFT) | MIGRATE_PFN_VALID;
}

struct migrate_vma {
	struct vm_area_struct	*vma;
	/*
	 * Both src and dst array must be big enough for
	 * (end - start) >> PAGE_SHIFT entries.
	 *
	 * The src array must not be modified by the caller after
	 * migrate_vma_setup(), and must not change the dst array after
	 * migrate_vma_pages() returns.
	 */
	unsigned long		*dst;
	unsigned long		*src;
	unsigned long		cpages;
	unsigned long		npages;
	unsigned long		start;
	unsigned long		end;

	/*
	 * Set to the owner value also stored in page->pgmap->owner for
	 * migrating out of device private memory.  If set only device
	 * private pages with this owner are migrated.  If not set
	 * device private pages are not migrated at all.
	 */
	void			*src_owner;
};

int migrate_vma_setup(struct migrate_vma *args);
void migrate_vma_pages(struct migrate_vma *migrate);
void migrate_vma_finalize(struct migrate_vma *migrate);

#endif /* CONFIG_MIGRATION */

#endif /* _LINUX_MIGRATE_H */