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
216
217
218
219
220
221
222
|
/* 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);
struct migration_target_control;
/*
* Return values from addresss_space_operations.migratepage():
* - negative errno on page migration failure;
* - zero on page migration success;
*/
#define MIGRATEPAGE_SUCCESS 0
/**
* struct movable_operations - Driver page migration
* @isolate_page:
* The VM calls this function to prepare the page to be moved. The page
* is locked and the driver should not unlock it. The driver should
* return ``true`` if the page is movable and ``false`` if it is not
* currently movable. After this function returns, the VM uses the
* page->lru field, so the driver must preserve any information which
* is usually stored here.
*
* @migrate_page:
* After isolation, the VM calls this function with the isolated
* @src page. The driver should copy the contents of the
* @src page to the @dst page and set up the fields of @dst page.
* Both pages are locked.
* If page migration is successful, the driver should call
* __ClearPageMovable(@src) and return MIGRATEPAGE_SUCCESS.
* If the driver cannot migrate the page at the moment, it can return
* -EAGAIN. The VM interprets this as a temporary migration failure and
* will retry it later. Any other error value is a permanent migration
* failure and migration will not be retried.
* The driver shouldn't touch the @src->lru field while in the
* migrate_page() function. It may write to @dst->lru.
*
* @putback_page:
* If migration fails on the isolated page, the VM informs the driver
* that the page is no longer a candidate for migration by calling
* this function. The driver should put the isolated page back into
* its own data structure.
*/
struct movable_operations {
bool (*isolate_page)(struct page *, isolate_mode_t);
int (*migrate_page)(struct page *dst, struct page *src,
enum migrate_mode);
void (*putback_page)(struct page *);
};
/* Defined in mm/debug.c: */
extern const char *migrate_reason_names[MR_TYPES];
#ifdef CONFIG_MIGRATION
extern void putback_movable_pages(struct list_head *l);
int migrate_folio(struct address_space *mapping, struct folio *dst,
struct folio *src, 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,
unsigned int *ret_succeeded);
extern struct page *alloc_migration_target(struct page *page, unsigned long private);
extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
int migrate_huge_page_move_mapping(struct address_space *mapping,
struct folio *dst, struct folio *src);
void migration_entry_wait_on_locked(swp_entry_t entry, pte_t *ptep,
spinlock_t *ptl);
void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
void folio_migrate_copy(struct folio *newfolio, struct folio *folio);
int folio_migrate_mapping(struct address_space *mapping,
struct folio *newfolio, struct folio *folio, 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, unsigned int *ret_succeeded)
{ return -ENOSYS; }
static inline struct page *alloc_migration_target(struct page *page,
unsigned long private)
{ return NULL; }
static inline int isolate_movable_page(struct page *page, isolate_mode_t mode)
{ return -EBUSY; }
static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
struct folio *dst, struct folio *src)
{
return -ENOSYS;
}
#endif /* CONFIG_MIGRATION */
#if defined(CONFIG_MIGRATION) && defined(CONFIG_NUMA)
extern void set_migration_target_nodes(void);
extern void migrate_on_reclaim_init(void);
extern bool numa_demotion_enabled;
extern int next_demotion_node(int node);
#else
static inline void set_migration_target_nodes(void) {}
static inline void migrate_on_reclaim_init(void) {}
static inline int next_demotion_node(int node)
{
return NUMA_NO_NODE;
}
#define numa_demotion_enabled false
#endif
#ifdef CONFIG_COMPACTION
bool PageMovable(struct page *page);
void __SetPageMovable(struct page *page, const struct movable_operations *ops);
void __ClearPageMovable(struct page *page);
#else
static inline bool PageMovable(struct page *page) { return false; }
static inline void __SetPageMovable(struct page *page,
const struct movable_operations *ops)
{
}
static inline void __ClearPageMovable(struct page *page)
{
}
#endif
static inline bool folio_test_movable(struct folio *folio)
{
return PageMovable(&folio->page);
}
static inline
const struct movable_operations *page_movable_ops(struct page *page)
{
VM_BUG_ON(!__PageMovable(page));
return (const struct movable_operations *)
((unsigned long)page->mapping - PAGE_MAPPING_MOVABLE);
}
#ifdef CONFIG_NUMA_BALANCING
extern int migrate_misplaced_page(struct page *page,
struct vm_area_struct *vma, int node);
#else
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 */
#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_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;
}
enum migrate_vma_direction {
MIGRATE_VMA_SELECT_SYSTEM = 1 << 0,
MIGRATE_VMA_SELECT_DEVICE_PRIVATE = 1 << 1,
MIGRATE_VMA_SELECT_DEVICE_COHERENT = 1 << 2,
};
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. The flags also need to
* be set to MIGRATE_VMA_SELECT_DEVICE_PRIVATE.
* The caller should always set this field when using mmu notifier
* callbacks to avoid device MMU invalidations for device private
* pages that are not being migrated.
*/
void *pgmap_owner;
unsigned long flags;
};
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 */
|
