diff options
Diffstat (limited to 'include/linux/migrate.h')
| -rw-r--r-- | include/linux/migrate.h | 78 |
1 files changed, 56 insertions, 22 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 069a89e847f3..ae5bb67a9ba1 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -19,27 +19,59 @@ struct migration_target_control; */ #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); -extern int migrate_page(struct address_space *mapping, - struct page *newpage, struct page *page, - enum migrate_mode mode); +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); -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); +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); @@ -60,15 +92,8 @@ static inline struct page *alloc_migration_target(struct page *page, static inline int isolate_movable_page(struct page *page, isolate_mode_t mode) { return -EBUSY; } -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) + struct folio *dst, struct folio *src) { return -ENOSYS; } @@ -91,13 +116,13 @@ static inline int next_demotion_node(int node) #endif #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); +bool PageMovable(struct page *page); +void __SetPageMovable(struct page *page, const struct movable_operations *ops); +void __ClearPageMovable(struct page *page); #else -static inline int PageMovable(struct page *page) { return 0; } +static inline bool PageMovable(struct page *page) { return false; } static inline void __SetPageMovable(struct page *page, - struct address_space *mapping) + const struct movable_operations *ops) { } static inline void __ClearPageMovable(struct page *page) @@ -110,6 +135,15 @@ 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); |