diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 106 |
1 files changed, 65 insertions, 41 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 4fe5ee67535b..8e4d6eda8a8d 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -167,8 +167,12 @@ enum pageflags { /* Remapped by swiotlb-xen. */ PG_xen_remapped = PG_owner_priv_1, - /* non-lru isolated movable page */ - PG_isolated = PG_reclaim, +#ifdef CONFIG_MIGRATION + /* movable_ops page that is isolated for migration */ + PG_movable_ops_isolated = PG_reclaim, + /* this is a movable_ops page (for selected typed pages only) */ + PG_movable_ops = PG_uptodate, +#endif /* Only valid for buddy pages. Used to track pages that are reported */ PG_reported = PG_uptodate, @@ -691,15 +695,12 @@ PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) /* * On an anonymous folio mapped into a user virtual memory area, * folio->mapping points to its anon_vma, not to a struct address_space; - * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. + * with the FOLIO_MAPPING_ANON bit set to distinguish it. See rmap.h. * - * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, - * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON + * On an anonymous folio in a VM_MERGEABLE area, if CONFIG_KSM is enabled, + * the FOLIO_MAPPING_ANON_KSM bit may be set along with the FOLIO_MAPPING_ANON * bit; and then folio->mapping points, not to an anon_vma, but to a private - * structure which KSM associates with that merged page. See ksm.h. - * - * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable - * page and then folio->mapping points to a struct movable_operations. + * structure which KSM associates with that merged folio. See ksm.h. * * Please note that, confusingly, "folio_mapping" refers to the inode * address_space which maps the folio from disk; whereas "folio_mapped" @@ -712,50 +713,27 @@ PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) * false before calling the following functions (e.g., folio_test_anon). * See mm/slab.h. */ -#define PAGE_MAPPING_ANON 0x1 -#define PAGE_MAPPING_MOVABLE 0x2 -#define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) -#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) - -static __always_inline bool folio_mapping_flags(const struct folio *folio) -{ - return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0; -} - -static __always_inline bool PageMappingFlags(const struct page *page) -{ - return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; -} +#define FOLIO_MAPPING_ANON 0x1 +#define FOLIO_MAPPING_ANON_KSM 0x2 +#define FOLIO_MAPPING_KSM (FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM) +#define FOLIO_MAPPING_FLAGS (FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM) static __always_inline bool folio_test_anon(const struct folio *folio) { - return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0; + return ((unsigned long)folio->mapping & FOLIO_MAPPING_ANON) != 0; } static __always_inline bool PageAnonNotKsm(const struct page *page) { unsigned long flags = (unsigned long)page_folio(page)->mapping; - return (flags & PAGE_MAPPING_FLAGS) == PAGE_MAPPING_ANON; + return (flags & FOLIO_MAPPING_FLAGS) == FOLIO_MAPPING_ANON; } static __always_inline bool PageAnon(const struct page *page) { return folio_test_anon(page_folio(page)); } - -static __always_inline bool __folio_test_movable(const struct folio *folio) -{ - return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == - PAGE_MAPPING_MOVABLE; -} - -static __always_inline bool __PageMovable(const struct page *page) -{ - return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == - PAGE_MAPPING_MOVABLE; -} - #ifdef CONFIG_KSM /* * A KSM page is one of those write-protected "shared pages" or "merged pages" @@ -765,8 +743,8 @@ static __always_inline bool __PageMovable(const struct page *page) */ static __always_inline bool folio_test_ksm(const struct folio *folio) { - return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == - PAGE_MAPPING_KSM; + return ((unsigned long)folio->mapping & FOLIO_MAPPING_FLAGS) == + FOLIO_MAPPING_KSM; } #else FOLIO_TEST_FLAG_FALSE(ksm) @@ -1137,7 +1115,53 @@ static inline bool folio_contain_hwpoisoned_page(struct folio *folio) bool is_free_buddy_page(const struct page *page); -PAGEFLAG(Isolated, isolated, PF_ANY); +#ifdef CONFIG_MIGRATION +/* + * This page is migratable through movable_ops (for selected typed pages + * only). + * + * Page migration of such pages might fail, for example, if the page is + * already isolated by somebody else, or if the page is about to get freed. + * + * While a subsystem might set selected typed pages that support page migration + * as being movable through movable_ops, it must never clear this flag. + * + * This flag is only cleared when the page is freed back to the buddy. + * + * Only selected page types support this flag (see page_movable_ops()) and + * the flag might be used in other context for other pages. Always use + * page_has_movable_ops() instead. + */ +TESTPAGEFLAG(MovableOps, movable_ops, PF_NO_TAIL); +SETPAGEFLAG(MovableOps, movable_ops, PF_NO_TAIL); +/* + * A movable_ops page has this flag set while it is isolated for migration. + * This flag primarily protects against concurrent migration attempts. + * + * Once migration ended (success or failure), the flag is cleared. The + * flag is managed by the migration core. + */ +PAGEFLAG(MovableOpsIsolated, movable_ops_isolated, PF_NO_TAIL); +#else /* !CONFIG_MIGRATION */ +TESTPAGEFLAG_FALSE(MovableOps, movable_ops); +SETPAGEFLAG_NOOP(MovableOps, movable_ops); +PAGEFLAG_FALSE(MovableOpsIsolated, movable_ops_isolated); +#endif /* CONFIG_MIGRATION */ + +/** + * page_has_movable_ops - test for a movable_ops page + * @page: The page to test. + * + * Test whether this is a movable_ops page. Such pages will stay that + * way until freed. + * + * Returns true if this is a movable_ops page, otherwise false. + */ +static inline bool page_has_movable_ops(const struct page *page) +{ + return PageMovableOps(page) && + (PageOffline(page) || PageZsmalloc(page)); +} static __always_inline int PageAnonExclusive(const struct page *page) { |