diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 140 |
1 files changed, 132 insertions, 8 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 1c3b6e5c8bfd..e66f7aa3191d 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -142,6 +142,15 @@ enum pageflags { PG_readahead = PG_reclaim, + /* + * Depending on the way an anonymous folio can be mapped into a page + * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped + * THP), PG_anon_exclusive may be set only for the head page or for + * tail pages of an anonymous folio. For now, we only expect it to be + * set on tail pages for PTE-mapped THP. + */ + PG_anon_exclusive = PG_mappedtodisk, + /* Filesystems */ PG_checked = PG_owner_priv_1, @@ -176,7 +185,7 @@ enum pageflags { * Indicates that at least one subpage is hwpoisoned in the * THP. */ - PG_has_hwpoisoned = PG_mappedtodisk, + PG_has_hwpoisoned = PG_error, #endif /* non-lru isolated movable page */ @@ -190,13 +199,81 @@ enum pageflags { #ifndef __GENERATING_BOUNDS_H +#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, + hugetlb_optimize_vmemmap_key); + +static __always_inline bool hugetlb_optimize_vmemmap_enabled(void) +{ + return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON, + &hugetlb_optimize_vmemmap_key); +} + +/* + * If the feature of optimizing vmemmap pages associated with each HugeTLB + * page is enabled, the head vmemmap page frame is reused and all of the tail + * vmemmap addresses map to the head vmemmap page frame (furture details can + * refer to the figure at the head of the mm/hugetlb_vmemmap.c). In other + * words, there are more than one page struct with PG_head associated with each + * HugeTLB page. We __know__ that there is only one head page struct, the tail + * page structs with PG_head are fake head page structs. We need an approach + * to distinguish between those two different types of page structs so that + * compound_head() can return the real head page struct when the parameter is + * the tail page struct but with PG_head. + * + * The page_fixed_fake_head() returns the real head page struct if the @page is + * fake page head, otherwise, returns @page which can either be a true page + * head or tail. + */ +static __always_inline const struct page *page_fixed_fake_head(const struct page *page) +{ + if (!hugetlb_optimize_vmemmap_enabled()) + return page; + + /* + * Only addresses aligned with PAGE_SIZE of struct page may be fake head + * struct page. The alignment check aims to avoid access the fields ( + * e.g. compound_head) of the @page[1]. It can avoid touch a (possibly) + * cold cacheline in some cases. + */ + if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) && + test_bit(PG_head, &page->flags)) { + /* + * We can safely access the field of the @page[1] with PG_head + * because the @page is a compound page composed with at least + * two contiguous pages. + */ + unsigned long head = READ_ONCE(page[1].compound_head); + + if (likely(head & 1)) + return (const struct page *)(head - 1); + } + return page; +} +#else +static inline const struct page *page_fixed_fake_head(const struct page *page) +{ + return page; +} + +static inline bool hugetlb_optimize_vmemmap_enabled(void) +{ + return false; +} +#endif + +static __always_inline int page_is_fake_head(struct page *page) +{ + return page_fixed_fake_head(page) != page; +} + static inline unsigned long _compound_head(const struct page *page) { unsigned long head = READ_ONCE(page->compound_head); if (unlikely(head & 1)) return head - 1; - return (unsigned long)page; + return (unsigned long)page_fixed_fake_head(page); } #define compound_head(page) ((typeof(page))_compound_head(page)) @@ -231,12 +308,13 @@ static inline unsigned long _compound_head(const struct page *page) static __always_inline int PageTail(struct page *page) { - return READ_ONCE(page->compound_head) & 1; + return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page); } static __always_inline int PageCompound(struct page *page) { - return test_bit(PG_head, &page->flags) || PageTail(page); + return test_bit(PG_head, &page->flags) || + READ_ONCE(page->compound_head) & 1; } #define PAGE_POISON_PATTERN -1l @@ -412,7 +490,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; } TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname) __PAGEFLAG(Locked, locked, PF_NO_TAIL) -PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) +PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) PAGEFLAG(Referenced, referenced, PF_HEAD) TESTCLEARFLAG(Referenced, referenced, PF_HEAD) @@ -447,7 +525,7 @@ PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) /* * Private page markings that may be used by the filesystem that owns the page * for its own purposes. - * - PG_private and PG_private_2 cause releasepage() and co to be invoked + * - PG_private and PG_private_2 cause release_folio() and co to be invoked */ PAGEFLAG(Private, private, PF_ANY) PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) @@ -572,6 +650,11 @@ __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) #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(struct folio *folio) +{ + return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0; +} + static __always_inline int PageMappingFlags(struct page *page) { return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; @@ -695,7 +778,20 @@ static inline bool test_set_page_writeback(struct page *page) return set_page_writeback(page); } -__PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) +static __always_inline bool folio_test_head(struct folio *folio) +{ + return test_bit(PG_head, folio_flags(folio, FOLIO_PF_ANY)); +} + +static __always_inline int PageHead(struct page *page) +{ + PF_POISONED_CHECK(page); + return test_bit(PG_head, &page->flags) && !page_is_fake_head(page); +} + +__SETPAGEFLAG(Head, head, PF_ANY) +__CLEARPAGEFLAG(Head, head, PF_ANY) +CLEARPAGEFLAG(Head, head, PF_ANY) /** * folio_test_large() - Does this folio contain more than one page? @@ -918,7 +1014,35 @@ PAGE_TYPE_OPS(Guard, guard) extern bool is_free_buddy_page(struct page *page); -__PAGEFLAG(Isolated, isolated, PF_ANY); +PAGEFLAG(Isolated, isolated, PF_ANY); + +static __always_inline int PageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnon(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} + +static __always_inline void SetPageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} + +static __always_inline void ClearPageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} + +static __always_inline void __ClearPageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnon(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + __clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} #ifdef CONFIG_MMU #define __PG_MLOCKED (1UL << PG_mlocked) |