From b33cc96c7020b923085046e5cf2e934f41c530ec Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Wed, 2 Oct 2024 16:25:30 +0100 Subject: [PATCH] mm: add PageAnonNotKsm() Check that this anonymous page is really anonymous, not anonymous-or-KSM. This optimises the debug check, but its real purpose is to remove the last two users of PageKsm(). [willy@infradead.org: fix assertions] Link: https://lkml.kernel.org/r/ZwApWPER7caIA_N3@casper.infradead.org Link: https://lkml.kernel.org/r/20241002152533.1350629-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Hildenbrand Cc: Alex Shi Signed-off-by: Andrew Morton --- include/linux/page-flags.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index cc839e4365c18..1fcef06a2d316 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -689,6 +689,13 @@ static __always_inline bool folio_test_anon(const struct folio *folio) return ((unsigned long)folio->mapping & PAGE_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; +} + static __always_inline bool PageAnon(const struct page *page) { return folio_test_anon(page_folio(page)); @@ -1137,14 +1144,14 @@ static __always_inline int PageAnonExclusive(const struct page *page) static __always_inline void SetPageAnonExclusive(struct page *page) { - VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); + VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(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(!PageAnonNotKsm(page), page); VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); }