Commit b33cc96c authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

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: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Alex Shi <alexs@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 76f1a826

include/linux/page-flags.h

+9 −2
Original line number Diff line number Diff line
@@ -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);

}