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) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alex Shi <alexs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2024-10-02 16:25:30 +01:00 committed by Andrew Morton
parent 76f1a82611
commit b33cc96c70

View File

@ -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);
}