On 2019-11-15 at 11:18 Li Xinhai wrote: >PageAnon() just checking on PAGE_MAPPING_ANON bit would cause page, >with PageKsm as true, been wrongly considered as PageAnon. Now, >checking the whole PAGE_MAPPING_FLAGS to avoid this error. > >Reported from: >https://lore.kernel.org/linux-mm/20191113000651.20677-1-rcampbell@xxxxxxxxxx/ > >Reported-by: Ralph Campbell <rcampbell@xxxxxxxxxx> >Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >Cc: Michal Hocko <mhocko@xxxxxxxx> >Signed-off-by: Li Xinhai <lixinhai.lxh@xxxxxxxxx> >--- > include/linux/page-flags.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > >diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h >index 1bf83c8..1849fc3 100644 >--- a/include/linux/page-flags.h >+++ b/include/linux/page-flags.h >@@ -461,7 +461,8 @@ static __always_inline int PageMappingFlags(struct page *page) > static __always_inline int PageAnon(struct page *page) > { > page = compound_head(page); >- return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; >+ return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == >+ PAGE_MAPPING_ANON; > } > > static __always_inline int __PageMovable(struct page *page) >-- >1.8.3.1 > The current semantics of PageAnon() for both KSM and !KSM are used in many places, so can't change it alone without change other code. Need skip this patch. - Xinhai
