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
