On Tue, 2023-01-31 at 15:17 -0800, Andrew Morton wrote: > On Tue, 31 Jan 2023 14:32:06 +0800 Kuan-Ying Lee < > Kuan-Ying.Lee@xxxxxxxxxxxx> wrote: > > > If we call folio_isolate_lru() successfully, we will get > > return value 0. We need to add this folio to the > > movable_pages_list. > > > > Fixes: 67e139b02d99 ("mm/gup.c: refactor > > check_and_migrate_movable_pages()") > > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@xxxxxxxxxxxx> > > > > ... > > > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -1914,7 +1914,7 @@ static unsigned long > > collect_longterm_unpinnable_pages( > > drain_allow = false; > > } > > > > - if (!folio_isolate_lru(folio)) > > + if (folio_isolate_lru(folio)) > > continue; > > > > list_add_tail(&folio->lru, movable_page_list); > > Thanks. What are the user-visible effects of this bug? Hi Andrew, I didn't hit bug on real devices. I observe this issue by tracing get_user_pages() call flow. Thanks.