On Fri, Jan 03, 2020 at 11:29:06AM -0800, David Rientjes wrote: >On Fri, 3 Jan 2020, Wei Yang wrote: > >> As all the other places, we grab the lock before manipulate the defer list. >> Current implementation may face a race condition. >> >> Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware") >> >> Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> >> >> --- >> I notice the difference during code reading and just confused about the >> difference. No specific test is done since limited knowledge about cgroup. >> >> Maybe I miss something important? > >The check for !list_empty(page_deferred_list(page)) must certainly be >serialized with doing list_del_init(page_deferred_list(page)). > Hi David Would you mind giving more information? You mean list_empty and list_del_init is atomic? -- Wei Yang Help you, Help me