On Mon 22-10-18 18:42:30, Tetsuo Handa wrote: > On 2018/10/22 17:48, Michal Hocko wrote: > > On Mon 22-10-18 16:58:50, Tetsuo Handa wrote: > >> Michal Hocko wrote: > >>> --- a/mm/oom_kill.c > >>> +++ b/mm/oom_kill.c > >>> @@ -898,6 +898,7 @@ static void __oom_kill_process(struct task_struct *victim) > >>> if (unlikely(p->flags & PF_KTHREAD)) > >>> continue; > >>> do_send_sig_info(SIGKILL, SEND_SIG_FORCED, p, PIDTYPE_TGID); > >>> + mark_oom_victim(p); > >>> } > >>> rcu_read_unlock(); > >>> > >>> -- > >> > >> Wrong. Either > > > > You are right. The mm might go away between process_shares_mm and here. > > While your find_lock_task_mm would be correct I believe we can do better > > by using the existing mm that we already have. I will make it a separate > > patch to clarity. > > Still wrong. p->mm == NULL means that we are too late to set TIF_MEMDIE > on that thread. Passing non-NULL mm to mark_oom_victim() won't help. Why would it be too late? Or in other words why would this be harmful? -- Michal Hocko SUSE Labs
