On Tue 08-12-15 07:19:42, Tetsuo Handa wrote: > Michal Hocko wrote: > > Yes you are right! The reference count should be incremented before > > publishing the new mm_to_reap. I thought that an elevated ref. count by > > the caller would be enough but this was clearly wrong. Does the update > > below looks better? > > I think that moving mmdrop() from oom_kill_process() to > oom_reap_vmas() xor wake_oom_reaper() makes the patch simpler. It surely is less lines of code but I am not sure it is simpler. I do not think we should drop the reference in a different path than it is taken. Maybe we will grow more users of wake_oom_reaper in the future and this is quite subtle behavior. > > rcu_read_unlock(); > > + if (can_oom_reap) > + wake_oom_reaper(mm); /* will call mmdrop() */ > + else > + mmdrop(mm); > - mmdrop(mm); > put_task_struct(victim); > } Thanks! -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>