On Tue 19-07-16 16:27:59, Andrew Morton wrote: > On Tue, 19 Jul 2016 14:05:39 +0200 Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > > > After this patch we should guarantee a forward progress for the OOM > > > killer even when the selected victim is sharing memory with a kernel > > > thread or global init. > > > > Could you replace the last two paragraphs with the following. Tetsuo > > didn't like the guarantee mentioned there because that is a too strong > > statement as find_lock_task_mm might not find any mm and so we still > > could end up looping on the oom victim if it gets stuck somewhere in > > __mmput. This particular patch didn't aim at closing that case. Plugging > > that hole is planned later after the next upcoming merge window closes. > > > > " > > In order to help a forward progress for the OOM killer, make sure > > that this really rare cases will not get into the way and hide > > the mm from the oom killer by setting MMF_OOM_REAPED flag for it. > > oom_scan_process_thread will ignore any TIF_MEMDIE task if it has > > MMF_OOM_REAPED flag set to catch these oom victims. > > > > After this patch we should guarantee a forward progress for the OOM > > killer even when the selected victim is sharing memory with a kernel > > thread or global init as long as the victims mm is still alive. > > " > > I tweaked it a bit: > > : In order to help forward progress for the OOM killer, make sure that > : this really rare case will not get in the way - we do this by hiding > : the mm from the oom killer by setting MMF_OOM_REAPED flag for it. > : oom_scan_process_thread will ignore any TIF_MEMDIE task if it has > : MMF_OOM_REAPED flag set to catch these oom victims. > : > : After this patch we should guarantee forward progress for the OOM > : killer even when the selected victim is sharing memory with a kernel > : thread or global init as long as the victims mm is still alive. Sounds good to me. 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>