Hello, Tetsuo. On Tue, Nov 03, 2015 at 11:32:06AM +0900, Tetsuo Handa wrote: > Tejun Heo wrote: > > If > > the possibility of sysrq getting stuck behind concurrency management > > is an issue, queueing them on an unbound or highpri workqueue should > > be good enough. > > Regarding SysRq-f, we could do like below. Though I think that converting > the OOM killer into a dedicated kernel thread would allow more things to do > (e.g. Oleg's memory zapping code, my timeout based next victim selection). I'm not sure doing anything to sysrq-f is warranted. If workqueue can't make forward progress due to memory exhaustion, OOM will be triggered anyway. Getting stuck behind concurrency management isn't that different a failure mode from getting stuck behind busy loop with preemption off. We should just plug them at the source. If necessary, what we can do is adding stall watchdog (can prolly combined with the usual watchdog) so that it can better point out the culprit. Thanks. -- tejun -- 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>