On Thu 25-08-11 14:14:20, David Rientjes wrote: > On Thu, 25 Aug 2011, Michal Hocko wrote: > > > > > > That's obviously false since we call oom_killer_disable() in > > > > > freeze_processes() to disable the oom killer from ever being called in the > > > > > first place, so this is something you need to resolve with Rafael before > > > > > you cause more machines to panic. > > > > > > > > I didn't mean suspend/resume path (that is protected by oom_killer_disabled) > > > > so the patch doesn't make any change. > > > > > > Confused... freeze_processes() does try_to_freeze_tasks() before > > > oom_killer_disable() ? > > > > Yes you are right, I must have been blind. > > > > Now I see the point. We do not want to panic while we are suspending and > > the memory is really low just because all the userspace is already in > > the the fridge. > > Sorry for confusion. > > > > I still do not follow the oom_killer_disable note from David, though. > > > > oom_killer_disable() was added to that path for a reason when all threads > are frozen: memory allocations still occur in the suspend path in an oom > condition and adding the oom_killer_disable() will cause those > allocations to fail rather than sending pointless SIGKILLs to frozen > threads. > > Now consider if the only _eligible_ threads for oom kill (because of > cpusets or mempolicies) are those that are frozen. We certainly do not > want to panic because other cpusets are still getting work done. We'd > either want to add a mem to the cpuset or thaw the processes because the > cpuset is oom. Sure. > > You can't just selectively skip certain threads when their state can be > temporary without risking a panic. That's why this patch is a > non-starter. > > A much better solution would be to lower the badness score that the oom > killer uses for PF_FROZEN threads so that they aren't considered a > priority for kill unless there's nothing else left to kill. Yes, sounds better. Thanks -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>