On Tue 05-12-17 23:07:53, Tetsuo Handa wrote: > Michal Hocko wrote: > > On Tue 05-12-17 22:17:27, Tetsuo Handa wrote: > > > Michal Hocko wrote: > > > > > I do understand the upsides you're advocating for - although you > > > > > haven't quantified them. They're just not worth the downsides. > > > > > > > > OK, fair enough. Let's drop the patch then. There is no _strong_ > > > > justification for it and what I've seen as "nice to have" is indeed > > > > really hard to quantify and not really worth merging without a full > > > > consensus. > > > > > > Dropping "mm,oom: move last second allocation to inside the OOM killer" > > > means dropping "mm,oom: remove oom_lock serialization from the OOM reaper" > > > together, right? > > > > No, I believe that we can drop the lock even without this patch. This > > will need more investigation though. > > We cannot drop the lock without this patch. This should be discussed in the respective thread. > > > The latter patch helped mitigating > > > schedule_timeout_killable(1) lockup problem though... > > > > > > Also, what is the alternative for "mm,oom: use ALLOC_OOM for OOM victim's > > > last second allocation" ? I proposed "mm, oom: task_will_free_mem(current) > > > should ignore MMF_OOM_SKIP for once." and rejected by you. I also proposed > > > "mm,oom: Set ->signal->oom_mm to all thread groups sharing the victim's mm." > > > and rejected by you. > > > > Yes, and so far I am not really sure we have to care all that much. I > > haven't seen any real world workload actually hitting this condition. > > > > Somebody will observe what Manish Jaggi observed. OOM with mlock()ed and/or > MAP_SHARED is irrelevant. There is always possibility that the OOM reaper > fails to reclaim memory due to mmap_sem contention (and results in extra > OOM kills). ... and we will try to handle this with due diligence as soon as we see those reports and see how serious they are. -- 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>
