On Fri 01-06-18 00:23:57, Tetsuo Handa wrote: > On 2018/05/31 19:44, Michal Hocko wrote: > > On Thu 31-05-18 19:10:48, Tetsuo Handa wrote: > >> On 2018/05/30 8:07, Andrew Morton wrote: > >>> On Tue, 29 May 2018 09:17:41 +0200 Michal Hocko <mhocko@xxxxxxxxxx> wrote: > >>> > >>>>> I suggest applying > >>>>> this patch first, and then fix "mm, oom: cgroup-aware OOM killer" patch. > >>>> > >>>> Well, I hope the whole pile gets merged in the upcoming merge window > >>>> rather than stall even more. > >>> > >>> I'm more inclined to drop it all. David has identified significant > >>> shortcomings and I'm not seeing a way of addressing those shortcomings > >>> in a backward-compatible fashion. Therefore there is no way forward > >>> at present. > >>> > >> > >> Can we apply my patch as-is first? > > > > No. As already explained before. Sprinkling new sleeps without a strong > > reason is not acceptable. The issue you are seeing is pretty artificial > > and as such doesn're really warrant an immediate fix. We should rather > > go with a well thought trhough fix. In other words we should simply drop > > the sleep inside the oom_lock for starter unless it causes some really > > unexpected behavior change. > > > > The OOM killer did not require schedule_timeout_killable(1) to return > as long as the OOM victim can call __mmput(). But now the OOM killer > requires schedule_timeout_killable(1) to return in order to allow the > OOM victim to call __oom_reap_task_mm(). Thus, this is a regression. > > Artificial cannot become the reason to postpone my patch. If we don't care > artificialness/maliciousness, we won't need to care Spectre/Meltdown bugs. > > I'm not sprinkling new sleeps. I'm just merging existing sleeps (i.e. > mutex_trylock() case and !mutex_trylock() case) and updating the outdated > comments. Sigh. So what exactly is wrong with going simple and do http://lkml.kernel.org/r/20180528124313.GC27180@xxxxxxxxxxxxxx ? -- Michal Hocko SUSE Labs
