Re: [patch] mm, oom: prevent soft lockup on memcg oom for UP systems

[Andrew Morton]

On Thu, 12 Mar 2020 11:07:15 -0700 (PDT) David Rientjes <rientjes@xxxxxxxxxx> wrote:

> On Thu, 12 Mar 2020, Tetsuo Handa wrote:
> 
> > > On Thu, 12 Mar 2020, Tetsuo Handa wrote:
> > > > > If you have an alternate patch to try, we can test it.  But since this 
> > > > > cond_resched() is needed anyway, I'm not sure it will change the result.
> > > > 
> > > > schedule_timeout_killable(1) is an alternate patch to try; I don't think
> > > > that this cond_resched() is needed anyway.
> > > > 
> > > 
> > > You are suggesting schedule_timeout_killable(1) in shrink_node_memcgs()?
> > > 
> > 
> > Andrew Morton also mentioned whether cond_resched() in shrink_node_memcgs()
> > is enough. But like you mentioned,
> > 
> 
> It passes our testing because this is where the allocator is looping while 
> the victim is trying to exit if only it could be scheduled.

What happens if the allocator has SCHED_FIFO?