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

[David Rientjes]

On Wed, 11 Mar 2020, Tetsuo Handa wrote:

> > diff --git a/mm/vmscan.c b/mm/vmscan.c
> > --- a/mm/vmscan.c
> > +++ b/mm/vmscan.c
> > @@ -2637,6 +2637,8 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc)
> >  		unsigned long reclaimed;
> >  		unsigned long scanned;
> >  
> > +		cond_resched();
> > +
> 
> Is this safe for CONFIG_PREEMPTION case? If current thread has realtime priority,
> can we guarantee that the OOM victim (well, the OOM reaper kernel thread rather
> than the OOM victim ?) gets scheduled?
> 

I think it's the best we can do that immediately solves the issue unless 
you have another idea in mind?

> >  		switch (mem_cgroup_protected(target_memcg, memcg)) {
> >  		case MEMCG_PROT_MIN:
> >  			/*
> > 
>