Re: [PATCH 1/2] sched: Make select_task_rq() require cpu_active() for user tasks

[Peter Zijlstra]

On Mon, May 28, 2018 at 08:45:16AM -0700, Paul Burton wrote:
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -1562,7 +1562,7 @@ int select_task_rq(struct task_struct *p
> >  	 *   not worry about this generic constraint ]
> >  	 */
> >  	if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
> > -		     !cpu_online(cpu)))
> > +		     (is_per_cpu_kthread(p) ? !cpu_online(cpu) : !cpu_active(cpu)))
> >  		cpu = select_fallback_rq(task_cpu(p), p);
> >  
> >  	return cpu;
> 
> Yes this looks good to me.
> 
> Are you planning to submit your change to introduce
> is_per_cpu_kthread(), or shall I?

I've got the lot; I just need to write a better changelog for my old
(now rebased) patch and make a small note in your patch, but will feed
them to Ingo when done.