Re: [PATCH RT v3 3/5] sched: migrate_dis/enable: Use rt_invol_sleep

[Scott Wood]

On Tue, 2019-09-17 at 09:59 +0200, Sebastian Andrzej Siewior wrote:
> On 2019-09-11 17:57:27 [+0100], Scott Wood wrote:
> > diff --git a/kernel/cpu.c b/kernel/cpu.c
> > index 885a195dfbe0..32c6175b63b6 100644
> > --- a/kernel/cpu.c
> > +++ b/kernel/cpu.c
> > @@ -308,7 +308,9 @@ void pin_current_cpu(void)
> >  	preempt_lazy_enable();
> >  	preempt_enable();
> >  
> > +	rt_invol_sleep_inc();
> >  	__read_rt_lock(cpuhp_pin);
> > +	rt_invol_sleep_dec();
> >  
> >  	preempt_disable();
> >  	preempt_lazy_disable();
> 
> I understand the other one. But now looking at it, both end up in
> rt_spin_lock_slowlock_locked() which would be the proper place to do
> that annotation. Okay.

FWIW, if my lazy migrate patchset is accepted, then there will be no users
of __read_rt_lock() outside rwlock-rt.c and it'll be moot.

-Scott