Re: [PATCH v2 2/5] preempt/dynamic: Introduce preempt mode accessors

[Mike Galbraith]

On Thu, 2021-11-11 at 04:35 +0100, Mike Galbraith wrote:
> On Thu, 2021-11-11 at 04:16 +0100, Mike Galbraith wrote:
> > On Wed, 2021-11-10 at 20:24 +0000, Valentin Schneider wrote:
> > >
> > > diff --git a/include/linux/sched.h b/include/linux/sched.h
> > > index 5f8db54226af..0640d5622496 100644
> > > --- a/include/linux/sched.h
> > > +++ b/include/linux/sched.h
> > > @@ -2073,6 +2073,22 @@ static inline void cond_resched_rcu(void)
> > >  #endif
> > >  }
> > >  
> > > +#ifdef CONFIG_PREEMPT_DYNAMIC
> > > +
> > > +extern bool is_preempt_none(void);
> > > +extern bool is_preempt_voluntary(void);
> > > +extern bool is_preempt_full(void);
> > > +
> > > +#else
> > > +
> > > +#define is_preempt_none() IS_ENABLED(CONFIG_PREEMPT_NONE)
> > > +#define is_preempt_voluntary()
> > > IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY)
> > > +#define is_preempt_full() IS_ENABLED(CONFIG_PREEMPT)
> >
> > I think that should be IS_ENABLED(CONFIG_PREEMPTION), see
> > c1a280b68d4e.
> >
> > Noticed while applying the series to an RT tree, where tglx
> > has done that replacement to the powerpc spot your next patch
> > diddles.
>
> Damn, then comes patch 5 properly differentiating PREEMPT/PREEMPT_RT.

So I suppose the powerpc spot should remain CONFIG_PREEMPT and become
CONFIG_PREEMPTION when the RT change gets merged, because that spot is
about full preemptibility, not a distinct preemption model.

That's rather annoying :-/

	-Mike