Re: [ANNOUNCE] 3.6.9-rt21

[Mike Galbraith <bitbucket@online.de>]

On Mon, 2012-12-17 at 16:35 +0100, Thomas Gleixner wrote: 
> On Sat, 15 Dec 2012, Mike Galbraith wrote:
> > On Wed, 2012-12-05 at 17:05 +0100, Thomas Gleixner wrote: 
> > > Dear RT Folks,
> > > 
> > > I'm pleased to announce the 3.6.9-rt21 release. 3.6.7-rt18, 3.6.8-rt19
> > > and 3.6.9-rt20 are not announced updates to the respective 3.6.y
> > > stable releases without any RT changes
> > > 
> > > Changes since 3.6.9-rt20:
> > > 
> > >    * Fix the PREEMPT_LAZY implementation on ARM
> > > 
> > >    * Fix the RCUTINY issues
> > > 
> > >    * Fix a long standing scheduler bug (See commit log of
> > >      sched-enqueue-to-head.patch)
> > 
> > That last has an oversight buglet.
> > 
> > sched: add missing userspace->kernel struct sched_param.sched_priority inversion
> > 
> > Signed-off-by: Mike Galbraith <bitbucket@online.de>
> > ---
> >  kernel/sched/core.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -4624,7 +4624,7 @@ static int __sched_setscheduler(struct t
> >  	p->sched_reset_on_fork = reset_on_fork;
> >  
> >  	oldprio = p->prio;
> > -	if (oldprio == param->sched_priority)
> > +	if (oldprio == (MAX_RT_PRIO - 1) - param->sched_priority)
> >  		goto out;
> >  
> >  	on_rq = p->on_rq;
> 
> Duh, yes. But there is another one here:
> 
> +               enqueue_task(rq, p, oldprio < param->sched_priority ?
> +                            ENQUEUE_HEAD : 0);
> 
> Bah. This reverse user/kernel priority nonsense really should go away!

Snort, I looked right at it too, looked perfectly fine :)

-Mike