Re: [git pull] scheduler updates for v2.6.27, phase #2

From: Peter Zijlstra
Date: Thu Jul 24 2008 - 07:16:01 EST


On Thu, 2008-07-24 at 04:09 -0700, Andrew Morton wrote:
> On Thu, 24 Jul 2008 12:43:13 +0200 Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
>
> > On Mon, 2008-07-21 at 13:16 -0700, Daniel Walker wrote:
> > > On Mon, 2008-07-21 at 21:23 +0200, Peter Zijlstra wrote:
> > >
> > > > Does this work for you?
> > > >
> > >
> > > Yours removed the warning .. I made an alternate one below only compile
> > > tested, your choice..
> >
> > How about this one - it seems there is a whole scala of new division
> > instructions these days... :-)
> >
>
> ain't life grand.
>
> >
> >
> > diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
> > index 47ceac9..3c38686 100644
> > --- a/kernel/sched_rt.c
> > +++ b/kernel/sched_rt.c
> > @@ -253,7 +253,7 @@ static int do_balance_runtime(struct rt_rq *rt_rq)
> >
> > diff = iter->rt_runtime - iter->rt_time;
> > if (diff > 0) {
> > - do_div(diff, weight);
> > + diff = div_u64((u64)diff, weight);
>
> Can't use div_s64() here?

I guess we could, but since we already established >0, I thought using
the u64 version might be slightly cheaper - but what do I know..

> > if (rt_rq->rt_runtime + diff > rt_period)
> > diff = rt_period - rt_rq->rt_runtime;
> > iter->rt_runtime -= diff;
> >

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/