Re: [PATCH] sched/rt: RT_RUNTIME_GREED sched feature

From: Peter Zijlstra
Date: Mon Nov 14 2016 - 04:21:36 EST


On Sun, Nov 13, 2016 at 12:53:28PM -0600, Christoph Lameter wrote:
> On Fri, 11 Nov 2016, Peter Zijlstra wrote:
>
> > On Fri, Nov 11, 2016 at 12:46:37PM -0600, Christoph Lameter wrote:
> > > On Thu, 10 Nov 2016, Daniel Vacek wrote:
> > >
> > > > I believe Daniel's patches are the best thing we can do in current
> > > > situation as the behavior now seems rather buggy and does not provide above
> > > > mentioned expectations set when rt throttling was merged with default
> > > > budget of 95% of CPU time. Nor if you configure so that it does (by
> > > > disabling RT_RUNTIME_SHARE), it also forces CPUs to go idle needlessly when
> > > > there still can be rt task running not really starving anyone. At least
> > > > till a proper rework of rt scheduling with DL Server is implemented.
> > >
> > > This looks like a fix for a bug and the company I work for is suffering
> > > as a result. Could we please merge that ASAP?
> > >
> >
> > What bug? And no, the patch has as many technical issues as it has
> > conceptual ones.
>
> There is a deadlock, Peter!!!

Describe please? Also, have you tried disabling RT_RUNTIME_SHARE ?