Re: [PATCH 6/6] sched: disabled rt-bandwidth by default

Mike Galbraith
2008-08-29T07:57:09Z

On Thu, 2008-08-28 at 14:53 -0400, Steven Rostedt wrote:
> On Thu, 28 Aug 2008, Linus Torvalds wrote:
> >
> > And I'm not really interested. Quite frankly, I suspect the "we want to
> > run something like pulseaudio with RT priorities" camp is the more common
> > one, and in that context I understand limiting SCHED_FIFO sounds perfectly
> > understandable.
>
> The fact that it actually limits a SCHED_FIFO task group, over a single
> task thread does bother me a little.

It bothers me some too. You have to patch/re-compile the kernel if you
need to turn it off and don't have SCHED_DEBUG enabled (not free).

I tripped over this recently while regression testing. I didn't expect
a gaggle of SCHED_RR tasks to be throttled on an otherwise idle box.
Hitting that perturbed test results in an unexpected manner, and sent me
off on a tangent.

-Mike