Re: report a bug about sched_rt

Peter Zijlstra
2009-07-24T15:59:52Z

On Fri, 2009-07-24 at 16:40 +0100, Jamie Lokier wrote:
> Peter Zijlstra wrote:
> > If you're using the bandwidth throttle to control your RT tasks so as
> > not to starve your SCHED_OTHER tasks, then I will call your system ill
> > designed.
>
> What mechanism should be used to avoid starving SCHED_OTHER tasks, in
> the event there are unforeseen bugs or unpredictable calculation times
> in an RT task?

For bugs the throttle works, like I said a well functioning system is
not supposed to hit the throttle, obviously a bug precludes the well
functioning qualification :-)

Unpredictable calculation times can be dealt with on the application
design level, for example using techniques such as outlined here:

http://feanor.sssup.it/~faggioli/papers/OSPERT-2009-dlexception.pdf

These really are things you should know about before writing an RT
application ;-)