Re: resend: KERNEL BUG: nice level should not affect SCHED_RR timeslice

Chris Friesen
2007-03-12T15:18:40Z

Con Kolivas wrote:

> Indeed we do change timeslice with nice on rt_tasks in mainline at the moment.
> Truth is most rt programming couldn't care less about timeslices, but your
> point about it deviating from the standard is valid. RSDL does not change
> timeslice with nice on SCHED_RR tasks so it's sort of getting addressed by
> proxy.

Unfortunately we have some vendor-supplied software that does care about
timeslices. It's a crazy thing with multiple SCHED_RR kernel threads
that don't really self-manage very well. They're spawned by a
SCHED_OTHER task and inherit its nice level.

We modified the startup for the spawning task to run it at a lower nice
level and were fairly surprised when the latency of message handling
went way up.

Chris