[Cbe-oss-dev] SCHED_IDLE documentation

[Ingo Molnar]

* Michael Kerrisk <mtk.manpages at googlemail.com> wrote:

> > > * What's the difference between SCHED_IDLE and SCHED_BATCH?
> >
> > SCHED_BATCH can still have nice levels from -20 to +19, it is a 
> > modified SCHED_OTHER/SCHED_NORMAL for "throughput oriented" 
> > workloads.
> 
> So, suppose we have two CPU intensive jobs, one SCHED_OTHER and the 
> other SCHED_BATCH.  If they have the same nice value, will/should the 
> scheduler favour one over the other?

yes - SCHED_BATCH does not modify the CPU usage proportion for 
CPU-intense tasks, it's their nice value that controls the proportion. 
What it will influence is wakeup behavior - i.e. wakeup-intense 
workloads should schedule less with SCHED_BATCH. (but how that is done 
is really fluid and will probably tweaked in the future.)

	Ingo