ppc32: Weird process scheduling behaviour with 2.6.24-rc

[Michel Dänzer]

On Fri, 2008-01-25 at 17:54 +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2008-01-23 at 13:42 +0100, Peter Zijlstra wrote:
> > Another question, do you have:
> >   CONFIG_FAIR_GROUP_SCHED=y
> > 
> > if so, does flipping that off have any effect?
> 
> Yes.
> 
> Here, I do the test of running 4 times the repro-case provided by Michel
> with nice 19 and a dd eating CPU with nice 0.
> 
> Without this option, I get the dd at 100% and the nice 19 shells down
> below it with whatever is left of the CPUs.
> 
> With this option, dd gets about 50% of one CPU and the niced processes
> still get most of the time.

Hmm, interesting. As I said before, I thought I had tested with this
disabled and not seen a difference, but I'll try again to confirm.


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer