Re: [REPORT] cfs-v4 vs sd-0.44

Al Boldi
2007-04-22T04:34:37Z

Con Kolivas wrote:
> On Sunday 22 April 2007 02:00, Ingo Molnar wrote:
> > * Con Kolivas <kernel@kolivas.org> wrote:
> > > > Feels even better, mouse movements are very smooth even under high
> > > > load. I noticed that X gets reniced to -19 with this scheduler.
> > > > I've not looked at the code yet but this looked suspicious to me.
> > > > I've reniced it to 0 and it did not change any behaviour. Still
> > > > very good.
> > >
> > > Looks like this code does it:
> > >
> > > +int sysctl_sched_privileged_nice_level __read_mostly = -19;
> >
> > correct.
>
> Oh I definitely was not advocating against renicing X, I just suspect that
> virtually all the users who gave glowing reports to CFS comparing it to SD
> had no idea it had reniced X to -19 behind their back and that they were
> comparing it to SD running X at nice 0. I think had they been comparing
> CFS with X nice -19 to SD running nice -10 in this interactivity soft and
> squishy comparison land their thoughts might have been different. I missed
> it in the announcement and had to go looking in the code since Willy just
> kinda tripped over it unwittingly as well.

I tried this with the vesa driver of X, and reflect from the mesa-demos
heavily starves new window creation on cfs-v4 with X niced -19. X reniced
to 0 removes these starves. On SD, X reniced to -10 works great.

Thanks!

--
Al