Re: [ck] Re: SD still better than CFS for 3d ?(was Re: 2.6.23-rc1)

Ingo Molnar
2007-07-30T19:02:21Z

* david@lang.hm <david@lang.hm> wrote:

> > Would you be interested in trying CFS and doing some numers perhaps?
> > It requires some work: you have to start up your favorite game in a
> > way that gives a reliable framerate number. (many games allow the
> > display of FPS in-game) In Quake3 i simply started the game and did
> > not move the player - that is something easy to reproduce.
>
> the one report that I saw said that the FPS numbers were overall the
> same, but what the reporter was seeing was that CFS was doing it in
> bursts of activity while SD was smoother. [...]

which report is that, precisely? I'm not aware of any such report past
CFS v14 or so.

> IIRC Linus responded with thoughts on granularity and the fact that
> changing from Hz 1000 to Hz 100 will increase the timeslices in CFS by
> 10x (which could be enough to trigger this sort of issue)

ah, you mean Kasper Sandberg's report? That turned out to be based on an
older CFS version, not v2.6.23-rc1. Kasper said he'll redo his tests,
and if there's still any regression left we'll fix it.

Ingo