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

david
2007-07-30T19:05:26Z

On Mon, 30 Jul 2007, Ingo Molnar wrote:

> * 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.

probably. I delete lkml messages pretty agressivly so I don't have them
around to refer to.

David Lang