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

From: Kenneth Prugh
Date: Mon Jul 30 2007 - 18:45:51 EST


Miguel Figueiredo wrote:
> Em Segunda, 30 de Julho de 2007 22:24, Kenneth Prugh escreveu:
>> Ingo Molnar wrote:
>>> * Kenneth Prugh <ken69267@xxxxxxxxx> wrote:
>>>> Ingo Molnar wrote:
>>>>> <large snip>
>>>> Hello, I have a gaming rig and would love to help benchmark with my
>>>> copy of UT2004(E6600 Core2 and a 7950GTO card). Or if you have
>>>> anything else that would better serve as a benchmark I could grab it
>>>> and try.
>>>>
>>>> The only problem is I don't know what 2 kernels I should be using to
>>>> test the schedulers. I assume 2.6.23-rc1 for CFS, but what about SD?
>>> .22-ck1 includes it, so that should be fine:
>>>
>>> http://ussg.iu.edu/hypermail/linux/kernel/0707.1/0318.html
>>>
>>> Ingo
>> Alright, Just got done with some testing of UT2004 between 2.6.23-rc1
>> CFS and 2.6.22-ck1 SD. This series of tests was run by spawning in a map
>> while not moving at all and always facing the same direction, while
>> slowing increasing the number of loops.
>>
>> CFS generally seemed a lot smoother as the load increased, while SD
>> broke down to a highly unstable fps count that fluctuated massively
>> around the third loop. Seems like I will stick to CFS for gaming now.
>>
>> Below you will find the results of my test with the average number of FPS.
>>
>> CFS | SD
>> UT2004 + 0 loops | 200 FPS UT2004 + 0 loops | 190 FPS
>> UT2004 + 1 loops | 195 FPS UT2004 + 1 loops | 190 FPS
>> UT2004 + 2 loops | 190 FPS UT2004 + 2 loops | 190 FPS
>> UT2004 + 3 loops | 189 FPS UT2004 + 3 loops | 136 FPS
>> UT2004 + 4 loops | 150 FPS UT2004 + 4 loops | 137 FPS
>> UT2004 + 5 loops | 145 FPS UT2004 + 5 loops | 136 FPS
>> UT2004 + 6 loops | 145 FPS UT2004 + 6 loops | 105 FPS
>> UT2004 + 7 loops | 118 FPS UT2004 + 7 loops | 104 FPS
>> UT2004 + 8 loops | 97 FPS UT2004 + 8 loops | 104 FPS
>> UT2004 + 9 loops | 94 FPS UT2004 + 9 loops | 89 FPS
>> UT2004 + 10 loops | 92 FPS UT2004 + 10 loops | 91 FPS
>
> can you apply the patch [1] that changes the behaviour of sched_yield on SD
> and report the results?
>
> SD should scale a lot better after the patch.
>
> 1 - http://bhhdoa.org.au/pipermail/ck/2007-July/008297.html
>

I Applied the patch. SD Seemed a bit smoother over the loads, although
that could be a placebo effect. It wasn't until the 8 or 9th loop
running that I could really notice that the fps were fluctuating in the
map without looking at the fps counter.

SD-Patched

UT2004 + 0 loops | 202 FPS
UT2004 + 1 loops | 201 FPS
UT2004 + 2 loops | 199 FPS
UT2004 + 3 loops | 143 FPS
UT2004 + 4 loops | 145 FPS
UT2004 + 5 loops | 145 FPS
UT2004 + 6 loops | 112 FPS
UT2004 + 7 loops | 110 FPS
UT2004 + 8 loops | 108 FPS
UT2004 + 9 loops | 90 FPS
UT2004 + 10 loops | 89 FPS

--
Kenneth Prugh - Ken69267
Gentoo AMD64 Arch Tester

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