Re: Sched - graphic smoothness under load - cfs-v13 sd-0.48

From: Miguel Figueiredo
Date: Sun May 20 2007 - 12:59:11 EST


Ray Lee wrote:
On 5/20/07, Miguel Figueiredo <elmig@xxxxxxxxxxxx> wrote:
As I tryied myself kernels 2.6.21, 2.6.21-cfs-v13, and 2.6.21-ck2 on the
same machine i found *very* odd those numbers you posted, so i tested
myself those kernels to see the numbers I get instead of talking about
the usage of kernel xpto feels like.

I did run glxgears with kernels 2.6.21, 2.6.21-cfs-v13 and 2.6.21-ck2
inside Debian's GNOME environment. The hardware is an AMD Sempron64 3.0
GHz, 1 GB RAM, Nvidia 6800XT.
Average and standard deviation from the gathered data:

* 2.6.21: average = 11251.1; stdev = 0.172
* 2.6.21-cfs-v13: average = 11242.8; stdev = 0.033
* 2.6.21-ck2: average = 11257.8; stdev = 0.067

Keep in mind those numbers don't mean anything we all know glxgears is
not a benchmark, their purpose is only to be used as comparison under
the same conditions.

Uhm, then why are you trying to use them to compare against Bill's
numbers? You two have completely different hardware setups, and this
is a test that is dependent upon hardware. Stated differently, this is
a worthless comparison between your results and his as you are
changing multiple variables at the same time. (At minimum: the
scheduler, cpu, and video card.)

The only thing i want to see it's the difference between the behaviour of the different schedulers on the same test setup. In my test -ck2 was a bit better, not 200% worse as in Bill's measurements. I don't compare absolute values on different test setups.


One odd thing i noticed, with 2.6.21-cfs-v13 the gnome's time applet in
the bar skipped some minutes (e.g. 16:23 -> 16:25) several times.

The data is available on:
http://www.debianPT.org/~elmig/pool/kernel/20070520/


How did you get your data? I am affraid your data it's wrong, there's no
such big difference between the schedulers...

It doesn't look like you were running his glitch1 script which starts
several in glxgears parallel. Were you, or were you just running one?

No i'm not, i'm running only one instance of glxgears inside the GNOME's environment.


--

Com os melhores cumprimentos/Best regards,

Miguel Figueiredo
http://www.DebianPT.org
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