Re: Linux 2.6.23

Nicholas Miell
2007-10-11T01:20:56Z

On Wed, 2007-10-10 at 12:14 +0200, Ingo Molnar wrote:
> * Nicholas Miell <nmiell@comcast.net> wrote:
>
> > Does CFS still generate the following sysbench graphs with 2.6.23, or
> > did that get fixed?
> >
> > http://people.freebsd.org/~kris/scaling/linux-pgsql.png
> > http://people.freebsd.org/~kris/scaling/linux-mysql.png
>
> as far as my testsystem goes, v2.6.23 beats v2.6.22.9 in sysbench:
>
> http://redhat.com/~mingo/misc/sysbench.jpg

That's nice to know. Note that I'm not actually involved in any of these
tests, just a somewhat interested bystander.

>
> As you can see it in the graph, v2.6.23 schedules much more consistently
> too. [ v2.6.22 has a small (but potentially statistically insignificant)
> edge at 4-6 clients, and CFS has a slightly better peak (which is
> statistically insignificant). ]
>
> ( Config is at http://redhat.com/~mingo/misc/config, system is Core2Duo
> 1.83 GHz, mysql-5.0.45, glibc-2.6. Nothing fancy either in the config
> nor in the setup - everything is pretty close to the defaults. )
>
> i'm aware of a 2.6.21 vs. 2.6.23 sysbench regression report, and it
> apparently got resolved after various changes to the test environment:
>
> http://jeffr-tech.livejournal.com/10103.html
>
> " [<CFS>] has virtually no dropoff and performs better under load than
> the default 2.6.21 scheduler. " (paraphrased)
>
> (The new link you posted, just a few hours after the release of v2.6.23,
> has not been reported to lkml before AFAICS - when did you become aware
> of it? If you learned about it before v2.6.23 it might have been useful
> to report it to the v2.6.23 regression list.)

According to my IRC logs, Jeffr pasted the URL at Oct 09 22:53:56 PDT.
He says he tried to contact you early in CFS's development, but got no
reply.

> At a quick glance there are no .configs or other testing details at or
> around that URL that i could use to reproduce their result precisely, so
> at least a minimal bugreport would be nice.
>

AFAICT, the configuration is described in
http://people.freebsd.org/~kris/scaling/mysql.html

--
Nicholas Miell <nmiell@comcast.net>