Best CONFIG_HZ value for scheduler testing?

Best CONFIG_HZ value for scheduler testing?

[Martin Steigerwald]

Hi Con and Ingo!

What would be the best CONFIG_HZ value for scheduler testing? I used 
1000HZ for a long time, but use 300HZ since 2.6.20. This worked well 
enough for sd-0.46 and previous versions and ck patches...

martin@deepdance:Computer/Deepdance/Kernel> grep "CONFIG_HZ=" */config*
2.6.13/config-2.6.13.3-tp23--2005-10-07:CONFIG_HZ=1000
2.6.13/config-2.6.13.4-tp23--2005-10-13:CONFIG_HZ=1000
2.6.13/config-2.6.13-tp23--2005-09-03:CONFIG_HZ=1000
2.6.13/config-2.6.13-tp23-ibmacpi-0.12--2005-09-06:CONFIG_HZ=1000
2.6.14/config-2.6.14.2-tp23--2005-11-13:CONFIG_HZ=1000
2.6.14/config-2.6.14.3-tp23-sws2-2.2-rc14--2005-12-08:CONFIG_HZ=1000
2.6.14/config-2.6.14.4-tp23-sws2-2.2-rc14--2005-12-23:CONFIG_HZ=1000
2.6.14/config-2.6.14.5-tp23-sws2-2.2-rc15--2005-12-30:CONFIG_HZ=1000
2.6.15/config-2.6.15.1-tp23-sws2-2.2-rc16--2006-01-17:CONFIG_HZ=1000
2.6.15/config-2.6.15.2-tp23-sws2-2.2--2006-02-01:CONFIG_HZ=1000
2.6.15/config-2.6.15.4-tp23-sws2-2.2--2006-02-16:CONFIG_HZ=1000
2.6.15/config-2.6.15.6-tp23-sws2-2.2--2006-03-18:CONFIG_HZ=1000
2.6.15/config-2.6.15.7-tp23-sws2-2.2--2006-04-14:CONFIG_HZ=1000
2.6.15/config-2.6.15.7-tp23-sws2-2.2_2--2006-05-31:CONFIG_HZ=1000
2.6.16/config-2.6.16.11-tp23-sws2-2.2.5--2006-04-28:CONFIG_HZ=1000
2.6.16/config-2.6.16.4-tp23-sws2-2.2.4--2006-04-12:CONFIG_HZ=1000
2.6.17/config-2.6.17.11-ck1-tp23-sws2-2.2.7:CONFIG_HZ=1000
2.6.17/config-2.6.17.1-tp23--2006-06-23:CONFIG_HZ=1000
2.6.17/config-2.6.17.1-tp23-sws2-2.2.6-xfs-fix--2006-06-28:CONFIG_HZ=1000
2.6.17/config-2.6.17.1-tp23-sws-2.2.5.3--2006-06-23:CONFIG_HZ=1000
2.6.17/config-2.6.17.7-tp23-sws2-2.2.7:CONFIG_HZ=1000
2.6.18/config-2.6.18-ck1-tp23-sws-2.2.8--2006-10-01:CONFIG_HZ=1000
2.6.19/config-2.6.19.1-ck2-tp23-sws2-2.2.9:CONFIG_HZ=1000
2.6.19/config-2.6.19.2-ck2-tp23-sws2-2.2.9.3:CONFIG_HZ=1000
2.6.20/config-2.6.20.1-ck1-tp23-sws2-2.2.9.7:CONFIG_HZ=300
2.6.20/config-2.6.20.3-ck1-tp23-sws2-2.2.9.9:CONFIG_HZ=300
2.6.20/config-2.6.20.4-ck1-tp23-rsdl-0.33-sws2-2.2.9.10:CONFIG_HZ=300
2.6.20/config-2.6.20.7-tp23-sws2-2.2.9.9-cfs-v5:CONFIG_HZ=300
2.6.20/config-2.6.20.7-tp23-sws2-2.2.9.9-cfs-v6-rc7:CONFIG_HZ=300
2.6.20/config-2.6.20.7-tp23-sws2-2.2.9.9-sd-0.46:CONFIG_HZ=300
2.6.20/config-2.6.20.7-tp23-sws2-2.2.9-sd-0.4.4:CONFIG_HZ=300

Any recommendation? I thought 300HZ was nice two to its compatibility with 
PAL and NTSC refresh rates, but then I have notebooks with LCD displays 
and do not use any TV cards whatsoever and it might be totally irrelevant 
to me.

Well 2.6.21 is out so I may switch to DYNTICKS soon anyway...

About scheduler test results on my two ThinkPads... These are just two 
ThinkPads - so my results are not that representative . By contacting the 
people on the linux-thinkpad mailinglist it might be possible to get 
broader test results[1]. I would be providing my precompiled kernels as 
Debian packages if you desired - they should work with Debian Etch, but 
they use libata PATA drivers.

[1] http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad

Regards,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

Re: Best CONFIG_HZ value for scheduler testing?

[Bill Davidsen]

Martin Steigerwald wrote:
> Hi Con and Ingo!
> 
> What would be the best CONFIG_HZ value for scheduler testing? I used 
> 1000HZ for a long time, but use 300HZ since 2.6.20. This worked well 
> enough for sd-0.46 and previous versions and ck patches...
> 
That's a good point, all the tests I've done are at 1000, that's just my 
default and I didn't bother to change it.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot

Re: Best CONFIG_HZ value for scheduler testing?

[Jan Engelhardt]

On Apr 27 2007 10:44, Martin Steigerwald wrote:
>
>Hi Con and Ingo!
>
>What would be the best CONFIG_HZ value for scheduler testing? I used 
>1000HZ for a long time, but use 300HZ since 2.6.20. This worked well 
>enough for sd-0.46 and previous versions and ck patches...

CONFIG_HZ=1337
(SCNR.)


Jan
--