Re: (ondemand) CPU governor regression between 2.6.23 and 2.6.24

From: Andrew Morton
Date: Sun Feb 03 2008 - 19:32:51 EST


On Sat, 26 Jan 2008 15:06:25 +0100 Toralf Förster <toralf.foerster@xxxxxx> wrote:

> I use a 1-liner for a simple performance check : "time factor 819734028463158891"
> Here is the result for the new (Gentoo) kernel 2.6.24:
>
> With the ondemand governor of the I get:
>
> tfoerste@n22 ~/tmp $ time factor 819734028463158891
> 819734028463158891: 3 273244676154386297
>
> real 0m32.997s
> user 0m15.732s
> sys 0m0.014s
>
> With the ondemand governor the CPU runs at 600 MHz,
> whereas with the performance governor I get :
>
> tfoerste@n22 ~/tmp $ time factor 819734028463158891
> 819734028463158891: 3 273244676154386297
>
> real 0m10.893s
> user 0m5.444s
> sys 0m0.000s
>
> (~5.5 sec as I expected) b/c the CPU is set to 1.7 GHz.
>
> The ondeman governor of previous kernel versions however automatically increased
> the CPU speed from 600 MHz to 1.7 GHz.
>
> My system is a ThinkPad T41, I'll attach the .config
>

Let's cc the cpufreq list.

If nothing happens (often the case), please raise a report at
bugzilla.kernel.org so we can track the presence of the regression.

Thanks.

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