[ltp] X60s and other CoreDuos / Battery LIfe - Kernel/CPU freq scaling issue?

[Tino Keitel]

On Sun, Oct 29, 2006 at 13:26:09 -0800, Ari El wrote:
> 
> Hi all,
> 
>    I know this have been discussed many times already.
> 
>    You might want to check this post anyways:
> 
>       
> http://www.nabble.com/thinkpad-x60-Battery-Life--%21-tf1971716.html#a7064764
> 
>     *maybe* there is an issue with either the L2400 CPU (and others,
> reportedly) or the Kernel (dapper & edgy, at least). What I can tell for
> sure is that setting powersave or performance governors (and fixing the
> frequency to 1GHz or 1.6Ghz) produces no difference *at all* in the battery
> power drain as reported by acpitool -B. I tested along many hours of use,
> taking many measurements in different use cases. 

Have you tried the userspace governor? AFAIK neither performance nor
powersave allow you to fix the CPU speed to a certain level. Actually,
I get this result with the performance governor:

$ cat scaling_governor 
performance
$ echo 1000000 > scaling_setspeed 
bash: scaling_setspeed: Permission denied

That's because the file scaling_setspeed just doesn't exist with the
performance governor.

Have you tried this?

$ echo "userspace" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo "userspace" > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
$ echo 1000000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
$ echo 1000000 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_setspeed

Regards,
Tino