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

Tino Keitel linux-thinkpad@linux-thinkpad.org
Mon, 30 Oct 2006 16:57:51 +0100


On Mon, Oct 30, 2006 at 05:51:47 -0800, Ari El wrote:
> 
> 
> 
> Tino Keitel-3 wrote:
> > 
> > 
> > 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
> > -- 
> > The linux-thinkpad mailing list home page is at:
> > http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
> > 
> > 
> 
> 
> Hi Tino, by setting the powersave governor, the kernel automatically selects
> the lowest available frequency (1000000) and keeps it there (that's the way
> this governor works). Likewise with performance, it selects the highest
> available freq.
> 
> Just in case I tried your userspace method too, results are exactly the
> same.
> 
> Since it looks like you have a core duo machine, can you mention if you
> actually see a difference in power consumption when change the frequency
> from 1G to 1.66G using this method? If so what is it (mW)? 

I do have a Core Duo machine, but it is not a notebook, so I can not
use ACPI to do any measurements. Maybe I can do some some real
measurements this weekend, also with one core disabled etc.

Regards,
Tino