On Tue, Jun 19, 2007 at 10:02:17AM +0000, Chris Clayton wrote:
> Hi,
>
> I've built and run powertop 1.7 and configured my system (Compaq Armada
> M700) with most of the hints. However, although I have built the ondemand
> cpu speed governor and can load it with modprobe, I cannot switch to that
> govenor. I get:
>
> $ echo -n ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> bash: echo: write error: Invalid argument
>
> The speedstep-smi scaling governor module is also loaded:
speedstep-smi isn't a governor it's the mechanism that allows speed
changes to occur. Unfortunatly it has a really high latency when it
does frequency changes. So high in fact, that using ondemand with
it can introduce a really large performance hit, so it's explicitly
prevented from being enabled.
(There's probably a message in dmesg telling you this when you try).
Dave
--
http://www.codemonkey.org.uk
_______________________________________________
Power mailing list
[email protected]
http://www.bughost.org/mailman/listinfo/power
