2004-03-15 22:34:40

by rutger

Subject: [BUG] P4 HT cpufreq driver doesn't share governor/frequency between siblings

Small bugreport, Pentium 4 Hyper-Threaded with SMP kernel (2.6.4-bk
from Mar 11) and p4-clockmod module loaded, gives:

# cd /sys/devices/system/cpu
# cat cpu*/cpufreq/scaling_governor
performance
performance
# echo powersave > cpu1/cpufreq/scaling_governor
# cat cpu*/cpufreq/scaling_governor
performance
powersave

Shouldn't the cpufreq driver be shared between the siblings?

--
Rutger Nijlunsing ---------------------------- rutger ed tux tmfweb nl
never attribute to a conspiracy which can be explained by incompetence
----------------------------------------------------------------------

2004-03-15 22:44:34

by Dave Jones

Subject: Re: [BUG] P4 HT cpufreq driver doesn't share governor/frequency between siblings

On Mon, Mar 15, 2004 at 11:33:58PM +0100, [email protected] wrote:
> Small bugreport, Pentium 4 Hyper-Threaded with SMP kernel (2.6.4-bk
> from Mar 11) and p4-clockmod module loaded, gives:
>
> # cd /sys/devices/system/cpu
> # cat cpu*/cpufreq/scaling_governor
> performance
> performance
> # echo powersave > cpu1/cpufreq/scaling_governor
> # cat cpu*/cpufreq/scaling_governor
> performance
> powersave
>
> Shouldn't the cpufreq driver be shared between the siblings?

Theoretically, as split-cores become more advanced, we will be able
to save power on unused cores. With the current P4's I'll bet it
makes little to no difference at all.

Dave