CPU Frequency-scaling for openSUSE 11.1 fix!

Bummer - the standard cpufreq just leaves my G5 iMac running at full speed at 1.8ghz, and no amount of cpufreq-util commands would make it actually scale. I could change it from performance down to powersave, but any attempt to use ondemand or even conservative would fail - due to the apple hardware taking too long of a transition, so it would default back to performance.

To make matters worse, there are no cpudyn or powernowd packages in openSuse afaik.

So, I just compiled and installed cpudyn, one of my favorites for ppc cpu frequency scaling.

1) Install make and gcc. (preface with sudo if you don't have a separate root account)

zypper install make
zypper install gcc

2) Download cpudyn-1.01.tgz from the project site:

http://mnm.uib.es/gallir/cpudyn/

3) Untar it to any convenient directory:

tar -zxvf cpudyn-1.0.1.tgz

4) Cd into the cpudyn directory, and change into the root user with su.

5) Compile it:

make

followed by

make install

6) To make it active at boot time, I just edited /etc/init.d/boot.local and added this line:

/etc/init.d/cpudyn start

Bingo!! Now when I check the cpu freq with cat /proc/cpuinfo or use other means to detect the frequency, at idle it shows 900mhz, and under load 1.8ghz.

Man, this was almost a deal-breaker for me. I HAD to have cpu frequency scaling working.

UPDATE - 21 Dec:
Reading through the changelog notes for cpudyn reveals that it may not be the best for multiprocessor machines. It will work on them, but according to the developer, if cpu0 gets a request to go to powersave, it will also do it for cpu1, which may be under load and not really need to be scaled back. So, the scaling operates in tandem, and may not be ideal for smp machines. Still, it may be better than nothing.