Thoughts from the abyss

I wanted to play around with cpuspeed tonight on CentOS 4.5, just because I was curious. Here’s a few notes on getting it going on a Thinkpad R40 running a mobile Celeron.

Make sure you don’t already have things started.

# lsmod | grep p4_clockmod

Add the module:

# modprobe p4_clockmod

Edit the cpuspeed.conf file to use the p4_clockmod:

# vim /etc/cpuspeed.conf
DRIVER="p4_clockmod"

# Uncomment the last two parameters

OPTS="$OPTS -a /proc/acpi/ac_adapter/*/state"
OPTS="$OPTS -t /proc/acpi/thermal_zone/*/temperature 75"

Turn on the service:

service cpuspeed start
chkconfig cpuspeed on

Now you can watch and see what it does:

cat /proc/cpuinfo | grep "cpu\ MHz"

And watch the CPU throttle up and down depending on need.

The only thing is reaction can be a little slow, and perhaps that’s
something I don’t have configured correctly.