How to use cpufrequtils

From ThinkWiki
Revision as of 19:19, 2 February 2006 by Gvy (Talk | contribs) (bright side)
Jump to: navigation, search
NOTE!
See the Dynamic Frequency Scaling HOWTO on how to avoid using cpu frequency scaling daemons by using the kernel builtin ondemand governor.


This package mainly has 2 programs:

/usr/bin/cpufreq-info
/usr/bin/cpufreq-set

cpufreq-info gives general device information:

xaiki@gonzo:~$ cpufreq-info
cpufrequtils 0.2: cpufreq-info (C) Dominik Brodowski 2004
Report errors and bugs to linux@brodo.de, please.
analyzing CPU 0:
  driver: speedstep-smi
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 500 MHz - 700 MHz
  available frequency steps: 700 MHz, 500 MHz
  available cpufreq governors: userspace, performance
  current policy: frequency should be within 500 MHz and 700 MHz.
                  The governor "userspace" may decide which speed to use
                  within this range.
  current CPU frequency is 700 MHz.

and cpufreq-set allows setting ... Never got it working ...

I've got -- you need to get userspace governor active:

  1. modprobe cpufreq_userspace
  2. echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Then cpufreq-set -f 500000 (or 700000) should do the job.