CPU周波数変更対応確認

ツールインストール

# aptitude install cpufrequtils
(中略)
CPUFreq Utilities: Setting ondemand CPUFreq governor...disabled, governor not available...done.

モジュールロード

# modprobe acpi-cpufreq
# ls /sys/devices/system/cpu/cpu0/
cpufreq  cpuidle  crash_notes  topology

デバイスの確認

# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance

対応周波数

# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
1500000 1400000 1200000 1000000 800000 600000
# cpufreq-info
cpufrequtils 004: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to cpufreq@lists.linux.org.uk, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 600 MHz - 1.50 GHz
  available frequency steps: 1.50 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz, 600 MHz
  available cpufreq governors: performance
  current policy: frequency should be within 600 MHz and 1.50 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.50 GHz (asserted by call to hardware).

モジュール検索

# find /lib/modules/`uname -r`/ -name '*.ko'|grep cpufreq_
/lib/modules/hoge/kernel/drivers/cpufreq/cpufreq_conservative.ko
/lib/modules/hoge/kernel/drivers/cpufreq/cpufreq_ondemand.ko
/lib/modules/hoge/kernel/drivers/cpufreq/cpufreq_userspace.ko
/lib/modules/hoge/kernel/drivers/cpufreq/cpufreq_stats.ko
/lib/modules/hoge/kernel/drivers/cpufreq/cpufreq_powersave.ko

modconfでkernel/drivers/cpufreq ondemandをロード

# lsmod | grep cpufreq_
cpufreq_ondemand        6476  1
freq_table              4224  2 cpufreq_ondemand,acpi_cpufreq

# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
ondemand performance
# echo "ondemand" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
ondemand performance
# echo "ondemand" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
ondemand
# cpufreq-info
cpufrequtils 004: cpufreq-info (C) Dominik Brodowski 2004-2006
Report errors and bugs to cpufreq@lists.linux.org.uk, please.
analyzing CPU 0:
  driver: acpi-cpufreq
  CPUs which need to switch frequency at the same time: 0
  hardware limits: 600 MHz - 1.50 GHz
  available frequency steps: 1.50 GHz, 1.40 GHz, 1.20 GHz, 1000 MHz, 800 MHz, 600 MHz
  available cpufreq governors: ondemand, performance
  current policy: frequency should be within 600 MHz and 1.50 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 600 MHz (asserted by call to hardware).

参考
http://d.hatena.ne.jp/quox/20091227/p1
http://nobu666.com/2006/10/23/415.html
http://rayearth.homelinux.net/pukiwiki/?Debian%2Fcpufreqd
http://myn.meganecco.org/2006081602