Cpufreq
時代はエコである．
うちのデスクトップPCは，ほとんどアイドル状態である．
しかし，アイドル状態でもCPUは動作周波数は最大値である．
ヒマなときは少しサボってもバチはあたらないんじゃない？
ということで動的にCPUの動作周波数を変更する設定を行う．
ツールのダウンロード．
% sudo pacman -S cpufrequtils
とりあえず，CPUの情報．
% sudo modprobe acpi-cpufreq % cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us.
hardware limits: 2.00 GHz - 3.17 GHz
available frequency steps: 3.17 GHz, 2.67 GHz, 2.33 GHz, 2.00 GHz
available cpufreq governors: performance
current policy: frequency should be within 2.00 GHz and 3.17 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 3.17 GHz.
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us.
hardware limits: 2.00 GHz - 3.17 GHz
available frequency steps: 3.17 GHz, 2.67 GHz, 2.33 GHz, 2.00 GHz
available cpufreq governors: performance
current policy: frequency should be within 2.00 GHz and 3.17 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency is 3.17 GHz.今は performanceしか選択できないが，
% sudo modprobe cpufreq_ondemand
とすれば，ondemandも選択可能になる．
起動時に有効にするためデーモンにたのむ．
/etc/conf.d/cpufreq
governor="ondemand"
として，/etc/rc.confのDAEMONSの欄に追加．
MODULES=(acpi-cpufreq cpufreq_ondemand !pcspkr !acer-wmi !acerhdf !usblp) （中略） DAEMONS=(syslog-ng cpufreq !network @crond @hal @alsa @net-profiles !sshd)
