CPU governor是调节处理器Turbo性能的策略，通过以下命令可以查看所有处理器的governor:
cpupower -c all frequency-info
详细的Intel Turbo Boost技术参考 Intel Turbo Boost技术和intel_pstate
手工设置powersave作为目标CPU governor:
sudo cpupower -c all frequency-set -g powersave
systemd和cpupower
RHEL/CentOS 7的systemd提供了cpupower.service配置 - /usr/lib/systemd/system/cpupower.service 内容如下：
[Unit]
Description=Configure CPU power related settings
After=syslog.target
[Service]
Type=oneshot
RemainAfterExit=yes
EnvironmentFile=/etc/sysconfig/cpupower
ExecStart=/usr/bin/cpupower $CPUPOWER_START_OPTS
ExecStop=/usr/bin/cpupower $CPUPOWER_STOP_OPTS
[Install]
WantedBy=multi-user.target
这个systemd启动服务脚本只需要创建一个软链接就可以使用:
systemctl enable cpupower.service
上述命令软件了 /etc/systemd/system/multi-user.target.wants/cpupower.service 到 /usr/lib/systemd/system/cpupower.service 的软链接。
然后可以启动服务
systemctl start cpupower.service
启动服务之后，可以通过systemd检查状态
systemctl status cpupower.service
输出显示
● cpupower.service - Configure CPU power related settings
Loaded: loaded (/usr/lib/systemd/system/cpupower.service; enabled; vendor preset: disabled)
Active: active (exited) since Tue 2017-06-13 19:06:05 CST; 1min 17s ago
Process: 22853 ExecStart=/usr/bin/cpupower $CPUPOWER_START_OPTS (code=exited, status=0/SUCCESS)
Main PID: 22853 (code=exited, status=0/SUCCESS)
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 15
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 16
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 17
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 18
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 19
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 20
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 21
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 22
Jun 13 19:06:05 controller cpupower[22853]: Setting cpu: 23
Jun 13 19:06:05 controller systemd[1]: Started Configure CPU power related ...s.
Hint: Some lines were ellipsized, use -l to show in full.
配置cpupower
默认的CPU governor配置是performance，这个设置可以从/etc/sysconfig/cpupower环境配置文件得到：
# See 'cpupower help' and cpupower(1) for more info
CPUPOWER_START_OPTS="frequency-set -g performance"
CPUPOWER_STOP_OPTS="frequency-set -g ondemand"
即默认配置下，cpupower.service启动将设置governor为performance，停止时则设置ondemand。
详细的调整 CPU governor 以及设置 Intel p-state 方法，请参考 Intel Turbo Boost技术和intel_pstate