systemd管理cpupower

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

参考

• How to set CPU governor at system boot
• Enable cpupower.service