cpupower调整CPU主频

cpupower调整CPU主频
1、调节策略
performance：将CPU频率固定⼯作在其⽀持的最⾼运⾏频率上，不动态调节，可以获取到最⼤的性能。

powersave: 将 CPU 频率设置为最低的所谓 “省电” 模式，CPU 会固定⼯作在其⽀持的最低运⾏频率上。

因此这两种 governors 都属于静态 governor，即在使⽤它们时 CPU 的运⾏频率不会根据系统运⾏时负载的变化动态作出调整。

这两种 governors 对应的是两种极端的应⽤场景，使⽤ performance governor 是对系统⾼性能的最⼤追求，⽽使⽤ powersave governor 则是对系统低功耗的最⼤追求。

userspace：最早的 cpufreq ⼦系统通过 userspace governor 为⽤户提供了这种灵活性。

系统将变频策略的决策权交给了⽤户态应⽤程序，并提供了相应的接⼝供⽤户态应⽤程序调节 CPU 运⾏频率使⽤。

ondemand：按需快速动态调整 CPU 频率，⼀有 cpu 计算量的任务，就会⽴即达到最⼤频率运⾏，等执⾏完毕就⽴即回到最低频率；ondemand：userspace 是内核态的检测，⽤户态调整，效率低。

conservative: 与 ondemand 不同，平滑地调整 CPU 频率，频率的升降是渐变式的, 会⾃动在频率上下限调整，和 ondemand 的区别在于它会按需分配频率，⽽不是⼀味追求最⾼频率；
2、查看当前cpu可⽤的策略
[root@CENTOS ~]# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
conservative userspace powersave ondemand performance
[root@CENTOS ~]#
查看cpu0可⽤的策略：cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
3、查看当前cpu⽣效的策略
[root@CENTOS ~]# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
conservative
[root@CENTOS ~]#
查看cpu0当前的策略：cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
4、查看当前CPU频率
[root@CENTOS ~]# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
1000000
[root@CENTOS ~]#
5、查看当前所有CPU的信息
[root@CENTOS ~]# cpupower -c all frequency-info
analyzing CPU 0:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 10.0 us
hardware limits: 1000 MHz - 1.90 GHz
available frequency steps: 1.90 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz
available cpufreq governors: conservative userspace powersave ondemand performance
current policy: frequency should be within 1000 MHz and 1.90 GHz.
The governor "conservative" may decide which speed to use
within this range.
current CPU frequency: 1000 MHz (asserted by call to hardware)
boost state support:
Supported: yes
Active: yes
6、设置所有CPU的模式
设置所有CPU为性能模式
[root@CENTOS57 ~]# cpupower -c all frequency-set -g performance
Setting cpu: 0
Setting cpu: 1
Setting cpu: 2
Setting cpu: 3
Setting cpu: 4
Setting cpu: 5
Setting cpu: 6
Setting cpu: 7
Setting cpu: 8
Setting cpu: 9
Setting cpu: 10
Setting cpu: 11
Setting cpu: 12
Setting cpu: 13
Setting cpu: 14
Setting cpu: 15
cpupower -c all frequency-set -g powersave
cpupower -c all frequency-set -g "conservative"
7、查看某个CPU的信息
[root@CENTOS57 ~]# cpupower -c 1 frequency-info
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 1
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us
hardware limits: 1000 MHz - 1.90 GHz
available frequency steps: 1.90 GHz, 1.90 GHz, 1.80 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz available cpufreq governors: conservative userspace powersave ondemand performance
current policy: frequency should be within 1000 MHz and 1.90 GHz.
The governor "performance" may decide which speed to use
within this range.
current CPU frequency: 1.90 GHz (asserted by call to hardware)
boost state support:
Supported: yes
Active: yes
cpupower -c 0 frequency-info #查看CPU0的信息
cpupower -c 1 frequency-info #查看CPU1的信息
cpupower -c 2 frequency-info #查看CPU2的信息
8、查看CPU的频率
[root@CENTOS57 ~]# cat /proc/cpuinfo | grep "cpu MHz*"
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000
cpu MHz : 1901.000。