CPU Governor 종류

 

* OnDemand : 현재 사용량에 따라 CPU frequnecy를 설정. CPU는 주파수를 빠르게 변경할 능력이 필요

* OnDemandX : 배터리 친화적인 OnDemand이며 I/O 스케줄러에 따라 성능이 크게 좌우.

* Conservative : 느린 OnDemand. 가능한 최저 속도에서 동작하도록 구현

  예) OnDemand는 min -> max로 바로 변경 / Conservative는 min -> lower -> mid -> hig -> max 변경

* Interactive : OnDemand처럼 CPU에 위치한 부하에 따라 주파수를 변경하나 훨씬 빠르게 반응

* Performance : CPU를 최고 주파수로 설정

* Powersave : CPU를 최저 주파수로 설정

* Userspace : 테스트를 위해 사용. CPU를 사용자가 지정한 주파수로 동작

 

현재 설정된 governors 확인

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

 

사용가능한 설정

# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

 

governors 변경

# echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

 

* /sys/devices/system/cpu/ -> cpu[n] n 수만큼 다 변경

 

예)

# echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu4/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu5/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu6/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu7/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu8/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu9/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu10/cpufreq/scaling_governor

# echo performance > /sys/devices/system/cpu/cpu11/cpufreq/scaling_governor