Linux下CPU的手动频率设定 CPU电源策略模式

http://www.51testing.com/html/20/n-3723920.html

 

 

[root@rk3328:~]# cd /sys/devices/system/cpu/cpufreq

[root@rk3328:/sys/devices/system/cpu/cpufreq]# cd ./policy0/                    
[root@rk3328:/sys/devices/system/cpu/cpufreq/policy0]# ls                       
affected_cpus               related_cpus                   scaling_governor     
cpuinfo_cur_freq            scaling_available_frequencies  scaling_max_freq     
cpuinfo_max_freq            scaling_available_governors    scaling_min_freq     
cpuinfo_min_freq            scaling_cur_freq               scaling_setspeed     
cpuinfo_transition_latency  scaling_driver                 stats    

查看CPU电源策略

除了传统的conservative (保守)，powersave（节能） ondemand（请求） performance（性能）4种模式之外，

还有了一个userspace模式，这说明系统可以支持PCPS.在该模式下用户可自行设置CPU频率(CPU支持的频率)

[root@rk3328:/sys/devices/system/cpu/cpufreq/policy0]# cat scaling_available_gov
ernors                                                                          
conservative ondemand userspace powersave interactive performance

支持的频率

[root@rk3328:/sys/devices/system/cpu/cpufreq/policy0]# cat scaling_available_fre
quencies                                                                        
408000 600000 816000 1008000 1200000 1296000 1392000

设置电源策略和频率

 echo userspace > scaling_governor

 echo 1392000 > scaling_setspeed

查看cpu频率

[root@rk3328:/sys/devices/system/cpu/cpufreq/policy0]# cat scaling_cur_freq     
1392000