cpufreq总概

 

cpufreq 涉及到的模块

此图中，1）notifier此事物的影响。

stats

 通过此接口可以看到每个频率运行的时间及调频的总次数。

在默认使用intel pstate的驱动时，看不到这些参数。

his gives the amount of time spent in each of the frequencies supported by
 this CPU. The cat output will have "<frequency> <time>" pair in each line, which
 will mean this CPU spent <time> usertime units of time at <frequency>. Output
 will have one line for each of the supported frequencies. usertime units here
 is 10mS (similar to other time exported in /proc).::
    <mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat time_in_state
     3600000 2089
     3400000 136
     3200000 34
     3000000 67
     2800000 172488 - **total_trans**
This gives the total number of frequency transitions on this CPU. The cat
 output will have a single count which is the total number of frequency
 transitions.::
    <mysystem>:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat total_trans
     20

 

P-state

In truth, a P-state is both a frequency and voltage operating point. Both are scaled as the P-state increases. 

是频率与电压 操作对。

其他资料

​​https://lenovopress.com/lp0870.pdf​​

​​https://www.kernel.org/doc/Documentation/cpu-freq/intel-pstate.txt​​

​​https://events.static.linuxfound.org/sites/events/files/slides/LinuxConEurope_2015.pdf​​

​​https://software.intel.com/content/www/us/en/develop/blogs/what-exactly-is-a-p-state-pt-1.html  ​​

​​http://www.wowotech.net/pm_subsystem/cpufreq_overview.html​​

​​https://wiki.archlinux.org/title/CPU_frequency_scaling​​    cpu freq和intel  p_state两个驱动使用说明

​​https://01.org/linux-thermal-daemon​​

​​https://github.com/intel/thermal_daemon​​  cpu温度监控