有限的 cpupower 策略扩展

Question

如何更改 cpufreq 策略范围？

$ cpupower frequency-info
analyzing CPU 0:
  driver: powernow-k8
  CPUs which run at the same hardware frequency: 0 1
  CPUs which need to have their frequency coordinated by software: 0 1
  maximum transition latency: 109 us
  hardware limits: 800 MHz - 2.00 GHz
  available frequency steps:  2.00 GHz, 1.80 GHz, 1.60 GHz, 800 MHz
  available cpufreq governors: conservative ondemand userspace powersave performance schedutil
  current policy: frequency should be within 800 MHz and 800 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency: Unable to call hardware
  current CPU frequency: 800 MHz (asserted by call to kernel)
  boost state support:
    Supported: no
    Active: no

您可以看到硬件限制为 2GHz，但策略限制为 800。尝试

$ sudo cpupower frequency-set --max 2000000 
Setting cpu: 0
Setting cpu: 1

但没有效果：

$ cpupower frequency-info --policy
analyzing CPU 0:
  current policy: frequency should be within 800 MHz and 800 MHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.

我尝试直接回显这些值：

echo 2000000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

没有骰子。

该问题发生在 xubuntu 17.04 x86_64 和最新的 Majnaro i686 上，所以我不认为它是特定于发行版的。