CPUpowerが安定して動作しません。

このトピックに関する私の最後の質問の後：'userspace' cpufreqガバナーは使用できず、CPU周波数を設定できません。、カーネルを数回アップグレードした後、別の問題に直面しました。 cpupowerがCPU周波数を安定した方法で表示して設定しないようです。

まず、いくつかの情報は次のとおりです。

# uname -a
Linux yoga 4.0.5-gentoo #3 SMP Tue Jul 21 08:43:04 HKT 2015 x86_64 Intel(R) Core(TM) i5-3317U CPU @ 1.70GHz GenuineIntel GNU/Linux

# cpupower 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: 782 MHz - 1.70 GHz
  available frequency steps: 1.70 GHz, 1.70 GHz, 1.60 GHz, 1.50 GHz, 1.40 GHz, 1.30 GHz, 1.20 GHz, 1.10 GHz, 1000 MHz, 900 MHz, 800 MHz, 782 MHz
  available cpufreq governors: conservative, ondemand, powersave, userspace, performance
  current policy: frequency should be within 782 MHz and 1.70 GHz.
                  The governor "performance" may decide which speed to use
                  within this range.
  current CPU frequency is 1.70 GHz (asserted by call to hardware).
  cpufreq stats: 1.70 GHz:90.12%, 1.70 GHz:0.00%, 1.60 GHz:0.64%, 1.50 GHz:0.00%, 1.40 GHz:0.00%, 1.30 GHz:0.00%, 1.20 GHz:0.00%, 1.10 GHz:0.00%, 1000 MHz:0.00%, 900 MHz:0.00%, 800 MHz:0.00%, 782 MHz:9.25%  (267)
  boost state support:
    Supported: yes
    Active: yes
    2400 MHz max turbo 4 active cores
    2400 MHz max turbo 3 active cores
    2400 MHz max turbo 2 active cores
    2600 MHz max turbo 1 active cores

今奇妙なことは次のとおりです。

# cpupower frequency-info|grep -P "The governor|CPU frequency"
                  The governor "performance" may decide which speed to use
  current CPU frequency is 1.70 GHz (asserted by call to hardware).

# grep MHz /proc/cpuinfo
cpu MHz         : 1701.000
cpu MHz         : 1701.000
cpu MHz         : 1701.000
cpu MHz         : 1701.000

# cpupower frequency-set -f 800
Setting cpu: 0
Setting cpu: 1
Setting cpu: 2
Setting cpu: 3

# cpupower frequency-info|grep -P "The governor|CPU frequency"
                  The governor "userspace" may decide which speed to use
  current CPU frequency is 1.70 GHz (asserted by call to hardware).

# grep MHz /proc/cpuinfo
cpu MHz         : 782.000
cpu MHz         : 782.000
cpu MHz         : 782.000
cpu MHz         : 782.000

# cpupower frequency-set -f 1700
Setting cpu: 0
Setting cpu: 1
Setting cpu: 2
Setting cpu: 3

# cpupower frequency-info|grep -P "The governor|CPU frequency"
                  The governor "userspace" may decide which speed to use
  current CPU frequency is 1.70 GHz (asserted by call to hardware).

# grep MHz /proc/cpuinfo                                      
cpu MHz         : 782.000
cpu MHz         : 782.000
cpu MHz         : 782.000
cpu MHz         : 782.000

# cpupower frequency-set -g performance
Setting cpu: 0
Setting cpu: 1
Setting cpu: 2
Setting cpu: 3

# cpupower frequency-info|grep -P "The governor|CPU frequency"
                  The governor "performance" may decide which speed to use
  current CPU frequency is 1.70 GHz (asserted by call to hardware).

# grep MHz /proc/cpuinfo
cpu MHz         : 1701.000
cpu MHz         : 1701.000
cpu MHz         : 1701.000
cpu MHz         : 1701.000

結論として：

1. 周波数を800に設定すると、cpupowerはこれを782に設定し、まだ1700と言います。（ハードウェアを呼び出して確認済み！）
2. 周波数をもう一度1700に設定すると、cpupowerは何もしません（まだ1700とマークされています）。
3. ガバナーを「パフォーマンス」に設定すると、cpupowerは最終的に周波数を1700に設定します。

CPUPowerを安定して動作させる方法はありますか？それともバグですか？