Ne peut pas utiliser "userspace" cpufreq gouverneur et définir la fréquence cpu

J'essaye de changer la fréquence de cpu sur mon ordinateur portable (fonctionnant sous Linux), et de ne pas avoir de succès.
Voici quelques détails:

# uname -a Linux yoga 3.12.21-gentoo-r1 #4 SMP Thu Jul 10 17:32:31 HKT 2014 x86_64 Intel(R) Core(TM) i5-3317U CPU @ 1.70GHz GenuineIntel GNU/Linux # cpufreq-info cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009 Report errors and bugs to [email protected], please. analyzing CPU 0: driver: intel_pstate CPUs which run at the same hardware frequency: 0 CPUs which need to have their frequency coordinated by software: 0 maximum transition latency: 0.97 ms. hardware limits: 800 MHz - 2.60 GHz available cpufreq governors: performance, powersave current policy: frequency should be within 800 MHz and 2.60 GHz. The governor "powersave" may decide which speed to use within this range. current CPU frequency is 2.42 GHz (asserted by call to hardware). (similar information for cpus 1, 2 and 3) # cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors performance powersave 

J'ai d'abord embedded le gouverneur de l'espace user dans le kernel, mais j'ai aussi essayé de le build en tant que module (avec les mêmes résultats); il a été chargé lors de l'exécution des commands ci-dessus (et je n'ai pas pu find de messages système lors du chargement):

 # lsmod Module Size Used by cpufreq_userspace 1525 0 (some other modules) 

Et voici les commands que j'ai essayées pour changer la fréquence:

 # cpufreq-set -f 800MHz Error setting new values. Common errors: - Do you have proper administration rights? (super-user?) - Is the governor you requested available and modprobed? - Trying to set an invalid policy? - Trying to set a specific frequency, but userspace governor is not available, for example because of hardware which cannot be set to a specific frequency or because the userspace governor isn't loaded? # cpufreq-set -g userspace Error setting new values. Common errors: - Do you have proper administration rights? (super-user?) - Is the governor you requested available and modprobed? - Trying to set an invalid policy? - Trying to set a specific frequency, but userspace governor is not available, for example because of hardware which cannot be set to a specific frequency or because the userspace governor isn't loaded? 

Des idées?

• CentOS conservateur gouverneur, belle erreur