From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933597Ab3GDDmK (ORCPT ); Wed, 3 Jul 2013 23:42:10 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:51236 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933508Ab3GDDmI (ORCPT ); Wed, 3 Jul 2013 23:42:08 -0400 Message-ID: <51D4EF6C.9040808@gmail.com> Date: Thu, 04 Jul 2013 11:43:40 +0800 From: Light User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Intel_pstate: One Core always 100% C0 state and never scale down Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I am using a laptop with Intel Ivy bridge core i7 3610QM. I updated my kernel to 3.10 and started to use intel_pstate as scaling driver: #cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver intel_pstate However I find that one of my four cores is always in C0 state even when there is no activities. I monitored it using i7z: Core [core-id] :Actual Freq (Mult.) C0% Halt(C1)% C3 % C6 % C7 % Temp Core 1 [0]: 3288.24 (32.97x) 99.7 0 0 0 0 83 Core 2 [1]: 3138.62 (31.47x) 1 0 0 0 99.7 74 Core 3 [2]: 3175.46 (31.84x) 1 0.891 0 0 99 76 Core 4 [3]: 3177.34 (31.86x) 1 0.21 0 0 99.3 71 Also cpu frequencies never scale down, resulting in very high temp. #cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor powersave It does say powersave, and my cpu is capable of 1.20Ghz to 3.30Ghz I don't know if I misconfigured or misunderstood something. Can someone tell me why? Thanks!