From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932385AbcBAUee (ORCPT ); Mon, 1 Feb 2016 15:34:34 -0500 Received: from er-systems.de ([148.251.68.21]:37925 "EHLO er-systems.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753562AbcBAUed (ORCPT ); Mon, 1 Feb 2016 15:34:33 -0500 Date: Mon, 1 Feb 2016 21:34:28 +0100 (CET) From: Thomas Voegtle X-X-Sender: thomas@er-systems.de To: philippe.longepe@intel.com cc: linux-kernel@vger.kernel.org, stephane.gasparini@intel.com, rafael.j.wysocki@intel.com Subject: Performance drop on Baytrail with 4.5-rc2 Message-ID: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII X-Virus-Checker-Version: clamassassin 1.2.4 with clamdscan / ClamAV 0.99/21333/Mon Feb 1 18:36:08 2016 signatures 55. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I have a Celeron J1900 system (Asrock Q1900B-ITX) always running the latest kernel. Since running the 4.5-rc2 kernel I have a performance drop in a ffmpeg benchmark compared to 4.4. Converting a piece of mpeg to mp4 (to /dev/null). 4.1 made the benchmark in 74s, 4.4 in 75s and now the 4.5-rc2 in 80s. As the benchmark is very stable in results I easily could bisest it down to the commit: commit e70eed2b64545ab5c9d2f4d43372d79762f1b985 Author: Philippe Longepe Date: Fri Dec 4 17:40:32 2015 +0100 cpufreq: intel_pstate: Account for non C0 time I can revert this commit on top on 4.5-rc2 (4 of 5 hunks) and then the benchmark is down to 76s. Was this intended to decrease energy consumption? Thomas