From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761197AbcIWQ5D (ORCPT ); Fri, 23 Sep 2016 12:57:03 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:52268 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761023AbcIWQ47 (ORCPT ); Fri, 23 Sep 2016 12:56:59 -0400 Date: Fri, 23 Sep 2016 18:56:32 +0200 From: Andreas Herrmann To: "Rafael J. Wysocki" , Viresh Kumar Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Stratos Karafotis , Thomas Renninger Subject: [PATCH v2 0/2] cpufreq: pcc-cpufreq: Re-introduce deadband effect to reduce number of frequency changes Message-ID: <20160923165632.GA9786@suselix.suse.de> References: <20160819121814.GA17296@suselix.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160819121814.GA17296@suselix.suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, following patches address the performance degradation due to commit 6393d6a102 (cpufreq: ondemand: Eliminate the deadband effect) on systems using pcc-cpufreq driver and ondemand governor. Patch 1 introduces a generic_map_load_to_freq function which is similar to what is used since commit 6393d6a102 (cpufreq: ondemand: Eliminate the deadband effect) to calculate freq_next in od_update. Patch 2 provides a specific function for pcc-cpufreq driver which falls back to the calculation that was in the used before commit 6393d6a102. I've also tested a pcc-specific function without deadband effect but using only 10 frequency values. That was suboptimal in comparison to patch 2. Here the performance data for this comparison (kernel compilation with different number of jobs): pcc specific map_load_to_freq pcc specific map_load_to_freq function (with deadband) function (10 frequency steps) # of jobs user sys elapsed % CPU user sys elapsed % CPU 2 413.19 102.34 250.97 205.00 426.21 106.32 260.00 204.00 4 390.56 120.79 127.25 401.20 408.38 124.03 132.63 401.00 8 354.22 140.09 64.20 769.60 383.33 146.31 68.70 770.40 16 384.20 148.69 37.07 1436.60 466.20 164.18 43.30 1455.00 32 496.70 152.77 25.15 2581.40 658.50 179.74 31.27 2680.60 64 399.48 49.13 12.80 3505.80 404.27 51.24 13.14 3467.00 120 406.52 46.89 13.60 3331.60 409.42 48.71 13.58 3371.40 Regards, Andreas