Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758587AbZJGHxQ (ORCPT ); Wed, 7 Oct 2009 03:53:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754469AbZJGHxQ (ORCPT ); Wed, 7 Oct 2009 03:53:16 -0400 Received: from smtp.nokia.com ([192.100.122.233]:30773 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753366AbZJGHxP (ORCPT ); Wed, 7 Oct 2009 03:53:15 -0400 Subject: Re: [BISECTED] "conservative" cpufreq governor broken From: Eero Nurkkala Reply-To: ext-eero.nurkkala@nokia.com To: ext Steven Noonan Cc: "linux-kernel@vger.kernel.org" , Thomas Gleixner , Rik van Riel , Venkatesh Pallipadi In-Reply-To: References: <1254814298.31336.63.camel@eenurkka-desktop> <1254825795.31336.204.camel@eenurkka-desktop> <1254832609.31336.290.camel@eenurkka-desktop> <1254893230.30157.28.camel@eenurkka-desktop> Content-Type: text/plain Organization: Nokia Date: Wed, 07 Oct 2009 10:49:38 +0300 Message-Id: <1254901778.30157.62.camel@eenurkka-desktop> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 07 Oct 2009 07:50:46.0654 (UTC) FILETIME=[E138D9E0:01CA4722] X-Nokia-AV: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1808 Lines: 45 On Wed, 2009-10-07 at 09:30 +0200, ext Steven Noonan wrote: > > Okay, wow, I'm a moron. I misread what cpu_idle() was intended to be > for. I thought that cpu_idle() was a function that was periodically > called whenever the CPU had nothing to do, but now I see that it's > actually the main loop. I should really read the code next time. > > I've moved the statistics printout code to the _inside_ of that > infinite loop and retested. I had it print every several hundred > iterations. Here's the results (note the machine was idle the whole > time, except for about the first 10-20 seconds while the machine > booted): > > [ 3.627716] timings[0]: 2250511125 / 3627716116 > [ 6.946216] timings[0]: 4780901366 / 6946213531 > [ 13.355182] timings[0]: 9385417604 / 13355183525 > [ 18.551304] timings[1]: 16300853077 / 18551301189 > [ 21.589039] timings[0]: 15984495433 / 21589037480 > [ 47.152733] timings[1]: 44386121538 / 47152731476 > [ 51.682630] timings[0]: 45713834076 / 51682628295 > [ 79.587359] timings[0]: 73524821916 / 79587356820 > [ 88.630110] timings[1]: 85324277596 / 88630109605 > [ 96.082386] timings[0]: 89691306072 / 96082384539 > Those look good. Well, might as well then go for: /drivers/cpufreq/cpufreq_conservative.c dbs_check_cpu() -> load = 100 * (wall_time - idle_time) / wall_time; <- What is your load? Let assume load is sane, look for (in dbs_check_cpu()) if (load < (dbs_tuners_ins.down_threshold - 10)) { whether it is taken ever...if not, what is your (dbs_tuners_ins.down_threshold - 10) ? - Eero -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/