Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755168AbZIJGxQ (ORCPT ); Thu, 10 Sep 2009 02:53:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754215AbZIJGxP (ORCPT ); Thu, 10 Sep 2009 02:53:15 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:55203 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752920AbZIJGxO (ORCPT ); Thu, 10 Sep 2009 02:53:14 -0400 Date: Thu, 10 Sep 2009 08:53:06 +0200 From: Ingo Molnar To: Serge Belyshev Cc: Con Kolivas , linux-kernel@vger.kernel.org, Peter Zijlstra , Mike Galbraith Subject: Re: Epic regression in throughput since v2.6.23 Message-ID: <20090910065306.GB3920@elte.hu> References: <20090906205952.GA6516@elte.hu> <87hbvdiogq.fsf@depni.sinp.msu.ru> <873a6xdqwq.fsf@depni.sinp.msu.ru> <20090909155223.GA12065@elte.hu> <87my53vo6d.fsf@depni.sinp.msu.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87my53vo6d.fsf@depni.sinp.msu.ru> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1579 Lines: 48 * Serge Belyshev wrote: > Ingo Molnar writes: > > > Thanks! > > > > I think we found the reason for that regression - would you mind > > to re-test with latest -tip, e157986 or later? > > > > If that works for you i'll describe our theory. > > > > Good job -- seems to work, thanks. Regression is still about 3% > though: http://img3.imageshack.us/img3/5335/epicbfstip.png Ok, thanks for the update. The problem is that i've run out of testsystems that can reproduce this. So we need your help to debug this directly ... A good start would be to post the -tip versus BFS "perf stat" measurement results: perf stat --repeat 3 make -j4 bzImage And also the -j8 perf stat result, so that we can see what the difference is between -j4 and -j8. Note: please check out latest tip and do: cd tools/perf/ make -j install To pick up the latest 'perf' tool. In particular the precision of --repeat has been improved recently so you want that binary from -tip even if you measure vanilla .31 or .31 based BFS. Also, it would be nice if you could send me your kernel config - maybe it's some config detail that keeps me from being able to reproduce these results. I havent seen a link to a config in your mails (maybe i missed it - these threads are voluminous). Ingo -- 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/