From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756039AbYEFLS6 (ORCPT ); Tue, 6 May 2008 07:18:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752138AbYEFLSs (ORCPT ); Tue, 6 May 2008 07:18:48 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:36211 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751571AbYEFLSs (ORCPT ); Tue, 6 May 2008 07:18:48 -0400 Date: Tue, 6 May 2008 05:18:31 -0600 From: Matthew Wilcox To: "Zhang, Yanmin" Cc: LKML Subject: Re: AIM7 40% regression with 2.6.26-rc1 Message-ID: <20080506111831.GG19219@parisc-linux.org> References: <1210052904.3453.30.camel@ymzhang> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1210052904.3453.30.camel@ymzhang> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 06, 2008 at 01:48:24PM +0800, Zhang, Yanmin wrote: > Comparing with kernel 2.6.25, ???AIM7 (use tmpfs) has ???more than 40% with 2.6.26-rc1 > on my 8-core stoakley, 16-core tigerton, and Itanium Montecito. Bisect located > below patch. > > 64ac24e738823161693bf791f87adc802cf529ff is first bad commit > commit 64ac24e738823161693bf791f87adc802cf529ff > Author: Matthew Wilcox > Date: Fri Mar 7 21:55:58 2008 -0500 > > Generic semaphore implementation > > > After I manually reverted the patch against 2.6.26-rc1 while fixing lots of > conflictions/errors, aim7 regression became less than 2%. 40%?! That's shocking. Can you tell which semaphore was heavily contended? I have a horrible feeling that it's the BKL. -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."