From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751619AbWDOVST (ORCPT ); Sat, 15 Apr 2006 17:18:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751620AbWDOVST (ORCPT ); Sat, 15 Apr 2006 17:18:19 -0400 Received: from smtp.osdl.org ([65.172.181.4]:32160 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751618AbWDOVSS (ORCPT ); Sat, 15 Apr 2006 17:18:18 -0400 Date: Sat, 15 Apr 2006 14:17:44 -0700 From: Andrew Morton To: "Martin J. Bligh" Cc: linux-kernel@vger.kernel.org, apw@shadowen.org Subject: Re: Clear performance regression on reaim7 in 2.6.15-git6 Message-Id: <20060415141744.042231a8.akpm@osdl.org> In-Reply-To: <4441452F.3060009@google.com> References: <4441452F.3060009@google.com> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Martin J. Bligh" wrote: > > OK, looking back through the perf results, these two graphs clearly show > a perf regression in reaim7 from 2.6.15 to 2.6.16-rc1. We're loosing > over 50% of the performance. > > http://test.kernel.org/abat/perf/reaim.moe.png > http://test.kernel.org/abat/perf/reaim.elm3b67.png Something very bad has allegedly been happening in -mm. It would have been nice to have heard about this problem in that multi-month wwindow there. Does no human look at these numbers? > Drilling down (there's not enough detail on the graphs for releases that > far back), I see it's actually between -git5 and -git6 > > These are both ia-32 NUMA machines, one is an x440, the other is NUMA-Q. The 2.6.15-git5 -> 2.6.15-git6 diff is enormous. I'd assume some bad thing got transferred into mainline then. How does one reproduce this? Which type of filesystem, which command line/config file? Thanks.