Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266110AbUFPDo3 (ORCPT ); Tue, 15 Jun 2004 23:44:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266114AbUFPDo3 (ORCPT ); Tue, 15 Jun 2004 23:44:29 -0400 Received: from bhhdoa.org.au ([216.17.101.199]:53521 "EHLO bhhdoa.org.au") by vger.kernel.org with ESMTP id S266110AbUFPDoR (ORCPT ); Tue, 15 Jun 2004 23:44:17 -0400 Message-ID: <1087348945.40cfa0d1c94a3@vds.kolivas.org> Date: Wed, 16 Jun 2004 11:22:25 +1000 From: Con Kolivas To: Nick Piggin Cc: Ingo Molnar , Linux Kernel Mailinglist , Andrew Morton , "Martin J. Bligh" , William Lee Irwin III , Linus Torvalds , markw@osdl.org Subject: Re: [PATCH] Performance regression in 2.6.7-rc3 References: <200406121028.06812.kernel@kolivas.org> <20040615045616.GA2006@elte.hu> <40CFB7B0.5090702@yahoo.com.au> In-Reply-To: <40CFB7B0.5090702@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT User-Agent: Internet Messaging Program (IMP) 3.2.2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1637 Lines: 40 Quoting Nick Piggin : > Ingo Molnar wrote: > >* Con Kolivas wrote: > >>with a little bit of detective work and help from Wli we tracked down that > > >>this patch caused it: > >>[PATCH] sched: improve wakeup-affinity > >> > > > >>A massive increase in idle time was observed and the throughput > >>dropped by 40% Reversing this patch gave these results: > >> > > > >>backsched1: http://khack.osdl.org/stp/293865/ > >>Composite Query Processing Power Throughput Numerical Quantity > >>193.93 145.95 257.67 > >> > >>It may be best to reverse this patch until the regression is better > >>understood. > >agreed. It is weird because Nick said that pgsql was tested with the > >patch - and we applied the patch based on those good results. Nick? > Sigh, yes, Mark did run a test for me, but I think it was dbt2-pgsql. > This one is dbt3-pgsql. Also, his system was a 4 logical CPU Xeon. > > Strangely enough, Mark's setup was showing a fairly large too-much-idle > regression not long ago, while these 8-ways weren't. > > Anyway, Linus has reverted my patch now, which is the right thing to > do. Your sync wakeup change is still in there, so that will hopefully > help bw_pipe scores. The sync wakeup change was worth about 1% detriment to this benchmark which, if offset by significant performance gains elsewhere, is worth tolerating. Con - 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/