From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: AIM9 regression Date: Wed, 24 Sep 2008 12:36:57 -0700 (PDT) Message-ID: <20080924.123657.217162945.davem@davemloft.net> References: <20080924051237.GA6173@gondor.apana.org.au> <20080923.221831.126801015.davem@davemloft.net> <20080924081603.08a5f808@extreme> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: herbert@gondor.apana.org.au, cl@linux-foundation.org, netdev@vger.kernel.org To: shemminger@vyatta.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:38998 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752040AbYIXThI (ORCPT ); Wed, 24 Sep 2008 15:37:08 -0400 In-Reply-To: <20080924081603.08a5f808@extreme> Sender: netdev-owner@vger.kernel.org List-ID: From: Stephen Hemminger Date: Wed, 24 Sep 2008 08:16:03 -0700 > On Tue, 23 Sep 2008 22:18:31 -0700 (PDT) > David Miller wrote: > > > From: Herbert Xu > > Date: Wed, 24 Sep 2008 13:12:37 +0800 > > > > > On Tue, Sep 23, 2008 at 01:14:27PM -0500, Christoph Lameter wrote: > > > > I just dont seem to be able to get 2.6.27 to behave in a speedy way network > > > > wise. Configured out various components (netfilter, etc etc) but I still keep > > > > getting these aim9 result against 2.6.22: > > > > > > Could you please compare this against something less ancient, > > > like 2.6.26 perhaps? > > > > Herbert, this is part of the tbench regression issues. Christoph > > took tbench from 2.6.22 until 2.6.27 and at basically every release > > tbench performance suffered noticably. > > > > Now, he's taking the AIM9 benchmark networking numbers and showing > > that the same exact effect is seen there too. > > > > It really behooves us to start doing something proactive about this > > blindingly obvious set of networking performance regressions through > > the past 6 or so releases instead of barking at the reporters saying > > things like "try this, try that, what's your config" etc. > > > > :-) > > These loopback benchmarks are often more sensitive to scheduler than networking > changes. When it gets to %20, I strong start to doubt that, and this is exactly what's happening here. What is it going to take to actually get someone to start profiling and analyzing this? :-)