From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753059Ab2BTBqO (ORCPT ); Sun, 19 Feb 2012 20:46:14 -0500 Received: from mga11.intel.com ([192.55.52.93]:63459 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751917Ab2BTBqM (ORCPT ); Sun, 19 Feb 2012 20:46:12 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="127239063" Subject: Re: TCP_STREAM performance regression on commit b3613118 From: "Alex,Shi" To: David Miller Cc: eric.dumazet@gmail.com, linux-kernel@vger.kernel.org, tim.c.chen@intel.com, ying.huang@intel.com, netdev@vger.kernel.org In-Reply-To: <20120217.133327.1178765872497293871.davem@davemloft.net> References: <1329466694.12669.2976.camel@debian> <1329472239.2861.3.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <20120217.133327.1178765872497293871.davem@davemloft.net> Content-Type: text/plain; charset="UTF-8" Date: Mon, 20 Feb 2012 09:44:13 +0800 Message-ID: <1329702253.14084.22.camel@debian> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2012-02-17 at 13:33 -0500, David Miller wrote: > From: Eric Dumazet > Date: Fri, 17 Feb 2012 10:50:39 +0100 > > > Le vendredi 17 février 2012 à 16:18 +0800, Alex,Shi a écrit : > >> The tcp_stream loop back performance has about 10% drop on the > >> commitment on our core2 2 sockets server. This commit has 2 > >> parents(7505afe28, 5983fe), but both of them have no regression. So > >> guess the impact just happened when this 2 parents joint. That beyond > >> our capability to dig it more. > >> > >> Any ideas? > > > > Most probably the more accurate truesize determination is responsible of > > this tcp regression, since some prior assumptions might be wrong. > > > > Want to give more information on the workload ? > > Is it a 32 or 64 bit kernel ? It is 64 bit kernel. Currently we only care 64bit. Will try to bring more statistic after our lab recovered. > > And let's start CC:'ing netdev too.