From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756227AbYEVRPw (ORCPT ); Thu, 22 May 2008 13:15:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753429AbYEVRPm (ORCPT ); Thu, 22 May 2008 13:15:42 -0400 Received: from 82-69-137-158.dsl.in-addr.zen.co.uk ([82.69.137.158]:41869 "EHLO uklogin.uk.level5networks.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752645AbYEVRPl (ORCPT ); Thu, 22 May 2008 13:15:41 -0400 Date: Thu, 22 May 2008 18:15:33 +0100 From: Ben Hutchings To: Jesper Krogh Cc: David Miller , Matheos.Worku@Sun.COM, yhlu.kernel@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: NIU - Sun Neptune 10g - Transmit timed out reset (2.6.24) Message-ID: <20080522171531.GZ28241@solarflare.com> References: <4824CBA1.8040703@sun.com> <4824CCF0.5050302@krogh.cc> <4824D1E1.10007@sun.com> <20080509.154538.28321777.davem@davemloft.net> <4835A007.7020601@krogh.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4835A007.7020601@krogh.cc> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jesper Krogh wrote: > David Miller wrote: > >From: Matheos Worku > >Date: Fri, 09 May 2008 15:36:17 -0700 > > > >>I have observed TX throughput degradation (and increased CPU > >>utilization) occurs with increased # of connections, when CPU count > 4 > >>CPUs. I don't think it is related to the driver (or HW). > > > >All transmits through a device are fully serialized currently, > >it's a known problem and something we plan to fix. > > I google'd up this one: > > http://vger.kernel.org/~davem/davem_tokyo08.pdf (slide 23+). > > Does this mean that I can expect every 10G card to have this limitation > under Linux? Or are some known to be better than others? > (I can probably justify paying for another 10G card if I can expect to > gain the last 400MB/s). [...] Our controller and driver can reach line rate for a single TCP/IPv4 stream, depending on the host system. I don't think we're alone in that, though there are few published benchmarks that don't involve TOEs. Ben. -- Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job.