From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arjan van de Ven Subject: Re: 2.6.19-rc1: Volanomark slowdown Date: Wed, 08 Nov 2006 16:55:18 +0100 Message-ID: <1163001318.3138.346.camel@laptopd505.fenrus.org> References: <1162924354.10806.172.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, davem@sunset.davemloft.net, kuznet@ms2.inr.ac.ru, netdev@vger.kernel.org Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:45719 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S965932AbWKHPzX (ORCPT ); Wed, 8 Nov 2006 10:55:23 -0500 To: tim.c.chen@linux.intel.com In-Reply-To: <1162924354.10806.172.camel@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 2006-11-07 at 10:32 -0800, Tim Chen wrote: > The patch > > [TCP]: Send ACKs each 2nd received segment > commit: 1ef9696c909060ccdae3ade245ca88692b49285b > http://kernel.org/git/? > p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1ef9696c909060ccdae3ade245ca88692b49285b > > reduced Volanomark benchmark throughput by 10%. > This is because Volanomark sends > short message (<100 bytes) on its TCP > connections. This patch increases the number of ACKs > traffic by 3.5 times. > > By adopting this patch, we assume that with > small segment, having short delay is important > enough that we are willing to reduce bandwidth > with more ACKs. I wonder if it's an option to use low priority QoS fields for these acks (heck I don't even know if ACKs have such fields in their packet) so that they can get dropped if there are more packets then there is bandwidth .... -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org