From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Heffner Subject: Re: [PATCH] apply cwnd rules to FIN packets with data Date: Mon, 05 Feb 2007 18:02:19 -0500 Message-ID: <45C7B77B.9060506@psc.edu> References: <45C7A87A.5050200@psc.edu> <20070205.145615.92339659.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from mailer2.psc.edu ([128.182.66.106]:59470 "EHLO mailer2.psc.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965017AbXBEXPL (ORCPT ); Mon, 5 Feb 2007 18:15:11 -0500 In-Reply-To: <20070205.145615.92339659.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org David Miller wrote: > From: John Heffner > Date: Mon, 05 Feb 2007 16:58:18 -0500 > >> This is especially important with TSO enabled. Currently, it will send >> a burst of up to 64k at the end of a connection, even when cwnd is much >> smaller than 64k. This patch still lets out empty FIN packets, but does >> not apply the special case to FINs carrying data. > > Good catch John. > > But I think the correct test on skb->len would be to just make > sure that it is <= REAL_MSS. > > What do you think about that? This would match the original intention > of the logic in the pre-TSO days. What was the intention of that logic? Actually, I think it would be better to leave the Nagle test as it was (which is implicitly < real_mss), because there is obviously no point in doing the nagle test when you know there is no more data that will be sent. However, I can't think of any reason why the cwnd test should not apply. -John