From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: TSO trimming question Date: Thu, 20 Dec 2007 20:36:58 -0800 (PST) Message-ID: <20071220.203658.19427671.davem@davemloft.net> References: <20071220.035621.147230372.davem@davemloft.net> <476A920D.6020401@psc.edu> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: ilpo.jarvinen@helsinki.fi, netdev@vger.kernel.org, herbert@gondor.apana.org.au To: jheffner@psc.edu Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:35861 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753254AbXLUEg6 convert rfc822-to-8bit (ORCPT ); Thu, 20 Dec 2007 23:36:58 -0500 In-Reply-To: <476A920D.6020401@psc.edu> Sender: netdev-owner@vger.kernel.org List-ID: =46rom: John Heffner Date: Thu, 20 Dec 2007 11:02:21 -0500 > David Miller wrote: > > From: "Ilpo_J=E4rvinen" > > Date: Thu, 20 Dec 2007 13:40:51 +0200 (EET) > >=20 > >> [PATCH] [TCP]: Fix TSO deferring > >> > >> I'd say that most of what tcp_tso_should_defer had in between > >> there was dead code because of this. > >> > >> Signed-off-by: Ilpo J=E4rvinen > >=20 > > Yikes!!!!! > >=20 > > John, we've been living a lie for more than a year. :-/ > >=20 > > On the bright side this explains a lot of small TSO frames I've bee= n > > seeing in traces over the past year but never got a chance to > > investigate. >=20 > Ouch. This fix may improve some benchmarks. >=20 > Re-checking this function was on my list of things to do because I ha= d=20 > also noticed some TSO frames that seemed a bit small. This clearly=20 > explains it. What I'll do for now is I'll put this into net-2.6.25 to let it "cook" for a while. It's an obvious fix but it's enabling code that's effectively been disabled for more than a year so something might turn up that we need to fix.