From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: Re: [PATCH] Disable TSO for non standard qdiscs Date: Thu, 31 Jan 2008 19:48:03 +0100 Message-ID: <47A217E3.60309@trash.net> References: <20080131124632.GA25299@basil.nowhere.org> <20080131092327.75b9c369@extreme> <20080131183322.GA4671@one.firstfloor.org> <47A20CDC.5090104@trash.net> <20080131183735.GC4671@one.firstfloor.org> <20080131100846.00934e25@extreme> <20080131185328.GD4671@one.firstfloor.org> <47A211A0.1040502@trash.net> <20080131190125.GE4671@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , netdev@vger.kernel.org To: Andi Kleen Return-path: Received: from stinky.trash.net ([213.144.137.162]:56306 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759696AbYAaSsJ (ORCPT ); Thu, 31 Jan 2008 13:48:09 -0500 In-Reply-To: <20080131190125.GE4671@one.firstfloor.org> Sender: netdev-owner@vger.kernel.org List-ID: Andi Kleen wrote: > On Thu, Jan 31, 2008 at 07:21:20PM +0100, Patrick McHardy wrote: >> Andi Kleen wrote: >>>> Then change TBF to use skb_gso_segment? Be careful, the fact that >>> That doesn't help because it wants to interleave packets >> >from different streams to get everything fair and smooth. The only >>> good way to handle that is to split it up and the simplest way to do >>> this is to just tell TCP to not do GSO in the first place. >> >> Thats not correct, TBF keeps packets strictly ordered unless > > My point was that without TSO different submitters will interleave > their streams (because they compete about the qdisc submission) > and then you end up with a smooth rate over time for all of them. > > If you submit in large chunks only (as TSO does) it will always > be more bursty and that works against the TBF goal. > > For a single submitter you would be correct. The TBF goal is not really fairness among different flows, but I agree, avoiding TSO in the first place seems to make more sense.