From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] sch_htb: ix the deficit overflows Date: Wed, 2 Dec 2009 10:32:04 +0000 Message-ID: <20091202103204.GA7724@ff.dom.local> References: <20091128000401.GA3713@ami.dom.local> <412e6f7f0911292026w704a70b8yc3af2c2473e05d34@mail.gmail.com> <20091130111020.GA7114@ff.dom.local> <20091202.012017.39623676.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: xiaosuo@gmail.com, hadi@cyberus.ca, netdev@vger.kernel.org, martin.devera@cdi.cz To: David Miller Return-path: Received: from mail-bw0-f227.google.com ([209.85.218.227]:62616 "EHLO mail-bw0-f227.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751278AbZLBKcG (ORCPT ); Wed, 2 Dec 2009 05:32:06 -0500 Received: by bwz27 with SMTP id 27so41264bwz.21 for ; Wed, 02 Dec 2009 02:32:10 -0800 (PST) Content-Disposition: inline In-Reply-To: <20091202.012017.39623676.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Dec 02, 2009 at 01:20:17AM -0800, David Miller wrote: > From: Jarek Poplawski > Date: Mon, 30 Nov 2009 11:10:20 +0000 > > > On Mon, Nov 30, 2009 at 12:26:33PM +0800, Changli Gao wrote: > >> And > >> if we use IMQ to shape traffic, the skb will be defragmented by > >> conntrack, and its size will be larger than MTU. > > > > IMQ is a very nice thing, but it's considered broken as well, so it > > can't be the reason for changing HTB. > > If you don't like IMQ, fine. Simply consider TSO and GSO as another > set of mechanisms that can introduce this condition. > > Because we toss large SKBs all over the strack quite freely, > protections like those suggested by Changli make perfect sense. > > We really don't have an MTU for packets within our stack any more. > The code, by default, need to be able to handle anything. Alas, an MTU is still a crucial parameter for some schedulers. Anyway, I hope Changli wasn't mislead to treat my private opinions in this or any other thread as decisive. Otherwise, I'm sorry. Jarek P.