From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH REPOST 1/2] NET: Accurate packet scheduling for ATM/ADSL (kernel) Date: Tue, 17 Oct 2006 09:07:24 -0400 Message-ID: <1161090444.5555.13.camel@jzny2> References: <1161041677.6247.1.camel@ras.pc.brisbane.lube> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, David Miller , Patrick McHardy , Jesper Dangaard Brouer Return-path: Received: from mx02.cybersurf.com ([209.197.145.105]:30114 "EHLO mx02.cybersurf.com") by vger.kernel.org with ESMTP id S1750872AbWJQNH1 (ORCPT ); Tue, 17 Oct 2006 09:07:27 -0400 Received: from mail.cyberus.ca ([209.197.145.21]) by mx02.cybersurf.com with esmtp (Exim 4.30) id 1GZofJ-0006R3-40 for netdev@vger.kernel.org; Tue, 17 Oct 2006 09:07:29 -0400 To: Russell Stuart In-Reply-To: <1161041677.6247.1.camel@ras.pc.brisbane.lube> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 2006-17-10 at 09:34 +1000, Russell Stuart wrote: > The Linux traffic's control engine inaccurately calculates > transmission times for packets sent over ADSL links. For > some packet sizes the error rises to over 50%. This occurs > because ADSL uses ATM as its link layer transport, and ATM > transmits packets in fixed sized 53 byte cells. > > This changes the kernel rate table lookup, to be able to lookup > packet transmission times over all ATM links, including ADSL, > with perfect accuracy. The accuracy is dependent on the rate > table that is calculated in userspace by iproute2 command tc. > > A longer presentation of the patch, its rational, what it > does and how to use it can be found here: > http://www.stuart.id.au/russell/files/tc/tc-atm/ > > A earlier version of the patch, and a _detailed_ empirical > investigation of its effects can be found here: > http://www.adsl-optimizer.dk/ > > Signed-off-by: Jesper Dangaard Brouer > Signed-off-by: Russell Stuart ACKed-by: Jamal Hadi Salim When Patrick has his patch ready after this goes in we can revisit. cheers, jamal