From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Subject: Re: [PATCH 0/2] NET: Accurate packet scheduling for ATM/ADSL Date: Wed, 14 Jun 2006 16:32:29 +0100 Message-ID: <44902C0D.1010709@andyfurniss.entadsl.com> References: <1150278004.26181.35.camel@localhost.localdomain> <1150286766.5233.15.camel@jzny2> Reply-To: lists@andyfurniss.entadsl.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Jesper Dangaard Brouer , hawk@diku.dk, russell-tcatm@stuart.id.au, lartc@mailman.ds9a.nl, netdev@vger.kernel.org, Stephen Hemminger Return-path: Received: from s2.ukfsn.org ([217.158.120.143]:10376 "EHLO mail.ukfsn.org") by vger.kernel.org with ESMTP id S964916AbWFNPby (ORCPT ); Wed, 14 Jun 2006 11:31:54 -0400 To: hadi@cyberus.ca In-Reply-To: <1150286766.5233.15.camel@jzny2> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org jamal wrote: > I have taken linux-kernel off the list. > > Russell's site is inaccessible to me (I actually think this is related > to some DNS issues i may be having) and your masters is too long to > spend 2 minutes and glean it; so heres a question or two for you: > > - Have you tried to do a long-lived session such as a large FTP and > seen how far off the deviation was? That would provide some interesting > data point. > - To be a devil's advocate (and not claim there is no issue), where do > you draw the line with "overhead"? Me and many others have run a smilar hack for years, there is also a userspace project still alive which does the same. The difference is that without it I would need to sacrifice almost half my 288kbit atm/dsl showtime bandwidth to be sure of control. With the modification I can run at 286kbit / 288 and know I will never have jitter worse than the bitrate latency of a mtu packet. The 286 figure was choses to allow a full buffer to drain/ allow for timer innaccuracy etc. On a p200 with tsc, 2.6.12 it's never gone over for me - though talking of timers I notice on my desktop 2.6.16 I gain 2 minutes a day now. Andy.