From owner-freebsd-net@FreeBSD.ORG Tue Aug 26 19:43:05 2008 Return-Path: Delivered-To: net@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 17A70106567E for ; Tue, 26 Aug 2008 19:43:05 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from proxy.meer.net (proxy.meer.net [64.13.141.13]) by mx1.freebsd.org (Postfix) with ESMTP id D5E228FC19 for ; Tue, 26 Aug 2008 19:43:04 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from mail.meer.net (mail.meer.net [64.13.141.3]) by proxy.meer.net (8.14.2/8.14.2) with ESMTP id m7QJh0Al036787; Tue, 26 Aug 2008 12:43:03 -0700 (PDT) (envelope-from gnn@neville-neil.com) Received: from mail2.meer.net (mail2.meer.net [64.13.141.16]) by mail.meer.net (8.13.3/8.13.3/meer) with ESMTP id m7QJgtH3025388; Tue, 26 Aug 2008 12:42:55 -0700 (PDT) (envelope-from gnn@neville-neil.com) Received: from minion.local.neville-neil.com (209.249.190.254.available.above.net [209.249.190.254] (may be forged)) (authenticated bits=0) by mail2.meer.net (8.14.1/8.14.1) with ESMTP id m7QJgtYP007064; Tue, 26 Aug 2008 12:42:55 -0700 (PDT) (envelope-from gnn@neville-neil.com) Date: Tue, 26 Aug 2008 15:42:54 -0400 Message-ID: From: gnn@FreeBSD.org To: "Bjoern A. Zeeb" In-Reply-To: <20080826144130.S66593@maildrop.int.zabbadoz.net> References: <20080821203519.GA51534@onelab2.iet.unipi.it> <48AE23FF.9070009@FreeBSD.org> <48AF08B7.4090804@FreeBSD.org> <48AF330B.4010802@FreeBSD.org> <20080825190207.GA73478@zibbi.meraka.csir.co.za> <20080825194038.GA75840@zibbi.meraka.csir.co.za> <20080826144130.S66593@maildrop.int.zabbadoz.net> User-Agent: Wanderlust/2.15.5 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?ISO-8859-4?Q?Goj=F2?=) APEL/10.7 Emacs/22.2.50 (i386-apple-darwin9.4.0) MULE/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII X-Canit-CHI2: 0.50 X-Bayes-Prob: 0.5 (Score 0, tokens from: ) X-Spam-Score: 0.10 () [Tag at 5.00] COMBINED_FROM X-CanItPRO-Stream: default X-Canit-Stats-ID: 1353637 - e5d7f640476c X-Scanned-By: CanIt (www . roaringpenguin . com) on 64.13.141.13 Cc: net@FreeBSD.org Subject: Re: Small patch to multicast code... X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Aug 2008 19:43:05 -0000 At Tue, 26 Aug 2008 14:50:33 +0000 (UTC), Bjoern A. Zeeb wrote: > > On Tue, 26 Aug 2008, George V. Neville-Neil wrote: > > Hi, > > > At Mon, 25 Aug 2008 21:40:38 +0200, > > John Hay wrote: > >> > >> I have tried it and it does fix my problem. RIP2 over multicast works > >> again. :-) > > > > Good to hear. I'm waiting on a bit more feedback but I think I'll be > > checking this in soon, with a big comment talking about the > > performance implications etc. > > So wait a second; what was the m_pullup vs. m_dup thing? Has anyone > actually tried that? I mean using a sledgehammer if a mitten would be > enough is kind of .. uhm. You get it. Perhaps I'm confused, I've been off dealing with other issues for a few days, but m_pullup doesn't make a copy of the packet or its fields, only makes sure that it's contiguous in memory. Am I wrong in that? Since the bug is that two pieces of code modify the same data, in ways that interfere, I'm not sure how we can avoid making a copy. It might be nice to limit the copy, but we'd still need two copies, one for the loopback device and one for the real device. Best, George