From owner-freebsd-net@FreeBSD.ORG Fri Feb 17 17:00:40 2012 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 27EDE1065716 for ; Fri, 17 Feb 2012 17:00:40 +0000 (UTC) (envelope-from luigi@onelab2.iet.unipi.it) Received: from onelab2.iet.unipi.it (onelab2.iet.unipi.it [131.114.59.238]) by mx1.freebsd.org (Postfix) with ESMTP id DD0FA8FC18 for ; Fri, 17 Feb 2012 17:00:39 +0000 (UTC) Received: by onelab2.iet.unipi.it (Postfix, from userid 275) id DC44A73027; Fri, 17 Feb 2012 18:18:35 +0100 (CET) Date: Fri, 17 Feb 2012 18:18:35 +0100 From: Luigi Rizzo To: Marcel Moolenaar Message-ID: <20120217171835.GA20283@onelab2.iet.unipi.it> References: <338757D1-6B1E-49CF-983F-5D5851066FD3@xcllnt.net> <20120217082342.GA15346@onelab2.iet.unipi.it> <54272F2A-28FE-4388-9450-EBFB5F7C26EC@xcllnt.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54272F2A-28FE-4388-9450-EBFB5F7C26EC@xcllnt.net> User-Agent: Mutt/1.4.2.3i Cc: net@freebsd.org Subject: Re: Abstracting struct ifnet 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: Fri, 17 Feb 2012 17:00:40 -0000 On Fri, Feb 17, 2012 at 08:52:31AM -0800, Marcel Moolenaar wrote: > > On Feb 17, 2012, at 12:23 AM, Luigi Rizzo wrote: > >> > >> Thoughts, feedback and suggestion are welcome, > > > > I do like the idea, but the amount of changes will be massive > > (see below). The thing that worries me the most is that it > > will introduce huge changes between different releases, unless > > we backport the accessors (while keeping the underlying struct ifnet > > frozen so we preserve the kernel ABI). > > Hi Luigi, > > That's a good point. When we have something to work with on -current > and ideally with only a few drivers changed, we not only have a > hybrid approach in -current, which allows us to stage the work, we > also have the inherent support for backward compatibility. This then > can be put in 9-stable to allow for "the new network" drivers to be > used in a 9-stable code base as well. > > As for the amount of change: yes, it's large. But I think it's a > good investment and an enabler for structural ifnet rework. I definitely agree that it is a good investment, especially considering that I am doing this all the times when i port FreeBSD stuff to linux... The linux version of netmap, which i just completed, was mostly done playing tricks to remap struct ifnet to struct net_device... cheers luigi