From owner-freebsd-net@FreeBSD.ORG Fri Feb 17 16:52:46 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 0B1221065673 for ; Fri, 17 Feb 2012 16:52:46 +0000 (UTC) (envelope-from marcel@xcllnt.net) Received: from mail.xcllnt.net (mail.xcllnt.net [70.36.220.4]) by mx1.freebsd.org (Postfix) with ESMTP id 8AA2C8FC08 for ; Fri, 17 Feb 2012 16:52:45 +0000 (UTC) Received: from [172.23.7.53] (natint3.juniper.net [66.129.224.36]) (authenticated bits=0) by mail.xcllnt.net (8.14.5/8.14.5) with ESMTP id q1HGqUdU004318 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Fri, 17 Feb 2012 08:52:43 -0800 (PST) (envelope-from marcel@xcllnt.net) Mime-Version: 1.0 (Apple Message framework v1257) Content-Type: text/plain; charset=us-ascii From: Marcel Moolenaar In-Reply-To: <20120217082342.GA15346@onelab2.iet.unipi.it> Date: Fri, 17 Feb 2012 08:52:31 -0800 Content-Transfer-Encoding: 7bit Message-Id: <54272F2A-28FE-4388-9450-EBFB5F7C26EC@xcllnt.net> References: <338757D1-6B1E-49CF-983F-5D5851066FD3@xcllnt.net> <20120217082342.GA15346@onelab2.iet.unipi.it> To: Luigi Rizzo X-Mailer: Apple Mail (2.1257) 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 16:52:46 -0000 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. FYI, -- Marcel Moolenaar marcel@xcllnt.net