From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: PATCH: Network Device Naming mechanism and policy Date: Fri, 9 Oct 2009 22:23:08 -0700 Message-ID: <20091010052308.GA12458@kroah.com> References: <20091009140000.GA18765@mock.linuxdev.us.dell.com> <20091009210909.GA9836@auslistsprd01.us.dell.com> <20091009194401.036da080@nehalam> <20091010044056.GA5350@mock.linuxdev.us.dell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephen Hemminger , netdev@vger.kernel.org, linux-hotplug@vger.kernel.org, Narendra_K@dell.com, jordan_hargrave@dell.com To: Matt Domsch Return-path: Content-Disposition: inline In-Reply-To: <20091010044056.GA5350@mock.linuxdev.us.dell.com> Sender: linux-hotplug-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Oct 09, 2009 at 11:40:57PM -0500, Matt Domsch wrote: > The fundamental roadblock to this is that enumeration != naming, > except that it is for network devices, and we keep changing the > enumeration order. No, the hardware changes the enumeration order, it places _no_ guarantees on what order stuff will be found in. So this is not the kernel changing, just to be clear. Again, I have a machine here that likes to reorder PCI devices every 4th or so boot times, and that's fine according to the PCI spec. Yeah, it's a crappy BIOS, but the manufacturer rightly pointed out that it is not in violation of anything. > Today, port naming is completely nondeterministic. If you have but > one NIC, there are few chances to get the name wrong (it'll be eth0). > If you have >1 NIC, chances increase to get it wrong. That is why all distros name network devices based on the only deterministic thing they have today, the MAC address. I still fail to see why you do not like this solution, it is honestly the only way to properly name network devices in a sane manner. All distros also provide a way to easily rename the network devices, to place a specific name on a specific MAC address, so again, this should all be solved already. No matter how badly your BIOS teams mess up the PCI enumeration order :) thanks, greg k-h