From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH] udev: create empty regular files to represent net interfaces Date: Thu, 29 Oct 2009 16:49:35 +0000 Message-ID: <1256834975.2827.63.camel@achroite> References: <20091016214024.GA10091@ldl.fc.hp.com> <20091022063619.GB6321@ldl.fc.hp.com> <20091027205551.GA31963@auslistsprd01.us.dell.com> <20091029131125.GA13809@auslistsprd01.us.dell.com> <20091029142554.GA16869@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Matt Domsch , Kay Sievers , dann frazier , linux-hotplug@vger.kernel.org, Narendra_K@dell.com, netdev@vger.kernel.org, Jordan_Hargrave@dell.com, Charles_Rose@dell.com To: Greg KH Return-path: In-Reply-To: <20091029142554.GA16869@kroah.com> Sender: linux-hotplug-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 2009-10-29 at 07:25 -0700, Greg KH wrote: > On Thu, Oct 29, 2009 at 08:11:25AM -0500, Matt Domsch wrote: > > Netdev team - are you in agreement that having multiple names to > > address the same netdevice is a worthwhile thing to add, to allow a > > variety of naming schemes to exist simultaneously? If not, this wh= ole > > discussion will be moot, and my basic problem, that the ethX naming > > convention is nondeterministic, but we need determinism, remains > > unresolved. >=20 > I'm still totally confused as to why you think this. What is wrong w= ith > what we do today, which is name network devices in a deterministic > manner by their MAC in userspace? That name goes into the kernel, an= d > everyone uses the same name and is happy. >=20 > If you don't like naming by MAC, then pick some other deterministic > naming scheme that works for your hardware and write udev rules for i= t. >=20 > You could easily name them in a way that could keep the lowest number > (eth0) for the lowest PCI id if you so desired and your BIOS guarante= ed > it. >=20 > This way the kernel has only one name, and so does userspace, and > everyone is happy. =EF=BB=BFI thought there was a general trend in udev development to pro= vide default rules that work for almost everyone, so few users/administrator= s need to override or add to them. Compare disks and net devices: 1. Stable kernel device id Disks: block device number =EF=BB=BFNet devices: ifindex 2. Unique identifier (across reboot) Disks: label or UUID (each with limitations) Net devices: (MAC address, subtype) =EF=BB=BF 3. Name assignment mechanism Disks: kernel suggests a name; udev can assign any number =EF=BB=BFNet devices: kernel assigns a single name; udev can override i= t 4. Default name assignment policy Disks: names disk by device path (id), label and UUID =EF=BB=BFNet devices: assigns arbitrary stable names per (MAC address, = subtype) 5. Naming by users Disks: user can identify by any method without having to choose on a system-wide basis Net devices: user must identify by single name; policy can be overridde= n on a system-wide basis I fully understand the technical reasons for differences 3-5, but why should users have to put up with it? Ben. --=20 Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html