Return-path: Received: from mail-yk0-f180.google.com ([209.85.160.180]:54053 "EHLO mail-yk0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbaC2JxD (ORCPT ); Sat, 29 Mar 2014 05:53:03 -0400 Received: by mail-yk0-f180.google.com with SMTP id 19so1609810ykq.25 for ; Sat, 29 Mar 2014 02:53:02 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20140328.214254.1620280677250220442.davem@davemloft.net> References: <20140328.172107.16072208664321602.davem@davemloft.net> <20140328.214254.1620280677250220442.davem@davemloft.net> From: Tom Gundersen Date: Sat, 29 Mar 2014 10:46:02 +0100 Message-ID: (sfid-20140329_105310_172685_A91BAD70) Subject: Re: [PATCH v5 0/4] Provide netdev naming-policy via sysfs To: David Miller Cc: David Herrmann , netdev , Johannes Berg , Linux Wireless List , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sat, Mar 29, 2014 at 2:42 AM, David Miller wrote: > From: Tom Gundersen > Date: Fri, 28 Mar 2014 23:39:57 +0100 > >> You mean coordinate with each other in userspace? If so, I still don't >> see how this can ever be anything else than fragile. It will depend on >> each userspace component actually opting in to whatever scheme we >> devise, and does so correctly. > > Isn't that essentially what dbus is? > > A way for seperate userland components to coordinate their > activities? The protocol is not the problem. The issue is that this information only exists reliably in the kernel, so we need to get it from there somehow. > I just simply don't like all of these ramdom keys getting > added all over the place to guide udev behavior wrt. some > other entity. Well, in this case udev is sort of doing a bit of the kernel's work, and it needs some information from the kernel to do it reliably. Another approach would be for the kernel to just assign predictable interface names to devices to begin with and we would never have to touch them. You have all the information so that would be relatively easy. The issue I see with that is that there are several ways to generate predictable names, and the user may want to chose between them, so this is arguably policy that should not be in the kernel. If you don't think that's a problem, I'd be happy to submit a patch to move all this logic from udev to the kernel, just let me know how you see it. Cheers, Tom