From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757900AbZEDQVH (ORCPT ); Mon, 4 May 2009 12:21:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752737AbZEDQUx (ORCPT ); Mon, 4 May 2009 12:20:53 -0400 Received: from gate.in-addr.de ([212.8.193.158]:49552 "EHLO mx.in-addr.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752586AbZEDQUw (ORCPT ); Mon, 4 May 2009 12:20:52 -0400 Date: Mon, 4 May 2009 18:20:11 +0200 From: Lars Marowsky-Bree To: Kay Sievers , Alan Jenkins Cc: Michael Riepe , Alan Cox , Greg KH , Andrew Morton , linux-kernel , Jan Blunck Subject: Re: [PATCH] driver-core: devtmpfs - driver core maintained /dev tmpfs Message-ID: <20090504162011.GO17956@suse.de> References: <20090501061701.GB19234@kroah.com> <20090430234312.a63fa5cf.akpm@linux-foundation.org> <20090501065527.GA19773@kroah.com> <20090501120359.05bacb48@lxorguk.ukuu.org.uk> <20090501141846.4b833700@lxorguk.ukuu.org.uk> <49FC8EE4.6040408@googlemail.com> <9b2b86520905021255t4a4812dcrcbcc32f36acd6039@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Ctuhulu: HASTUR User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2009-05-02T23:47:03, Kay Sievers wrote: > It is not about missing events, it is about the bootstrap step we > would like to avoid. Buffering events, or reading all device > information from sysfs at this stage introduces a hard checkpoint, > where we need to bring a process up process these events and create > nodes for them. Only after that we can start other things in userspace > which depend on a working /dev, and with the kernel populated one, we > can just go ahead. So if udevd was present before the kernel started scanning devices this would not be as much of a problem, would it? (Couldn't udevd trigger the device scan? Could it be started so early as for this not to matter?) And isn't part of the problem that you have a choke point in the dependency graph - namely "/dev working" as a predicate for running certain services/scripts - instead of more fine-grained dependencies for just the devices they need? Regards, Lars -- SuSE Labs, OPS Engineering, Novell, Inc. SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nürnberg) "Experience is the name everyone gives to their mistakes." -- Oscar Wilde