From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751793AbZHLE3B (ORCPT ); Wed, 12 Aug 2009 00:29:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751362AbZHLE3A (ORCPT ); Wed, 12 Aug 2009 00:29:00 -0400 Received: from casper.infradead.org ([85.118.1.10]:58471 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751258AbZHLE3A (ORCPT ); Wed, 12 Aug 2009 00:29:00 -0400 Date: Tue, 11 Aug 2009 21:31:28 -0700 From: Arjan van de Ven To: Greg KH Cc: David Dillow , Andi Kleen , Greg KH , Alan Cox , linux-kernel@vger.kernel.org, Kay Sievers , Jan Blunck , Harald Hoyer , Scott James Remnant Subject: Re: [PATCH] Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Message-ID: <20090811213128.2f2a3093@infradead.org> In-Reply-To: <20090812003433.GA25392@kroah.com> References: <20090805182805.GA7534@kroah.com> <20090805185136.GA21442@kroah.com> <87ljlxhrnr.fsf@basil.nowhere.org> <1249575658.19886.8.camel@lap75545.ornl.gov> <20090806183147.GA28409@suse.de> <1249772876.22248.34.camel@obelisk.thedillows.org> <20090810153943.GB7652@kroah.com> <1250001374.22248.65.camel@obelisk.thedillows.org> <20090811145523.GD14368@basil.fritz.box> <1250036727.26788.7.camel@obelisk.thedillows.org> <20090812003433.GA25392@kroah.com> Organization: Intel X-Mailer: Claws Mail 3.7.1 (GTK+ 2.14.7; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 11 Aug 2009 17:34:33 -0700 Greg KH wrote: > On Tue, Aug 11, 2009 at 08:25:27PM -0400, David Dillow wrote: > > On Tue, 2009-08-11 at 16:55 +0200, Andi Kleen wrote: > > > > No, not really. It isn't hard to make a static /dev, or a > > > > rescue initrd for the cases with dynamic device numbers. > > > > > > There's a world between strictly controlled embedded and fully > > > general distributions. > > > > Sure, and I've acknowledged that. But it doesn't mean this needs a > > kernel solution. > > > > > I want a dynamic /dev, but a fast one that doesn't need initrd or > > > slows down booting. > > > > So use Eric/Arjan's program that does it in 60ms -- you get a > > dynamic /dev, no initrd, fast boot, and no kernel changes required. > > Their program only handles it for a reconstruction of /dev based on > sysfs one time at boot. It does not handle things that are added or > discovered by the system after that, you need udev for that. > > So it's a great hack for boot time stuff, but not a complete /dev > management replacement yeah you want udev for that anyway for various reasons... (not that udev is expensive per se, the expensive part of it is the exec of modprobe a hundred times... beyond that udev seems pretty cheap to me) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org