From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.43) id 1DziaO-0004jW-H3 for garchives@archives.gentoo.org; Mon, 01 Aug 2005 22:16:41 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.4/8.13.4) with SMTP id j71MFlVl013382; Mon, 1 Aug 2005 22:15:47 GMT Received: from perch.kroah.org (mail.kroah.org [69.55.234.183]) by robin.gentoo.org (8.13.4/8.13.4) with ESMTP id j71ME5Z3026434 for ; Mon, 1 Aug 2005 22:14:06 GMT Received: from [192.168.0.10] (c-24-22-115-24.hsd1.or.comcast.net [24.22.115.24]) (authenticated) by perch.kroah.org (8.11.6/8.11.6) with ESMTP id j71MEHw07131 for ; Mon, 1 Aug 2005 15:14:17 -0700 Received: from greg by echidna.kroah.org with local (masqmail 0.2.19) id 1DziXs-0bf-00 for ; Mon, 01 Aug 2005 15:14:04 -0700 Date: Mon, 1 Aug 2005 15:14:04 -0700 From: Greg KH Cc: gentoo-dev@lists.gentoo.org Subject: Re: [gentoo-dev] devfs is dead, let's move on Message-ID: <20050801221403.GA2244@kroah.com> References: <20050706224651.GA19853@kroah.com> <1120745893.11567.42.camel@cgianelloni.nuvox.net> <20050708171252.GD29606@kroah.com> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@gentoo.org Reply-to: gentoo-dev@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050708171252.GD29606@kroah.com> User-Agent: Mutt/1.5.8i X-Archives-Salt: 12665670-d63d-4339-ab44-27305bf62232 X-Archives-Hash: 46ec6e3cdca7282f98fb1114e75e44e1 On Fri, Jul 08, 2005 at 10:12:52AM -0700, Greg KH wrote: > On Thu, Jul 07, 2005 at 10:18:12AM -0400, Chris Gianelloni wrote: > > On Wed, 2005-07-06 at 15:46 -0700, Greg KH wrote: > > > To start with, the 061 version of udev offers a big memory savings if > > > you use the "default" kernel name of a device[3]. If you do that, it does > > > not create a file in its database in /dev/.udevdb/ > > > > So if we were to switch to udev 061 in genkernel, it would shrink memory > > usage in our initrd/initramfs, provided we made everything use the LSB > > device names/nodes, versus the devfs ones, correct? > > Not in the initrd/initramfs, but in the tmpfs partition that udev uses > to create the /dev entries. Well, I guess you could say the > "initrd/initramfs" if that is where udev is mounted on early startup (I > haven't looked at how genkernel does this in a long time, sorry.) > > And yes, the memory savings is there, if we use the LSB names only vs > the devfs name and the symlink like we currently do. > > To see this, look at how much space /dev/.udevdb/ takes up right now > with 062 udev. Then change the following rules in > /etc/udev/rules.d/50-udev.rules with the diff at the end of this email. > Then reboot and look at the size of the /dev/.udevdb/ directory again. > I think you will notice a huge space savings. Ok, 064-r1 version of udev does this for tty and console devices. The old devfs names are now gone. Because of this, and some other config file tweaks, starting udev now only takes .5 seconds on my old, slow laptop, instead of 5 seconds. Hopefully others will also see such an increase. Now to implement the persistent block device names that we showed everyone at OLS... thanks, greg k-h -- gentoo-dev@gentoo.org mailing list