From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755554AbYIDHNi (ORCPT ); Thu, 4 Sep 2008 03:13:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751899AbYIDHN2 (ORCPT ); Thu, 4 Sep 2008 03:13:28 -0400 Received: from curtis.curtisfong.org ([66.43.110.51]:45850 "EHLO curtis.curtisfong.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751892AbYIDHN1 (ORCPT ); Thu, 4 Sep 2008 03:13:27 -0400 Message-ID: <48BF8A80.50209@mrv.com> Date: Thu, 04 Sep 2008 00:13:04 -0700 From: nyet User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Frans Meulenbroeks CC: Andrew Morton , Nye Liu , linux-kernel@vger.kernel.org Subject: Re: [PATCH] INITRAMFS: Add option to preserve mtime from INITRAMFS cpio images References: <20080805195232.GA5183@curtisfong.org> <20080903202938.GA9065@curtisfong.org> <20080903152231.6b82d9bf.akpm@linux-foundation.org> <20080903223114.GA9456@mrv.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Frans Meulenbroeks wrote: > 2008/9/4 Nye Liu : > >> On Wed, Sep 03, 2008 at 03:22:31PM -0700, Andrew Morton wrote: >> >>>> From: Nye Liu >>>> >>>> When unpacking the cpio into the initramfs, mtimes are not preserved by >>>> default. This patch adds an INITRAMFS_PRESERVE_MTIME option that allows mtimes >>>> stored in the cpio image to be used when constructing the initramfs. For >>>> embedded applications that run exclusively out of the initramfs, this is >>>> invaluable. >>>> >>> Why is it "invlauable". Please explain this value in full detail - >>> it's the whole reason for merging the patch! >>> >> When building embedded application initramfs images, its nice to know >> when the files were actually created during the build process - that >> makes it easier to see what files were modified when so we can compare >> the files that are being used on the image with the files used during >> the build process. This might help (for example) to determine if the >> target system has all the updated files you expect to see w/o having to >> check MD5s etc. >> > > Hm. > > "Invaluable" != "nice to know". > > What worries me is that this code is executed at boot time (when > populating the ramfs). > For embedded systems a fast boot time is often important. > I admit that the net effect of this on boot time is marginal (but some > might consider having mtime a marginal benefit), and 100 cents also > make a dollar, so my suggestion would be to either reject this patch > or make it optional (e.g. depending on some debug config flag). > > Best regards, Frans. > An earlier rev patch made it optional. I can resubmit of course.