Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755825Ab0HIIxA (ORCPT ); Mon, 9 Aug 2010 04:53:00 -0400 Received: from www84.your-server.de ([213.133.104.84]:40984 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484Ab0HIIw7 (ORCPT ); Mon, 9 Aug 2010 04:52:59 -0400 Subject: Re: [PATCH] Add quick erase format option From: Stefani Seibold To: David Woodhouse Cc: "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , Artem Bityutskiy , "linux-mtd@lists.infradead.org" , Artem Bityutskiy In-Reply-To: <1281343038.12908.25.camel@localhost> References: <1281342353-18180-1-git-send-email-stefani@seibold.net> <1281343038.12908.25.camel@localhost> Content-Type: text/plain; charset="ISO-8859-15" Date: Mon, 09 Aug 2010 10:52:54 +0200 Message-ID: <1281343974.18398.13.camel@wall-e.seibold.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.2 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1555 Lines: 39 Am Montag, den 09.08.2010, 09:37 +0100 schrieb David Woodhouse: > On Mon, 2010-08-09 at 09:25 +0100, stefani@seibold.net wrote: > > From: Stefani Seibold > > > > This patch add a quick format option which skips erasing of already erased > > flash blocks. This is useful for first time production environments where > > the flash arrived erased. > > > > Signed-off-by: Stefani Seibold > > This scares me, given the lengths we had to go to in JFFS2 to cope with > blocks which *look* like they're erased, but which actually start losing > data as soon as you start writing to them because the erase didn't > complete. > I know the drawback. This is why it is only an option which must be enabled. And in most use cases there is a subsequent ubimkvol, which will fail if the flash is not correct initialized. Flash are normally delivered erased. So this save in our production environment (Nokia Siemens Networks) about 5 minutes per device (256 MB NOR CFI Flash). The old JFFS2 was very fast to install the first time on a flash, it was only a simple mount of the MTD partition. Which the quick format option i have now only a slightly first time installation overhead compared to JFFS2. Without this option the overhead is more than 5 minutes. - Stefani -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/