From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 5 May 2001 09:53:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 5 May 2001 09:53:24 -0400 Received: from 4dyn183.delft.casema.net ([195.96.105.183]:27404 "EHLO abraracourcix.bitwizard.nl") by vger.kernel.org with ESMTP id ; Sat, 5 May 2001 09:53:21 -0400 Message-Id: <200105051352.PAA14913@cave.bitwizard.nl> Subject: Re: [PATCH] SMP race in ext2 - metadata corruption. In-Reply-To: <200105041820.f44IKec11204@vindaloo.ras.ucalgary.ca> from Richard Gooch at "May 4, 2001 12:20:40 pm" To: Richard Gooch Date: Sat, 5 May 2001 15:52:46 +0200 (MEST) CC: Linus Torvalds , Rogier Wolff , Alan Cox , volodya@mindspring.com, Alexander Viro , Andrea Arcangeli , linux-kernel@vger.kernel.org From: R.E.Wolff@BitWizard.nl (Rogier Wolff) X-Mailer: ELM [version 2.4ME+ PL60 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Richard Gooch wrote: > > - next boot, init(8) checks the file, and if it exists, opens the root > FS block device and reads in each block listed in the file. The > effect is to warm the buffer cache extremely quickly. The head will > move in one direction, grabbing data as it flys by. I expect this > will take around 1 second FYI: Around 1992 or 1993, I rewrote Minix-fsck to do this instead of seeking all over the place. Cut the total time to fsck my filesystem from around 30 to 28 seconds. (remember the days of small filesystems?) That's when I decided that this was NOT an interesting project: there was very little to be gained. The explanation is: A seek over a few tracks isn't much slower than a seek over hundreds of tracks. Almost any "skip" in linear access incurs the average 6ms rotational latency anyway. Roger. -- ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 ** *-- BitWizard writes Linux device drivers for any device you may have! --* * There are old pilots, and there are bold pilots. * There are also old, bald pilots.