From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 4 May 2001 07:41:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 4 May 2001 07:41:23 -0400 Received: from 13dyn74.delft.casema.net ([212.64.76.74]:34310 "EHLO abraracourcix.bitwizard.nl") by vger.kernel.org with ESMTP id ; Fri, 4 May 2001 07:41:07 -0400 Message-Id: <200105041140.NAA03391@cave.bitwizard.nl> Subject: Re: [PATCH] SMP race in ext2 - metadata corruption. In-Reply-To: from Linus Torvalds at "May 3, 2001 10:21:04 am" To: Linus Torvalds Date: Fri, 4 May 2001 13:40:54 +0200 (MEST) CC: 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 Linus Torvalds wrote: > > On Thu, 3 May 2001, Alan Cox wrote: > > Ditto for some CD based stuff. You burn the important binaries to the front > > of the CD, then at boot dd 64Mb to /dev/null to prime the libraries and > > avoid a lot of seeking during boot up from the CD-ROM. > > > > However I could do that from an initrd before mounting > > Ehh. Doing that would be extremely stupid, and would slow down your boot > and nothing more. Ehhh, Linus, Linearly reading my harddisk goes at 26Mb per second. By analyzing my boot process I determine that 50M of my disk is used during boot. I can then reshuffle my disk to have that 50M of data at the beginning and reading all that into 50M of cache, I can save thousands of 10ms seeks. Boot time would go from several tens of seconds to 2 seconds worth of DISK IO plus several seconds of pure CPU time. This doesn't work if I don't have the memory to cache 50M of disk-blocks. Is this simply: Don't try this then? 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.