Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763886AbXHEK6t (ORCPT ); Sun, 5 Aug 2007 06:58:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757102AbXHEK6m (ORCPT ); Sun, 5 Aug 2007 06:58:42 -0400 Received: from unthought.net ([212.97.129.88]:3346 "EHLO unthought.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756359AbXHEK6l (ORCPT ); Sun, 5 Aug 2007 06:58:41 -0400 Date: Sun, 5 Aug 2007 12:20:21 +0200 From: Jakob Oestergaard To: Jeff Garzik Cc: Linus Torvalds , Ingo Molnar , Peter Zijlstra , linux-mm@kvack.org, Linux Kernel Mailing List , miklos@szeredi.hu, akpm@linux-foundation.org, neilb@suse.de, dgc@sgi.com, tomoki.sekiyama.qu@hitachi.com, nikita@clusterfs.com, trond.myklebust@fys.uio.no, yingchao.zhou@gmail.com, richard@rsk.demon.co.uk, david@lang.hm Subject: Re: [PATCH 00/23] per device dirty throttling -v8 Message-ID: <20070805102021.GA4246@unthought.net> Mail-Followup-To: Jakob Oestergaard , Jeff Garzik , Linus Torvalds , Ingo Molnar , Peter Zijlstra , linux-mm@kvack.org, Linux Kernel Mailing List , miklos@szeredi.hu, akpm@linux-foundation.org, neilb@suse.de, dgc@sgi.com, tomoki.sekiyama.qu@hitachi.com, nikita@clusterfs.com, trond.myklebust@fys.uio.no, yingchao.zhou@gmail.com, richard@rsk.demon.co.uk, david@lang.hm References: <20070803123712.987126000@chello.nl> <20070804063217.GA25069@elte.hu> <20070804070737.GA940@elte.hu> <20070804103347.GA1956@elte.hu> <20070804163733.GA31001@elte.hu> <46B4C0A8.1000902@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46B4C0A8.1000902@garzik.org> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1481 Lines: 40 On Sat, Aug 04, 2007 at 02:08:40PM -0400, Jeff Garzik wrote: > Linus Torvalds wrote: > >The "relatime" thing that David mentioned might well be very useful, but > >it's probably even less used than "noatime" is. And sadly, I don't really > >see that changing (unless we were to actually change the defaults inside > >the kernel). > > > I actually vote for that. IMO, distros should turn -on- atime updates > when they know its needed. Oh dear. Why not just make ext3 fsync() a no-op while you're at it? Distros can turn it back on if it's needed... Of course I'm not serious, but like atime, fsync() is something one expects to work if it's there. Disabling atime updates or making fsync() a no-op will both result in silent failure which I am sure we can agree is disasterous. Why on earth would you cripple the kernel defaults for ext3 (which is a fine FS for boot/root filesystems), when the *fundamental* problem you really want to solve lie much deeper in the implementation of the filesystem? Noatime doesn't solve the problem, it just makes it "less horrible". If you really need different filesystem performance characteristics, you can switch to another filesystem. There's plenty to choose from. -- / jakob - 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/