Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760621AbXHEXpN (ORCPT ); Sun, 5 Aug 2007 19:45:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756980AbXHEXpB (ORCPT ); Sun, 5 Aug 2007 19:45:01 -0400 Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:50204 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751463AbXHEXpA (ORCPT ); Sun, 5 Aug 2007 19:45:00 -0400 Date: Mon, 6 Aug 2007 09:43:56 +1000 From: David Chinner To: Jeff Garzik Cc: Jakob Oestergaard , Linus Torvalds , miklos@szeredi.hu, akpm@linux-foundation.org, neilb@suse.de, dgc@sgi.com, tomoki.sekiyama.qu@hitachi.com, Ingo Molnar , Peter Zijlstra , linux-mm@kvack.org, Linux Kernel Mailing List , 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: <20070805234356.GI31489@sgi.com> References: <20070804063217.GA25069@elte.hu> <20070804070737.GA940@elte.hu> <20070804103347.GA1956@elte.hu> <20070804163733.GA31001@elte.hu> <46B4C0A8.1000902@garzik.org> <20070805102021.GA4246@unthought.net> <46B5A996.5060006@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46B5A996.5060006@garzik.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1387 Lines: 45 On Sun, Aug 05, 2007 at 06:42:30AM -0400, Jeff Garzik wrote: > Jakob Oestergaard wrote: > >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 > > No, they are nothing alike, and you are just making yourself look silly > if you compare them. fsync has to do with fundamental guarantees about > data. Hi Jeff - just as a point to note, I think you should check the spec for fsync before stating that: "It is explicitly intended that a null implementation is permitted." and "... fsync() might or might not actually cause data to be written where it is safe from a power failure." http://www.opengroup.org/onlinepubs/009695399/functions/fsync.html So fsync() does not have to provide the fundamental guarantees you think it should. Note - I'm not saying that this is at all sane (it's crazy, IMO), I'm just pointing out that a "nofsync" mount option to avoid fsync overhead is a legal thing to do.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - 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/