From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756133AbYESA3i (ORCPT ); Sun, 18 May 2008 20:29:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753662AbYESA31 (ORCPT ); Sun, 18 May 2008 20:29:27 -0400 Received: from BISCAYNE-ONE-STATION.MIT.EDU ([18.7.7.80]:59396 "EHLO biscayne-one-station.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753368AbYESA30 (ORCPT ); Sun, 18 May 2008 20:29:26 -0400 Date: Sun, 18 May 2008 20:28:38 -0400 From: Theodore Tso To: Eric Sandeen , Andrew Morton , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 0/4] (RESEND) ext3[34] barrier changes Message-ID: <20080519002838.GB8335@mit.edu> Mail-Followup-To: Theodore Tso , Eric Sandeen , Andrew Morton , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <482DDA56.6000301@redhat.com> <20080516130545.845a3be9.akpm@linux-foundation.org> <482DF44B.50204@redhat.com> <20080516220315.GB15334@shareable.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080516220315.GB15334@shareable.org> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) X-Spam-Flag: NO X-Spam-Score: 0.00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 16, 2008 at 11:03:15PM +0100, Jamie Lokier wrote: > The MacOS X folks decided that speed is most important for fsync(). > fsync() does not guarantee commit to platter. *But* they added an > fcntl() for applications to request a commit to platter, which SQLite > at least uses. I don't know if MacOS X uses barriers for filesystem > operations. Out of curiosity, exactly *what* semantics did MacOS X give fsync(), then? Did it simply start the process of staging writes to disk, but not wait for the writes to hit the platter before returning? That's basically the equivalent of ext3's barrier=0. - Ted