Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756824AbZCZUo5 (ORCPT ); Thu, 26 Mar 2009 16:44:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755432AbZCZUos (ORCPT ); Thu, 26 Mar 2009 16:44:48 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:35179 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752222AbZCZUor (ORCPT ); Thu, 26 Mar 2009 16:44:47 -0400 Date: Thu, 26 Mar 2009 20:42:09 +0000 From: Alan Cox To: Matthew Garrett Cc: Linus Torvalds , Theodore Tso , Ingo Molnar , Jan Kara , Andrew Morton , Arjan van de Ven , Peter Zijlstra , Nick Piggin , Jens Axboe , David Rees , Jesper Krogh , Linux Kernel Mailing List , Oleg Nesterov , Roland McGrath Subject: Re: ext3 IO latency measurements (was: Linux 2.6.29) Message-ID: <20090326204209.1da6e791@lxorguk.ukuu.org.uk> In-Reply-To: <20090326200258.GA10313@srcf.ucam.org> References: <20090325235041.GA11024@duck.suse.cz> <20090326090630.GA9369@elte.hu> <20090326113705.GV32307@mit.edu> <20090326140312.GB14822@elte.hu> <20090326144707.GA6239@mit.edu> <20090326170714.GF6239@mit.edu> <20090326185900.166a1097@lxorguk.ukuu.org.uk> <20090326200258.GA10313@srcf.ucam.org> X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 657 Lines: 16 > before performing the update. So while relatime doesn't conform, the > practical difference is meaningless. You can't depend on atime being > updated in a timely manner. POSIX says a disk write interrupted by a signal can be a short write. If you do this in practice all hell breaks loose. A conforming implementation needs to conform with expectations not just play lawyer games with users systems. Alan -- 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/