Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756472Ab0KJO5V (ORCPT ); Wed, 10 Nov 2010 09:57:21 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:32832 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756208Ab0KJO5U (ORCPT ); Wed, 10 Nov 2010 09:57:20 -0500 Date: Wed, 10 Nov 2010 09:57:12 -0500 From: Christoph Hellwig To: Theodore Tso Cc: Dave Chinner , Linus Torvalds , Jens Axboe , dave b , Sanjoy Mahajan , Jesper Juhl , Chris Mason , Ingo Molnar , Pekka Enberg , Aidar Kultayev , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Peter Zijlstra , Nick Piggin , Arjan van de Ven , Thomas Gleixner , Corrado Zoccolo , Shaohua Li , Steven Barrett Subject: Re: 2.6.36 io bring the system to its knees Message-ID: <20101110145712.GB22073@infradead.org> References: <20101105014334.GF13830@dastard> <4CD696B4.6070002@kernel.dk> <20101110013255.GR2715@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 933 Lines: 12 On Wed, Nov 10, 2010 at 09:33:29AM -0500, Theodore Tso wrote: > The chance that this occurs using data=writeback in ext4 is much less, BTW, because with delayed allocation we delay updating the inode until right before we write the block. I have a plan for changing things so that we write the data blocks *first* and then update the metadata blocks second, which will mean that ext4 data=ordered will go away entirely, and we'll get both the safety and as well as avoiding the forced data page writeouts during journal commits. That's the scheme used by XFS and btrfs in one form or another. Chris also had a patch to implement it for ext3, which unfortunately fell under the floor. -- 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/