From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 3D43C6B0087 for ; Wed, 10 Nov 2010 09:57:22 -0500 (EST) Date: Wed, 10 Nov 2010 09:57:12 -0500 From: Christoph Hellwig 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: Sender: owner-linux-mm@kvack.org 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 List-ID: 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org