From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 488766B0085 for ; Sun, 7 Nov 2010 07:08:34 -0500 (EST) Message-ID: <4CD696B4.6070002@kernel.dk> Date: Sun, 07 Nov 2010 13:08:20 +0100 From: Jens Axboe MIME-Version: 1.0 Subject: Re: 2.6.36 io bring the system to its knees References: <20101105014334.GF13830@dastard> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: dave b Cc: Sanjoy Mahajan , Dave Chinner , Jesper Juhl , Chris Mason , Ingo Molnar , Pekka Enberg , Aidar Kultayev , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Linus Torvalds , Andrew Morton , Peter Zijlstra , Nick Piggin , Arjan van de Ven , Thomas Gleixner , Ted Ts'o , Corrado Zoccolo , Shaohua Li , Steven Barrett List-ID: On 2010-11-06 15:10, dave b wrote: > I now personally have thought that this problem is the kernel not > keeping track of reads vs writers properly or not providing enough > time to reading processes as writing ones which look like they are > blocking the system.... > > If you want to do a simple test do an unlimited dd (or two dd's of a > limited size, say 10gb) and a find / > Tell me how it goes :) ( the system will stall) > (obviously stop the dd after some time :) ). > > http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/4561 > iirc can reproduce this on plain ext3. As already mentioned, ext3 is just not a good choice for this sort of thing. Did you have atimes enabled? -- Jens Axboe -- 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