Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934013Ab2JLM55 (ORCPT ); Fri, 12 Oct 2012 08:57:57 -0400 Received: from mail.avalus.com ([89.16.176.221]:59504 "EHLO mail.avalus.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933817Ab2JLM5z (ORCPT ); Fri, 12 Oct 2012 08:57:55 -0400 Date: Fri, 12 Oct 2012 13:57:50 +0100 From: Alex Bligh Reply-To: Alex Bligh To: Alan Cox cc: linux-kernel@vger.kernel.org, Alex Bligh Subject: Re: Local DoS through write heavy I/O on CFQ & Deadline Message-ID: In-Reply-To: <20121011144634.7017e270@pyramind.ukuu.org.uk> References: <0B138F62-16BF-4295-9AD9-64C0BB39FCE2@alex.org.uk> <20121011144634.7017e270@pyramind.ukuu.org.uk> X-Mailer: Mulberry/4.0.8 (Mac OS X) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1036 Lines: 30 Alan, --On 11 October 2012 14:46:34 +0100 Alan Cox wrote: >> We have reproduced this on multiple hardware environments, using 3.2 >> (/proc/version_signature gives "Ubuntu 3.2.0-29.46-generic 3.2.24"). >> Anecdotally we believe the situation has worsened since 3.0. > > I've certainly seen this on 3.0 and 3.2, but do you still see it on > 3.5/6 ? We've just tested this. We see exactly the same issue on 3.6.1 using the current build of the Ubuntu Quantal kernel, which is: Linux version 3.6.1-030601-generic (apw@gomeisa) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #201210071322 SMP Sun Oct 7 17:23:28 UTC 2012 More details (including full logs for that kernel) at: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1064521 -- Alex Bligh -- 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/