From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934161Ab3BTLkJ (ORCPT ); Wed, 20 Feb 2013 06:40:09 -0500 Received: from hibox-130.abo.fi ([130.232.216.130]:56396 "EHLO centre.hibox.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757742Ab3BTLkH (ORCPT ); Wed, 20 Feb 2013 06:40:07 -0500 Message-ID: <5124B613.6040400@hibox.fi> Date: Wed, 20 Feb 2013 13:40:03 +0200 From: Marcus Sundman User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Jan Kara CC: linux-kernel@vger.kernel.org Subject: Re: Debugging system freezes on filesystem writes References: <508DB432.2030208@hibox.fi> <20121101190119.GA27294@quack.suse.cz> <50932DAC.7040702@hibox.fi> <20121107161730.GB23654@quack.suse.cz> <509C4339.2090506@hibox.fi> <509D014B.2080709@hibox.fi> <20121113135159.GA18651@quack.suse.cz> <50A592BA.8050709@hibox.fi> <20121121233021.GA8730@quack.suse.cz> <50B4E6F2.6010000@hibox.fi> <20121205153216.GF5706@quack.suse.cz> <51248C5F.4040606@hibox.fi> In-Reply-To: <51248C5F.4040606@hibox.fi> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam_score: -2.7 X-Spam_bar: -- Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20.02.2013 10:42, Marcus Sundman wrote: > On 05.12.2012 17:32, Jan Kara wrote: >> I see. Maybe you could have something like >> while true; do echo w >/proc/sysrq-trigger; sleep 10; done >> running in the background? > > Sure, but I suspect it'll take until the worst is over before it > manages to load and execute that "echo w". Here is a big run of sysrq-triggering, all while I was uncompressing a big rar file causing the whole system to be utterly unusable. NB: Even with realtime I/O-priority the sysrq couldn't be triggered between 12:41:54 and 12:42:49, as you can see from the dmesg-3.txt file. $ sudo ionice -c 1 su # ionice realtime: prio 4 # while true; do sleep 10; echo w >/proc/sysrq-trigger; done ^C # tail -n +1700 /var/log/syslog >dmesg-3.txt http://sundman.iki.fi/dmesg-3.txt Regards, Marcus