From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755566Ab2J1XXv (ORCPT ); Sun, 28 Oct 2012 19:23:51 -0400 Received: from hibox-130.abo.fi ([130.232.216.130]:43953 "EHLO centre.hibox.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754108Ab2J1XXu (ORCPT ); Sun, 28 Oct 2012 19:23:50 -0400 X-Greylist: delayed 2635 seconds by postgrey-1.27 at vger.kernel.org; Sun, 28 Oct 2012 19:23:50 EDT Message-ID: <508DB432.2030208@hibox.fi> Date: Mon, 29 Oct 2012 00:39:46 +0200 From: Marcus Sundman User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121017 Thunderbird/16.0.1 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Debugging system freezes on filesystem writes Content-Type: text/plain; charset=UTF-8; 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 Hi, I have a big problem with the system freezing and would appreciate any help on debugging this and pinpointing where exactly the problem is, so it could be fixed. So, whenever I write to the disk the system comes to a crawl or freezes altogether. This happens even when the writing processes are running on nice '19' and ionice 'idle'. (E.g. a 10 second compile could freeze the system for several minutes, rendering the computer pretty much unusable for anything interesting.) Here you can see a 20 second gap even in superhigh priority: # nice -n -20 ionice -c1 iostat -t -m -d -x 1 > http://pastebin.com/j5qnh2VV I'm currently running 3.5.0-17-lowlatency on the ZenBook UX31E, using the NOOP I/O scheduler on the SanDisk SSD U100. The chipset seems to be Intel QS67. I've had this same problem on 3.2.0 generic and lowlatency kernels. The syslog says nothing relevant before/during/after these freezes. Any ideas on finding the culprit? Regards, Marcus