From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [Bug 18632] "INFO: task" dpkg "blocked for more than 120 seconds. Date: Thu, 9 Jun 2011 11:32:17 +0800 Message-ID: <20110609033217.GA10741@localhost> References: <201106082138.p58Lchgj002615@demeter2.kernel.org> <20110608150241.8412a63d.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , linux-fsdevel@vger.kernel.org, "bugzilla-daemon@bugzilla.kernel.org" , daaugusto@gmail.com, kernel-bugzilla@cygnusx-1.org, listposter@gmail.com, justincase@yopmail.com, clopez@igalia.com To: Andrew Morton Return-path: Received: from mga09.intel.com ([134.134.136.24]:2089 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755162Ab1FIDcV (ORCPT ); Wed, 8 Jun 2011 23:32:21 -0400 Content-Disposition: inline In-Reply-To: <20110608150241.8412a63d.akpm@linux-foundation.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, Jun 09, 2011 at 06:02:41AM +0800, Andrew Morton wrote: > (udate by email because bugzilla is broken) > > On Wed, 8 Jun 2011 21:38:43 GMT > bugzilla-daemon@bugzilla.kernel.org wrote: > > > https://bugzilla.kernel.org/show_bug.cgi?id=18632 > > I always get a bit worried when I see dm-crypt involved - it doesn't > seem terribly well-behaved or reliable. > > That being said, some of the other reports here indicate that we are > hitting a sync() livelock, sometimes fsync(). These comments all mention "blocked sync(1) on concurrent heavy writes". Comment #6 From Douglas Augusto Comment #12 From Nathan Grennan Comment #16 From justincase@yopmail.com Comment #23 From Carlos Alberto Lopez Perez Comment #17 From Justin Wheeler is special in that fio is doing read-only IO. Is it updating the mtime and the mtime writes are in turn starved by the higher-priority continuous reads? (or at least the write speed cannot keep up with the new mtime dirties) > A pile of patches from > Wu Fengguang which could/should address these issues is about to hit > the linux-next tree. Some livelock fixes will show up in tomorrow's linux-next tree. As for now the fixes are available here: git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback.git fs-writeback Thanks, Fengguang