From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753920AbcBOTAE (ORCPT ); Mon, 15 Feb 2016 14:00:04 -0500 Received: from mail-qg0-f43.google.com ([209.85.192.43]:32939 "EHLO mail-qg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752721AbcBOS7O (ORCPT ); Mon, 15 Feb 2016 13:59:14 -0500 Date: Mon, 15 Feb 2016 13:59:12 -0500 From: Tejun Heo To: kernel test robot Cc: lkp@01.org, LKML , Andrew Morton , Chris Mason , Michal Hocko , Ulrich Obergfell , Don Zickus Subject: Re: [lkp] [workqueue] 82607adcf9: BUG: workqueue lockup - pool cpus=0 flags=0x4 nice=0 stuck for 42s! Message-ID: <20160215185912.GJ3965@htj.duckdns.org> References: <87y4ao6qx3.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87y4ao6qx3.fsf@yhuang-dev.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Sun, Feb 14, 2016 at 09:07:04AM +0800, kernel test robot wrote: > FYI, we noticed the below changes on > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > commit 82607adcf9cdf40fb7b5331269780c8f70ec6e35 ("workqueue: implement lockup detector") > > > [ 75.684302] virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver > [ 88.791869] ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 11 > [ 88.795120] virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver > [ 90.789792] BUG: workqueue lockup - pool cpus=0 flags=0x4 nice=0 stuck for 42s! > [ 90.794158] Showing busy workqueues and worker pools: > [ 90.796507] workqueue cgroup_pidlist_destroy: flags=0x0 > [ 90.798976] pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 Was the VM not executing for a long time? I can't think why cgroup_pidlist_destroy would hang for over 40s. Thanks. -- tejun