From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752932AbaH2Kun (ORCPT ); Fri, 29 Aug 2014 06:50:43 -0400 Received: from e06smtp16.uk.ibm.com ([195.75.94.112]:49047 "EHLO e06smtp16.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752325AbaH2Kul (ORCPT ); Fri, 29 Aug 2014 06:50:41 -0400 Message-ID: <54005AFB.2010604@de.ibm.com> Date: Fri, 29 Aug 2014 12:50:35 +0200 From: Christian Borntraeger User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Tejun Heo CC: linux-kernel@vger.kernel.org, linux-s390 Subject: WARNING: at kernel/workqueue.c:845 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14082910-3548-0000-0000-0000012FABD3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tejun, with kvm/next (pretty close to 3.17-rc1) as KVM guest I get the following warning in one of my stress tests: [ 0.296047] ------------[ cut here ]------------ [ 0.296050] WARNING: at kernel/workqueue.c:809 [ 0.296051] Modules linked in: [ 0.296054] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0-rc1+ #172 [ 0.296056] task: 0000000000934618 ti: 000000000091c000 task.ti: 000000000091c000 [ 0.296062] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3 Krnl GPRS: 0000000000000001 00000000063bed00 0000000000996740 0000000000000000 [ 0.296065] 000000000000000d 000000000000036a ffffffff00000000 0000000000000000 [ 0.296067] 000000000620e400 0000000000001201 0000000000001201 04000000009f6700 [ 0.296068] 000000000639b700 0000000000000000 00000000001453e8 00000000063fbc80 [ 0.296078] Krnl Code: 0000000000145416: 95002000 cli 0(%r2),0 000000000014541a: a774fff4 brc 7,145402 #000000000014541e: a7f40001 brc 15,145420 [ 0.296083] TCP: cubic registered [ 0.296084] >0000000000145422: 92012000 mvi 0(%r2),1 [ 0.296086] 0000000000145426: a7f4ffee brc 15,145402 000000000014542a: 0707 bcr 0,%r7 000000000014542c: ebdff0800024 stmg %r13,%r15,128(%r15) [ 0.296092] Initializing XFRM netlink socket [ 0.296094] 0000000000145432: a7f13fe0 tmll %r15,16352 [ 0.296096] Call Trace: [ 0.296099] ([<0000000000001201>] 0x1201) [ 0.296102] [<00000000001545dc>] ttwu_do_activate.constprop.97+0x64/0x7c [ 0.296103] [<00000000001550ce>] sched_ttwu_pending+0x7e/0xd4 [ 0.296104] [<0000000000156bea>] scheduler_ipi+0x62/0x168 [ 0.296107] [<0000000000113482>] smp_handle_ext_call+0xbe/0xdc [ 0.296111] [<000000000010b3dc>] do_ext_interrupt+0xb4/0xd4 [ 0.296113] [<00000000001833be>] handle_irq_event_percpu+0x76/0x204 [ 0.296115] [<00000000001870e8>] handle_percpu_irq+0x6c/0x98 [ 0.296116] [<0000000000182a02>] generic_handle_irq+0x46/0x68 [ 0.296117] [<000000000010b78a>] do_IRQ+0x5e/0x84 [ 0.296120] [<0000000000634840>] ext_skip+0x42/0x46 [ 0.296121] [<0000000000633fce>] vtime_stop_cpu+0x4a/0x9c [ 0.296122] ([<0000000000000000>] (null)) [ 0.296124] [<0000000000103816>] arch_cpu_idle+0x92/0xa0 [ 0.296126] [<000000000016bb9a>] cpu_startup_entry+0x15a/0x228 [ 0.296127] [<00000000009a5ae4>] start_kernel+0x408/0x418 [ 0.296128] [<0000000000100020>] _stext+0x20/0x80 [ 0.296129] Last Breaking-Event-Address: [ 0.296130] [<000000000014541e>] wq_worker_waking_up+0x5e/0x6c [ 0.296133] ---[ end trace 68915e61d289d806 ]--- [ 0.296137] reboot: Restarting system [ 0.296141] ------------[ cut here ]------------ The test is basically to start 50 KVM guests that only have a kernel + busybox ramdisk with rcS calling reboot. One or two guests of these 50 have thing warning pretty soon. With 3.16 as guest everything runs fine. Do you have any idea what might be wrong or do I need to bisect? Christian