From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752941AbdFNPPz (ORCPT ); Wed, 14 Jun 2017 11:15:55 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38739 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752112AbdFNPPx (ORCPT ); Wed, 14 Jun 2017 11:15:53 -0400 Date: Wed, 14 Jun 2017 08:15:48 -0700 From: "Paul E. McKenney" To: Tejun Heo Cc: jiangshanlai@gmail.com, linux-kernel@vger.kernel.org Subject: Re: WARN_ON_ONCE() in process_one_work()? Reply-To: paulmck@linux.vnet.ibm.com References: <20170501165747.GA993@linux.vnet.ibm.com> <20170501183807.GA7054@linux.vnet.ibm.com> <20170501184402.GB8921@htj.duckdns.org> <20170501185819.GJ3956@linux.vnet.ibm.com> <20170505171159.GA10296@linux.vnet.ibm.com> <20170613205837.GB7359@htj.duckdns.org> <20170613223103.GX3721@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170613223103.GX3721@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17061415-2213-0000-0000-000001DC924E X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007231; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00874701; UDB=6.00435428; IPR=6.00654789; BA=6.00005421; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015823; XFM=3.00000015; UTC=2017-06-14 15:15:50 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17061415-2214-0000-0000-00005680F371 Message-Id: <20170614151548.GA14462@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-14_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1706140257 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 13, 2017 at 03:31:03PM -0700, Paul E. McKenney wrote: > On Tue, Jun 13, 2017 at 04:58:37PM -0400, Tejun Heo wrote: > > Hello, Paul. > > > > On Fri, May 05, 2017 at 10:11:59AM -0700, Paul E. McKenney wrote: > > > Just following up... I have hit this bug a couple of times over the > > > past few days. Anything I can do to help? > > > > My apologies for dropping the ball on this. I've gone over the hot > > plug code in workqueue several times but can't really find how this > > would happen. Can you please apply the following patch and see what > > it says when the problem happens? > > I have fired it up, thank you! > > Last time I saw one failure in 21 hours of test runs, so I have kicked > of 42 one-hour test runs. Will see what happens tomorrow morning, > Pacific Time. And none of the 42 runs resulted in a workqueue splat. I will try again this evening, Pacific Time. Who knows, maybe your diagnostic patch is the fix. ;-) Thanx, Paul