From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 449A8C43613 for ; Mon, 24 Jun 2019 04:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14AD6208CA for ; Mon, 24 Jun 2019 04:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727834AbfFXEfA (ORCPT ); Mon, 24 Jun 2019 00:35:00 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:55666 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726812AbfFXEfA (ORCPT ); Mon, 24 Jun 2019 00:35:00 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5O4WOQs060473 for ; Mon, 24 Jun 2019 00:34:59 -0400 Received: from e16.ny.us.ibm.com (e16.ny.us.ibm.com [129.33.205.206]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tag07m2tw-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 24 Jun 2019 00:34:59 -0400 Received: from localhost by e16.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 24 Jun 2019 05:34:53 +0100 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5O4YqoP52494796 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 24 Jun 2019 04:34:52 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C40EFB205F; Mon, 24 Jun 2019 04:34:52 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A2072B2064; Mon, 24 Jun 2019 04:34:52 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.80.233.94]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 24 Jun 2019 04:34:52 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id 9B35016C3305; Sun, 23 Jun 2019 21:34:55 -0700 (PDT) Date: Sun, 23 Jun 2019 21:34:55 -0700 From: "Paul E. McKenney" To: Alan Stern Cc: Akira Yokosawa , Andrea Parri , Boqun Feng , Daniel Lustig , David Howells , Jade Alglave , Luc Maranget , Nicholas Piggin , Peter Zijlstra , Will Deacon , Herbert Xu , Kernel development list Subject: Re: [PATCH 3/3] tools: memory-model: Improve data-race detection Reply-To: paulmck@linux.ibm.com References: <91a9c6f8-7bbf-376d-b1e0-0e2693c84ee8@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 19062404-0072-0000-0000-0000043FDB4C X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00011318; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000286; SDB=6.01222444; UDB=6.00643227; IPR=6.01003593; MB=3.00027438; MTD=3.00000008; XFM=3.00000015; UTC=2019-06-24 04:34:57 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19062404-0073-0000-0000-00004CAFF662 Message-Id: <20190624043455.GB26519@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-24_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906240037 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jun 23, 2019 at 11:15:06AM -0400, Alan Stern wrote: > On Sun, 23 Jun 2019, Akira Yokosawa wrote: > > > Hi Paul and Alan, > > > > On 2019/06/22 8:54, Paul E. McKenney wrote: > > > On Fri, Jun 21, 2019 at 10:25:23AM -0400, Alan Stern wrote: > > >> On Fri, 21 Jun 2019, Andrea Parri wrote: > > >> > > >>> On Thu, Jun 20, 2019 at 11:55:58AM -0400, Alan Stern wrote: > > >>>> Herbert Xu recently reported a problem concerning RCU and compiler > > >>>> barriers. In the course of discussing the problem, he put forth a > > >>>> litmus test which illustrated a serious defect in the Linux Kernel > > >>>> Memory Model's data-race-detection code. > > > > I was not involved in the mail thread and wondering what the litmus test > > looked like. Some searching of the archive has suggested that Alan presented > > a properly formatted test based on Herbert's idea in [1]. > > > > [1]: https://lore.kernel.org/lkml/Pine.LNX.4.44L0.1906041026570.1731-100000@iolanthe.rowland.org/ > > Yes, that's it. The test is also available at: > > https://github.com/paulmckrcu/litmus/blob/master/manual/plain/C-S-rcunoderef-2.litmus > > Alan > > > If this is the case, adding the link (or message id) in the change > > log would help people see the circumstances, I suppose. > > Paul, can you amend the change log? > > > > I ran herd7 on said litmus test at both "lkmm" and "dev" of -rcu and > > confirmed that this patch fixes the result. > > > > So, > > > > Tested-by: Akira Yokosawa Thank you both! I will apply these changes tomorrow morning, Pacific Time. Thanx, Paul