From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752437AbdLGCR0 (ORCPT ); Wed, 6 Dec 2017 21:17:26 -0500 Received: from mx0b-00010702.pphosted.com ([148.163.158.57]:35384 "EHLO mx0b-00010702.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752194AbdLGCRY (ORCPT ); Wed, 6 Dec 2017 21:17:24 -0500 X-Greylist: delayed 431 seconds by postgrey-1.27 at vger.kernel.org; Wed, 06 Dec 2017 21:17:24 EST References: <20171129175605.GA863@jcartwri.amer.corp.natinst.com> <20171206234622.GZ3326@worktop> User-agent: mu4e 0.9.13; emacs 24.5.50.1 From: Gratian Crisan To: Peter Zijlstra Cc: Julia Cartwright , Thomas Gleixner , Gratian Crisan , linux-kernel@vger.kernel.org, Darren Hart , Ingo Molnar Subject: Re: PI futexes + lock stealing woes In-reply-to: <20171206234622.GZ3326@worktop> Date: Wed, 06 Dec 2017 20:09:28 -0600 Message-ID: <87y3mf8f1j.fsf@ni.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [70.112.162.13] X-ClientProxiedBy: DM3PR12CA0045.namprd12.prod.outlook.com (2603:10b6:0:56::13) To MWHPR0401MB3593.namprd04.prod.outlook.com (2603:10b6:301:78::32) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: a727ab25-3348-470a-3761-08d53d178ee9 X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(5600026)(4604075)(4534020)(4602075)(4627115)(201703031133081)(201702281549075)(2017052603286);SRVR:MWHPR0401MB3593; X-Microsoft-Exchange-Diagnostics: 1;MWHPR0401MB3593;3:jY5KSDbQF57vo6u0Fc6NMFy/28G8Ye2Bofy33bHvhuV+Xuz97ZWTrBOzlkjhujXZVB9N3SAXmkU6v1MznK6P4i+Xr+af9Uu3HKJswXa8Z/Pk3bc/dJktQaOt0GY2nimLWOwYQgA3RKrA/hJqwTVI6jrOociLNvbDjKGENd4+IOF6JfLg4dMglgp7OwMGjQx9QHyls4lOm5knSF2f5GDg5ozb9BtYbDSwOr8jltTRgKLgLIBWHDtaVnaBLZOZK4KL;25:5PaHJCEO2vZm6M+rvvLT0ZT/kRBYUUNx7f/BGSJj87FBDmNGrLu+Yc7JpJ6xM4UVBEYytb8YwBvFeUG/7sqfYyUndFtkfBm4vM6OpmGgeD0z2VknO6o6FZRvGhEb+YCdHz35G6O2Ep7GX3mKwFczV/aXnAwczIYFtkjUnnJOdS5g6tBu1Xofu5sOUBChVYR8k7p6e+TQ63P9Uq0mezKWXoyleZ0ZORq8o2e6oSU1MTndFNGq5QdLiN9M2UDRTbzT0hyJ6exuyTERHsu26wD1dHL8bBIHda5Uy1jxb4f6iK3pvklzaeEG3rPStuph6vfc6sAI/Tu5F1Q5FbRvIbdb+g==;31:qJCUy19EP8bVzWfkCPOQtBlPr9aCfo8lAE9PUzNME1C4A/CuCZStpv9LxoRIJ1qs8fPATIuzDhx6YLw7N/TYmSOFCi9hDEPeudlaUsFi6Mrz28OPVBDzuLnaos6HBUTxaeIZ1C10m5ou2GS/JICtzybgombp045jVCroOAylXVoU/36qsldu/9U4ZXpYGMcjKQBqSGxArfSVz4QVn2ToLdAIi263aEpziYnrdIn7NMU= X-MS-TrafficTypeDiagnostic: MWHPR0401MB3593: X-Microsoft-Exchange-Diagnostics: 1;MWHPR0401MB3593;20: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;4:XbGIjz3ow/k/AeX4hmkB/shiy+4bBWDZ+zXjdw/EtFv7hDuzZlkxcXf/LnyIBa20YGshlj8tfcGJAIedu7o/K13cyOaoJlYSzg2dDleMdAu/Gin5hxVMAz4IDOnZotXHlQ98LpuAG0hMWUy9E5UJXPc4a4SEUrzKOPIHDe7brALAdvW5KjxqeP7+UaF81dXxJyK6ABOLxXJJnUt56ladZRgcPSQ16997PGfBL1Qo6GmMuOd5eabA/H7R4xagrf4OsIwyRe54rjhEhy0pOFCOYw== X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(6040450)(2401047)(8121501046)(5005006)(3231022)(10201501046)(93006095)(93001095)(3002001)(6041248)(20161123564025)(20161123555025)(20161123560025)(20161123562025)(201703131423075)(201702281528075)(201703061421075)(201703061406153)(20161123558100)(6072148)(201708071742011);SRVR:MWHPR0401MB3593;BCL:0;PCL:0;RULEID:(100000803101)(100110400095);SRVR:MWHPR0401MB3593; X-Forefront-PRVS: 05143A8241 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(366004)(346002)(376002)(199004)(189003)(24454002)(4326008)(81166006)(81156014)(48376002)(8676002)(2950100002)(2906002)(6916009)(54906003)(16586007)(229853002)(58126008)(6246003)(50466002)(36756003)(6116002)(3846002)(7736002)(305945005)(6666003)(53936002)(33646002)(105586002)(25786009)(106356001)(8936002)(68736007)(5660300001)(478600001)(101416001)(97736004)(86362001)(52116002)(6496006)(66066001)(47776003)(76176011)(83506002)(51416003)(316002)(6486002)(16526018);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR0401MB3593;H:clockwork;FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; X-Microsoft-Exchange-Diagnostics: =?us-ascii?Q?1;MWHPR0401MB3593;23:mz48TGm4oktRUeJVisE6Bjs+lVvzsq9MbjjffHZ?= =?us-ascii?Q?r3YJolvEmkxKXDzMQi+FLw+Csfy7FeHI56enGaGHuI/V3OlkIBlbhBg+xwBY?= =?us-ascii?Q?MtkEuUajgCRWubPCEqqIsDh33fT/uKr61UNRYgZxyS3jQdeic0IO1A3QCacA?= =?us-ascii?Q?iJGy1HKHpU5Z0b+WzOuStcSdcRKr924i9Y7cSYlSEmZHPjcQ+ZjBp4U0/0nV?= =?us-ascii?Q?/YSMcP586OAey3Z6xDRnAwtwX2uynlR5zwyhUc+PSHYJhf4Wzhfs9R9a9Uwc?= =?us-ascii?Q?I7q3FOS9EFEaOPciqoQ8YIygQB9f0N5Vo/oEStz1wKRVnAx2U5u5ap1PAAd4?= =?us-ascii?Q?7Di9g2yYTGXrkkhwWxUCG/ul556xriFqXv583WUusXwaSrr5wM1l2dgH9rmV?= =?us-ascii?Q?rMYnr47XTUfJz2gDL90LC+bqkfkcl6vKPfX0LtUpv2iG2Z4C1EC1wDXU295Q?= =?us-ascii?Q?8R63W8eXSnTHfDoKGl9P5L8ayR3325+/Zn+pByCVn5KwzpP1HudZ33kNyNb1?= =?us-ascii?Q?RSlzuuStfnctQleG4LezU44C5z2F8yzsjaGp3iUVkR/bvYv7JgfrJw+dr4kk?= =?us-ascii?Q?zrowLBEp6MZMTuxikrbCQj00iagSP7St1Lm/We0OWi717+AgPYG+lN4oHb1S?= =?us-ascii?Q?zjtNJCYvVOTp4y+UygceDYGunaYap4hLTy2xzH/RxxBycByEfaD6OL4FbBIt?= =?us-ascii?Q?9S9eb4ECM3VyxEv24ewvVd6lPPR3glHXRFKi2zqsZow1gutgzuLBXLw7wP2W?= =?us-ascii?Q?7XD2/mFjd6zzN4EqDIhrFWTK1yB6AyPevx3oMEgrFdeh4Tl79Wllow4XcYkp?= =?us-ascii?Q?7eiYItjtAGNA8dTwY0X/XOpucmk0iGBuW/tieEZP2VZt1ZpK6m9DGuQMi4x/?= =?us-ascii?Q?smj+Oth/VnoOTn6Dsc/rkMxxTGOsMdhCMuoEOE6U0tOYBlN7OpCfa2iBVOTg?= =?us-ascii?Q?MjDl8Ee1uQfQsosp5lZxyb2Gt3nnUaw8OFogHCuY94/qHCgjlMMuli7I6P1x?= =?us-ascii?Q?X2VAqkLkXqCfGgjZ1Kcvo9r5O6usahp1BnQi4b7qv6wkxvKG/ylOnBO0knpw?= =?us-ascii?Q?mIAzV5HYXD+VcxvhHFDsZzls5W0rIhCyDytAwCvQlFgCn5VM1ate+CMYpxGS?= =?us-ascii?Q?km9fQqJUzZ4o=3D?= X-Microsoft-Exchange-Diagnostics: 1;MWHPR0401MB3593;6:bI/lQ4gT7hWEA4x3MY/VQhdk6+z3BdN7csIEiY751xkUy8WmHf2LxgeW/ZGgG62tBlU9XIZDsl8/Yy+KcgsFkRbvy9Ia+LjCI87tOAf8ayi8rDNJiwxiwSMg6iW+Nd9fpdMAwRU6Pf7MEA7pGG5wPqLTpxQyPQPvY8zvTpCiaczO5MD5KNb3rsqgjiZvB6mDkwkkwDATEhMGjzMMySAbZCHpP8qUjHqhEvzKr4RxieXOQVVnvZ8VKkaMAdsw+kYcpyX+DFvMIAd2NZwkExlQJtw9jGc0K8l65EG9mKq0KxB/1WXstJ5de/lvGW20xfRUH1aNccgzdCJkgeKrbpvJiBeiRNtFtkTeSkaqrtl9seI=;5:QDqRrBQB/Ua4VdTRE5ZRDp7li7cQI82KtJ13KgAzQ66h6dZYCWfRQG5HUJJWf8RasA1hLHk1eHk2FWIhNXTUjqb+1Np2QkboSKEQIpdCQicigeG1nIVR8u29jmeNYSgvlyDk6YSl3ETbc5B7wjEQAmJg1/et3jhmuJNgis9AFzk=;24:5jz1WGYwjVtzLMTXFWZZZ0Q5LOSk3x9/ElIzFg6IXLqR0edr4a5CFjL8TqFeBGphCPzfoe372aN30GKeEr3a5U4IQrGiWmKLIUD7AQ+2h5g=;7:IgDuse1F3MvxCkt20+jG+Vxd01shihsHJhSMvLkzDtlmrQ5nK0pL3J9fLS49FKKukvDowhOCaIKudQKNs/6KZ4oRzaHrTwmBShI/lMQZDZG/uKkezvL0Yw+OhjcNDyZ/HHrD1QlgaPrbFJXGgU1SRcEQK/QUxXqccb0ipm1soqINnzEt59BAoOG9a/nl6MLbDR7UBQ7n71oOLOHhOrQtKnSmYtXXiVoySEa3kuoiOiSj6b0goySnZ2PDNVMuBKgG SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-OriginatorOrg: ni.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Dec 2017 02:09:32.7734 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: a727ab25-3348-470a-3761-08d53d178ee9 X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 87ba1f9a-44cd-43a6-b008-6fdb45a5204e X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR0401MB3593 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-12-06_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=inbound_policy_notspam policy=inbound_policy score=30 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=30 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1712070030 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: > On Wed, Nov 29, 2017 at 11:56:05AM -0600, Julia Cartwright wrote: > >> fixup_owner() used to have additional seemingly relevant checks in place >> that were removed 73d786bd043eb ("futex: Rework inconsistent >> rt_mutex/futex_q state"). > > *groan*... yes. I completely missed that extra case also applied to > requeue_pi (requeue always did hurt my brain). FWIW I have been testing for about two days now with the fixup_owner() hunk of 73d786bd043eb ("futex: Rework inconsistent rt_mutex/futex_q state") reverted. So far it hasn't hit the race/deadlock. It normally takes around 8 hours to reproduce. I've also tried Julia's msleep() trick for expanding the race window for the last 4 hours or so of testing and it seems to be still going. Thanks, Gratian