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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8771AC433F5 for ; Sat, 5 Feb 2022 16:58:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C6EF96B009A; Sat, 5 Feb 2022 11:58:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C1E4D6B009B; Sat, 5 Feb 2022 11:58:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ABE326B009C; Sat, 5 Feb 2022 11:58:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0142.hostedemail.com [216.40.44.142]) by kanga.kvack.org (Postfix) with ESMTP id 9D15A6B009A for ; Sat, 5 Feb 2022 11:58:49 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 482DD181B5EA7 for ; Sat, 5 Feb 2022 16:58:49 +0000 (UTC) X-FDA: 79109335578.16.04CD6DB Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf05.hostedemail.com (Postfix) with ESMTP id 924A9100002 for ; Sat, 5 Feb 2022 16:58:48 +0000 (UTC) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 2158uUVV015025; Sat, 5 Feb 2022 08:58:38 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=facebook; bh=s2vIlAN/7DsTxLiP+mwrPc0mOmUin6NW3bRsxKydZ4M=; b=Ulk3+gg4Y+T4cbmvtkS4IYNUbhPTxGTXWU13ShGYoC4lNRfVyidgORBSIwJDocDobYnA 972k/Aee33geuclOFOMlweyQHKrq9+7Ren3J6fKkvd24P//SKFRs6QhbMwKL0q9y9s/t m+Ax2ZglKB0jzuwjZBBjUEdsXNcfQrHenuQ= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3e1p5m1k0w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Sat, 05 Feb 2022 08:58:38 -0800 Received: from NAM10-DM6-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.36.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 5 Feb 2022 08:58:37 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=gMy3ltpeTCz/aQHOmSIX4yk743lpFTCGQTHPCNFmzI/cCT8GnS2XU7vf10U7mNYuorS73LEo/8xYHuzYOQaChAPqD3cSydgvAj110xsFs7G4LTwMeu+YUuk0dJxfPQeQRTEPueP01/ft4ub4X5ErfYHW3/3e5XQUKzuSYes7YZihuOVHWHj0WWUm5ISMSlPTZG4G5O7R9LYQN26/ysvHnEmdfLqRxXCz/BPaoR8rHawm1ZShH3fDpzcKzsAQruZO42Rvrd/I/pjt3ejLH2oegSrybvKL3aktxil+u2kCDoZdyOMm6Qi5tU5BGJMKCN0V7kqX/eVpeYwrA+JRP2nS+A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=s2vIlAN/7DsTxLiP+mwrPc0mOmUin6NW3bRsxKydZ4M=; b=c3I9gU4H1eU+svRVuymp2UX85exajj3p4pLGfdeY6CfbsFThzlQYlLWgLqfzCQePf25GarL4Fgek2IuAxjVbF4go94alPVqTAIx17IrEOKFnQSGD0SKE62nvzKMz03fV8LKRzhScZlvPHsgtGjpYwjDplmZNcxl/HyQed1Fi62mCqyXq8PztWuNh1XFgPvdFPfwZrQmEWonGSE9UcfO3XkWoMG02j+B810Wxj4vuvDSf/j5uhEI7XIYj733r2JyRY+wDk1vwPo6iKvfl82jqWlf+XLXZS8WG6AUqaSFUdAPlroLefBv9n0OO+mXBbHw8zkGwYkdQpOEADTq3LPw1/A== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none Received: from BYAPR15MB4136.namprd15.prod.outlook.com (2603:10b6:a03:96::24) by SN7PR15MB4240.namprd15.prod.outlook.com (2603:10b6:806:109::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.17; Sat, 5 Feb 2022 16:58:31 +0000 Received: from BYAPR15MB4136.namprd15.prod.outlook.com ([fe80::d4ac:5796:5198:ecd2]) by BYAPR15MB4136.namprd15.prod.outlook.com ([fe80::d4ac:5796:5198:ecd2%3]) with mapi id 15.20.4930.022; Sat, 5 Feb 2022 16:58:31 +0000 Date: Sat, 5 Feb 2022 08:58:26 -0800 From: Roman Gushchin To: Andrew Morton CC: , , Alexander Egorenkov , Waiman Long , Tejun Heo , Johannes Weiner , Shakeel Butt , Jeremy Linton , Subject: Re: [PATCH RESEND] mm: memcg: synchronize objcg lists with a dedicated spinlock Message-ID: References: <20220203151912.87d47b82c1bc3f0d56be0e3a@linux-foundation.org> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20220203151912.87d47b82c1bc3f0d56be0e3a@linux-foundation.org> X-ClientProxiedBy: MWHPR12CA0030.namprd12.prod.outlook.com (2603:10b6:301:2::16) To BYAPR15MB4136.namprd15.prod.outlook.com (2603:10b6:a03:96::24) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 8fda6154-e4c6-43a2-ab15-08d9e8c8bcc2 X-MS-TrafficTypeDiagnostic: SN7PR15MB4240:EE_ X-Microsoft-Antispam-PRVS: X-FB-Source: Internal X-MS-Oob-TLC-OOBClassifiers: OLM:6430; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR15MB4136.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(366004)(316002)(4744005)(52116002)(6506007)(83380400001)(6512007)(186003)(7416002)(9686003)(6916009)(86362001)(6666004)(5660300002)(2906002)(66556008)(508600001)(4326008)(8936002)(8676002)(54906003)(66476007)(6486002)(38100700002)(66946007)(67856001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?AARTkhwWiLD7xCiMPZRdrGbGhX9RbiwDudIWPwxhOv9OOLvsXHfKMMszV5Bw?= =?us-ascii?Q?rv9yi7SWNqlhS6gZ+9hzBR42egnWfVbNwf5jEUCsAO0dzrHxHPvlZN/FNqx9?= =?us-ascii?Q?pwB3oF5i+SZ5Wx1T/CNLVnDahvKEWvaaJLvFow/qiFhRtzvI/qsXU9HsGNDe?= =?us-ascii?Q?mBObpD7rMNb1WT1kZUql9nhzTNOpP9bsH8aPiEkAy43jYKYQqC4A6rJgsaEy?= =?us-ascii?Q?beNRNIfB+711v06/0cGfvT0MDmCwC2vBjkTNPsI2AmLZf+rYiHqvxER1+Xcc?= =?us-ascii?Q?tv/Rrr30hOy86SWn8lmvD/jnrY0GfT0fnuWdDO3TDJtjPczPt7+kdjWnhPCZ?= =?us-ascii?Q?ERUBP+rzsutQ8QZVYbDJ3PMalg3JtcqfZ3N8KYGLBcoIb9koFDW5EYBWj5Gr?= =?us-ascii?Q?Eg6vS6K7d8qH65En/phSwHqliJj2UdfsgYISzh3MsyschMuUvrPzsUiRShJL?= =?us-ascii?Q?SrLg86K3jXmxdEZWOfnF66epdCfwHNSlOUSlD3BlG6MrxqfMfO1E4Jx1MbQf?= =?us-ascii?Q?+2FbD/ISMj/BAKvLdOuYA5o5Ahg04+zq+DzFxrYSzs/rr1bTY/AL0xMR/VhI?= =?us-ascii?Q?oZVAtIHSZL49XBP3I1ofYf4ie9U39rmx7Pr0KBN2TEcdjk4RblnMrnd7uL0l?= =?us-ascii?Q?I6p2zB+6+XOyeBh2g905i66kLokEaledN5nrijbvaQMwgswbMMt2khvZRAk2?= =?us-ascii?Q?Wk5WVIGTJV0VlewgfHyHUXboHS2ztm8llOzrjOrbJOuaetjd47d8tvysc95M?= =?us-ascii?Q?rU0wmv1wlfFbp0dt8sKY2HmkN/K9wi5hj+2LZy8Grt4+qvEppoEYRNWItku5?= =?us-ascii?Q?9r6JvmUli3PfznpFSvkbfLNjLSB7PBjNVM6em049dDylkF7MPnRKiYHJjWHE?= =?us-ascii?Q?vNyW3XooXG3W/3BKEQzItGJ9+FX8CVkZwkxBc36V9CwRt0S986Nn81OzpgG7?= =?us-ascii?Q?Ohvv8Z7ob71Bh1e5yr4QQs17M+iXXZdy62km62DH3i8OaAKYXJNdBBqOSuzl?= =?us-ascii?Q?tGK22XaG5TUrpU2PA8V+uk+6gQR3U4ibTfXl3kigUUTQxHcLcsq3RBWTpFMI?= =?us-ascii?Q?iAeErW+T/ERFSgnUQfuXuivFWaZNppFMXUYGsrS64xOfitMBvYRiwsG7aYWf?= =?us-ascii?Q?JIaOuXgRCPY9OUy+GkP+rpX29kD6RUHBSlE2S9HdGsoEnjMcoziWKarKF0a6?= =?us-ascii?Q?Hr4KmABXy+4s/BGodAwzhjCDAUYMdjzgNyMtfaVEqQkG8YdQh1fpjgu45RGm?= =?us-ascii?Q?WmP7LlwGtK5c0jYznA2w4ZnUt4pAoO8De4qG31Oi/dXsG8wEWxWldRmK5U36?= =?us-ascii?Q?Ne8lH4TmeUQ8so8X3jwKSyGnBf5pHe+SeqGSPSAtJiFND+ShKYREl9fvAsDB?= =?us-ascii?Q?02OrYMKFOzpu49Vrz6elYJfXJeyQeCmYGaB2T2jx6NwkiY0dkisNFM1GA29I?= =?us-ascii?Q?H7s2n9nKc5nEfSjQQDTs446sPl1F7McYUnicaxX86fZMAxItkLUSOO7GXw7h?= =?us-ascii?Q?HmU3W51YODRPHSbqLoY2k7bvnYWrz1G1nnyi5896f4Bcx0GMaMK8dNaLDxBI?= =?us-ascii?Q?UvmJUKJjxVy+WE9G0gcRqpEqJVOx1RbRLkEPEK/Z?= X-MS-Exchange-CrossTenant-Network-Message-Id: 8fda6154-e4c6-43a2-ab15-08d9e8c8bcc2 X-MS-Exchange-CrossTenant-AuthSource: BYAPR15MB4136.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Feb 2022 16:58:30.9957 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: jS+3StTmYWeOIKv+iaKzU6/ZnxYycOAC2lBNPPhaCETS+70UMIKvgWHn3JvAnwMo X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR15MB4240 X-OriginatorOrg: fb.com X-Proofpoint-GUID: zH9xBOVOWo2rPp56TisqnTSQWTn5aar0 X-Proofpoint-ORIG-GUID: zH9xBOVOWo2rPp56TisqnTSQWTn5aar0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-02-05_12,2022-02-03_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=fb_outbound_notspam policy=fb_outbound score=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 mlxscore=0 mlxlogscore=494 impostorscore=0 spamscore=0 clxscore=1015 adultscore=0 phishscore=0 malwarescore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2202050114 X-FB-Internal: deliver Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=fb.com header.s=facebook header.b=Ulk3+gg4; spf=pass (imf05.hostedemail.com: domain of "prvs=3035ab2c82=guro@fb.com" designates 67.231.145.42 as permitted sender) smtp.mailfrom="prvs=3035ab2c82=guro@fb.com"; dmarc=pass (policy=reject) header.from=fb.com X-Rspam-User: nil X-Rspamd-Queue-Id: 924A9100002 X-Stat-Signature: 4m3otg1fgr9rary8pr7y6cm1id7kotr5 X-Rspamd-Server: rspam12 X-HE-Tag: 1644080328-419493 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Feb 03, 2022 at 03:19:12PM -0800, Andrew Morton wrote: > On Tue, 1 Feb 2022 14:33:04 -0800 Roman Gushchin wrote: > > > Alexander reported a circular lock dependency revealed by the mmap1 > > ltp test: > > LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1)) > > > > ... > > > > Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") > > I'm thinking it needs cc:stable. It sounds unlikely that we'll hit it > in real life, but lockdep splats are concerning and I expect downstream > kernel consumers will end up merging this anyway, for this reason. > I agree. I'm somewhat surprised that we haven't seen any such warnings until recently, so I guess some recent kmem accounting change made it more probable. Anyway, it feels like it's a low risk change and I see no reasons to not backport it to stable. Thank you!