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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA64EC77B6C for ; Wed, 12 Apr 2023 23:37:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229792AbjDLXhp (ORCPT ); Wed, 12 Apr 2023 19:37:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229508AbjDLXhn (ORCPT ); Wed, 12 Apr 2023 19:37:43 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEFA71BE4 for ; Wed, 12 Apr 2023 16:37:42 -0700 (PDT) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33CJTCIk031279; Wed, 12 Apr 2023 23:37:27 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=corp-2023-03-30; bh=oXjLXjmbD2NNLHuIhYF9UAWAaQ8eY5zneEMPVLtZ8D4=; b=Br89UcukvjhXLYhbQPLKxe7cgQPY0uizPSQEHz0PkRm8mvzY1A5kYup2LTL9fUI31ZM+ Fukf2niT2D8k8IYSeSGJOxXGcZEwUs5PMzufyVJslAf6zua4xtwlv0AoG3f+zt0SkCQQ zJ6A1s4AGAE67n088ORG7CU6opElQ9oQG/VvdatgEMmC8fdsXBk89M68/Y4S+gk6YLY/ /h+nYBQc1zek5yikGOprr4rAndaMkccriMTotMUj96CInzEc0JgJr7baiLxRWSMUaOky 3FS0qTV8Nvcix+rJVmbB1de8QzEsWxvMexsBKJcnOKa+mO2m6Yhd6IM2cDJZwYDbw2WJ Qg== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3pu0e7hjua-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 12 Apr 2023 23:37:26 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 33CMaPAU039697; Wed, 12 Apr 2023 23:37:25 GMT Received: from nam12-dm6-obe.outbound.protection.outlook.com (mail-dm6nam12lp2174.outbound.protection.outlook.com [104.47.59.174]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3puwbqudyx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 12 Apr 2023 23:37:25 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=YtGmMm0R9DF+7LXimM99XpI3vK4mICfbFQZEpg/LofJdOBRc3UV3nSfMErpiKM4QraBVAb/+O0gLdOYnAyqdZKh4ES8hot6dU7EvV/rXzMOklt6XlXcaFEen3O6fG/rTyR6kzM4KeqN+ZeVbckvszwO9BoiIgw9eKvvCdBAqu8mZu/4ZD3Ij4UVt2jcdf3ORl0U/fBuu0zdS0cdkBrluks0c1JjZp5YpUs/Gd3h3+iXpmPJdr4+lbv19OpwSy0CdnraB5V9ao5eZHEsWPxcaH3xadBt6BVV2bY9wop44iQ6LBVLPQElrO6RH1Gs6joeEoBde2X6MtgGB2zMjivCE3A== 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=oXjLXjmbD2NNLHuIhYF9UAWAaQ8eY5zneEMPVLtZ8D4=; b=RoxHKEu97TTHvVr4Lg1dECpADrlwNYeKD+7zf9ug+jpyK46lAiP4hBYJi3d9G0YzjfHQEBEvr9GmYeNgYYWT4gbogGRzV+iN89AucodtTM74vrqGK1CLOBoafJxJK3Z7GtRT5o0iKOF5UVDah9c/36jLaKT9yDTHAx7ZSKBSxjSdqGdR7/Ivu+AOPbPxHDC/PkYK8Ot/Y+i1aW/F1NzqH3yLt7UNlRzW8FXSzitiETWMNHD8P3X3qeQulSRlMbYaaM84r9ONs5kDej/21/GSwOMFPB5BbszV9IflN8yPdO8i9EdPZfcpxIYd+BncLcRJskWlYtV16M9mVEsy1ZRaRw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=oXjLXjmbD2NNLHuIhYF9UAWAaQ8eY5zneEMPVLtZ8D4=; b=tG5qiIhERBeL81viBnp4F5B8rIHMZ+tTMa41+Axuv0kK+AY+OPIY3Ea3LDlgibAiYEw0eEfRf/WMVLJEQoL3osLIrbK2P547UJ1NKdkuH/s3hOERV9sIY31LfudmyAIIJFMV2TYpDAZ3QL8dY2Ff+QnekGV6LSpgJhc4ZKrwSKs= Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by CH3PR10MB6833.namprd10.prod.outlook.com (2603:10b6:610:150::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6277.31; Wed, 12 Apr 2023 23:37:23 +0000 Received: from BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::ffb:de39:b76b:52eb]) by BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::ffb:de39:b76b:52eb%3]) with mapi id 15.20.6298.030; Wed, 12 Apr 2023 23:37:23 +0000 Date: Wed, 12 Apr 2023 16:37:19 -0700 From: Mike Kravetz To: Andrew Morton , Tony Luck Cc: Liu Shixin , Naoya Horiguchi , Miaohe Lin , Muchun Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -next] mm: hwpoison: support recovery from HugePage copy-on-write faults Message-ID: <20230412233719.GC4759@monkey> References: <20230411092741.780679-1-liushixin2@huawei.com> <20230412181350.GA22818@monkey> <20230412145718.0bcb7dd98112a3010711ad0b@linux-foundation.org> <20230412222138.GB4759@monkey> <20230412155618.720e6b3aa5be6444f7889ea6@linux-foundation.org> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230412155618.720e6b3aa5be6444f7889ea6@linux-foundation.org> X-ClientProxiedBy: MW3PR06CA0002.namprd06.prod.outlook.com (2603:10b6:303:2a::7) To BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BY5PR10MB4196:EE_|CH3PR10MB6833:EE_ X-MS-Office365-Filtering-Correlation-Id: 628fec0c-8eaf-4403-3e09-08db3baedd7f 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:BY5PR10MB4196.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(7916004)(136003)(376002)(366004)(396003)(39860400002)(346002)(451199021)(6486002)(478600001)(8676002)(66476007)(66556008)(54906003)(4326008)(41300700001)(110136005)(66946007)(316002)(86362001)(33656002)(53546011)(6666004)(6512007)(26005)(1076003)(6506007)(83380400001)(2906002)(9686003)(5660300002)(44832011)(8936002)(186003)(33716001)(38100700002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?aEwZfFXGqL6gneCyis5pIK+dWx/cyyjFG2eYvitj4vXeJp5yZSraMm5Pm3rM?= =?us-ascii?Q?gNjfEUlxhkW9A4OV+0phEPTLB5cn+z/6bU2lNGeypaTffEg1WMOeiNX6TRJq?= =?us-ascii?Q?COOBsxwrUci9ON7VQ1ncuPktah2B6oTa6KZmhfEpwTUV400rlI21pGyRuzrG?= =?us-ascii?Q?zLghjDginRWwliYmadaCIUORQlFVf/3FrlbOx1kwN6brVbmxpoQms8+tSHRy?= =?us-ascii?Q?/KhsTEsDQZTaYEUB5HFxLPZkhENAPnSWN781n6lpcpzfe9WiNVVJRUHQlF6e?= =?us-ascii?Q?jZ0E3DBeI5uRK4WAXGYEJ46za41+Xn2rAfxFGojxKrLafAEPKtBeB1t2yRCM?= =?us-ascii?Q?wzMhFZceuLQQqxJQTsXThE8vaW6lnFf1fonwyfKH076JHfSwKiz1wpFXW+zI?= =?us-ascii?Q?ArhON7HwjNrObM5przif40C9UJijyr3Ac8eWiZC6QFq6aochPZ8iISntSJzF?= =?us-ascii?Q?nlsBZUf9RXxCrS7oHpxmujkOo5D+XJMVT8mujIRm2QUPWnmKTPH9j+cO737S?= =?us-ascii?Q?B3IcyMQzBdCmHEbD0A9wTxZMiHHe1JgUi72vYlA2VQeEZIu4jij8KLE98bsb?= =?us-ascii?Q?l2PycPcRKnOHGghmb7MH40yqxZ/RY5v9/Cat41wKvzNoeJu/ZcDuONYG6P0n?= =?us-ascii?Q?k2tzKMRmbVBobwP+FDKHmiEEy4n3n7wHlUY4U3dilt75X9oPcD0Vm/Go/TCp?= =?us-ascii?Q?C/r0nXwH8cMPhbyuu/9sFrNSebGlE49TjEAnZubv/w6i7hXHzuIgJZdnc44/?= =?us-ascii?Q?tbYkIjDRXCeV/3A7BjapP4OAuDzXmRGAXaQK+MPfEoHMvQUf6NVL/nsKDRGk?= =?us-ascii?Q?prxXGcdvKuuxVRy5RVxMIG5Er1XLBdGatWunV9MHFrS8Qe12tdD5W7OVmRmh?= =?us-ascii?Q?xp3tGtJUN7F78u9GlCSODJ04fENki7GVtONkzqGK3sp9ND5/Be5TATP2eEEU?= =?us-ascii?Q?XCNsdmDTHTbt1Ban5ZOFxqUudw8zeeO95Na6upw4ZrdeV25J2HTRIgLUDKGf?= =?us-ascii?Q?r0TbQxutBD2KjXQbVWjjQ0l5ddD/z8l8RnsCOrnFmuERmVCwPQGejumEUGX4?= =?us-ascii?Q?iaQ4y9/U3HNtQJsuqaOLcsheSiQmmdOyC8o4/PWzmol1w+0u2eUWOUH0vNYz?= =?us-ascii?Q?z/pUx25c7jH1amtvv+UPhc+nw2ISmPcc+6I7jEm9ZMwbeelCS4G7v4Hui0lA?= =?us-ascii?Q?FHtJFK2bCsXAJ6iF+Orp7X3m3yIFvxx+OIDbr8NWo7qWwswkH65Aco2PqKfX?= =?us-ascii?Q?/P+cwSOHGo2WN9LFvkNoQXSk0KcZtfw6hTkHevVQTOAi42pTSFUM0jNNnWQu?= =?us-ascii?Q?0JUdm6/X+ivBYZEEARgBtAS0VHlzFLB0CTyT53dHRsYv6TFS115rXkPPk/VF?= =?us-ascii?Q?cORT3h7It/OLWrPhLhVI6U0mlm/pw0PngxP3GZ8bYm9CmA6iRF2WM4FMZ/Wo?= =?us-ascii?Q?pyx2IeOvBObZBcTV3geAJvdjFvkkjG3AYGdzvkv16m29aDZeFyi1etP4UQVy?= =?us-ascii?Q?0zBIlsXLkEltdCYyEaS8uX7Ia8HAjDBTkq1NM8npE9ErMFVaALBll0Pnfu9M?= =?us-ascii?Q?dshrI0xCrwQEX0HuuM+N0TPH/yzw5Gkcl8E1/Nbi?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?us-ascii?Q?NrUpvL0hm4CbvFwHy/HEg3WjnP8tow7bv6NM7nWsSgZ9DEcuviA0w9o5UY2i?= =?us-ascii?Q?GLTZVl9SCSBRgOxmuWrw42bJV60I4yi/Yg+qKKSI7HBbBJ+KTi892yqkiO9X?= =?us-ascii?Q?W5Twc9cnjxF3irTI4s4WA0S8wwi/hgewMs2Y4hBMQPB+HB3POEwytV/9WaYz?= =?us-ascii?Q?F9oiHxHGxgCoZI6F7AASkREPiU/KyCbr3Lh05x8VuQOIpKpnN+ovlVfEOVJy?= =?us-ascii?Q?v9TXqgMXLRyUfl0TOSx3XiWPcTDljNPSb9rqHa4McXKdqMZEHetIdSTyj03m?= =?us-ascii?Q?IBKAeYg27vvwVJhrJYq8EKWmW1QRks5yz4o+S2FXjoy0fkPS7W8+KqN93A9r?= =?us-ascii?Q?f0RkraXTE41o36Wpv+D5s4LSeW7PhFnUmv0ELnP8SmE9SxiHH+Nn5TVZ7g27?= =?us-ascii?Q?6FnYUtCRS0wm7FhGZTg/2Gx5EKnM/Tng9w/IM5in9tr7QSPxW90ss712xgr1?= =?us-ascii?Q?pP67gQccIGaRjx8n5AC1BbDbAIMicqZj9dbo7nUS/b87qY4wKIaoYr2/uZf6?= =?us-ascii?Q?Cp/hppHZQzO28R482rSk2FkzW+PH28XvcsaiAb+TBjeQbcmJNDRvvYWx8vHQ?= =?us-ascii?Q?jl+bvHkJswPW6KqnDF28fWrKJzIG5h5HJnxhPFetikEGIs1jagShMLu3Atsv?= =?us-ascii?Q?CRqQSMQPy4c97SNI6aEIf6x1uU5OtWvUA4UKXx5IOewqSTUCqBggKCfR0/lN?= =?us-ascii?Q?3XmGuN/wmo9quin3LxdVqAZZ5eFeo7jT2+2tyifCAZQx2G3JP/7vc2Ls9qAy?= =?us-ascii?Q?h7m6A942jwl4jaAuadGU86qrynYq9D1kxdIgoT/NvldM7UbotSOJU/MN/nGC?= =?us-ascii?Q?3ddzJ22N87WJt2HT7AQHDC246s3VeCyIm7zeaxuA+46tbMKfZVM08nFRsDnp?= =?us-ascii?Q?cm0IDeOBPhNsuR8h9cRBG28dafm+K0bOh6/2m8sDu+2HMabGgN9epoqQwqgB?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 628fec0c-8eaf-4403-3e09-08db3baedd7f X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Apr 2023 23:37:23.1698 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: xjIs2vqPdsuw8EHB2Za1hVql1ChV6Mdihninj7TvnDKopvA0t0BQpmyBnD9Yl4LbSbeS3iyVOa9VagcRNGdZrw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR10MB6833 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-12_13,2023-04-12_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 mlxscore=0 malwarescore=0 suspectscore=0 bulkscore=0 spamscore=0 phishscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304120200 X-Proofpoint-ORIG-GUID: qrnmlOzO7bLaaztxz0lD1gsQwBJJyaqF X-Proofpoint-GUID: qrnmlOzO7bLaaztxz0lD1gsQwBJJyaqF Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/12/23 15:56, Andrew Morton wrote: > On Wed, 12 Apr 2023 15:21:38 -0700 Mike Kravetz wrote: > > > > > Commit a873dfe1032a ("mm, hwpoison: try to recover from copy-on write > > > > faults") introduced the routine copy_user_highpage_mc() to gracefully > > > > handle copying of user pages with uncorrectable errors. Previously, > > > > such copies would result in a kernel crash. hugetlb has separate code > > > > paths for copy-on-write and does not benefit from the changes made in > > > > commit a873dfe1032a. > > > > I was just going to suggest adding the line, > > > > Hence, copy-on-write of hugetlb user pages with uncorrectable errors > > will result in a kernel crash as was the case with 'normal' pages before > > commit a873dfe1032a. > > > > However, I'm guessing it might be more clear if we start with the > > runtime effects. Something like: > > > > copy-on-write of hugetlb user pages with uncorrectable errors will result > > in a kernel crash. This is because the copy is performed in kernel mode > > and in general we can not handle accessing memory with such errors while > > in kernel mode. Commit a873dfe1032a ("mm, hwpoison: try to recover from > > copy-on write faults") introduced the routine copy_user_highpage_mc() to > > gracefully handle copying of user pages with uncorrectable errors. However, > > the separate hugetlb copy-on-write code paths were not modified as part > > of commit a873dfe1032a. > > Sounds good. So I assume cc:stable is desirable. I do not think cc:stable is necessary/desirable. Why? a873dfe1032a was an enhancement to better handle copying pages with memory errors in the kernel. IIUC, we never handled that situation in the past. I would not call the fact that it did not take hugetlb into account a bug. Although, some might argue that it should have addressed all callers of copy_user_highpage which would have included hugetlb. IMO, There would be little to gain by backporing to 6.1 as the issue of copying pages with errors has existed forever. Perhaps Tony will comment as I was not involved in a873dfe1032a. > I can't actually get the patch to apply to anything. Can we please > have a redo against current -linus? -- Mike Kravetz