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 B7F36EB64DA for ; Sat, 1 Jul 2023 00:22:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B56888E005E; Fri, 30 Jun 2023 20:22:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B050A8E0059; Fri, 30 Jun 2023 20:22:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 97ED38E005E; Fri, 30 Jun 2023 20:22:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 895898E0059 for ; Fri, 30 Jun 2023 20:22:15 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 5098A403E0 for ; Sat, 1 Jul 2023 00:22:15 +0000 (UTC) X-FDA: 80961141030.19.E120198 Received: from NAM04-MW2-obe.outbound.protection.outlook.com (mail-mw2nam04on2043.outbound.protection.outlook.com [40.107.101.43]) by imf22.hostedemail.com (Postfix) with ESMTP id 16587C000D for ; Sat, 1 Jul 2023 00:22:11 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=OKBgkdna; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf22.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.101.43 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1688170932; a=rsa-sha256; cv=pass; b=KMdY06UdNP3NQA4qksoi75eMZNwxmmkdGn0dMFgPAw/kmfGgRDT+7FQlvqvvsXfBTfxzXa FrcaF6+9ePjMHJDiQGH1qKOTxE7y+Bs3GJRKNVoCqKn0FBkrl0HUB+UGg1PsenoH4zv5g/ VNM6buhmGmEAlV6oErVvaYh/MZUL6GE= ARC-Authentication-Results: i=2; imf22.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=OKBgkdna; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf22.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.101.43 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1688170932; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ooq3MQzmKRmXdQM/907lnst5vBUUKH3HCCuxooMDUOM=; b=GC+hZogD1dhhHEf2am9glmv7hPL6QL1PS+EnGLIBnr5y6C/ddd2NJCLPJCBiQcthnWFPtc v+0e4v6AKcih1KN//nkNX8GwRgObfdihDtbM317/Ub3DkgP8SEGhS9WfI5E4tz2YzyUyuZ v4Zq4HLAPnZ+ZDOygYaqgUQxEU62ks0= ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=aOmKMeUQD+RH/nbtRPJfF9dX02G6A9SzOCgN3MeU8I16egt65KjpexIVgXw1tGhIM4JEtJIyG2wIicTVwpxAfXF86HuJ6zdCjipNnbEDZ9NAvE/A/+qi2rMfaR0Qy8xvEE5Dpg5wa+RvQtQT/np3B7l7ckFiyuqcUP0sVIbUgz4AEuMnmnAiM11LAJBZAYGHUUlhlooeNuk8Ddv+q2pJ7W3sTtbmapDTreYuV/Z7EaX8h6xGPtC6acDywq1FlhMhyescBIMpFvGRlR9r8LIS0w3t0e4a3LM4Xy0CuRcTR1zNeMusz9VKwjt1XFIe+scbRAA5DjDnrPwJgkJvOQn3Kg== 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=ooq3MQzmKRmXdQM/907lnst5vBUUKH3HCCuxooMDUOM=; b=E6ice91VbQA8jTm4RgCfOCJzerythrJuDtOJS+QfqI83PpjoLvOvqg7MWxqqlnK6hu4ZkaN+dOLjTkwtlELNincL6kPSVW7E+qjsFJjuqfgVyPHbC0bZB/eHR5Mfo3V6hDMtVvv59N5VG3VeGUoLK+i5g3m4kH4lK06mW4AtakPdZpTL0PZI5Xu+836QwO1YUnqFsQhX8PzRx3B7X+CeeOC+MGR7KdoLKfwZ+pEHvF8LdrIGVlBIY8zXZHzfq60RQwq9zi7Ns/3jSEaFE0SYiIeidqdBmQ/fqZnCbJGTouEYONq5tQy18mjus3PQE7bLyddkDB38/r6bJvn14H6v5w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.117.161) smtp.rcpttodomain=arm.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=ooq3MQzmKRmXdQM/907lnst5vBUUKH3HCCuxooMDUOM=; b=OKBgkdnaBW/q5I9KDnTOIjWIlTkl1f3+IGppY3xyPrwv2QWyE6WzTyacH6ffo7UirZvO0oRi8GmGMyaDp2m7ZP1+Tsy+wpmdx/2rG1w00Zg1SEr6bGut/8MUJQLYD8bZITEBwJVuwWCIHVfnR1l9R7py7kAG2L2vB9NneEzspPkpPOGjKVx9+APA7wLJ8n4gpNmUHs1xrV24SzAd7PW7/3pIM5FzX+0QPZr1r9FhbHed8PQ+MQU94EAaUl4XDwVRRF3N6FfbokJSSiiYv5zQAybVZIY5Y8s3MGmraWMehmvA3j2cwQ9BK+tBebdUYWs1GWQia3xJ+jas52VKFJterQ== Received: from MW4PR04CA0034.namprd04.prod.outlook.com (2603:10b6:303:6a::9) by BL1PR12MB5850.namprd12.prod.outlook.com (2603:10b6:208:395::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6521.21; Sat, 1 Jul 2023 00:22:08 +0000 Received: from CO1NAM11FT057.eop-nam11.prod.protection.outlook.com (2603:10b6:303:6a:cafe::21) by MW4PR04CA0034.outlook.office365.com (2603:10b6:303:6a::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6544.22 via Frontend Transport; Sat, 1 Jul 2023 00:22:08 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.117.161) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.117.161 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.117.161; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.117.161) by CO1NAM11FT057.mail.protection.outlook.com (10.13.174.205) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6521.43 via Frontend Transport; Sat, 1 Jul 2023 00:22:07 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) by mail.nvidia.com (10.129.200.67) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.5; Fri, 30 Jun 2023 17:21:57 -0700 Received: from [10.110.48.28] (10.126.231.35) by rnnvmail201.nvidia.com (10.129.68.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.37; Fri, 30 Jun 2023 17:21:56 -0700 Message-ID: Date: Fri, 30 Jun 2023 17:21:56 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH] mm/hugetlb.c: fix a bug within a BUG(): inconsistent pte comparison Content-Language: en-US To: Ryan Roberts , Andrew Morton CC: LKML , , Adrian Hunter , Al Viro , Alex Williamson , Alexander Potapenko , Alexander Shishkin , Andrey Konovalov , Andrey Ryabinin , "Christian Brauner" , Christoph Hellwig , "Daniel Vetter" , Dave Airlie , Dimitri Sivanich , Dmitry Vyukov , Ian Rogers , Jason Gunthorpe , Jiri Olsa , Johannes Weiner , "Kirill A . Shutemov" , Lorenzo Stoakes , Mark Rutland , Matthew Wilcox , Miaohe Lin , Michal Hocko , Mike Kravetz , Mike Rapoport , Muchun Song , Namhyung Kim , Naoya Horiguchi , "Oleksandr Tyshchenko" , Pavel Tatashin , Roman Gushchin , SeongJae Park , Shakeel Butt , "Uladzislau Rezki" , Vincenzo Frascino , "Yu Zhao" References: <20230630013203.1955064-1-jhubbard@nvidia.com> <05ea6668-3dca-23ed-56c8-bbf8079d93cd@arm.com> From: John Hubbard In-Reply-To: <05ea6668-3dca-23ed-56c8-bbf8079d93cd@arm.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.126.231.35] X-ClientProxiedBy: rnnvmail201.nvidia.com (10.129.68.8) To rnnvmail201.nvidia.com (10.129.68.8) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1NAM11FT057:EE_|BL1PR12MB5850:EE_ X-MS-Office365-Filtering-Correlation-Id: 4a687684-f882-4d4d-1cd3-08db79c9346a 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:216.228.117.161;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc6edge2.nvidia.com;CAT:NONE;SFS:(13230028)(4636009)(396003)(376002)(136003)(346002)(39860400002)(451199021)(40470700004)(36840700001)(46966006)(53546011)(82310400005)(36860700001)(47076005)(110136005)(478600001)(54906003)(83380400001)(336012)(16576012)(2616005)(26005)(2906002)(16526019)(426003)(4744005)(86362001)(70206006)(41300700001)(7406005)(7416002)(36756003)(4326008)(8676002)(356005)(5660300002)(31696002)(82740400003)(7636003)(40480700001)(70586007)(40460700003)(316002)(8936002)(186003)(31686004)(43740500002);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Jul 2023 00:22:07.6251 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 4a687684-f882-4d4d-1cd3-08db79c9346a X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.161];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT057.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR12MB5850 X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 16587C000D X-Stat-Signature: wk9datgyeyrcqbdwtnjgazrc7xhkwuo5 X-HE-Tag: 1688170931-182535 X-HE-Meta: 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 GuXD+TFJ KQSlb7nx178OvO1RbLJMDC4s+ywCL+ay8ZV0/guG2oeFA+hhzw48i630fSHw8lZqeWU8Fev/70dvVcfJSskmfaVGyHFblHh2dpuCHOIvMKhQ5LTBwvAvi3OMVQZjcOby7FHuKKSQ9fUfJLckdjOz6kB0EhNy+08Pc9gfUEnIHPPQVeFrLv0z4tYYTE+wFrTzdWMLvE8C+5DMVzACLx6aFIDIaXS5kQv0g6yAB9i6R0gJN9l9Ddpj/iWo+yUOkEvel2E9ARDrvaLGCFLiajNjbCkqfEWcN6uj3jznQR0xTWoCWZZ3ENu6NI8X+Ydoye07WFbnu0DndB/q6mDJv8Ng67Xw6820lOlMlRQL+ 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 6/30/23 03:07, Ryan Roberts wrote: ... >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index bce28cca73a1..73fbeb8f979f 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -7246,7 +7246,12 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, >> pte = (pte_t *)pmd_alloc(mm, pud, addr); >> } >> } >> - BUG_ON(pte && pte_present(ptep_get(pte)) && !pte_huge(ptep_get(pte))); >> + >> + if (pte) { >> + pte_t pteval = ptep_get(pte); > > Given the PTL is not held here, I think this should technically be > ptep_get_lockless()? > Oh yes. I'll change it to that and send a v2, thanks! thanks, -- John Hubbard NVIDIA