From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM11-CO1-obe.outbound.protection.outlook.com (mail-co1nam11on2064.outbound.protection.outlook.com [40.107.220.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C674320D for ; Mon, 20 Feb 2023 20:34:23 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=F93Li0DgAqbCxqdP+rZpunYdYTDRgRj6c9In86/FX8hFBrBFXNNvSgpQtYiBhIycCIxtQcNjWGJNnh5LzCvrtAS6vlbbS5serBdMC167f2nEBYn57kAccO5Z9GWEaEBn1b//BvfTDHkvPU77YRD/uuF4JjH7IGZ32/A7bZAytOv+DbqoAbRlcJFJ3VrYI+L1GOs9DLJzMLcL3zucuynDx9W27K9kbhlx6tgAobNkseSGM0WKAPgfCbPOc5DFUCMjVuPuCrRrY4VgFaaa80mGPkxtCMcdV8qCew1fgufMOfX3rB0KIhgp/dd6Eb8hHyZaDK9i3Iul0gSPlKR0YkU4/Q== 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=A0GngpEAj0k1OWgyk0D03qOWG2sQkyN2bOfyqNVfyHI=; b=kmA+BfDSRMHp997ibtwX/9pPKR0sStZVbyogjWxy35S3GAJ2jkB+tWRP8MQN2973mcroVzR+JxziTBgkBB9Uh6t+rvWhKuieeW5V1+OTPUP21f+WmkXxiClcUttr0Z1IQkbVmeDRtNhUJyL6GJEY4FpXOihAbQ2LJUffBSe+c+dyWeb4GpP8q2eZivN6tryzsQD7PikbL5WRR/4lT8Apj5f4v7d9neP13iOFQEk/OMVe18vFY7BDVTQ3aBwaRo/wxXDik8TJEYmEfhJee5mVXwNQ8Jew/Ahb6mHoy9GP7uCaDjBRENMF4KLJM8e7w3iJNZru5+JO3n+WL8XR2Jad2Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=google.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=A0GngpEAj0k1OWgyk0D03qOWG2sQkyN2bOfyqNVfyHI=; b=iA1Zm3T0iL4pmL1di7tZAx/lpkS+H8ndcwxMAbqcc5AepZKD1BKGpcGk5Iw3oa9UdtHhvSgbjpe+/6m+Nl99P6e6oel24FNeGmNMYOmHmqL1Q/bgT7H7JULeg6HkSGVDsdTuhx8jplp8CgO1srmLIGjO89+7VbLWa2BhL3173mo= Received: from DM6PR03CA0042.namprd03.prod.outlook.com (2603:10b6:5:100::19) by DS0PR12MB7560.namprd12.prod.outlook.com (2603:10b6:8:133::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6111.19; Mon, 20 Feb 2023 20:34:21 +0000 Received: from DM6NAM11FT037.eop-nam11.prod.protection.outlook.com (2603:10b6:5:100:cafe::9c) by DM6PR03CA0042.outlook.office365.com (2603:10b6:5:100::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6111.20 via Frontend Transport; Mon, 20 Feb 2023 20:34:21 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by DM6NAM11FT037.mail.protection.outlook.com (10.13.172.122) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.6111.19 via Frontend Transport; Mon, 20 Feb 2023 20:34:21 +0000 Received: from localhost (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Mon, 20 Feb 2023 14:34:20 -0600 Date: Mon, 20 Feb 2023 14:31:27 -0600 From: Michael Roth To: Hugh Dickins CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH RFC v8 18/56] x86/fault: fix handle_split_page_fault() to work with memfd backed pages Message-ID: <20230220203127.o4mf2bcrlwgsmf7z@amd.com> References: <20230220183847.59159-1-michael.roth@amd.com> <20230220183847.59159-19-michael.roth@amd.com> <29e9ed33-52eb-fbb4-5358-76939df747a9@google.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <29e9ed33-52eb-fbb4-5358-76939df747a9@google.com> X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6NAM11FT037:EE_|DS0PR12MB7560:EE_ X-MS-Office365-Filtering-Correlation-Id: 5053471c-e46e-4a48-8340-08db1381d8ed 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:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230025)(4636009)(396003)(376002)(346002)(39860400002)(136003)(451199018)(36840700001)(40470700004)(46966006)(6916009)(83380400001)(40460700003)(36756003)(86362001)(5660300002)(36860700001)(7406005)(7416002)(2906002)(81166007)(8936002)(356005)(40480700001)(47076005)(82310400005)(426003)(336012)(70206006)(966005)(1076003)(8676002)(82740400003)(478600001)(70586007)(44832011)(186003)(54906003)(26005)(41300700001)(2616005)(4326008)(16526019)(316002)(36900700001);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Feb 2023 20:34:21.3585 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5053471c-e46e-4a48-8340-08db1381d8ed X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT037.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB7560 On Mon, Feb 20, 2023 at 11:57:59AM -0800, Hugh Dickins wrote: > On Mon, 20 Feb 2023, Michael Roth wrote: > > > From: Hugh Dickins > > No. > > > > > When the address is backed by a memfd, the code to split the page does > > nothing more than remove the PMD from the page tables. So immediately > > install a PTE to ensure that any other pages in that 2MB region are > > brought back as in 4K pages. > > > > Signed-off-by: Hugh Dickins > > No. Suggested-by would be okay. > > > Cc: Hugh Dickins > > Thanks. I'm really sorry to be such a jobsworth, > and have nothing more constructive to say than I did before in > https://lore.kernel.org/linux-mm/7f2228c4-1586-2934-7b92-1a9d23b6046@google.com/ > (please re-read), but adding a Signed-off-by where none was given is wrong; > and I'm not ever going to comprehend enough of the context to give it. Hi Hugh, Sorry for the mix-up, I'd intended to remove this patch before submitting. I'll make sure to remove it from future postings. > > Best of luck for the series, Thank you! -Mike > Hugh > > > Signed-off-by: Ashish Kalra > > Signed-off-by: Michael Roth > > --- > > mm/memory.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/mm/memory.c b/mm/memory.c > > index e68da7e403c6..33c9020ba1f8 100644 > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -4999,6 +4999,11 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) > > static int handle_split_page_fault(struct vm_fault *vmf) > > { > > __split_huge_pmd(vmf->vma, vmf->pmd, vmf->address, false, NULL); > > + /* > > + * Install a PTE immediately to ensure that any other pages in > > + * this 2MB region are brought back in as 4K pages. > > + */ > > + __pte_alloc(vmf->vma->vm_mm, vmf->pmd); > > return 0; > > } > > > > -- > > 2.25.1