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 99FF7C433EF for ; Thu, 20 Jan 2022 13:18:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 127396B0099; Thu, 20 Jan 2022 08:18:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0D7C86B009C; Thu, 20 Jan 2022 08:18:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EB9436B009D; Thu, 20 Jan 2022 08:18:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0045.hostedemail.com [216.40.44.45]) by kanga.kvack.org (Postfix) with ESMTP id DEAC46B0099 for ; Thu, 20 Jan 2022 08:18:24 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 9D393181D6050 for ; Thu, 20 Jan 2022 13:18:24 +0000 (UTC) X-FDA: 79050719328.27.4D4EF40 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (mail-mw2nam10on2045.outbound.protection.outlook.com [40.107.94.45]) by imf08.hostedemail.com (Postfix) with ESMTP id 08D39160041 for ; Thu, 20 Jan 2022 13:18:23 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=kJt+t/E+W1oizAjojUlEhPRL35vHO+rO/EeAt7FDX4Mk61xVLGQ2tUqxoUbj2tdmytwRDRCI+//WsZTG8eUfTyNHA6K4rR8UYNWhnvr3TuOWuXrntOqklJqeaH8JMpRVVru6gwci7sF9chN2JPYMbI1vxDA4GhxhJyua39nbFJRvU6QAz+kJV8mTt3SnccrcA8KGaPLciNw8PxMlNt5wvmrZtsLqlY0exmJgZpsaiCNsLFp5KiOSMHSTC7ffGrq6uy84l1PGVWBpDSayuRBXImp5Z2LfeVC0wEmRG6LqJxkL+mfebG5p2AmrUq9kMsIqpodWeNqHe7PJU/4SW2pWtw== 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=nepc3Y2HTNDMj+dBQ9ABzJu2k/FiUKmg30JJbke4DBY=; b=VgGpHr9Gqg7Vqf96xiwqK8dR3ehtJOi5F8/nYZzMTa9NeJS0OYyIz1XxAy7LnpYezzqEB4Q6i3pUv/GPemI/w6xpkY/6dOxROurGYW7yAQ52PE/DvW/j9RcKr7nMQ6KNyNjcQcDqucm+MsK6fr4/3L3w+/ugX8Dl8pfZ7Z75REjvxkduRZ3QWL/hDgzUigLKlHRlXrA9wpzTJShOOWwHPzqfwYOeJDLwjV8VsH9b0HHrNSoL0NY9oD0LqjKf/Ci5EqEPJDVYdWV19PxRP8FJCtEtH8Jtmqsc/CbOt+9xhSk381z0xW3CRxLTEXNLIvUIBczgKoczdcFZVsM88hUFDw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 12.22.5.235) smtp.rcpttodomain=amd.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=nepc3Y2HTNDMj+dBQ9ABzJu2k/FiUKmg30JJbke4DBY=; b=AkLc0cWQ2a2H/2ilprYU5oWbHCF06FwBzHWKq1AAshQo4Je0y/UJFvQuoCMXtCNVPiEKECdiKrmywBEjs+kJ0KBMCSIywf9GReIPsbsdgJ6uNA0jh81xwWX6bQf0v8KNGEJZZ1YNt7E5hu4KsD7Hv8GdPHqjvyplHOFOVq9WG6O6FLaceF16WxVTuWvdznEsSIMmAMu63qUCCuaK6OgV+0vVENLTNnzbs/wqPtuIFO1Cdr59kCgCgsxvfXCo5JDZRtTa+afjgjSuaoYwN2234flRxe6Z5Enr1NiDPCoYoTb1rr8BGIpIrjxeMOBiHn6XTAVTNtJ5wCWM4K6B7hgXFQ== Received: from BN6PR14CA0038.namprd14.prod.outlook.com (2603:10b6:404:13f::24) by CH0PR12MB5043.namprd12.prod.outlook.com (2603:10b6:610:e2::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4909.7; Thu, 20 Jan 2022 13:18:21 +0000 Received: from BN8NAM11FT013.eop-nam11.prod.protection.outlook.com (2603:10b6:404:13f:cafe::f4) by BN6PR14CA0038.outlook.office365.com (2603:10b6:404:13f::24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4909.7 via Frontend Transport; Thu, 20 Jan 2022 13:18:21 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 12.22.5.235) 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 12.22.5.235 as permitted sender) receiver=protection.outlook.com; client-ip=12.22.5.235; helo=mail.nvidia.com; Received: from mail.nvidia.com (12.22.5.235) by BN8NAM11FT013.mail.protection.outlook.com (10.13.176.182) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.20.4909.7 via Frontend Transport; Thu, 20 Jan 2022 13:18:21 +0000 Received: from rnnvmail201.nvidia.com (10.129.68.8) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Thu, 20 Jan 2022 13:18:20 +0000 Received: from nvdebian.localnet (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_CBC_SHA384) id 15.2.986.9; Thu, 20 Jan 2022 05:18:17 -0800 From: Alistair Popple To: Alex Sierra , Joao Martins CC: , , , , , , , , , , , Subject: Re: [PATCH v3 03/10] mm/gup: fail get_user_pages for LONGTERM dev coherent type Date: Fri, 21 Jan 2022 00:18:15 +1100 Message-ID: <2432841.uOC12ROH9Y@nvdebian> In-Reply-To: <008b5ff4-dd53-d652-46dd-5ce771c69a0a@oracle.com> References: <20220110223201.31024-1-alex.sierra@amd.com> <20220110223201.31024-4-alex.sierra@amd.com> <008b5ff4-dd53-d652-46dd-5ce771c69a0a@oracle.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Originating-IP: [10.126.231.35] X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To rnnvmail201.nvidia.com (10.129.68.8) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 7c433adb-d488-4440-8849-08d9dc1754f9 X-MS-TrafficTypeDiagnostic: CH0PR12MB5043:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:8273; 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:12.22.5.235;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:mail.nvidia.com;PTR:InfoNoRecords;CAT:NONE;SFS:(4636009)(36840700001)(40470700002)(46966006)(8676002)(26005)(107886003)(53546011)(5660300002)(110136005)(83380400001)(54906003)(426003)(9686003)(8936002)(70586007)(86362001)(336012)(316002)(70206006)(9576002)(4326008)(966005)(82310400004)(186003)(36860700001)(16526019)(7416002)(81166007)(47076005)(40460700001)(33716001)(2906002)(508600001)(356005)(39026012)(36900700001);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Jan 2022 13:18:21.6071 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 7c433adb-d488-4440-8849-08d9dc1754f9 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[12.22.5.235];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: BN8NAM11FT013.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB5043 X-Stat-Signature: s936zqxio6xs4bhn78y58zj663i5p86j Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=AkLc0cWQ; dmarc=pass (policy=reject) header.from=nvidia.com; spf=none (imf08.hostedemail.com: domain of apopple@nvidia.com has no SPF policy when checking 40.107.94.45) smtp.mailfrom=apopple@nvidia.com X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 08D39160041 X-HE-Tag: 1642684703-657325 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 Thursday, 20 January 2022 11:36:21 PM AEDT Joao Martins wrote: > On 1/10/22 22:31, Alex Sierra wrote: > > Avoid long term pinning for Coherent device type pages. This could > > interfere with their own device memory manager. For now, we are just > > returning error for PIN_LONGTERM Coherent device type pages. Eventually, > > these type of pages will get migrated to system memory, once the device > > migration pages support is added. > > > > Signed-off-by: Alex Sierra > > --- > > mm/gup.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/mm/gup.c b/mm/gup.c > > index 886d6148d3d0..9c8a075d862d 100644 > > --- a/mm/gup.c > > +++ b/mm/gup.c > > @@ -1720,6 +1720,12 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, > > * If we get a movable page, since we are going to be pinning > > * these entries, try to move them out if possible. > > */ > > + if (is_device_page(head)) { > > + WARN_ON_ONCE(is_device_private_page(head)); > > + ret = -EFAULT; > > + goto unpin_pages; > > + } > > + > > Wouldn't be more efficient for you failing earlier instead of after all the pages are pinned? Rather than failing I think the plan is to migrate the device coherent pages like we do for ZONE_MOVABLE, so leaving this here is a good place holder until that is done. Currently we are missing some functionality required to do that but I am hoping to post a series fixing that soon. > Filesystem DAX suffers from a somewhat similar issue[0] -- albeit it's more related to > blocking FOLL_LONGTERM in gup-fast while gup-slow can still do it. Coherent devmap appears > to want to block it in all gup. > > On another thread Jason was suggesting about having different pgmap::flags to capture > these special cases[1] instead of selecting what different pgmap types can do in various > different places. > > [0] https://lore.kernel.org/linux-mm/6a18179e-65f7-367d-89a9-d5162f10fef0@oracle.com/ > [1] https://lore.kernel.org/linux-mm/20211019160136.GH3686969@ziepe.ca/ >