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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BD833CD4853 for ; Wed, 4 Sep 2024 16:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To: Content-Transfer-Encoding:Content-Type:References:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JfRPJ9xccEQ7Cfoq4bi+s3amrT5AxL1N5YgB7wLpebs=; b=XTAS15oV6UZhrT+/fQDzOFcYIT 9TN60NXlMs+Y5uBZ/0yz9tXEF80vdVWhc0ScQUNiRpWoG7NeSkLPe5gYhgffKsH1pUXtaJrKNx3Ua pXzXWZZifNS8qaxWBhKZI/FJ2Ma5kzqxRqc5L+aD5bNP7d6cWVzL0bXURFhz2/OQdJB1/FVvyNYgj jje13GOPEhEuR+zkUIAVvuw3lxjZaMmMI0oV8XLVKDfGK1bPyOij2iAZjmWal6xQ7RdxrtzVSjSaj 7RYDe/ZFpPOPlqwXs5BMFj4Sj4kbHAlwG0Kuo+MxRfV+XlCFE2pkpYdGJozuY/TBg9Z+EEGIqUBPO Gv9XQmRw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1slt7N-00000005JUh-1fMJ; Wed, 04 Sep 2024 16:44:29 +0000 Received: from mail-dm6nam12on20627.outbound.protection.outlook.com ([2a01:111:f403:2417::627] helo=NAM12-DM6-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1slt6Q-00000005JIY-1QH1 for linux-arm-kernel@lists.infradead.org; Wed, 04 Sep 2024 16:43:31 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=cafzEwjfOXdPny2hjtVYmaznoDK6PsuHlV26422LKfoTu59HjSo0HRTrG/WJmI+U7KVfXvw/ZzMa4nuHkpGOWpgaL0Lp1uyDMyvVDMz2LcIKLpzBzuurZ20+ApZbiLP1vj1zW90me5IlpCMtmhEDzDP+4IE+p48EjQDlnxofaKxanCzMjtda0lkNZgRK3ePZd1ZDL2R1dmN8SZ48zj7T+9opWjLDhHWQCDPKG3tkfgHyH6BoU1+4b9r2Fm7LJBbBSaxlYo6PG4c8QICoDj6/MkRBG/xmecN6VIastEY9wZlPBF5m4ZVd7tWfTGLuAYTPH6zm0WS4K3oWOS2vy99IEA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=JfRPJ9xccEQ7Cfoq4bi+s3amrT5AxL1N5YgB7wLpebs=; b=pAgRrbOHkf678U4yWXE6asbRg2Or50GCzIEv/vKh3O5DqM3nJU0VU74jMFC8AeV+1+DAunFWdEAxaE+0Osm9WL2BtyIw56+yZ1o5g7bXZbgi0tp+yEVO8A75GuZlAGnVr83K0Imyf5JAupwHZr1jFqw3kkVxTEe41V6vGx9XjRBbVhd+YxZMi+FQexKQpvU5M4BuNwpUPvS/srOjLUA6g7QBAUlVOm9CK7Qm6lTL6ypTrzJDleMCibCG3Go4n/mE/KKiimO4hV5+eUmo2uzHBHbDx7vLNrlQ339N95INDeVL5U5MQe8y6RusZ3tyat2fR6L1QxQTWLb3WZStG2Zs1w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; 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=JfRPJ9xccEQ7Cfoq4bi+s3amrT5AxL1N5YgB7wLpebs=; b=auer/DmOY9SrhKF3EIglfGsiZPPcn0BcEgSB/ig638kPTfHkFR1i4Vs12ea2XI9hI51HRim+tjp8HNwKaSgur0QigH6lAqAU/v7EdVePMTsuj3HXEmiht8PtTafDFMp2NylB78HWp3D6/iyjUfFBEWalFF011xRdNvNAI70efX5fP9wA/s3V33aqJm/fbW20Z+HbGbJIMfUv3Ue7tIQQpaCIHzfKaBjlF+aPqxvSpcvQXtSaBapqe9OC0R1CDocBjmYXb7tBnYOpA54aQEHJwsHiDAv8lCgMtn6HZWcYWfBYh3X9RA2863Obvjqg8fF/FpBSAlmaUrN9B6r+I0/V+g== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB7763.namprd12.prod.outlook.com (2603:10b6:610:145::10) by SA1PR12MB9004.namprd12.prod.outlook.com (2603:10b6:806:388::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7918.25; Wed, 4 Sep 2024 16:43:25 +0000 Received: from CH3PR12MB7763.namprd12.prod.outlook.com ([fe80::8b63:dd80:c182:4ce8]) by CH3PR12MB7763.namprd12.prod.outlook.com ([fe80::8b63:dd80:c182:4ce8%3]) with mapi id 15.20.7918.024; Wed, 4 Sep 2024 16:43:25 +0000 Date: Wed, 4 Sep 2024 13:43:24 -0300 From: Jason Gunthorpe To: Jiaqi Yan Cc: Peter Xu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Gavin Shan , Catalin Marinas , x86@kernel.org, Ingo Molnar , Andrew Morton , Paolo Bonzini , Dave Hansen , Thomas Gleixner , Alistair Popple , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sean Christopherson , Oscar Salvador , Borislav Petkov , Zi Yan , Axel Rasmussen , David Hildenbrand , Yan Zhao , Will Deacon , Kefeng Wang , Alex Williamson , ankita@nvidia.com Subject: Re: [PATCH v2 00/19] mm: Support huge pfnmaps Message-ID: <20240904164324.GO3915968@nvidia.com> References: <20240826204353.2228736-1-peterx@redhat.com> <20240828142422.GU3773488@nvidia.com> <20240828234958.GE3773488@nvidia.com> <20240904155203.GJ3915968@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: MN2PR20CA0026.namprd20.prod.outlook.com (2603:10b6:208:e8::39) To CH3PR12MB7763.namprd12.prod.outlook.com (2603:10b6:610:145::10) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB7763:EE_|SA1PR12MB9004:EE_ X-MS-Office365-Filtering-Correlation-Id: aecdc2b3-d482-4aa6-b416-08dccd00b201 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|376014|7416014|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?VHB1TEx1SkdDNnIxU0VRa01PeGhZUG5vK2pWSXdCRTZpK3pVaGdVUDNmam8w?= =?utf-8?B?M1ZxUDJ1QXE0OWdqWW1RNzlZUTgvQ1c0cmlIMmxyUXBrbE1ZdGxJNUZHbVhw?= =?utf-8?B?SWp1cW5MLzFOU1ZJa1duaitzamRDUGpJbWNUd0xsd05XajZrZ3cvM3A3V0Jm?= =?utf-8?B?eHF4TDJoeU1iUERMMStseWpaRndDUitMUmxXLzdzc1h0NWlqVUc4ekNvL2h5?= =?utf-8?B?RXZkd0JCWis2VUc3TWFXKzZvdnhwVTMwQUlRdEZKZkVjZlVUSXd4ZUpzU29u?= =?utf-8?B?QlYrUGVwRFhCS2FTc3ViTnNFMGthQWdSeG9RT3l4TUtIeWdzKzhXZStMM0tJ?= =?utf-8?B?SC9hN1FzUlloR2ZDbWJVOVc0d2k1d3RHZjFCMkhBRDN0MHlQd0R4NlgvNHNV?= =?utf-8?B?OWM1VXBIRDNETVYvYUZyL0xwOWJIdUVCWDIveklnM1pxOUIrOXluaVNTLzM5?= =?utf-8?B?ZVNJL1lYdjh0dVMwbDNzc2NtSHNKMDBjUHBWNWdXQ3Q1U0ZGanYyYzJ3WXMz?= =?utf-8?B?N3VhWnVQRUM3ZmlDb05sdDVwVHloMnV1ZUdSaFgwaVc0SGdGb0o1VkhQOEpI?= =?utf-8?B?eGxXeE9SNCtkeG54U0pRcGcrSUx0bDBvZ0V2eGhJbHlidzYrT3JpWWEwbUNv?= =?utf-8?B?blpvbVUwSkM2OE5yMUl1M0JVSThaVzNtdmxrQkYvZFRoM3ErcjlZTmpzbXJk?= =?utf-8?B?ZlN2bUdjQm1oQjZMbnB6di91Ulp6VEc0cERnZmZFL0xlWk02SnNFU3dmaVdp?= =?utf-8?B?MkJlOSs4UjdvZ2ZVZHZvU1M5ZUVKS0tJV0c3VjcyOTB5N2ZWVGFacmhqY0dR?= =?utf-8?B?RjhHS3hIQVRabjRUQXBKV3JrY1BPYU9HOXNNcmViSGJaeEdVSG1HYUFkRzdL?= =?utf-8?B?V2pzUmlpMk5GNUlWVG5xcjVDT1FVQXhPNEFiSlB6ZW0ya3FCMVpzdlk5bFB2?= =?utf-8?B?SHdlVXJ1ZnlVZCtkWFRoSlRIbHF3c0YvYWlHWG02ekNWTzQ0RkxXSW5IQjFs?= =?utf-8?B?YzNKUHNMTVlhaG1iMnN6aDZ0Z2NyRy9FaVZHVFEvQnEwZGptVmcwSFRmTXJK?= =?utf-8?B?c2haT0M4UjRINUlQMDdoTTV6TVIzVDRJNEVoWm5ZNXg3UVphSzJiK3h2Qmc0?= =?utf-8?B?ZElJKzdxdm9MMy9jbHdzTzlWbk9CRkYrdlRQQ2VCQllBQTUrUmFGT3YxSHpB?= =?utf-8?B?SnZ2SlNDL0tPeHdsZVFta2IwamRkL1ZjOVBaZ0RSKzR3YWJwNkZod3gzVXdv?= =?utf-8?B?MjdKSGgzOEd3VndLUVc0eXlVY2dvNTZJVXhDT1VNTDZ5VnZ3bVYvaUV4V3RV?= =?utf-8?B?OVNLYlByZHJOQmhxc1FyQXNFWUxkLytzR2FzWENUcW15L0NWeCtDbjFPcUJC?= =?utf-8?B?L3lJcmVBckdqM20wUkk5RkhVNlVEalRoNk9oQjAzWngwdDVXdzRlMnA1bnpl?= =?utf-8?B?SFhsOHNkNXFTWmVyaWtCVStYc1dZc3pVQ3R0dytmdEk1RXRXQmxTWXFuNmZK?= =?utf-8?B?VDlRZUNTbDRLL0NlcUVSYTBBUVJ1TG1HNEFXNHJwcWhQUTU3VkJId3JuVkpq?= =?utf-8?B?Z0twOUJRdVFGZGMwMkJyZVhGd1pERk4ycEV6WjBva3FVTktRMkxRQ2VMUTVB?= =?utf-8?B?Ni82SGljalEzalBJL0lnek5KRmpNUjZYTTFyeHJucDZmSWpTVEljOUEzUU1N?= =?utf-8?B?T2t2MFJNYXJ1c3l6V0lJUytVa3FPNGhtMmRzNE44Mzhtd2g3M0tHVVhZSk0z?= =?utf-8?B?L3hGL2QyYXBZbk40MGFSOTdjQWN4Ujd5c0pWUDJia1d0SEUvYVhPTjQ3SnVD?= =?utf-8?B?YVdxS0VmTmtxdWFsZ2NWdz09?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB7763.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(376014)(7416014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ckJxUlZWRjB6VkRDQjNNZE4wKzhuTllXamI2VDVyc2VTRlA5aFVvTll1ODds?= =?utf-8?B?YVYrd2h1MW44bkM4M1VaaCtOdWZXKzlwa3lObkJVeGx1eG91aGhMZVVQNDZk?= =?utf-8?B?Z21kM2FMWGdpWFFpdkdLYkZ6RmQ2SDJlOVpBMi9TUnhzZmRsbXdLekM0R09p?= =?utf-8?B?WUlmcGs5ejh0aW5yWk10eEkzeVU5bmIzMjloOGI2WEZDRDhJNDhaREpMbXFC?= =?utf-8?B?bThkdmdNMWlnM0hKZ3ROQ1BVc0NGMGIxd3FML1I0czhVb1ozSzN4QjZuQUdQ?= =?utf-8?B?cmVpNFc3Z2puek9HbW1tZnJKRkc1WmZCQTc2cy9Rcmp5WkJneFBmM25oaTBw?= =?utf-8?B?SnRHUHV4d0k0SGlzZENOSy9mbmVtUDBMVXFPTndaZXBQQjQrNEJVOWVSL0pB?= =?utf-8?B?emMzZjY1bENCNThTZHRGM3J5Vm42dDBlbWdzUDFDV1ZoaWVOMXA0RmRUN2RR?= =?utf-8?B?aXBOTzJkNFRGV0J3RjNDTnB0SSsyT1ZJVU1rd1AxdVo0SDdKc3lyOFNTOENB?= =?utf-8?B?Q2hoZ0FkNWNXb29ocGorSDdGS1BVUU8zU3J2VFJWV0t1QWRYTWdkVjlMOFFv?= =?utf-8?B?TmlDRy8zZE5Eb1RmeUlYUVlQaXZxVVRlUm1iWWdPTnNlQ2FoSHZ5RXNoSFIy?= =?utf-8?B?K0JzYVE0Yjh0a0dVN3Via25tSGZ3ZWNDUHlIekNuMWhkbWJxR2VhOXdxY2g2?= =?utf-8?B?L1V4R2thTnN2SFQ5SjZaR2JCTVJtQ2pjMGtNNnpuVGhQOVdBeURLSDBuNFhO?= =?utf-8?B?R0ZVNFJOenZRd0V6ckVBZ3RkWW5IU2VDWC9mUkVuLzRaYW5JQkZocW1TcXNh?= =?utf-8?B?UXc4dXBONDlHczdOeHdRdkNKZEx5WlJlNktvcVBmNXkvMEkxYTRiZGV1Zy8r?= =?utf-8?B?RGVsTW9rN3Vxb0R3dHpLa29zTFBxT1Zob0htUUdieExGaHlwM21jU2NEMjJC?= =?utf-8?B?cndjQlVhaVQ5UjM0SDA1Wno4clRrc2IwbWVDV1pCZmFpT1ZLNWFQb3dJNVdN?= =?utf-8?B?WXdCUDdWcTVwaWNjSGZIN0JDVWxRaUtONWZpcUJYRDFSOGxZU3REL0hlVTZE?= =?utf-8?B?S0RDRkkrNDh1R1pxUlBrV1VqZVd2VW9pd09QZlZONkg0VGVtQzJRRFNDNExz?= =?utf-8?B?VE8ycy8vcldIY2Vxb0c1U1R1UzhBTnBWMHgrT2Q4WVhJZWFpMjJUL3R1bVBJ?= =?utf-8?B?UDRtaXY1c3gxWGcrMTFmWE1lOGtHSG9QUENXTkhrcnN4SUN6NHo4MHBxVUhv?= =?utf-8?B?b1BHWGJSay9URlo0V1kxUkNQMGV0OGM1bmluZ21uSk1VMjlETERCL0JpaEUv?= =?utf-8?B?WUhXa1hzWFNqcng5cmJjakhMUGJwVTl0U2ozS1pnUE5BQ2NkbTNkTSt3SWFF?= =?utf-8?B?ZFd2SUNNb1l4U2YyRmNqSjdoQTRaSGQvMTFCaWw3aExRb0YrKzh5ZUVURW9a?= =?utf-8?B?Ym1JazgxaUVTenNYMHVxQXVVb2lUSk0vQmhBc1gxVldWVy9YMmIvLzlhUTFl?= =?utf-8?B?Wll2RnlFWjcybjYyMGRYWnNLQjJHdE1JamRPVUNDSFlFeGFUNzNDbDRCR0RL?= =?utf-8?B?SE01QVYrQTY1UW5MdzZZQ2x5T3dXNnBtdlNiOWQvQnJTVFJPbnZGbEdRdzU2?= =?utf-8?B?Ry9maFdodDUxRUFSdDUxYmViK01US3dOOFFybUJVa2F5T2RPNTZEVEZmWmRK?= =?utf-8?B?Y0YwQXJBNUUwTEwwQmZTNXVjSW1lRFFBTk1vTXF1QjE0K3J0ZTYrTVFKYVJK?= =?utf-8?B?UytFaWk4R05kTDkraVhURWxhYmJyWFhwMGx4K2RGY0JtVEFQR1JKcStGZzNo?= =?utf-8?B?TW1kR0VDNnFTOTFwMWJKT094eUhmeWJzcWF0TDQwRGdkenFIdzhITmVReHhO?= =?utf-8?B?SFpabmVIWmh5T1VtTm53ejVJRGdRTnpvWGFRYnFqeE1tenkyV003anNLZ1ZR?= =?utf-8?B?eTNPUE9KOFFLTmFPR0d4YWdIZGJoRGlnVVk5UXNjN3RMaE0yNjQyOGtHcUVB?= =?utf-8?B?ZGZTSU81TUwzK29STnpHK0Y2NjdVdGE1dk1LU0htMU1HSVk0Z1h0SjZISGlu?= =?utf-8?B?Sm9WU0drd004NFh4eWEyeHB6bktsZ3h3NThWMzN3ODVSWGdZVWZtVHoyelhk?= =?utf-8?Q?M24utk7p8xtKGfDSC45JeqpN7?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: aecdc2b3-d482-4aa6-b416-08dccd00b201 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB7763.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Sep 2024 16:43:25.1312 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: HxKieEx8/kOBAldJn1teb8FCfLxw3/7pkLEhsJ6PxNveLzLxXUX+40N40jPDYJMl X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB9004 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240904_094330_406652_8B3A07DB X-CRM114-Status: GOOD ( 17.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Sep 04, 2024 at 09:38:22AM -0700, Jiaqi Yan wrote: > On Wed, Sep 4, 2024 at 8:52 AM Jason Gunthorpe wrote: > > > > On Thu, Aug 29, 2024 at 12:21:39PM -0700, Jiaqi Yan wrote: > > > > > I think we still want to attempt to SIGBUS userspace, regardless of > > > doing unmap_mapping_range or not. > > > > IMHO we need to eliminate this path if we actually want to keep things > > mapped. > > > > There is no way to generate the SIGBUS without poking a 4k hole in the > > 1G page, as only that 4k should get SIGBUS, every other byte of the 1G > > is clean. > > Ah, sorry I wasn't clear. The SIGBUS will be only for poisoned PFN; > clean PFNs under the same PUD/PMD for sure don't need any SIGBUS, > which is the whole purpose of not unmapping. You can't get a SIGBUS if the things are still mapped. This is why the SIGBUS flow requires poking a non-present hole around the poisoned memory. So keeping things mapped at 1G also means giving up on SIGBUS. Jason