From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SA9PR02CU001.outbound.protection.outlook.com (mail-southcentralusazon11013019.outbound.protection.outlook.com [40.93.196.19]) (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 9EA30361667; Fri, 25 Sep 2026 21:02:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.93.196.19 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790370127; cv=fail; b=C9yaH2ia3xHSB/mLXlbqXD06lrmAi6sLHmJdHI9eaXDUXdVDj0ZxBcqSF8EgEEloq2nlydZEkHHlTKsmOHw3HF0SUBGr8zpG31mQZ+lceQ2nuYLT2A8K4c8P3Mc49kTf1SuYR8cUBjjDRHfS4UcxFk/8cIeqEQcyY8cYFNeuSpg= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790370127; c=relaxed/simple; bh=SUMlbruU9xfNrYZ36GVGpU1Ez/0NmVG8drGcjKXKPZw=; h=Content-Type:Date:Message-Id:Subject:Cc:To:From:References: In-Reply-To:MIME-Version; b=WOEA3nQ1P6Z0M+CknV+vwV+gGV5DXJZAf7ZPvAHsU/zC6ZD1VOReerISUqJqSdfEV9poXs5RF1nC7cGjqd/vbaFfEcgrP79L8SiQAH4vTFJMGGx5l8gmB8mRrVfTBy4C4BOdnUs0XzsyI2u30ntzyh00/oLi/9o4MTTgSmVD/Do= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=qU6hRrBN; arc=fail smtp.client-ip=40.93.196.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="qU6hRrBN" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=BSN1YvUeJz8JZ7+rYvwHguK61Z5DVBjm4pJakGf8J39leaBgGauyVS5hf1XEACCglSuQ8Djk4CEJUvFuaIDQmSmV355GmZZqlhmJJmMoXvPgid1pK5183whysIjaH+3Jta+LFceqdMH4thLAquh1vbn/a4GuojkSbmSf3C0i3SG70WSDdgdGNfcv3X3jrnijLR8zHDs/tdSiMDhxajbGy/pWpEUZVgmxUHdL2oLoa3o5ZRCiqELLNG2GiMTgVV3kh5dvfeU6W33GrNpRQe4AgLjAiZhJfo+cep0qhVsluxZZC8QKDlw56YsBDe+wjnNR5/636huWK3Tv/g4YcwQUpg== 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=jcqA/8ravJEVTJI6stmpYCqH+repWWqzPh8/7ZJwres=; b=uzINNDfH2f/WBhyUywzk9PbTOY/65E23ZtWYxT7fDi+khiP+CVwB606A/+zF2Q84862akhCbmjRToA6Vv2cZLJJb7CnrygibgY28jPYeh35h115r7PNNNCJ+SB9xdmzxQQZsgYq1MlQ3iwgvrBQEEST19Yz97SPLEMVb2GXD5m3L1RbxxAl7iQgPjJNMXgnsOlqVeByY/TcfO5XIyFRO9T/4vAkHHVhQWk43L9kP5WezVqawRQYEhBlj5ZIWwJb+VDAYinuW0FBtTuap/EhitC52pN7bH/R9Fl4ZRYUqcY81q5sXSR1iG996TmMEWF2NjQcquk1iXSu1T0dTX3aQQg== 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=jcqA/8ravJEVTJI6stmpYCqH+repWWqzPh8/7ZJwres=; b=qU6hRrBNrpfqQxArV95wP+qUev44jq4pSajvpzCr21DsBnfcmDh/idv1k7N1yFCBbWeZqv3VY4T5zyr2l0ecEKVYeWjdU28TRhKHdAoIC3cU523/i81AEMc1gqjZBZPQWLMeWtqDV21XtzupbL0AIGZ0O2MetyWOEf1OgqCjg3ULQpzXEZxYFnbEFl67qqtM+NJyBa6YrTLqRxwaZtJNZBMQHHWnvoIyALrxe5zHW3uwJcBzAKPf8KY8Ox/8SMWwnLhgdlTIExwRJ1URFhHwRoMAoGrKlWvSQ0ladp4f7EZmfYotDQTg8A/UGld+FAQekKI6iyYwb2VpBs1IXvcTLg== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) by LV3PR12MB9353.namprd12.prod.outlook.com (2603:10b6:408:21b::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.451.19; Fri, 25 Sep 2026 21:01:57 +0000 Received: from IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16]) by IA0PR12MB8374.namprd12.prod.outlook.com ([fe80::d85f:4c87:ae84:3f16%6]) with mapi id 15.21.0451.014; Fri, 25 Sep 2026 21:01:57 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Fri, 25 Sep 2026 17:01:51 -0400 Message-Id: Subject: Re: [PATCH v3 09/40] docs: filesystems: update mmap_prepare docs for discontig kernel pgs Cc: , , , , , , , , , , , , , , , , , , , , , , , To: "Lorenzo Stoakes (ARM)" , "Andrew Morton" , "Liam R. Howlett" , "Vlastimil Babka" , "Jann Horn" , "Pedro Falcato" , "David Hildenbrand" , "Mike Rapoport" , "Suren Baghdasaryan" , "Michal Hocko" , "Jonathan Corbet" , "Greg Kroah-Hartman" , "Dennis Dalessandro" , "Jason Gunthorpe" , "Leon Romanovsky" , "Paul Moore" , "Stephen Smalley" , "Jaroslav Kysela" , "Takashi Iwai" , "Alexei Starovoitov" , "Daniel Borkmann" , "Andrii Nakryiko" , "Eduard Zingerman" , "Kumar Kartikeya Dwivedi" , "Baolin Wang" , "Nico Pache" , "Ryan Roberts" , "Dev Jain" , "Barry Song" , "Lance Yang" , "Usama Arif" , "Kiryl Shutsemau" , "Doug Gilbert" , "James E.J. Bottomley" , "Martin K. Petersen" , "Jaya Kumar" , "Simona Vetter" , "Helge Deller" , "Sebastian Reichel" , "John Hubbard" , "Peter Xu" , "Masami Hiramatsu" , "Oleg Nesterov" , "Peter Zijlstra" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "Dave Hansen" , , "Arnaldo Carvalho de Melo" , "Namhyung Kim" , "Mark Rutland" , "Rik van Riel" , "Harry Yoo" , "Juri Lelli" , "Vincent Guittot" , "Maarten Lankhorst" , "Maxime Ripard" , "Thomas Zimmermann" , "David Airlie" , "Will Deacon" , "Aneesh Kumar K.V" , "Nick Piggin" , "Arnd Bergmann" , "Muchun Song" , "Oscar Salvador" , "Matthew Wilcox (Oracle)" , "Jan Kara" , "Marc Zyngier" , "Oliver Upton" , "Catalin Marinas" , "Madhavan Srinivasan" , "Anup Patel" , "Paul Walmsley" , "Palmer Dabbelt" , "Albert Ou" , "Christian Borntraeger" , "Janosch Frank" , "Claudio Imbrenda" , "Alexander Gordeev" , "Gerald Schaefer" , "Heiko Carstens" , "Vasily Gorbik" , "David S. Miller" , "Andreas Larsson" , "Alexander Viro" , "Christian Brauner" , "Matthew Brost" , "Joshua Hahn" , "Rakie Kim" , "Byungchul Park" , "Gregory Price" , "Ying Huang" , "Alistair Popple" , "Chris Li" , "Kairui Song" , "Kemeng Shi" , "Nhat Pham" , "Baoquan He" , "Youngjun Park" , "Johannes Weiner" , "Qi Zheng" , "Shakeel Butt" , "Axel Rasmussen" , "Yuanchu Xie" , "Wei Xu" , "Chengming Zhou" , "Michal Hocko" , "Miklos Szeredi" , "Xu Xin" From: "Zi Yan" X-Mailer: aerc 0.22.0 References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-9-4583d8a23bca@kernel.org> In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-9-4583d8a23bca@kernel.org> X-ClientProxiedBy: YQBPR0101CA0090.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01:4::23) To IA0PR12MB8374.namprd12.prod.outlook.com (2603:10b6:208:40e::7) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: IA0PR12MB8374:EE_|LV3PR12MB9353:EE_ X-MS-Office365-Filtering-Correlation-Id: edf265e5-c947-4645-88d2-08df1b483c68 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|23010399003|376014|7416014|921020|10067099003|11063799006|4143699003|56012099006|18002099003|22082099003; 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:IA0PR12MB8374.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(23010399003)(376014)(7416014)(921020)(10067099003)(11063799006)(4143699003)(56012099006)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Q2tRYitWYnJMc1dRQUQ3QStxOGkyNXd3eVFJSnFXSE9QRXVQVGpJZ1pBQytx?= =?utf-8?B?ZC9nUUJzUTlvcnM3blROZUJQY2Zwd3NVS0VUVjNkeWkzekNIVExVdjRWNU9Z?= =?utf-8?B?dFUrTGxiK2c1bnUyWWYwOFEzS3ozcnpVaUZadWwzKzNjbkVnYlJyOHZDdEJi?= =?utf-8?B?RU13eXFidW95b1VWaFNHdW1DWVNmZUxrdzNvbG02ZFdGb29qb1FYb1dxbFg2?= =?utf-8?B?OGZaaXpjQ0JvelBnUFlhQUQ1WDlISUhCWFlSNi9uVDg5TTJZN2U2aGdqR0g1?= =?utf-8?B?eTF4NUljUXorZ09Wc29sNHczRE8yZ0xycEkrOTI3YmF6akQremFFZFkyRE1G?= =?utf-8?B?UEhFRFUwLzNOVzhVdmE4N0gxalRpb2xtOVEydWVzRlRHN01NWDlnZ0UvbmJE?= =?utf-8?B?Uk5BOTVldWpwVEp0WlBOUnBGbkhsb1dGT1hTSDlJS0taWnExc1dqbjdyN01z?= =?utf-8?B?Q01NRG4vN1lSOFBEY0hSeTBnZUI0OVZkM0FKVkxINkY4TnovblBlSldHb25m?= =?utf-8?B?R0lQV01IS3Q2ZEJ0UUpyakt1Tnh6aHZ4OHpQM2UwWTB3SkJFU3hIOWpCak4w?= =?utf-8?B?UU5rVXNXVno1ajJOWURTcmM0WTEwdDBxTHBQM0M0V0JUK0d4T0Z0bWM1NTl6?= =?utf-8?B?UWk5dFkzREZJb2pPS2VKTVF2Rng3ZWVJTlFnNVEzTGRTaHhXdGUwUlQ1Mjg2?= =?utf-8?B?Uy9qNEtSdTFMMDZXZ1QvQ08xUW5aOVAzalc5V2hYc1BVOUFvS0dVcjQyVlNM?= =?utf-8?B?K1hDSnNxbUEzMUtTWVI0Yno5UVZSblNoK0JzRjIwZ3ZsSXk1OStSaktVdVNw?= =?utf-8?B?SEJEMjB4bklaNWkvYkVpVDltdG1JRGkvRXJpYjFocTNNZndCRnc2d3paMmVX?= =?utf-8?B?ZlFCakk2dGNRcHNkRjYzeVAvcFNTenpmV2RYejUya0JacFNRQm5CM3RVM3ZO?= =?utf-8?B?KzNYcWZXUUk1ckcrWWJOdlpXNTBoRS81eTEvdC8yYm9oUzZ2VUhGRmR6bGtS?= =?utf-8?B?ZERqUVovZENLbmR4V0RiZjVzNmhLOXR2bUVLczdONWI1ajE1c3BpYWtyNlY0?= =?utf-8?B?SEVsNTU5UUZNUVBHVHorQlcxN2VpZ1lGbWxBRlR3TVJjcTBaTW1yOTg2OU5q?= =?utf-8?B?dEpsVExWVHBVQVNCZ0JDMk1sU1dkV05QT0xuWkh0VDdpTko5cFlQTGFvNDNn?= =?utf-8?B?ODJVanJGNFlIbTF5QkJpUXg2aERIaUFKaDBsYk01L3VzOS9HZmZqcjNidkZD?= =?utf-8?B?Q01pNW15UlRuZEtVak9TemJoUi9JUCtUaVRpaVliN25CZ0NxK1hjMGJXSVh5?= =?utf-8?B?dnlPNGJOVVdxVEJoYXJ4MnZtYlV3MTY4Y0Zva1hZdzJTc1Q3aDBLd2hhNll5?= =?utf-8?B?ZnJ5R2x6RlVhcUd2M3dxVmJJTFVKcHlFMjZpSk1YZDFHU0RiY296aFErYjNu?= =?utf-8?B?NFJYVjhKWDY5a3FBMEJSWGgzNDNuQms4cUl0dUoxTWI4ZFpVa2p5QkZVYndi?= =?utf-8?B?MWxOc2xxSEhCakhvOW9yb3B6VTNGNlFWTEVCU3V2TG1RekFuUUhMNmpySEVk?= =?utf-8?B?YVNJeUQxSVFiaUFQZWNWdFBXWWxYKzM3cWhCV1N3b3VnQkFEenc0bDZVeTZ4?= =?utf-8?B?ZitvVFk4d3A5R2k5MHZESFFtcE05cktIUmhNOHJSNGtjSmt1NkpmbzJTRnQ3?= =?utf-8?B?dC9ZNyttWXc3UCtZOCtJRjNzeTU5NGxnbnBFOGUrbFNsa1grQk80NVd1MTN2?= =?utf-8?B?ZXp3RGc0c0hrMTVibk5tWCtqeVp5TWsrMmE1UlI2TUJodEx2UW9UM3dWNWhI?= =?utf-8?B?OGVWY0dLUHpiakNYZmp2RUI2OVZ1T2RMNUY2dncrSndyY3ErZlBqSzFmaGFl?= =?utf-8?B?aHk3NXBXdU1tWG5ETHhQVmMxSFhNMmF5WlpVNkF1YkpEWjRORW93dkQzZjFO?= =?utf-8?B?OStlRXFRVlE5R2d2c3ZqbmIzSlA1SC8yTXltS2dIQU1xQ0d3OGg1N1p1cnZW?= =?utf-8?B?UGEvemwySHhpdk50cXdPbXJhQkR6L3JuSkhSSjdYaDhYR1kzVE1NREIyQXI4?= =?utf-8?B?TExkVmpCZTNYTFBseGtnaEJ4UE1wQ3VCMHpVTGxnT01WWUlaTzB0MlNJTjh6?= =?utf-8?B?YmxacmlxSHAvQ0hNdDIvTlJtRlV1QlY5VStON1dXbUlidVdGMWlkazB3K3c2?= =?utf-8?B?V09lVXpQemY3VGVkZnlkZzBSWXRzUHIzWHJXdytwSVROUng1bTV3bUtkRmo3?= =?utf-8?B?bXpUSUhVM1pCc0ZMYzV0ZVpqb1hXUENXYnlWWVFxZnFrMW5YRVdaY2VpdTRk?= =?utf-8?Q?omsE94nfnfBSyzrqtw?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: edf265e5-c947-4645-88d2-08df1b483c68 X-MS-Exchange-CrossTenant-AuthSource: IA0PR12MB8374.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Sep 2026 21:01:57.7097 (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: xEqkynh4TwubVa662mfBuxGxlo66Ffe0nJf8ROqgloPDEP1qMa83mZpLKehx6Pig X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9353 On Thu Sep 17, 2026 at 12:22 PM EDT, Lorenzo Stoakes (ARM) wrote: > Describe the newly introduced discontiguous kernel page mapping mechanism= , > detailing how to use it sensibly and how the API looks. > > Explicitly detail the various discontiguous actions available and how to > use them. > > Signed-off-by: Lorenzo Stoakes (ARM) > --- > Documentation/filesystems/mmap_prepare.rst | 81 ++++++++++++++++++++++++= ++++++ > 1 file changed, 81 insertions(+) > > +* ``discontig_kernel_map_page()`` - Maps a single page, correctly handli= ng > + compound pages (if the compound page is bigger than the remaining page= s in the > + VMA, then only those pages that fit will be mapped). For a compound pa= ge, the > + head page must be passed. > +* ``discontig_kernel_map_page_range()`` - Map an array of pages of a spe= cified > + size. Note that if the number of pages specified exceeds the VMA size = then an > + error will arise. Why do mapping a compound page and a page range have different behaviors on the bound? Either both do partial mappings or give errors when a given input cannot be mapped as a whole in the VMA. --=20 Best Regards, Yan, Zi