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Peter Anvin" , , "Stefano Stabellini" , "Oleksandr Tyshchenko" , , "Eric Biggers" , "Theodore Y. Ts'o" , "Jaegeuk Kim" , , "Oscar Salvador" , "Chao Yu" , , "Gao Xiang" , "Jan Kara" , "Yue Hu" , "Jeffle Xu" , "Sandeep Dhavale" , "Hongbo Li" , "Chunhai Guo" , , , "Steven Rostedt" , "Masami Hiramatsu" , "Mathieu Desnoyers" , "Matthew Brost" , "Joshua Hahn" , "Rakie Kim" , "Byungchul Park" , "Axel Rasmussen" , "Yuanchu Xie" , "Wei Xu" , , "Trond Myklebust" , "Anna Schumaker" , , "Song Liu" , "Yu Kuai" , "Ilya Dryomov" , "Alex Markuze" , "Viacheslav Dubeyko" , "Li Nan" , "Xiao Ni" , , , "Richard Weinberger" , "Zhihao Cheng" , , "Baoquan He" , "Pasha Tatashin" , "Pratyush Yadav" , "Jonathan Corbet" , "Dave Young" , "Shuah Khan" , , To: =?utf-8?q?J=C3=BCrgen_Gro=C3=9F?= , "David Hildenbrand" , "Matthew Wilcox (Oracle)" , "Andrew Morton" , "Muchun Song" , "Lorenzo Stoakes" , "Liam R. Howlett" , "Vlastimil Babka" , "Mike Rapoport" , "Suren Baghdasaryan" , "Michal Hocko" , "Baolin Wang" , "Nico Pache" , "Ryan Roberts" , "Dev Jain" , "Barry Song" , "Lance Yang" , "Usama Arif" , "Gregory Price" , "Ying Huang" , "Alistair Popple" , "Johannes Weiner" , "Qi Zheng" , "Shakeel Butt" , "Kairui Song" From: "Zi Yan" X-Mailer: aerc 0.21.0 References: <20260731-remove-pg_private-v1-0-142c97ba3562@nvidia.com> <5ca4d0e4-1747-45a7-a916-a7516bb1692b@suse.com> In-Reply-To: <5ca4d0e4-1747-45a7-a916-a7516bb1692b@suse.com> X-ClientProxiedBy: BN1PR13CA0008.namprd13.prod.outlook.com (2603:10b6:408:e2::13) 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_|PH7PR12MB6935:EE_ X-MS-Office365-Filtering-Correlation-Id: 22480e3c-b594-45b3-2d38-08def18ae4af X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|23010399003|1800799024|7416014|376014|56012099006|10067099003|11063799006|4143699003|22082099003|18002099003|921020; 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Instead of checking PG_private, all code is changed to >> check page/folio->private !=3D NULL instead. > > I'm a little bit worried that page/folio->private is in a union, so today > it could (in theory) be !=3D NULL while PG_private isn't set. > > Is it really not possible to enter a path where PG_private is tested whil= e > page/folio->private !=3D NULL due to the union being used otherwise (PG_p= rivate > not set)? Yes, it is possible. See: #5 in the exceptional users: erofs uses ->private for reverse linked list and in-flight counters without setting PG_private. I get rid of the first one and converted the second one to use folio_attach/detach/get_private() to follow the general ->private use pattern.. For non file system folios, anon swapcache puts swap_entry_t in ->private and hugetlb puts its flags in ->private. I added folio_test_fs_private() to exclude them, but this helper is planned to be used by core MM, since filesystem code should not encounter these two. --=20 Best Regards, Yan, Zi