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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 2/4] mm/huge_memory: move to next folio after folio_split() succeeds. 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?raTqxp5naUNMU760sizWcFGbjTGcRx9wedQ7lQh9IVRMIkrBVlmqmsH4vblS?= =?us-ascii?Q?e2XF/cZf8J92Qw3gOdBMwL3m4Si/7yAcM+3qvV/zEZjN/ENkP/4qFusT5pn0?= =?us-ascii?Q?4AhWPotpii0YdvAoe3tsudtrLVZVUFR+7q8KiuLOeSk3S08VnedyVAhI5sKx?= =?us-ascii?Q?m5Q0+OI8C6TKnEHDquICFRYkcceLUpEgBWhX1N8l+k0sZI2NV2rltRnMnpHw?= =?us-ascii?Q?jNdmsfFYKzam6uQsRuGC/AlcfAJOIp/F+a+qdND7n+dRMA8r79rJIvirZ2Rh?= =?us-ascii?Q?yQ3D/cAOqKLS3AAWAcGwctJ7npQRe91lfHqIy4s7EiTxqcFM/jRqaVFhqAor?= =?us-ascii?Q?GioER/aVft16WU/QPouFwZ/H7y3uyMqfg6EoPdzvBromIYL+fcI8kEbfacrL?= =?us-ascii?Q?ob/VWovUcEawFEhYNv0WsnfbQzpPI7SVsazH1oJ3i+aq2uay3D+Xr5ZAzbSu?= =?us-ascii?Q?yX91BV/q//Kn+onk7FtClSDlGzhaGIqV7CeD91G72QaMNOFA2rjfy5F/sxx5?= =?us-ascii?Q?xTi4aG3NF10EF23ZaFUmN9xqUfQAw9R2UnM0TAhrmyYJo0nVUORTA2A1QM8F?= =?us-ascii?Q?+Hy0W37oDBR9CHyEyxpvKF98gUq/QMNkGfqrMdy/F4uDiOHbxBspWKCx/3Ol?= =?us-ascii?Q?rdbd91yQKmo3k7pDKemk+HEETjhVsE5EVh2MxYmy/qWAeO+a9a2BfA5ttVgP?= =?us-ascii?Q?OcsMwm0MaPrALlKoKKhWNro4ldT8WAb305p2y/hOF0Jw3gcYvN2hRvz/YIkU?= =?us-ascii?Q?4F7p386yeDDnJlTDhRs2mfpwjcoSaV2OMOI+kz7QyzYQY5CoInMYZvIpeqrD?= =?us-ascii?Q?eGcQlAxtnQEGmPhy0avzSynlrvmaQN/8O+RdBnvoXirW+Yc0AKafwy7K11a+?= =?us-ascii?Q?aav8IjEDi7WLwXdh3bAJbcHB4arQSHol45e/owr3Z50SnWb3PXkOaOgvAYje?= =?us-ascii?Q?Cdb7QJFwtFoQUXYKUy1uAwkPly0ZvQBHCqMDsENDUScgu9LZNp30VpLCsZOr?= =?us-ascii?Q?BynSmaRM4v78iHT2i+YXuxV6VVxvqjMCNMLpGdB2OfsQnGBwoCov/yNBtQaP?= =?us-ascii?Q?nb4pGTfR06zro5lpSNZc5jWXktVWuerdCb2cOWOdJ7N8JisT5689NlFPvMGR?= =?us-ascii?Q?jXd66uFArajnG15tm+fHuvPoM4Z6J+q/kTH5uMvtuAAGkfRCLrFRwJmpPKLt?= =?us-ascii?Q?hs46hQvJsL9yBEyrs2QRI8GHalcp+tlcLhxMhqAYrrLjirGyrDb5vPVbaGPO?= =?us-ascii?Q?5zEY9KD0YnzIK3IA3lcgBww3YS7w2/PB3hRGpcMoQAtx7p2P0+t4JLCCe2kD?= =?us-ascii?Q?PmfNBRUxeaYT4KfagIVCSHaoqVBZjsZQeRe+N+WF9G/JLRZ/Op6GRpJbvtif?= =?us-ascii?Q?kxK6eA/q5unDfE87dwWL8auqOpAgtjwYD9JEphQrMtKhSbg8md3HY7Vm7acP?= =?us-ascii?Q?PQmMd/jfv+lZ09h69WXGuQfwDGEBFIyKQF66WHvDjHGvJzPHeEfxz25p5HmH?= =?us-ascii?Q?TRj4F0fiOkHSa+1dtEM3ijySUM+BumAD0wbvI8VTaAtyB3CSmZFvMtSGkoDs?= =?us-ascii?Q?Xl4J/rK27uTeS7ixYaruTR3Er07skgAC0MNocJWT?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 86de2f6f-a0db-4a96-043e-08ddd4f5a625 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Aug 2025 14:29:27.7148 (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: 0Str24LBYMlQ743mzQ1vDuqFEtfqq2iUH7JjoM1iZSJ9j4XtqOJ+D6gTkHF8iy6O X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH8PR12MB7304 On 6 Aug 2025, at 8:47, David Hildenbrand wrote: > On 06.08.25 04:20, Zi Yan wrote: >> Current behavior is to move to next PAGE_SIZE and split, but that make= s it >> hard to check after-split folio orders. This is a preparation patch to= >> allow more precise split_huge_page_test check in an upcoming commit. >> >> split_folio_to_order() part is not changed, since split_pte_mapped_thp= test >> relies on its current behavior. >> >> Signed-off-by: Zi Yan >> --- > > [...] > >> + nr_pages =3D folio_nr_pages(folio); >> + >> if (!folio_test_anon(folio)) { >> mapping =3D folio->mapping; >> target_order =3D max(new_order, >> @@ -4385,15 +4388,16 @@ static int split_huge_pages_pid(int pid, unsig= ned long vaddr_start, >> if (!folio_test_anon(folio) && folio->mapping !=3D mapping) >> goto unlock; >> - if (in_folio_offset < 0 || >> - in_folio_offset >=3D folio_nr_pages(folio)) { >> + if (in_folio_offset < 0 || in_folio_offset >=3D nr_pages) { >> if (!split_folio_to_order(folio, target_order)) >> split++; >> } else { >> - struct page *split_at =3D folio_page(folio, >> - in_folio_offset); >> - if (!folio_split(folio, target_order, split_at, NULL)) >> + struct page *split_at =3D >> + folio_page(folio, in_folio_offset); > > Can we add an empty line here, and just have this in a single line, ple= ase (feel free to exceed 80chars if it makes the code look less ugly). Sure. > >> + if (!folio_split(folio, target_order, split_at, NULL)) { >> split++; >> + addr +=3D PAGE_SIZE * nr_pages; > > Hm, but won't we do another "addr +=3D PAGE_SIZE" in the for loop? You are right. Will fix it with addr +=3D PAGE_SIZE * (nr_pages - 1); Thanks. Best Regards, Yan, Zi