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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?spJmirXlzkT364voE/FJp5msRNVcgpXXY+vqja1iZ3AIcP4bOk8qXYNgPiJi?= =?us-ascii?Q?fXYR46RLDC8mh121rC9SAypTmWk7dn+eHLyU/+rpSbj2+H7gRJalaGFbHw01?= =?us-ascii?Q?UCE49V5ho1re4iZbyLcFOKSMd8k8e8hmztW5pkU/A+lKYQeezIvwwy/cA0KF?= =?us-ascii?Q?ZNcDGljkfioyjANUQ+vONqzMFuMHYZZWo3MM2I2hX8lQGMe49a3PR00emDAP?= =?us-ascii?Q?WFvK5fDuSZBdnlKV5CK78B21fGaYmLKeOJeahjYNhhjywwmEGldOmjj9Fjqw?= =?us-ascii?Q?IpUU6+irzGTg9wnu3Sq3pOMPYwIOUwFg5iCouaNKJUebsrruwuk2/VBxLmdm?= =?us-ascii?Q?z9Vue3/Y0lnbwaOiXy8GyJGE696mOVrGSF4iL+osnT1Haum8kd9b1g1uc/Aw?= =?us-ascii?Q?gfeoq4PzJ5KTZspYjxOSU3K0swZh0uzIOPJwUFfVAzdL7YM3F04jnRFDKqu9?= =?us-ascii?Q?xD/k1NY/cVhgxzgW3BLLst0A5ONji+8/Dy2syWoik3AZaIyeN09F1P9VHIcN?= =?us-ascii?Q?0XhHvrw1z5xDZvXl4dxfGESCBgMk+E4FWQdjY/QLtKND2Y8nX+yleCdEeHOt?= =?us-ascii?Q?U2+FMUHRCW8L7JRWiyorQWo6vps2wyqT7Nrdoe8uSDf5nBHqU9FlWtVK9HhM?= =?us-ascii?Q?rIaQaXC5XUgQTAh7sCkgJZNd+EcfTALSeFnXfMcyuVgYphvwzbYrktx6071B?= =?us-ascii?Q?7zJPHZwIfanLTty6q5CTNL6ZmTaFiKyayyN2/kd/q+Ayo7VRZCOIo11Z7Qrp?= =?us-ascii?Q?k8ajI1fy9jSSoqVj7K4+iH5njLhB5QkQxnyWLJkE5ZNqm+/a5LbNUO7uag7r?= =?us-ascii?Q?7DmCiq+vSADtLTW5/OSHwqJubrVxkGksfMxyH6hSeDI5BU+jfZkR3bbE28uJ?= =?us-ascii?Q?8++XMdR9gDx/3COdiVufPCkBSKq28UQCMH1tJjBXDbvRYeV6O/Hud7U51VGS?= =?us-ascii?Q?eegdpgNZngnE6r7I97gsfi5McR68KriVGPqMGDmwSKExydwIHro+MzHEfALt?= =?us-ascii?Q?K57bATki9aueLd0cCci9edWZz6bQdXEpHc04HPfAcFws2RDpVcOTkRLBMz+s?= =?us-ascii?Q?sHYZ4Z5iKtbtOnUbfFH9MjBdgDON6Ru8uE09OGYOWiqDdOdLnHRCHlzZtici?= =?us-ascii?Q?GM31C4hvEnWuvBoen9B9B+kztv8QGZloMExzbsB8pmwFGp8bxjtxJKcSwogj?= =?us-ascii?Q?0GmxcLYnvqblxExBDt34Nme4aUtbWHkGjI+AdjrVqCZRtICbYpL3Ou2ZbFlk?= =?us-ascii?Q?uqO2YdgqwMBN0waPVy0VJEXHFkaUWD1Gi5arwl4Sz9mWBP3AemrVCOFC8f8I?= =?us-ascii?Q?3Edlpx6DxeU+KO0zjkBxqhPCw958exBtrrLcy7NiP9BJ31uk1odKH7FE9NQQ?= =?us-ascii?Q?pS5LHa44Zq+Kl+B1Jy+MajxaP6k8dyENkSZ0WiImPO/WLGKUNCxnrLMQyesr?= =?us-ascii?Q?aKcvZAhBI3aEEuSWALHnoVCBVThwvDWNz0nEzEMf27WPpSiX3JUChZml0uPB?= =?us-ascii?Q?cYM5OZWTOMMfJ8EqovMEoNm3z7z871NrxGdYJ7YvGxeBx15rbKi9MW0xUnrO?= =?us-ascii?Q?XUixRDN8dabIp4bVcCSe1BRouKS5fHoXiLEomEa6?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3201b4bf-7a10-4def-930a-08dd1ec640a9 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Dec 2024 18:11:39.4773 (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: IQtroX3kzKBRMmU3dYD7sCBHVhnbLcfS0fbFP0VRH9GxiSxszRTb11kd89z8SW4s X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR12MB6169 On 17 Dec 2024, at 1:43, Ryan Roberts wrote: > On 17/12/2024 04:18, Matthew Wilcox wrote: >> On Mon, Dec 16, 2024 at 10:20:54PM +0530, Dev Jain wrote: >>> -static int hpage_collapse_scan_pmd(struct mm_struct *mm, >>> +static int hpage_collapse_scan_ptes(struct mm_struct *mm, >> >> i don't think this is necessary at all. you're scanning a pmd. >> you might not be scanning in order to collapse to a pmd, but pmd >> is the level you're scanning at. >> > > Sorry Matthew, I don't really understand this statement. Prior to the change we > were scanning all PTE entries in a PTE table with the aim of collapsing to a PMD > entry. After the change we are scanning some PTE entries in a PTE table with the > aim of collapsing to either to a multi-PTE-mapped folio or a single-PMD-mapped > folio. > > So personally I think "scan_pmd" was a misnomer even before the change - we are > scanning the ptes. But there are still a lot of scan_pmd code in the function, for example, VM_BUG_ON(address & ~HPAGE_PMD_MASK), _pte < pte + HPAGE_PMD_NR in the function. These need to be changed along with function renaming. If after the change only a subset of PTEs are scanned within a PMD, maybe a scan_range parameter can be added. Best Regards, Yan, Zi