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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?nQdSYpJvZElZXjMh2WMwdV0CcqPNwpWXeqrESBHxZyd5YboziP/ZdsUmHGTR?= =?us-ascii?Q?3rQRZ85gqMv5LSlSthnOl5zIgmF2a49bJtLyZ+KOfMzWWyZ+87ZjxiVXD91S?= =?us-ascii?Q?+9IWa1fVc73BgY2hjrT6y4dcYhqdfUyLv8xvu55z82vMw4Rx+tePNNOAvf+V?= =?us-ascii?Q?B2fDsmWuGnkDQzdy19Aeox6B3MY3qqLaxAQhklXENE7FkhYI6oBJ4YG7Ao/a?= =?us-ascii?Q?JraF5WEGHly6FrU4pF5TFBHVE2q4gn0sKH/PlsXyFqdERaRFBQDs8SNHOQai?= =?us-ascii?Q?kcdP6+WpfS1Zpf8CjwcZiUHIfwShY8JXejhZ5GiXD9cWcR8fB7FvXP2/qj3H?= =?us-ascii?Q?/cFP/7paX+lxSckkrkGzzvm137yCkYnfPPnei+ip/qUb8l7IwMKyGdGQV+Zo?= =?us-ascii?Q?0EqENihUZ3uBG/bBf6qgu5O/OH1CQq8PmFqfRrxUSP38NPSqa8MXajxvLdXS?= =?us-ascii?Q?HRi/+tb9jIFXe1PtMfPUAdaJUyNu8zDyH/zWV8ziP8/KPHND0aBh8qb6K5Ol?= =?us-ascii?Q?xwtAVesHguPcpvXCwbE1HKYZeMx7Hcb5fjAan1DV06RGAOklKruVti6Hsl6N?= =?us-ascii?Q?Fr1oW0G9PtL6OBqve6qUr9JR+tP5Kgzp6OiaMjkoT0GLwZpYFl+u02G8QcRV?= =?us-ascii?Q?7U9vpQzc6xyNvGtCaTa0QEqOCKVtce9yONo4lK3KLJaeS1am8/qfFrv1vW4x?= =?us-ascii?Q?7V8Loj9BnjyAu4Jpbp/x1YyMkc6KmhCO1WiTs2Aa7G5fiouEkQL3rGoAh04Z?= =?us-ascii?Q?87BrPzoiUSTxBxLLh8IQfyO+Et7hY7AMP6kdz7NypKHpQtU+F0Zq12BqJrMK?= =?us-ascii?Q?kdKevpF0k5igjG8KXNVNd+dYUx0yJUmKHDGM5KhH1BwyRAYv056QF2opLJEv?= =?us-ascii?Q?txAL9EfSgrzTpL7YbH43xuGSru9bKAzUwOQLUJQy4xvavtN0yY0dgKdymFP+?= =?us-ascii?Q?/keDVsYZpbvBN1/DabyzhiPlLxUMt6D97JK5QIxz6PuOPTAU5e4t8ERt/9iC?= =?us-ascii?Q?56fJMJetBA/SbgrY8SMiMeABryijrceIyjHFFnI2MOIFNzhEEEh55E+b2nvy?= =?us-ascii?Q?Z0ekCtkxdNigw3OHHLWdX3OnzgI8JvTZw7ZpB2MT5TdEXgTKYAoy2FbtEIvU?= =?us-ascii?Q?6ixmEv6ItxlMvnxDTJkSbfEQ+NAmwkVsBj8O7st+9N3dEyMVhR1MQp6uq+5e?= =?us-ascii?Q?1Jd6Dh+zJTs8IGwtHhDjdzjH2K4mncxJX7+4PWLQ9M2chw15qpK+Meps9MPf?= =?us-ascii?Q?G+xK8EySwzMgroMVZx1e1i7fKlh1jqZUynFMKHAlVOsup7Z/AfvyS+Q5kSCA?= =?us-ascii?Q?e7tqH3Y2SXiwa2DXBCPk2+9B64TELXPZj2GWy6wNCsMOrTmLwSTJ35yvHa8l?= =?us-ascii?Q?Ib4BgC7O4x4/+tlHOfWPWp/BLSdoc9R0LANHcjOfFCSsMM08tVpxkav4FNs2?= =?us-ascii?Q?S/jeqsA4TycNhKdN4P6rUsaCvPF/MFqcdgJwpJi3D8834uFR4XflfhbepAHl?= =?us-ascii?Q?1KZu8ntT7P5laURgBkSdHvuYPZK1x1zyWMbYpO2QH+lmkYh+JmQvt5glqAA+?= =?us-ascii?Q?sg6U98mAJ4EEHM1OdxojlsXiwUekF4Jq0do3BSBCFJdOlNlI4BxfLnwAFGzG?= =?us-ascii?Q?whzsW7SWIjIZHZI3XE5xoFImmFX6Mnev2N4hpV4+AXSxvUu1KqdrXXzr9IMu?= =?us-ascii?Q?zlthV+FRMxmnWZZ2HdYItkvlmi2iKCad0bvuIIOi//MD4MD4sH/RP376cKFk?= =?us-ascii?Q?s90yvMws2A=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ff75421a-f588-47d9-ff54-08de64ddcfb0 X-MS-Exchange-CrossTenant-AuthSource: CY1PR12MB9601.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Feb 2026 17:41:37.0992 (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: bTqwBcqHsVKwuAVLOx0/NkbdgrSEkH45lrZ/rCWPqsvOVDIJZe4DeyQRpV2eve1O X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR12MB7032 On Tue, Feb 03, 2026 at 02:29:55PM +0000, Pavel Begunkov wrote: > The proposal consists of two parts. The first is a small in-kernel > framework that allows a dma-buf to be registered against a given file > and returns an object representing a DMA mapping. What is this about and why would you need something like this? The rest makes more sense - pass a DMABUF (or even memfd) to iouring and pre-setup the DMA mapping to get dma_addr_t, then directly use dma_addr_t through the entire block stack right into the eventual driver. > Tushar was helping and mention he got good numbers for P2P transfers > compared to bouncing it via RAM. We can already avoid the bouncing, it seems the main improvements here are avoiding the DMA map per-io and allowing the use of P2P without also creating struct page. Meanginful wins for sure. Jason