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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?K8LoouH4JBUm+yL/yXgRaRgLYCystTJqFBtPv/BhH65xz86QQBI/k/bQkYIr?= =?us-ascii?Q?U5NbZVci85BR7r51KQjSO7iSNAR7oPHW/D8bCfNmou8Ny5pEZ8vrYqgtdIr2?= =?us-ascii?Q?ShRb777rmkGrdQeUiY/fahrrtAVXfZ35kwQCv/oMup7+NZDkafMnDIGsRz+S?= =?us-ascii?Q?7h96a44yjCfexAdmPdvrAwo+ksPpi925gTxmSfl1edH8frzFqknHq1TZj72+?= =?us-ascii?Q?AkTcGP9uiq4K5v9s6M1rA90KM0NL0YblIGXRadBRlufQZl7LekL2X1UXLDdX?= =?us-ascii?Q?u4VKMcSnGidH4eFEzlCPZ9P9htba/82Sqqn5MBodBOZvfevm3jo27MGRA4DM?= =?us-ascii?Q?ayoyLNkhb2oz480IzmafZmFvyJIVAmx1NWnjYChLnFca41jRInTDG7FiP1ld?= =?us-ascii?Q?aKUhrXWP7UUVrMFxN3nRrXMRNo1NqVeT2ynUYqig0fyBR9qJ1pMqKr0WbJxQ?= =?us-ascii?Q?J3oZ8cf0p2KUPgL+RlLA0XX/TkuWFwPMAVfGn5s7AVfTrtisGx+52+USAbSx?= =?us-ascii?Q?naoshB3TmtNeitv7JsBKOk6ZC7Q/1FTJyGBX9E2SUoOTG6eYYB52zo0p/Pyf?= =?us-ascii?Q?186LJ+ZFG1rhkU0129y4ax7yyoTlU6UrnyFLnVfMrsT9RfknSFoPVBiwUS24?= =?us-ascii?Q?D1Uwi2hrPbv5Qn7sKbAgh3ZCjWrq64xPHXnGoRRBcd8zIRuoUUS6+Zv+1AIS?= =?us-ascii?Q?AUuMhwn1Ch4ekc9nnRU3K6vj2PfX70/UaG9lA/rYl013j/7HYe7ts71kWxS0?= =?us-ascii?Q?VhAg7xXbVZL+uuKX1aY2b5iDBSO3g45HWiSDYa09fD5JYo0ntCmJxKd9PKt7?= =?us-ascii?Q?Z8Ce5qlunXX3Tp3LWCZfJisBZGcSPESOUIJtiNvdYimUsOdHUIEXhl7UAK51?= =?us-ascii?Q?tt2UjwvougvAM4WyR5am4dLFrJht/WJuIxqBddVnMS/aIaCwGbWiLpI4DUYk?= =?us-ascii?Q?+Sqspwu28oIURX8ThZZoPcl2zb47LK3SKRQfvdplMrwqQ/8DLeJj2ph1gPFc?= =?us-ascii?Q?8QyepTEmQ0MQoJ/aONXIEt6b7whbmPCKHlATt/1HbMd6QPtxd1jd3glsNf8j?= =?us-ascii?Q?zU7WRTu79xAOFHiV7z9A87eGhifBYTiDrZ2xno78f8q4XKgqFKhmhZl5SsyU?= =?us-ascii?Q?gCUbaoAyRVWgIMXbgPbk1yp/zvs2stj6Dgz5oYXLRbAcTcP2KcmwLpv0fJic?= =?us-ascii?Q?+GVGV3s8LKFGd/3mp2arub5xICv7fHqJNH3E1O/uO0lltqsKvdjL+11l6v1Q?= =?us-ascii?Q?m6H+21rhF3IxSwoh4bNJZNGFc+/2JqeLaXgOU7aWwJouf9Gew5QbdmuF+qY6?= =?us-ascii?Q?in3mXhq3mge508qqSKChXrUUGxuSsTfLxZJT2ChEnmZ/wvglgt+ffvs7VX0a?= =?us-ascii?Q?XUn+dL2FNA5N6jnpdanwctLunIaCzW1GOqB7eLnRYs9IxOcX9McpZDrEGauR?= =?us-ascii?Q?NSWu7/8bO9b5CnxzRrjJXkZq1Zhe04sfjXdOYk9cx3B9lQHkzEVWvO1Ted0V?= =?us-ascii?Q?qD/ddlVYwwoU0rWc06mrozwsaZm4TFwgMAq8tv7mr1hW2IXE+nLLU/cJh0B0?= =?us-ascii?Q?8HZ1f7z4MqBTBXi22+oFJ2DRzjdBKoOGuJzBO/C0o2HGqpt6KpSsfPzz1Mig?= =?us-ascii?Q?RB04Yk7tGjBIY22ZjbZeP4i1xAoj/sNJlhSAj5dcXKKqfZvgpQe+OBvEj3+K?= =?us-ascii?Q?bdrFxSxBv46JeEkWed8vzLjCxCfhqBDahuE85NgKLdzY6a57JQ07Bdn5LfLl?= =?us-ascii?Q?ZgA0WEyy+w=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 65894b57-7b5f-4bfe-3df1-08da4a1c8395 X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jun 2022 13:32:35.5044 (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: 0dRMrHxKbKlrfHaiEH5AlqCHOQtrsNMTNzsj5S1YfyV1kf0XBlYXlWlv1SXwgMSo X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN6PR12MB1746 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 09, 2022 at 02:19:06PM +0100, Robin Murphy wrote: > Is there a significant benefit to keeping both paths, or could we get away > with just always using RCU? Realistically, pagetable pages aren't likely to > be freed all that frequently, except perhaps at domain teardown, but that > shouldn't really be performance-critical, and I guess we could stick an RCU > sync point in iommu_domain_free() if we're really worried about releasing > larger quantities of pages back to the allocator ASAP? I think you are right, anything that uses the iommu_iotlb_gather may as well use RCU too. IIRC the allocators already know that RCU is often sitting on freed-memory and have some contigency to flush it out before OOMing, so nothing special should be needed. Jason