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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?VOTw/OMGwEkAgJ20wC/f0AnUVRmmnKKnIo6Rur4jTwwWrSRvyaVk2pRuZHLi?= =?us-ascii?Q?YEcNsGcH8tP6WHavuyFyCbpelOEJ/tdU/Z53otjQY0zr6IWyi5KH/YXltc1Q?= =?us-ascii?Q?azg+eHg7723H0ExxzpZBI9/QfIuBCup8BBZjzuvGzqcCTTCV+N7SwrMu62/k?= =?us-ascii?Q?YvrN4SsEvSsCG7wN2JCPBGTYyULxkzL/M/RFqTHWosgL2QMldUJ3cB/xOjlK?= =?us-ascii?Q?M74JGuR8pyRP0oPa/SY/5VMLde2MS1L4rlgP9+MZ6NL/g/XxlZdpEoVhKc9l?= =?us-ascii?Q?vnSk5/ZNiELECDzfSbmHWghaxY6qP5hE4Ep/10V3SlnPmCpMHFK6N433PG0U?= =?us-ascii?Q?NNkGPUx7/sUjAbAq10P/u0nPb5BkTojoLINngulMg4GiNBd6OC6dFDZmhHzf?= =?us-ascii?Q?rKEXSLsFexweh1LRDoFbBPr8/TYy3ETY0ravLjXQK9f2dn6e0/wfIwySaBKU?= =?us-ascii?Q?SGayJPXvyMQ/Wi9xW1dLwVbS7HXxJzFHhgpGHLruGJh7E1F3jI9CLcz5c0Fy?= =?us-ascii?Q?LD6x3Ujr7+djV86snnpXIzulTBy5Rxzhny97t9rC53Mbhafnj9MXyzGOMPtg?= =?us-ascii?Q?6JJedW8sthucbhXVd3P+gB6EMtL6kb345hHek2UQuGvtrOrythmWo6q/lOFy?= =?us-ascii?Q?R5Uwie4mCWMJuzNGKRBwjdWh5PZkYSYlGxlbK43XH1UaTyCzaZ5SlhOiEwyP?= =?us-ascii?Q?9VCi4dOg83Zgf2l6qnJTzNrh4sGutdmyuyYy+Y9LOykQpVnRr2HKXSKc+W/O?= =?us-ascii?Q?FFErYQwNWChZqx1vDluIyoA86wAn5gP6XMaXcwqdKTqHxIOf+m1Nx1NkCQ7a?= =?us-ascii?Q?zwwi34wVqe7kHpOhTwmYhhShL2+MJ+mqIkfSXRby1KCLNqM/ha3y7djhO9jo?= =?us-ascii?Q?IZTsDXwiwmrH4/r9vWw17n9iu1jFa4J9hrgFjhUZu5QvSlyuI0ZeaO5plZp5?= =?us-ascii?Q?PPHMmtM1XF8aV/F+TUJaJFCUq7+hV7uiJpt8Cot3sAk2PGVyFH5WpAVtG0nj?= =?us-ascii?Q?H4q3pgy1KgPpHj4pdLNOF54PjJVaz6kYugzK7mgPI30KLU+iarfGgAp6AEFQ?= =?us-ascii?Q?USJxBHRR7Suv0R7g5hm/nF7IGVB73lPsjYbqwaloQFEb8L+oNshcXzbdWfXn?= =?us-ascii?Q?0a0EdafBpM0WsEA3dmSkn4cwEb7V063vy72aumkLG14PrmHXQang4+nBIf/M?= =?us-ascii?Q?2U3klgKp/gb0FSlxrzNdfg/zWb1copPFOOVTFDOv9RsAtXLpdkq6EyeXIpYG?= =?us-ascii?Q?EeyfeCa2VDp3ciPN44OTN5rhSL6BGm4RPzNgXVIzFYT9Dyq7QOjQhPQPV62m?= =?us-ascii?Q?KoT2Dwwd8FXvoOaIXMvXlbVLjO+uaIc4czO/LDQa0TSpJdjZpUabedtTJIfZ?= =?us-ascii?Q?SDK186QYbMlUfBi6dn2+FfAprE/6dHmr3LfUzXVKHt2J/ZKaW4UI1fbNsclN?= =?us-ascii?Q?JaKOjEzI3EMB3Lb6nrLg4IRXwNqzk8H0HKL2gtE+FUZNaJtzpAlUsy5bp0RW?= =?us-ascii?Q?YpsdVosJQnZItj5/z/XVTPDSb3+Ly/s6HG1Cv1Q8vFRD/rI9EPB2yr5auyLP?= =?us-ascii?Q?PhbQRlo/B+hRHoIykQbiJzgzghwkAlQwzC8LjgQD7KSzy7PA9FueEyWewuc9?= =?us-ascii?Q?k2zwWrzRazx1+gq6kyaJuXA/5/7QhtGGXlPGgT+TAiimIUp4i1WBhNFX1ECA?= =?us-ascii?Q?5AqrqDXRY5Nopa+im2sLJik0qs/6V2weU+bJYggXCJYMr5QY?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1201225a-d063-4c3d-7619-08df20bcb154 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Oct 2026 19:38:11.2470 (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: oKTMIiOAkaF5pGBha2Lt6qoIVg8xL3enBooGcc4yBItSunzIBa2C2cx3amMZ3qGoyiUsznRMBduBqFHJ9PUh/Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB7938 Hi Tejun, On Fri, Oct 02, 2026 at 07:30:16AM -1000, Tejun Heo wrote: > Hello, Andrea. > > On Thu, Oct 01, 2026 at 09:12:16PM +0200, Andrea Righi wrote: > > + if ((p->scx.flags & SCX_TASK_IMMED) && !proxy_put) { > > p->scx.flags |= SCX_TASK_REENQ_PREEMPTED; > > scx_do_enqueue_task(rq, p, SCX_ENQ_REENQ, -1); > > I wonder whether IMMED should matter for a blocked donor at all. IMMED > should trigger a reenqueue iff the task is not being serviced by a CPU. A > donor under proxy execution is being serviced. The CPU is working on its > behalf and there's nothing the scheduler can do to make it go faster by > placing it elsewhere. If so, a donor with slice left can stay on the local > DSQ regardless of IMMED and of which put this is, and > SCX_RQ_PROXY_PICK_PENDING isn't needed. The deferred local check would need > the same exemption as the task stays SCX_TASK_IMMED. I think you're right, the donor's progress depends on its mutex owner, so re-enqueuing the donor alone can't make it run sooner. Therefore we can just keep it local, remove SCX_RQ_PROXY_PICK_PENDING and simplify the code. > > > + /* Delegate retained donor admission to its owning BPF scheduler. */ > > + if (p->is_blocked) { > > + if (WARN_ON_ONCE(!sch)) > > + goto switch_class; > > + WARN_ON_ONCE(!(sch->ops.flags & SCX_OPS_ENQ_BLOCKED)); > > + scx_do_enqueue_task(rq, p, 0, -1); > > + goto switch_class; > > + } > > Can this be folded into the following block? scx_do_enqueue_task() already > adds SCX_ENQ_BLOCKED, so a !p->is_blocked test on the ENQ_LAST condition > would route donors to the plain enqueue. Agreed. Thanks! -Andrea