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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?BO1hXjW4W9jcODp/6MHE+SKyk/DXd0J9n2A+Kivd2+dP0f2za8I1y18Cc9rs?= =?us-ascii?Q?QUDMv5HxCyK3zOje0HJZXQmLYBIr4m77SUQ3Qz22rEPhwSjzIur1qRoyxehs?= =?us-ascii?Q?ljGnESqb/Z1orEtZFlMRTc2hvxCfao8gIaigEUXei+LnADucyx/kehIogS6V?= =?us-ascii?Q?R6+A3NeEdCT8TJw2CHeuU+Uc99y8IJEgOVqn5rvHOHegtgnOd9ASwjdUcQ5T?= =?us-ascii?Q?JrGJJU8hO/F+795DGECObqz/0GkdvUht0FGDrvwRLjuuBDu5utUvbN895YY4?= =?us-ascii?Q?S3V2LugTrq7BfDpzI4LaAR8bnLqc10vSlzMQY6U7xtH00W2xsn6HSEi4Qs1V?= =?us-ascii?Q?E2OatuAFdAqZ0KuGYdggyRoQuSw/DZWjnWhSyfKBwnIEuAHGjf5sTmSqsq+C?= =?us-ascii?Q?qWn41Mzc4PKnSxSWVXDL0AmY8VaEMwedPRpoMdGHqDx6fYIArvrRh5Avc1rd?= =?us-ascii?Q?1TRshN5y0t5CKDQDduECuyo5FBhb2ApzrPICjnOp2s5iQm/Xp8/YJ6o5+krG?= =?us-ascii?Q?cau3pYY3G5QREKGSGY3uHaivh7E4AmyGG14RtPPDLjpwZ5hIaFpQEyh36VSz?= =?us-ascii?Q?MDDPoFwjHOLB4giS9CzOWDQbpyCCogG/fm7UjKZf6/51E4hBrbvo6nuWs/iF?= =?us-ascii?Q?9gg1QNykpCYmbfggaak9sYi0bYRmTvlpqbH2dIjST0m9WboWl0ymwkINzRNm?= =?us-ascii?Q?N7MvpweHfHNfW3STdj1wf8WOK+mX1yCMZIKXuNvBKJ+QibA4sARkBsT+4yet?= =?us-ascii?Q?J2X6bb4eUUCTfYOmTZTr6FSqinZpmLA1xOoneJvWvNL4zUk6vZHNhrHkOLmV?= =?us-ascii?Q?IvjldPOD18Jh4Y04DFNMTg1ej6s/Fj+405OeP5HcbaGYucEuuRl7SNGkwtTF?= =?us-ascii?Q?z2KUlWgaqTvi1hDWyFJN1zmj/3RlFJlW23maKwz/VK8h/dz4K/jRVSbl/Nl1?= =?us-ascii?Q?sFoNJrqc5wvz0gvj6RYrv9p8kmNf8InE4S8MmnDZq2qQwmQpNFVul1FvrQcS?= =?us-ascii?Q?5E5vUL8DmFGz86f2PDy86wZl2FCAMFx+dXTsdLDxY8t3wQFUWWGpf7EfieDq?= =?us-ascii?Q?9DuqDVHWN0B24/nfoJwO9qXGADRQvVlAGdY9x+9XTiQyObwSBIL85j9CAXC8?= =?us-ascii?Q?PcVOM1veyBXcekawP4xrViGuty/n64l2HCt1mMIHr2LOFLHtpaWQi6LjlR4f?= =?us-ascii?Q?2KCZBnBD3/lCeaFkPsGRFFdvYCX54BIJIQQ2Mh69NlR9RuJ05XXPAB/vNSg1?= =?us-ascii?Q?7yb1AQ9Ryp1P+weppXRkrO60I6SCsTcBq0QtQHcrF87sYNxfEptbBDYCLGBd?= =?us-ascii?Q?UUMELT1Gncz4c5l1yMndzPk/ymHNHCpSiQnSnoobgZ4AHyaBUYU+Y4RAq7P7?= =?us-ascii?Q?K7FkukXP2xw/n4c4QSJJXkggitegoSxSObTqrEfOkShAohdMBQvGgbHNNaen?= =?us-ascii?Q?o7w2SJO9rN2L6ON6nAau4sgJ9Wa2TrCWZFWl2KiVbsNrNeXo8f+IEh3rQoPY?= =?us-ascii?Q?SaVMM8WrpZWTZ1hcHoIo7WsXKVV4ALo5ABadw1ENC2+O3EQTZy/onXNhF2qc?= =?us-ascii?Q?ZefJZ5TAx0ourqbZDZhhcadJjA5VgiIk/6igWHZAngpYgEQcx7L6NaclTVj3?= =?us-ascii?Q?2kOjqFRwykJXcNpqoJOXZUApG/CnE7ZrBqbFq5ALIJHg4MJk0Z+ZV1jraUR4?= =?us-ascii?Q?XQARmUH0sKQRDyWeico4RjNl152mzODtralIzzF3O2abCK8mUJxlk6fA9XVv?= =?us-ascii?Q?DSYsiLSFiQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 89a4269a-7ff4-422d-75ad-08dede5ec75b X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Jul 2026 08:39:39.2284 (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: vj+2zKoteByUAc4Lg1WoTrpbBfwSp8VdvC9VEBShUDM8Lw/uWriGm2qxFqYXhmNLzb/dB6YjZnmZJunpEozsOA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH1PPFDA9B3771F With proxy-exec, pick_next_task() can return a task with blocked_on set (a proxy donor). put_prev_set_next_task() then calls set_next_task_scx() on this "ghost" task even though the task only provides scheduling context and never actually runs. Calling ops.running() for such a donor produces a spurious running event. Simply suppressing ops.running() is not sufficient because the following put_prev_task_scx() would still invoke ops.stopping(), resulting in an unpaired stopping event. Introduce SCX_TASK_IS_RUNNING to track whether a task entered a real running transition. Set and clear the flag independently of ops.running() and ops.stopping(), as the callbacks are independently optional. Invoke ops.running() only for non-blocked tasks and invoke ops.stopping() only after a real running transition. This keeps the callbacks paired for proxy donors while preserving stopping notifications for schedulers which only implement ops.stopping(). This is a preparatory change for enabling proxy execution together with sched_ext. The explicit running-state tracking is also required by later donor-based accounting: it prevents an EXT owner executing for a non-EXT donor from being treated as the active EXT scheduling context when it is dequeued. Signed-off-by: Andrea Righi --- include/linux/sched/ext.h | 2 ++ kernel/sched/ext/ext.c | 33 +++++++++++++++++++++++++-------- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/include/linux/sched/ext.h b/include/linux/sched/ext.h index 75cb8b119fb79..c6f58e1a66cdb 100644 --- a/include/linux/sched/ext.h +++ b/include/linux/sched/ext.h @@ -102,6 +102,8 @@ enum scx_ent_flags { SCX_TASK_SUB_INIT = 1 << 4, /* task being initialized for a sub sched */ SCX_TASK_IMMED = 1 << 5, /* task is on local DSQ with %SCX_ENQ_IMMED */ + SCX_TASK_IS_RUNNING = 1 << 6, /* entered a real running transition */ + /* * Bits 8 to 10 are used to carry task state: * diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index 5241b55a58eca..6b7efb19d2843 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -1989,9 +1989,13 @@ static bool dequeue_task_scx(struct rq *rq, struct task_struct *p, int core_deq_ * information meaningful to the BPF scheduler and can be suppressed by * skipping the callbacks if the task is !QUEUED. */ - if (SCX_HAS_OP(sch, stopping) && task_current(rq, p)) { - update_curr_scx(rq); - SCX_CALL_OP_TASK(sch, stopping, rq, p, false); + if (task_current(rq, p) && + (p->scx.flags & SCX_TASK_IS_RUNNING)) { + if (SCX_HAS_OP(sch, stopping)) { + update_curr_scx(rq); + SCX_CALL_OP_TASK(sch, stopping, rq, p, false); + } + p->scx.flags &= ~SCX_TASK_IS_RUNNING; } if (SCX_HAS_OP(sch, quiescent) && !task_on_rq_migrating(p)) @@ -2686,9 +2690,17 @@ static void set_next_task_scx(struct rq *rq, struct task_struct *p, bool first) p->se.exec_start = rq_clock_task(rq); - /* see dequeue_task_scx() on why we skip when !QUEUED */ - if (SCX_HAS_OP(sch, running) && (p->scx.flags & SCX_TASK_QUEUED)) - SCX_CALL_OP_TASK(sch, running, rq, p); + /* + * See dequeue_task_scx() for why we skip when !QUEUED. A blocked proxy + * donor is also skipped because it provides scheduling context but never + * runs itself. + */ + if ((p->scx.flags & SCX_TASK_QUEUED) && !task_is_blocked(p)) { + if (SCX_HAS_OP(sch, running)) + SCX_CALL_OP_TASK(sch, running, rq, p); + + p->scx.flags |= SCX_TASK_IS_RUNNING; + } clr_task_runnable(p, true); @@ -2791,8 +2803,13 @@ static void put_prev_task_scx(struct rq *rq, struct task_struct *p, update_curr_scx(rq); /* see dequeue_task_scx() on why we skip when !QUEUED */ - if (SCX_HAS_OP(sch, stopping) && (p->scx.flags & SCX_TASK_QUEUED)) - SCX_CALL_OP_TASK(sch, stopping, rq, p, true); + if ((p->scx.flags & SCX_TASK_QUEUED) && + (p->scx.flags & SCX_TASK_IS_RUNNING)) { + if (SCX_HAS_OP(sch, stopping)) + SCX_CALL_OP_TASK(sch, stopping, rq, p, true); + + p->scx.flags &= ~SCX_TASK_IS_RUNNING; + } if (p->scx.flags & SCX_TASK_QUEUED) { set_task_runnable(rq, p); -- 2.55.0