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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?2MN5YvoYebM8pTYTmU0rhDIgSXHxKoMhWyeDQVTP7hMNsoBvJ3/vDW1p6wIy?= =?us-ascii?Q?A672wjW9CT5Qm1HABbKLFjzVIo/y/qWXmVIPVKgxAElAGGDSilKeR+cTU2tW?= =?us-ascii?Q?R8AntN66R5JzVJFqddlCQ/PIYzyM7EiypctUOm7Z7m7kEh0//Wc6ZTtOAt0e?= =?us-ascii?Q?yF/8gKQzAX5HCTLXocJ10eVhTlzyJ5EeepcxV0ERDwp/sjtKoI+SIyfEFubj?= =?us-ascii?Q?XQKJW0+/CccbtlDEJRh7kx5SQfzER/rQtmd15xrrxCR62HkUm8Fy2HG3yBMM?= =?us-ascii?Q?4BoDRDNxqXPFLSLTnIKsKn66AdnqgFne0oI4A+ECbc9n6hlylFYFw1CWGM1j?= =?us-ascii?Q?SqBFKZeJDUw2k6bMUSGGk+kqq9f3ebY8W+XZTF8Xh5ZPUGMSFUartYhuh+Gj?= =?us-ascii?Q?5ebhLluh50vXpfaHvCdJ5zNxSE/twVcnG61IgWvm+TxtdhQuRKXJ5AOLpPcS?= =?us-ascii?Q?bI65wQ09d0xaF0Xi7rIQ1od+JmVo+vp1lFyKoEKkTVc10gBey2diBHonxeF0?= =?us-ascii?Q?GK8blL2SbBEImWQf63VWQr5QyLLBQfTOGXGn/T+RCHCT0HN5aO5dMCBnNAcg?= =?us-ascii?Q?iMRKdksf09HiWf5GR9rMjf+85ehJLFKAT2CClDx3sHw1/TKoyykE1R4fEthV?= =?us-ascii?Q?C9DJsCy4RYDPsgOLnKR4EJPfktk2C3j4cP1q1PD3FCrNpBFc5MMk72WLtBfq?= =?us-ascii?Q?bCA2f5gA1F1bvt0HaBPNBaGAzGtlwQTNMOgrdnOuG7wUjpeOQ2RpkityZ0Yr?= =?us-ascii?Q?2k5gcDp2uj3MTBOwJarQvfWiXEqYIq4V1sxJMUoLM2fVYzYWY/Y3ZKbU9H8W?= =?us-ascii?Q?CeElgP1KcbQATk6JKEzw9SInUj7cJxXR5A9gRHRN5QfdAVnD76nQVYirLCD3?= =?us-ascii?Q?v9f5gKImAt6oINWD3qCQIwyQQJe2v1c0XQRttppn1QsyyKVo9nQj1phPbL+b?= =?us-ascii?Q?WpQfIGx2b0ExvbzNA2ttChMpieqn+Crvi6+Ffs/SF25tDGIrMo2xks6EboLx?= =?us-ascii?Q?FPtuQnSBaqI2oIlYSn+p4sHRshoWrCTGcYfgaJ7zs/5bOIuR8AJ4+2UnPzha?= =?us-ascii?Q?VPjvWqDVySgDXMz8yTA6vcFuqJc2QbHZmqYTNRHMVaYapCJFo32TEoaQLXvP?= =?us-ascii?Q?q7w/wbbZKwvLHxDwasmtsbanSzh/dbQk+0I0PmIIpbG6+J6wKHeRlA5ggg1F?= =?us-ascii?Q?hW/vY4QGnRG10+lZ9w9r6A9bSWAVai0SCVOdAu+3suN+DYBO/0zwszCmGgTn?= =?us-ascii?Q?OlO1BpzZLm6v9Gx9ZbuCuf8Eb2fQUs473H0NLR4Pmvlk7X1cJXslLxLOMJur?= =?us-ascii?Q?Rrv+uUIRezjxkO++lTmEpsVtvrIpqEDsjQDAA/CcpXFuOuBJ8RESPttwSrVh?= =?us-ascii?Q?+n2oSNeJOkR8Bl4A4BqdBj2Td8WjzwQZGuhnWWaAC0duh9H1+k3fCkVw7TXl?= =?us-ascii?Q?7eU5UP6n6U/em1hIHgC73tizaYhPgvGfjA4BodGWHjIKrn0/x4Q1RT11jLmO?= =?us-ascii?Q?m3NXkoNPMBv+UfP8Hda/FJzNgQtT84Eje/C7gQhXTxzzsRL/opP8YMLO/YYP?= =?us-ascii?Q?9QBway/9FnYAz/tv3sPDQ98Zdh3bUdE6Uq4sNGmEWrzSzS+c2FOtKt0WkUyk?= =?us-ascii?Q?3qV4Crlmf8trFk2IZSgC8bjialPFmVlkpHHozaphSGY+ISQpSvdcTAG5x9gn?= =?us-ascii?Q?BMdcDvm/cGX4gDcvglzFR00fGJv7rhegSatbRhrK0qFYrHr3EMOh8MYFITPl?= =?us-ascii?Q?QLaRQVYE5A=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ce6a90e7-bf7d-4bfb-061d-08dee2b39704 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Jul 2026 20:56:49.5130 (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: /6OUODnlPqlNb1iAK/84Fus6bZqC34JH75KIXwDlwVVjB0WzJVOBJnQxSNlg1JXdBr9JHLR9wvANpbk2hIEFJw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH8PR12MB7255 With proxy-exec, pick_next_task() can return a task with p->is_blocked 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_RUN_TRACKED to track whether a task entered an ops.running()/stopping() session. 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 entering a tracked session. 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 803da0f1e5092..5da12d6562b8e 100644 --- a/include/linux/sched/ext.h +++ b/include/linux/sched/ext.h @@ -103,6 +103,8 @@ 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_RUN_TRACKED = 1 << 6, /* task is in an ops.running()/stopping() session */ + /* * 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 2035b71671a75..9836667356c89 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -2208,9 +2208,13 @@ 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_RUN_TRACKED)) { + if (SCX_HAS_OP(sch, stopping)) { + update_curr_scx(rq); + SCX_CALL_OP_TASK(sch, stopping, rq, p, false); + } + p->scx.flags &= ~SCX_TASK_RUN_TRACKED; } if (SCX_HAS_OP(sch, quiescent) && !task_on_rq_migrating(p)) @@ -2912,9 +2916,17 @@ 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) && !p->is_blocked) { + if (SCX_HAS_OP(sch, running)) + SCX_CALL_OP_TASK(sch, running, rq, p); + + p->scx.flags |= SCX_TASK_RUN_TRACKED; + } clr_task_runnable(p, true); @@ -3020,8 +3032,13 @@ 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_RUN_TRACKED)) { + if (SCX_HAS_OP(sch, stopping)) + SCX_CALL_OP_TASK(sch, stopping, rq, p, true); + + p->scx.flags &= ~SCX_TASK_RUN_TRACKED; + } if (p->scx.flags & SCX_TASK_QUEUED) { set_task_runnable(rq, p); -- 2.55.0