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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?5KfjlibT6jQHZXW2UNbobCJj0Ls9RmFblGbAFR3P0ft2FxVpKloD11uzx85f?= =?us-ascii?Q?YcWttSJYIkBuFJbxBpBJGOMfIzqKk69mBLhuZVFQEt9PtEaB9lQy2RJjmV48?= =?us-ascii?Q?JGTnmQaNDdgo233SaHiYPOuGTzZLAVLBWB3MSFLyELh3bSSpQ6yON3UPYtUV?= =?us-ascii?Q?MwH/CJdmoe1HbCYvLrDOW5uBBWhQ+/RcHMujylu+fVdb51Nn56lGPfofE6t1?= =?us-ascii?Q?9m1As5+4JwOc147lQoMMfpZi7YWa+Wn6uP45Gx/5aoOscZEuRF+JFCdM4EH9?= =?us-ascii?Q?0ZWNryUpeXShzFUOwzWfFA+ZE7vPzVsDNWXKFGTzLEQtcynjob64iCOHRGsb?= =?us-ascii?Q?azXtyaHApekJcKwbOzZsLDr3zQaxEtFm4Ynqta0Tbb99gpgz9gFtMMEd2g/R?= =?us-ascii?Q?RtKTOw5PSoOyVGcZ0dXdcnPxW6xTxmpreOQmDCKd1QvT3zW9i+hlTeNUOFaJ?= =?us-ascii?Q?PlHLuxT9+IJ3s1SImrc1eGqBrskfr7qwa9CuqNSaiBeyp2Dm1jy24YLUC5Ai?= =?us-ascii?Q?qVjDCKj3O3q8tGV8s8eRi34OvrTRCUq6+T1BM4BWAzdpeafe6gC87PXkdz75?= =?us-ascii?Q?d7gH/r4u6aCDvIU1mEEOj2EWT6k18bW6SHNexDAJJRWo8XGXwcfzLGY1Xj3Y?= =?us-ascii?Q?1pD9K4+d1G1tSNCMBvSm2TeS52ApYeu8VA0q1AjXnB8+os1Xf8RTr9Iiw2t6?= =?us-ascii?Q?DKopzBK2Bx9Fx2EwOhcARPnSbpP25xyUd0PdvhAyvMauLGJNA148myFvjJjv?= =?us-ascii?Q?Jli01enAg/rLm2gyXIAd6YY3fs2gDHD5iFPRxD7iS9HM4qYcDlS37RhLI+LW?= =?us-ascii?Q?jMg2tvQPuMikQiEU5evfgK9lW8Pi4dkq+x8VEMkd9PGWRfo2Bbkv58Say/RF?= =?us-ascii?Q?CG30T39Abk/mAyolOsQGxbkVwT+AJmgihhoCRu8y6BysLJy6GFXAkDE1Kv+A?= =?us-ascii?Q?j4mQaNYlSdaC5XOt6VRRqqSqC3thNBh3bnia+0l4jPacPCaWlKE3s7wVaMJ2?= =?us-ascii?Q?5WEtjJijO4mHru98Cx7AjD7EDNaTsK41HQfbH+/FcObPWJrX8PgYzPqvnSwk?= =?us-ascii?Q?+UWWEg7H/SkoAfZTSztxgpHCW9kONlgxW0vl4Du2qYd3DaT5oKpSRIyox/fV?= =?us-ascii?Q?2nFCO0DXwoW01e6GSWz5Bw10nQmnSjrerMTCWwOknq1Vklx647RQ1RcQ+ekT?= =?us-ascii?Q?UdvsHHw036rzC5GYqrKo84Z+k9r8nmzNYPaS2Iyguf3VzI+3yESFqiq5zJX/?= =?us-ascii?Q?Eb8NgcvHRAqYKxBJAk6vyNHGXJSkLGv0LBZG3dtdt0s+JZu/fTDrQ9UCYEt0?= =?us-ascii?Q?lAW+ik4ZucF+Quz6BaLE9tmrJNfpI/cVYbTkpv64+odwflNUiiCLV/RCgeNM?= =?us-ascii?Q?1ixrzj60I0DfXzX0IHZ9K5daogqpjmHjxugxbsVGI8znCmcAh34V8jKGpBR1?= =?us-ascii?Q?rW6G5p7F0Hhivil07KRBNVEnVR+XahVCTRY3o3eDXt8M618xg+j6j7KW4d0Y?= =?us-ascii?Q?Ys3OsPUAM26LC/V6OX0YAN5Ux6KiJGVrTQaU8L/hy2sfr17YRlxNj+k3weT5?= =?us-ascii?Q?CnlNZuaj2i8IG2TdoQuAbAAYLiBjptrfhiflJJPj4Vm2Ahwq43Hgo//RC6MJ?= =?us-ascii?Q?hCT3Nd0FTbIZtdHgtBXpnx3UhvROH+qFs9tWr4/9WFdbKsFrIzPNXmLNG3NV?= =?us-ascii?Q?BAAP275eWyd936sdZLGRh5Ws/a0iUc7jAcsiD9H4d2nMN3mPXARx8qb0x1Wn?= =?us-ascii?Q?GXJ1mipHmg=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: cb558abb-15a2-4415-b5d7-08dee33d5e06 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Jul 2026 13:23:04.4366 (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: fVcwReV3QL9tDzFygSYZlhO5gURnwMPsN92ktJR35uakXuPQIWpQ9Dc8cCA5ezbpNPUsn+g4CMXN9A5QQRtr6A== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN7PPFFF39339DD 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 cd43283e54d8d..ecef4cd9be1fa 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -2209,9 +2209,13 @@ 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)) @@ -2913,9 +2917,17 @@ 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); @@ -3021,8 +3033,13 @@ 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