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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 38Qf/y+kasLvE0mjJ0EZZOvR0qdFb5oOUbpzTEq+KspMXlLEmUYiTqhX4SGqYjXyXaQ0BiHoH89IP9f0UN7aVhpgGHmrkpbV2eKBWnA44IQL8IZrHcUhKIYVYXkMNN9O4CeliG9RIRUQ7g75ZsDWo1ex+j0Eup/m15osnBt0yH9M7I9lTELop9KyFTTltRORc6TVxnp2ZbaBUtwS2hleF0mDJUv8ufqwMohH/69liXvehXfsPUvlo2oM5n4+Hjq+8B8+r/1X+9wJBg6+ywiyc5Fsz5eNMGItY652rloXtt87xEVqzbaz+GT5GmdWShG817ybaoyrjDyfCTkB8dzQrFIaw4hMK3FSog/yTPrLzvd0F7Can8C1y65oBsK09xhfV5NO0lYp+W94nx/hswmxTuNoYbGpdTXTrrjV6LSN9brgFDd0LgOUj2sqblwAY7IC X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 May 2026 02:53:23.2432 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 84ce0a02-92c0-40d7-138d-08deb163f6c6 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: DS2PEPF00003445.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB8082 Hello John, On 5/14/2026 7:06 AM, John Stultz wrote: > So looking at the callstack when I see the failure: > proxy_find_task() > proxy_force_return() > proxy_resched_idle() <- sets rq->donor to idle > attach_one_task() > wakeup_preempt() > wakeup_preempt_fair() After this point, I would have expected we called idle class's wakeup_preempt() since that is the donor context ... > update_protect_slice() <- called with the donor's se > calc_delta_fair() > __calc_delta() <- div by zero > > Basically we end up in wakeup_preempt_fair() with rq->donor == > rq->idle because we earlier called proxy_resched_idle(). Could you check if following makes things better: (Only build tested) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3ae5f19c1b7e..77f4ebe8f5c7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6653,6 +6653,7 @@ static inline void proxy_set_task_cpu(struct task_struct *p, int cpu) static inline struct task_struct *proxy_resched_idle(struct rq *rq) { put_prev_set_next_task(rq, rq->donor, rq->idle); + rq->next_class = &idle_sched_class; rq_set_donor(rq, rq->idle); set_tsk_need_resched(rq->idle); return rq->idle; --- I'm just getting started for the day so it'll be a while before I actually get to test this on top of flat cgroup bits which I haven't yet run with SCHED_PROXY_EXEC enabled. -- Thanks and Regards, Prateek