[bisected][mainline]Kernel warnings at kernel/sched/cpudeadline.c:219

[Peter Zijlstra]

On Wed, Oct 08, 2025 at 07:41:10AM +0530, Venkat Rao Bagalkote wrote:
> Greetings!!!
> 
> 
> IBM CI has reported a kernel warnings while running CPU hot plug operation
> on IBM Power9 system.
> 
> 
> Command to reproduce the issue:
> 
> drmgr -c cpu -r -q 1
> 
> 
> Git Bisect is pointing to below commit as the first bad commit.

Does something like this help?

(also, for future reference, please don't line wrap logs, it makes them
very hard to read)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 198d2dd45f59..65f37bfcd661 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8328,6 +8328,7 @@ static inline void sched_set_rq_offline(struct rq *rq, int cpu)
 		BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
 		set_rq_offline(rq);
 	}
+	dl_server_stop(&rq->fair_server);
 	rq_unlock_irqrestore(rq, &rf);
 }