Re: [PATCH 05/12] sched: Move sched_class::prio_changed() into the change pattern

[Peter Zijlstra <peterz@infradead.org>]

On Tue, Jan 13, 2026 at 12:53:09PM +0100, Peter Zijlstra wrote:
> On Tue, Jan 13, 2026 at 04:35:02PM +0530, K Prateek Nayak wrote:
> 
> > Does enabling WARN_DOUBLE_CLOCK warn of a double clock update before
> > hitting this warning?
> 
> setup_new_dl_entity() -> update_rq_clock() seems like it will trip that
> in this case.

Something like so to fix: 9f239df55546 ("sched/deadline: Initialize dl_servers after SMP")


--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -752,8 +752,6 @@ static inline void setup_new_dl_entity(s
 	struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
 	struct rq *rq = rq_of_dl_rq(dl_rq);
 
-	update_rq_clock(rq);
-
 	WARN_ON(is_dl_boosted(dl_se));
 	WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
 
@@ -1834,6 +1832,7 @@ void sched_init_dl_servers(void)
 		rq = cpu_rq(cpu);
 
 		guard(rq_lock_irq)(rq);
+		update_rq_clock(rq);
 
 		dl_se = &rq->fair_server;