From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 13 Jan 2026 11:57:14 +0000 (+0100)
Subject: sched/deadline: Avoid double update_rq_clock()
X-Git-Tag: v6.18.7~112
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f32d9e475a41f521634a133f6bf98ee0e2aae445;p=thirdparty%2Fkernel%2Fstable.git

sched/deadline: Avoid double update_rq_clock()

[ Upstream commit 4de9ff76067b40c3660df73efaea57389e62ea7a ]

When setup_new_dl_entity() is called from enqueue_task_dl() ->
enqueue_dl_entity(), the rq-clock should already be updated, and
calling update_rq_clock() again is not right.

Move the update_rq_clock() to the one other caller of
setup_new_dl_entity(): sched_init_dl_server().

Fixes: 9f239df55546 ("sched/deadline: Initialize dl_servers after SMP")
Reported-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Link: https://patch.msgid.link/20260113115622.GA831285@noisy.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d3be71d5a9ccc..465592fa530ef 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -761,8 +761,6 @@ static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
 	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));
 
@@ -1623,6 +1621,7 @@ void sched_init_dl_servers(void)
 		rq = cpu_rq(cpu);
 
 		guard(rq_lock_irq)(rq);
+		update_rq_clock(rq);
 
 		dl_se = &rq->fair_server;