From: John Stultz <jstultz@google.com>
Date: Thu, 14 May 2026 23:47:17 +0000 (+0000)
Subject: sched: Switch rq->next_class on proxy_resched_idle()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04f80f8b12a02fa2e0827c8f37eb357adca8ce44;p=thirdparty%2Fkernel%2Flinux.git

sched: Switch rq->next_class on proxy_resched_idle()

K Prateek noticed we weren't setting the rq->next_class in
proxy_resched_idle(), when I was debugging an issue seen with
CONFIG_SCHED_PROXY_EXEC and some of Peter's new patches, and
suggested this fix.

So set rq->next_class when we temporarily switch the donor to
idle, so we don't accidentally call wakeup_preempt_fair()
with idle as the donor.

Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260514234732.3170197-1-jstultz@google.com
---

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3ae5f19c1b7eb..77f4ebe8f5c7b 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;