The following commit has been merged into the sched/core branch of tip:

Commit-ID:     8039addbe5a56e4108b1bea57aa5b3f70750fed9
Gitweb:        https://git.kernel.org/tip/8039addbe5a56e4108b1bea57aa5b3f70750fed9
Author:        Ingo Molnar <mingo@kernel.org>
AuthorDate:    Wed, 28 May 2025 10:09:05 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 13 Jun 2025 08:47:19 +02:00

sched/smp: Use the SMP version of __task_needs_rq_lock()

Simplify the scheduler by making CONFIG_SMP=y code in
__task_needs_rq_lock() unconditional.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20250528080924.2273858-25-mingo@kernel.org
---
 kernel/sched/core.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d20fea6..82b7cdb 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4312,14 +4312,12 @@ static bool __task_needs_rq_lock(struct task_struct *p)
 	if (p->on_rq)
 		return true;
 
-#ifdef CONFIG_SMP
 	/*
 	 * Ensure the task has finished __schedule() and will not be referenced
 	 * anymore. Again, see try_to_wake_up() for a longer comment.
 	 */
 	smp_rmb();
 	smp_cond_load_acquire(&p->on_cpu, !VAL);
-#endif
 
 	return false;
 }