[tip: sched/core] sched/smp: Use the SMP version of __task_needs_rq_lock()

From: tip-bot2 for Ingo Molnar
Date: Fri Jun 13 2025 - 03:42:35 EST


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@xxxxxxxxxx>
AuthorDate: Wed, 28 May 2025 10:09:05 +02:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250528080924.2273858-25-mingo@xxxxxxxxxx
---
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;
}