[tip: sched/core] sched: Simplify ttwu_runnable()

["tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>]

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

Commit-ID:     56e50ff567810db208cc37d9e17b8df044a9158c
Gitweb:        https://git.kernel.org/tip/56e50ff567810db208cc37d9e17b8df044a9158c
Author:        Peter Zijlstra <peterz@infradead.org>
AuthorDate:    Tue, 26 May 2026 12:00:59 +02:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Tue, 02 Jun 2026 12:26:10 +02:00

sched: Simplify ttwu_runnable()

Note that both proxy and delayed tasks have ->is_blocked set. Use this one
condition to guard both paths.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260526113322.714832584%40infradead.org
---
 kernel/sched/core.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d579518..5a317f6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3764,9 +3764,6 @@ static inline void proxy_reset_donor(struct rq *rq)
  */
 static inline bool proxy_needs_return(struct rq *rq, struct task_struct *p)
 {
-	if (!p->is_blocked)
-		return false;
-
 	/*
 	 * Typically per __set_task_cpu(), task_cpu(p) == p->wake_cpu.
 	 *
@@ -3875,10 +3872,12 @@ static int ttwu_runnable(struct task_struct *p, int wake_flags)
 		return 0;
 
 	update_rq_clock(rq);
-	if (p->se.sched_delayed)
-		enqueue_task(rq, p, ENQUEUE_NOCLOCK | ENQUEUE_DELAYED);
-	if (proxy_needs_return(rq, p))
-		return 0;
+	if (p->is_blocked) {
+		if (p->se.sched_delayed)
+			enqueue_task(rq, p, ENQUEUE_NOCLOCK | ENQUEUE_DELAYED);
+		if (proxy_needs_return(rq, p))
+			return 0;
+	}
 	if (!task_on_cpu(rq, p)) {
 		/*
 		 * When on_rq && !on_cpu the task is preempted, see if