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From: Peter Zijlstra <peterz@infradead.org>
To: John Stultz <jstultz@google.com>,
	K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Joel Fernandes <joelagnelf@nvidia.com>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Qais Yousef <qyousef@layalina.io>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Zimuzo Ezeozue <zezeozue@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Metin Kaya <Metin.Kaya@arm.com>
Cc: Xuewen Yan <xuewen.yan94@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: kuyo chang <kuyo.chang@mediatek.com>
Cc: hupu <hupu.gm@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: Mike Galbraith <efault@gmx.de>
Subject: [PATCH 6/6] sched: Simplify ttwu_runnable()
Date: Tue, 26 May 2026 13:16:15 +0200	[thread overview]
Message-ID: <20260526113322.714832584@infradead.org> (raw)
In-Reply-To: <20260526111609.433880331@infradead.org>

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>
---
 kernel/sched/core.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3764,9 +3764,6 @@ static inline void proxy_reset_donor(str
  */
 static inline bool proxy_needs_return(struct rq *rq, struct task_struct *p)
 {
-	if (!p->is_blocked)
-		return false;
-
 	scoped_guard(raw_spinlock, &p->blocked_lock) {
 		/* Task is waking up; clear any blocked_on relationship */
 		__clear_task_blocked_on(p, NULL);
@@ -3860,10 +3857,12 @@ static int ttwu_runnable(struct task_str
 		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



  parent reply	other threads:[~2026-05-26 11:37 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-26 11:16 [PATCH 0/6] sched/proxy: doodles Peter Zijlstra
2026-05-26 11:16 ` [PATCH 1/6] sched/proxy: Remove superfluous clear_task_blocked_in() Peter Zijlstra
2026-05-26 23:39   ` John Stultz
2026-05-26 23:54     ` John Stultz
2026-05-27  8:59       ` Peter Zijlstra
2026-05-28 23:20     ` John Stultz
2026-05-29  6:45       ` K Prateek Nayak
2026-05-29  7:14         ` John Stultz
2026-05-29  8:24           ` K Prateek Nayak
2026-05-29  8:47         ` Peter Zijlstra
2026-05-29  8:50           ` Peter Zijlstra
2026-05-29 10:46           ` K Prateek Nayak
2026-05-30  2:56             ` John Stultz
2026-05-29  9:33         ` Peter Zijlstra
2026-05-29  6:48       ` John Stultz
2026-05-29  7:58         ` K Prateek Nayak
2026-05-29 10:06           ` Peter Zijlstra
2026-05-29 10:54             ` K Prateek Nayak
2026-06-04 18:45   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2026-05-26 11:16 ` [PATCH 2/6] sched/proxy: Optimize try_to_wake_up() Peter Zijlstra
2026-05-27  1:56   ` John Stultz
2026-06-04 18:45   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2026-05-26 11:16 ` [PATCH 3/6] sched: Be more strict about p->is_blocked Peter Zijlstra
2026-05-27  1:56   ` John Stultz
2026-06-04 18:45   ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2026-05-26 11:16 ` [PATCH 4/6] sched/proxy: Switch proxy to use p->is_blocked Peter Zijlstra
2026-05-26 14:57   ` Peter Zijlstra
2026-05-26 19:48     ` John Stultz
2026-05-27  2:25   ` John Stultz
2026-05-27  8:29     ` Peter Zijlstra
2026-06-04 18:45       ` [tip: sched/core] sched/proxy: Only return migrate when needed tip-bot2 for Peter Zijlstra
2026-06-04 18:45   ` [tip: sched/core] sched/proxy: Switch proxy to use p->is_blocked tip-bot2 for Peter Zijlstra
2026-05-26 11:16 ` [PATCH 5/6] sched/proxy: Remove PROXY_WAKING Peter Zijlstra
2026-06-01 10:54   ` Peter Zijlstra
2026-06-01 20:32     ` John Stultz
2026-06-02  5:22       ` K Prateek Nayak
2026-06-02  6:58         ` John Stultz
2026-06-02 10:02         ` Peter Zijlstra
2026-06-04 18:29           ` John Stultz
2026-06-04 18:41             ` Peter Zijlstra
2026-06-02  3:19     ` K Prateek Nayak
2026-06-04 18:45   ` [tip: sched/core] " tip-bot2 for K Prateek Nayak
2026-05-26 11:16 ` Peter Zijlstra [this message]
2026-06-04 18:45   ` [tip: sched/core] sched: Simplify ttwu_runnable() tip-bot2 for Peter Zijlstra
2026-05-26 11:45 ` [PATCH 0/6] sched/proxy: doodles Peter Zijlstra

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