linux-kernel - [PATCH 10/15] sched/fair: Propagate enqueue flags into place

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Message-ID: <20230531124604.274010996@infradead.org>
Date:   Wed, 31 May 2023 13:58:49 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     mingo@...nel.org, vincent.guittot@...aro.org
Cc:     linux-kernel@...r.kernel.org, peterz@...radead.org,
        juri.lelli@...hat.com, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, corbet@....net, qyousef@...alina.io,
        chris.hyser@...cle.com, patrick.bellasi@...bug.net, pjt@...gle.com,
        pavel@....cz, qperret@...gle.com, tim.c.chen@...ux.intel.com,
        joshdon@...gle.com, timj@....org, kprateek.nayak@....com,
        yu.c.chen@...el.com, youssefesmat@...omium.org,
        joel@...lfernandes.org, efault@....de, tglx@...utronix.de
Subject: [PATCH 10/15] sched/fair: Propagate enqueue flags into place_entity()

This allows place_entity() to consider ENQUEUE_WAKEUP and
ENQUEUE_MIGRATED.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/sched/fair.c  |   10 +++++-----
 kernel/sched/sched.h |    1 +
 2 files changed, 6 insertions(+), 5 deletions(-)

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4909,7 +4909,7 @@ static inline void update_misfit_status(
 #endif /* CONFIG_SMP */
 
 static void
-place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
+place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 {
 	u64 vslice = calc_delta_fair(se->slice, se);
 	u64 vruntime = avg_vruntime(cfs_rq);
@@ -4998,7 +4998,7 @@ place_entity(struct cfs_rq *cfs_rq, stru
 	 * on average, halfway through their slice, as such start tasks
 	 * off with half a slice to ease into the competition.
 	 */
-	if (sched_feat(PLACE_DEADLINE_INITIAL) && initial)
+	if (sched_feat(PLACE_DEADLINE_INITIAL) && (flags & ENQUEUE_INITIAL))
 		vslice /= 2;
 
 	/*
@@ -5021,7 +5021,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, st
 	 * update_curr().
 	 */
 	if (curr)
-		place_entity(cfs_rq, se, 0);
+		place_entity(cfs_rq, se, flags);
 
 	update_curr(cfs_rq);
 
@@ -5048,7 +5048,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, st
 	 * we can place the entity.
 	 */
 	if (!curr)
-		place_entity(cfs_rq, se, 0);
+		place_entity(cfs_rq, se, flags);
 
 	account_entity_enqueue(cfs_rq, se);
 
@@ -12053,7 +12053,7 @@ static void task_fork_fair(struct task_s
 	curr = cfs_rq->curr;
 	if (curr)
 		update_curr(cfs_rq);
-	place_entity(cfs_rq, se, 1);
+	place_entity(cfs_rq, se, ENQUEUE_INITIAL);
 	rq_unlock(rq, &rf);
 }
 
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -2174,6 +2174,7 @@ extern const u32		sched_prio_to_wmult[40
 #else
 #define ENQUEUE_MIGRATED	0x00
 #endif
+#define ENQUEUE_INITIAL		0x80
 
 #define RETRY_TASK		((void *)-1UL)