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From: Kirill Tkhai <tkhai@yandex.ru>
To: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
	Kirill Tkhai <ktkhai@parallels.com>,
	Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@gmail.com>
Subject: [PATCH v2 2/3] sched/dl: Cleanup prio_changed_dl()
Date: Wed, 01 Oct 2014 01:04:35 +0400	[thread overview]
Message-ID: <20140930210428.5258.32223.stgit@localhost> (raw)
In-Reply-To: <20140930210412.5258.35299.stgit@localhost>

From: Kirill Tkhai <ktkhai@parallels.com>

rq->curr task can't be in "dequeued" state in prio_changed_dl().
(The only place we can have that is __schedule()). So, we delete
rq->curr check.

Also delete "else" branch which is dead code (switched_to_dl()
is not interested in dequeued tasks and we are not interested
in balancing in this case).

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
---
 kernel/sched/deadline.c |   50 +++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 63f8b4a..38b4f19 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1638,35 +1638,33 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p)
 static void prio_changed_dl(struct rq *rq, struct task_struct *p,
 			    int oldprio)
 {
-	if (task_on_rq_queued(p) || rq->curr == p) {
+	if (!task_on_rq_queued(p))
+		return;
 #ifdef CONFIG_SMP
-		/*
-		 * This might be too much, but unfortunately
-		 * we don't have the old deadline value, and
-		 * we can't argue if the task is increasing
-		 * or lowering its prio, so...
-		 */
-		if (!rq->dl.overloaded)
-			pull_dl_task(rq);
-
-		/*
-		 * If we now have a earlier deadline task than p,
-		 * then reschedule, provided p is still on this
-		 * runqueue.
-		 */
-		if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline) &&
-		    rq->curr == p)
-			resched_curr(rq);
-#else
-		/*
-		 * Again, we don't know if p has a earlier
-		 * or later deadline, so let's blindly set a
-		 * (maybe not needed) rescheduling point.
-		 */
+	/*
+	 * This might be too much, but unfortunately
+	 * we don't have the old deadline value, and
+	 * we can't argue if the task is increasing
+	 * or lowering its prio, so...
+	 */
+	if (!rq->dl.overloaded)
+		pull_dl_task(rq);
+	/*
+	 * If we now have a earlier deadline task than p,
+	 * then reschedule, provided p is still on this
+	 * runqueue.
+	 */
+	if (dl_time_before(rq->dl.earliest_dl.curr, p->dl.deadline) &&
+	    rq->curr == p)
 		resched_curr(rq);
+#else
+	/*
+	 * Again, we don't know if p has a earlier
+	 * or later deadline, so let's blindly set a
+	 * (maybe not needed) rescheduling point.
+	 */
+	resched_curr(rq);
 #endif /* CONFIG_SMP */
-	} else
-		switched_to_dl(rq, p);
 }
 
 const struct sched_class dl_sched_class = {


  reply	other threads:[~2014-09-30 21:04 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-30 21:04 [PATCH v2 1/3] sched/dl: Implement cancel_dl_timer() to use in switched_from_dl() Kirill Tkhai
2014-09-30 21:04 ` Kirill Tkhai [this message]
2014-10-02  9:36   ` [PATCH v2 2/3] sched/dl: Cleanup prio_changed_dl() Peter Zijlstra
2014-10-02  9:52     ` Kirill Tkhai
2014-10-21 16:24       ` Juri Lelli
2014-10-21 16:33         ` Kirill Tkhai
2014-10-22  9:33           ` Juri Lelli
2014-10-23 23:04         ` Wanpeng Li
2014-10-24  9:26           ` Juri Lelli
2014-09-30 21:04 ` [PATCH v2 3/3] sched/fair: Delete resched_cpu() from idle_balance() Kirill Tkhai
2014-10-03  5:28   ` [tip:sched/core] " tip-bot for Kirill Tkhai
2014-10-02  9:34 ` [PATCH v2 1/3] sched/dl: Implement cancel_dl_timer() to use in switched_from_dl() Peter Zijlstra
2014-10-02 10:05   ` Kirill Tkhai
2014-10-21 10:30     ` Juri Lelli
2014-10-21 10:48       ` Kirill Tkhai
2014-10-21 11:41         ` Juri Lelli
2014-10-21 14:21           ` Kirill Tkhai
2014-10-22 10:00             ` Juri Lelli
2014-10-23  8:39               ` Kirill Tkhai

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