From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Fri, 27 Nov 2009 14:44:43 +0000 (+0100)
Subject: sched: Clean up ttwu() rq locking
X-Git-Tag: firefly_0821_release~10186^2~986
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=7b8a5273c87b4229bb83bbb1282424e2af0af214;p=firefly-linux-kernel-4.4.55.git

sched: Clean up ttwu() rq locking

commit ab19cb23313733c55e0517607844b86720b35f5f upstream

Since set_task_clock() doesn't rely on rq->clock anymore we can simplyfy
the mess in ttwu().

Optimize things a bit by not fiddling with the IRQ state there.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/kernel/sched.c b/kernel/sched.c
index e3d92940c66e..89bce0258d90 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2379,16 +2379,14 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
 	if (task_contributes_to_load(p))
 		rq->nr_uninterruptible--;
 	p->state = TASK_WAKING;
-	task_rq_unlock(rq, &flags);
+	__task_rq_unlock(rq);
 
 	cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
 	if (cpu != orig_cpu)
 		set_task_cpu(p, cpu);
 
-	rq = task_rq_lock(p, &flags);
-
-	if (rq != orig_rq)
-		update_rq_clock(rq);
+	rq = __task_rq_lock(p);
+	update_rq_clock(rq);
 
 	WARN_ON(p->state != TASK_WAKING);
 	cpu = task_cpu(p);