[069/123] sched: Clean up ttwu() rq locking

From: Greg KH
Date: Sat Sep 18 2010 - 15:47:10 EST


From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>

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@xxxxxxxxx>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Mike Galbraith <efault@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
kernel/sched.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2379,16 +2379,14 @@ static int try_to_wake_up(struct task_st
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);


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