[tip:sched/urgent] sched: Clean up ttwu() rq locking

tip-bot for Peter Zijlstra
2009-12-09T09:54:40Z

Commit-ID: ab19cb23313733c55e0517607844b86720b35f5f
Gitweb: http://git.kernel.org/tip/ab19cb23313733c55e0517607844b86720b35f5f
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Fri, 27 Nov 2009 15:44:43 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 9 Dec 2009 10:03:04 +0100

sched: Clean up ttwu() rq locking

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>
---
kernel/sched.c | 13 +++++--------
1 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 1f9c6d9..c92670f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2371,17 +2371,14 @@ 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) {
- local_irq_save(flags);
- rq = cpu_rq(cpu);
- update_rq_clock(rq);
+ if (cpu != orig_cpu)
set_task_cpu(p, cpu);
- local_irq_restore(flags);
- }
- rq = task_rq_lock(p, &flags);
+
+ rq = __task_rq_lock(p);
+ update_rq_clock(rq);

WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p);