sched: Remove rq argument from ttwu_stat()

In order to call ttwu_stat() without holding rq->lock we must remove
its rq argument. Since we need to change rq stats, account to the
local rq instead of the task rq, this is safe since we have IRQs
disabled.

Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152729.394638826@chello.nl

Author: Peter Zijlstra

kernel/sched.c

@@ -2410,9 +2410,11 @@ static void update_avg(u64 *avg, u64 sample)
 #endif
 
 static void
-ttwu_stat(struct rq *rq, struct task_struct *p, int cpu, int wake_flags)
+ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
 {
 #ifdef CONFIG_SCHEDSTATS
+	struct rq *rq = this_rq();
+
 #ifdef CONFIG_SMP
 	int this_cpu = smp_processor_id();
 
@@ -2561,9 +2563,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
 	ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING);
 out_running:
 	ttwu_post_activation(p, rq, wake_flags);
-	ttwu_stat(rq, p, cpu, wake_flags);
 	success = 1;
 	__task_rq_unlock(rq);
+
+	ttwu_stat(p, cpu, wake_flags);
 out:
 	raw_spin_unlock_irqrestore(&p->pi_lock, flags);
 	put_cpu();
@@ -2600,7 +2603,7 @@ static void try_to_wake_up_local(struct task_struct *p)
 		ttwu_activate(rq, p, ENQUEUE_WAKEUP);
 
 	ttwu_post_activation(p, rq, 0);
-	ttwu_stat(rq, p, smp_processor_id(), 0);
+	ttwu_stat(p, smp_processor_id(), 0);
 out:
 	raw_spin_unlock(&p->pi_lock);
 }