sched: Update rq clock earlier in unthrottle_cfs_rq

In this function we are making use of rq->clock right before the
update of the rq clock, let's just call update_rq_clock() just
before that to avoid using a stale rq clock value.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -2319,12 +2319,14 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 	se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];
 
 	cfs_rq->throttled = 0;
+
+	update_rq_clock(rq);
+
 	raw_spin_lock(&cfs_b->lock);
 	cfs_b->throttled_time += rq->clock - cfs_rq->throttled_clock;
 	list_del_rcu(&cfs_rq->throttled_list);
 	raw_spin_unlock(&cfs_b->lock);
 
-	update_rq_clock(rq);
 	/* update hierarchical throttle state */
 	walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);