[tip:sched/core] sched: Factor out the on_null_domain() checks in trigger_load_balance()

[tip-bot for Daniel Lezcano <tipbot@zytor.com>]

Commit-ID:  c726099ec224be8078d91072207053ff9a1ad6fc
Gitweb:     http://git.kernel.org/tip/c726099ec224be8078d91072207053ff9a1ad6fc
Author:     Daniel Lezcano <daniel.lezcano@linaro.org>
AuthorDate: Mon, 6 Jan 2014 12:34:45 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 13 Jan 2014 13:47:35 +0100

sched: Factor out the on_null_domain() checks in trigger_load_balance()

The test on_null_domain is done twice in the trigger_load_balance function.

Move the test at the begin of the function, so there is only one check.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389008085-9069-9-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/sched/fair.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d7220d1..b24b6cf 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6878,11 +6878,13 @@ static inline int on_null_domain(struct rq *rq)
 void trigger_load_balance(struct rq *rq)
 {
 	/* Don't need to rebalance while attached to NULL domain */
-	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(rq)))
+	if (unlikely(on_null_domain(rq)))
+		return;
+
+	if (time_after_eq(jiffies, rq->next_balance))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq) && likely(!on_null_domain(rq)))
+	if (nohz_kick_needed(rq))
 		nohz_balancer_kick();
 #endif
 }