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From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, Mike Galbraith <efault@gmx.de>,
        Paul Turner <pjt@google.com>, Alex Shi <alex.shi@intel.com>,
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        Vincent Guittot <vincent.guittot@linaro.org>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: [PATCH 1/5] sched: remove one division operation in find_buiest_queue()
Date: Thu, 28 Mar 2013 16:58:52 +0900
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Remove one division operation in find_buiest_queue().

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6f238d2..1d8774f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4911,7 +4911,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 				     struct sched_group *group)
 {
 	struct rq *busiest = NULL, *rq;
-	unsigned long max_load = 0;
+	unsigned long busiest_load = 0, busiest_power = SCHED_POWER_SCALE;
 	int i;
 
 	for_each_cpu(i, sched_group_cpus(group)) {
@@ -4942,10 +4942,9 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 		 * the load can be moved away from the cpu that is potentially
 		 * running at a lower capacity.
 		 */
-		wl = (wl * SCHED_POWER_SCALE) / power;
-
-		if (wl > max_load) {
-			max_load = wl;
+		if (wl * busiest_power > busiest_load * power) {
+			busiest_load = wl;
+			busiest_power = power;
 			busiest = rq;
 		}
 	}
-- 
1.7.9.5