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>,
Preeti U Murthy <preeti@linux.vnet.ibm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Namhyung Kim <namhyung@kernel.org>,
Joonsoo Kim <js1304@gmail.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: [PATCH v2 1/3] sched: remove one division operation in find_buiest_queue()
Date: Fri, 2 Aug 2013 10:50:21 +0900 [thread overview]
Message-ID: <1375408223-10934-2-git-send-email-iamjoonsoo.kim@lge.com> (raw)
In-Reply-To: <1375408223-10934-1-git-send-email-iamjoonsoo.kim@lge.com>
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 c61a614..eaae77e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4931,7 +4931,7 @@ 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)) {
@@ -4962,10 +4962,9 @@ 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
next prev parent reply other threads:[~2013-08-02 1:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-02 1:50 [PATCH v2 0/3] optimization, clean-up about fair.c Joonsoo Kim
2013-08-02 1:50 ` Joonsoo Kim [this message]
2013-08-02 1:50 ` [PATCH v2 2/3] sched: factor out code to should_we_balance() Joonsoo Kim
2013-08-02 4:22 ` Preeti U Murthy
2013-08-02 9:05 ` 김준수
2013-08-02 9:26 ` Preeti U Murthy
2013-08-02 10:32 ` Peter Zijlstra
2013-08-05 4:22 ` Preeti U Murthy
2013-08-05 7:21 ` Joonsoo Kim
2013-08-02 10:20 ` Peter Zijlstra
2013-08-05 7:22 ` Joonsoo Kim
2013-08-02 7:51 ` Vincent Guittot
2013-08-02 9:08 ` Joonsoo Kim
2013-08-02 1:50 ` [PATCH v2 3/3] sched: clean-up struct sd_lb_stat Joonsoo Kim
2013-08-02 4:40 ` Preeti U Murthy
2013-08-05 7:32 ` Joonsoo Kim
2013-08-06 9:22 ` Preeti U Murthy
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