[PATCH 1/2] sched: reduce calculation effort in fix_small_imbalance

From: Lei Wen
Date: Fri Jun 14 2013 - 02:19:06 EST


Actually all below item could be repalced by scaled_busy_load_per_task
(sds->busiest_load_per_task * SCHED_POWER_SCALE)
/sds->busiest->sgp->power;

Signed-off-by: Lei Wen <leiwen@xxxxxxxxxxx>
---
kernel/sched/fair.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c61a614..28052fa 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4727,20 +4727,17 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
pwr_now /= SCHED_POWER_SCALE;

/* Amount of load we'd subtract */
- tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
- sds->busiest->sgp->power;
- if (sds->max_load > tmp)
+ if (sds->max_load > scaled_busy_load_per_task) {
pwr_move += sds->busiest->sgp->power *
- min(sds->busiest_load_per_task, sds->max_load - tmp);
-
- /* Amount of load we'd add */
- if (sds->max_load * sds->busiest->sgp->power <
- sds->busiest_load_per_task * SCHED_POWER_SCALE)
- tmp = (sds->max_load * sds->busiest->sgp->power) /
- sds->this->sgp->power;
- else
+ min(sds->busiest_load_per_task,
+ sds->max_load - scaled_busy_load_per_task);
tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
sds->this->sgp->power;
+ } else
+ tmp = (sds->max_load * sds->busiest->sgp->power) /
+ sds->this->sgp->power;
+
+ /* Amount of load we'd add */
pwr_move += sds->this->sgp->power *
min(sds->this_load_per_task, sds->this_load + tmp);
pwr_move /= SCHED_POWER_SCALE;
--
1.7.10.4

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