From: Joonsoo Kim Remove one division operation in find_busiest_queue() by using crosswise multiplication: wl_i / power_i > wl_j / power_j := wl_i * power_j > wl_j * power_i Signed-off-by: Joonsoo Kim [peterz: expanded changelog] Signed-off-by: Peter Zijlstra --- kernel/sched/fair.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5018,7 +5018,7 @@ static struct rq *find_busiest_queue(str 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)) { @@ -5049,10 +5049,9 @@ static struct rq *find_busiest_queue(str * 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; } } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/