Since for max_load and this_load, they are the value that already be scaled. It is not reasonble to get a minimum value between the scaled and non-scaled value, like below example. min(sds->busiest_load_per_task, sds->max_load);
Also add comment over in what condition, there would be cpu power gain in move the load. Signed-off-by: Lei Wen <lei...@marvell.com> --- kernel/sched/fair.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 28052fa..77a149c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4692,7 +4692,7 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) { unsigned long tmp, pwr_now = 0, pwr_move = 0; unsigned int imbn = 2; - unsigned long scaled_busy_load_per_task; + unsigned long scaled_busy_load_per_task, scaled_this_load_per_task; if (sds->this_nr_running) { sds->this_load_per_task /= sds->this_nr_running; @@ -4714,6 +4714,9 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) return; } + scaled_this_load_per_task = sds->this_load_per_task + * SCHED_POWER_SCALE; + scaled_this_load_per_task /= sds->this->sgp->power; /* * OK, we don't have enough imbalance to justify moving tasks, * however we may be able to increase total CPU power used by @@ -4721,28 +4724,35 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds) */ pwr_now += sds->busiest->sgp->power * - min(sds->busiest_load_per_task, sds->max_load); + min(scaled_busy_load_per_task, sds->max_load); pwr_now += sds->this->sgp->power * - min(sds->this_load_per_task, sds->this_load); + min(scaled_this_load_per_task, sds->this_load); pwr_now /= SCHED_POWER_SCALE; /* Amount of load we'd subtract */ if (sds->max_load > scaled_busy_load_per_task) { pwr_move += sds->busiest->sgp->power * - min(sds->busiest_load_per_task, + min(scaled_busy_load_per_task, sds->max_load - scaled_busy_load_per_task); - tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) / - sds->this->sgp->power; + tmp = scaled_busy_load_per_task; } else - tmp = (sds->max_load * sds->busiest->sgp->power) / - sds->this->sgp->power; + tmp = sds->max_load; + /* Scale to this queue from busiest queue */ + tmp = (tmp * 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); + min(scaled_this_load_per_task, sds->this_load + tmp); pwr_move /= SCHED_POWER_SCALE; /* Move if we gain throughput */ + /* + * The only possibilty for below statement be true, is: + * sds->max_load is larger than scaled_busy_load_per_task, while, + * scaled_this_load_per_task is larger than sds->this_load plus by + * the scaled scaled_busy_load_per_task moved into this queue + */ if (pwr_move > pwr_now) env->imbalance = sds->busiest_load_per_task; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/