sched/fair: Correct unit of load_above_capacity

In calculate_imbalance() load_above_capacity currently has the unit
[capacity] while it is used as being [load/capacity]. Not only is it
wrong it also makes it unlikely that load_above_capacity is ever used
as the subsequent code picks the smaller of load_above_capacity and
the avg_load

This patch ensures that load_above_capacity has the right unit
[load/capacity].

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
[ Changed changelog to note it was in capacity unit; +rebase. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1461958364-675-4-git-send-email-dietmar.eggemann@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 23381056b4b546dd2bff42734a074253b17f8697..218f8e83db731e4afe4d4aaf7d7919a588087a12 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7067,9 +7067,11 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
        if (busiest->group_type == group_overloaded &&
            local->group_type   == group_overloaded) {
                load_above_capacity = busiest->sum_nr_running * SCHED_CAPACITY_SCALE;
-               if (load_above_capacity > busiest->group_capacity)
+               if (load_above_capacity > busiest->group_capacity) {
                        load_above_capacity -= busiest->group_capacity;
-               else
+                       load_above_capacity *= NICE_0_LOAD;
+                       load_above_capacity /= busiest->group_capacity;
+               } else
                        load_above_capacity = ~0UL;
        }