[tip:sched/core] sched/fair: Correct unit of load_above_capacity

[tip-bot for Morten Rasmussen]

Commit-ID:  cfa10334318d8212d007da8c771187643c9cef35
Gitweb:     http://git.kernel.org/tip/cfa10334318d8212d007da8c771187643c9cef35
Author:     Morten Rasmussen <morten.rasmussen@xxxxxxx>
AuthorDate: Fri, 29 Apr 2016 20:32:40 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 12 May 2016 09:55:33 +0200

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@xxxxxxx>
[ Changed changelog to note it was in capacity unit; +rebase. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1461958364-675-4-git-send-email-dietmar.eggemann@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 kernel/sched/fair.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2338105..218f8e8 100644
--- 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;
 	}