Add the blocked utilization contribution to group sched_entity
utilization (se->avg.utilization_avg_contrib) and to get_cpu_usage().
With this change cpu usage now includes recent usage by currently
non-runnable tasks, hence it provides a more stable view of the cpu
usage. It does, however, also mean that the meaning of usage is changed:
A cpu may be momentarily idle while usage is >0. It can no longer be
assumed that cpu usage >0 implies runnable tasks on the rq.
cfs_rq->utilization_load_avg or nr_running should be used instead to get
the current rq status.

cc: Ingo Molnar <mi...@redhat.com>
cc: Peter Zijlstra <pet...@infradead.org>

Signed-off-by: Morten Rasmussen <morten.rasmus...@arm.com>
---
 kernel/sched/fair.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ad07398..e40cd88 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2789,7 +2789,8 @@ static long 
__update_entity_utilization_avg_contrib(struct sched_entity *se)
                __update_task_entity_utilization(se);
        else
                se->avg.utilization_avg_contrib =
-                                       group_cfs_rq(se)->utilization_load_avg;
+                               group_cfs_rq(se)->utilization_load_avg +
+                               group_cfs_rq(se)->utilization_blocked_avg;
 
        return se->avg.utilization_avg_contrib - old_contrib;
 }
@@ -5046,13 +5047,17 @@ static int select_idle_sibling(struct task_struct *p, 
int target)
 
 static int get_cpu_usage(int cpu)
 {
+       int sum;
        unsigned long usage = cpu_rq(cpu)->cfs.utilization_load_avg;
+       unsigned long blocked = cpu_rq(cpu)->cfs.utilization_blocked_avg;
        unsigned long capacity_orig = capacity_orig_of(cpu);
 
-       if (usage >= capacity_orig)
+       sum = usage + blocked;
+
+       if (sum >= capacity_orig)
                return capacity_orig;
 
-       return usage;
+       return sum;
 }
 
 /*
-- 
1.9.1

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