[PATCH 4/7] sched: Track group sched_entity usage contributions

From: Vincent Guittot
Date: Tue Oct 07 2014 - 08:16:46 EST


From: Morten Rasmussen <morten.rasmussen@xxxxxxx>

Adds usage contribution tracking for group entities. Unlike
se->avg.load_avg_contrib, se->avg.utilization_avg_contrib for group
entities is the sum of se->avg.utilization_avg_contrib for all entities on the
group runqueue. It is _not_ influenced in any way by the task group
h_load. Hence it is representing the actual cpu usage of the group, not
its intended load contribution which may differ significantly from the
utilization on lightly utilized systems.

cc: Paul Turner <pjt@xxxxxxxxxx>
cc: Ben Segall <bsegall@xxxxxxxxxx>

Signed-off-by: Morten Rasmussen <morten.rasmussen@xxxxxxx>
---
kernel/sched/debug.c | 3 +++
kernel/sched/fair.c | 5 +++++
2 files changed, 8 insertions(+)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index e0fbc0f..efb47ed 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -94,8 +94,10 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
P(se->load.weight);
#ifdef CONFIG_SMP
P(se->avg.runnable_avg_sum);
+ P(se->avg.running_avg_sum);
P(se->avg.avg_period);
P(se->avg.load_avg_contrib);
+ P(se->avg.utilization_avg_contrib);
P(se->avg.decay_count);
#endif
#undef PN
@@ -633,6 +635,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
P(se.avg.running_avg_sum);
P(se.avg.avg_period);
P(se.avg.load_avg_contrib);
+ P(se.avg.utilization_avg_contrib);
P(se.avg.decay_count);
#endif
P(policy);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d6de526..d3e9067 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2381,6 +2381,8 @@ static inline u64 __synchronize_entity_decay(struct sched_entity *se)
return 0;

se->avg.load_avg_contrib = decay_load(se->avg.load_avg_contrib, decays);
+ se->avg.utilization_avg_contrib =
+ decay_load(se->avg.utilization_avg_contrib, decays);
se->avg.decay_count = 0;

return decays;
@@ -2525,6 +2527,9 @@ static long __update_entity_utilization_avg_contrib(struct sched_entity *se)

if (entity_is_task(se))
__update_task_entity_utilization(se);
+ else
+ se->avg.utilization_avg_contrib =
+ group_cfs_rq(se)->utilization_load_avg;

return se->avg.utilization_avg_contrib - old_contrib;
}
--
1.9.1

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