Re: [PATCH v9 02/10] sched: Track group sched_entity usage contributions

From: Morten Rasmussen
Date: Fri Nov 21 2014 - 07:34:26 EST


s/usage/utilization/ in subject.

On Mon, Nov 03, 2014 at 04:54:39PM +0000, Vincent Guittot wrote:
> From: Morten Rasmussen <morten.rasmussen@xxxxxxx>
>
> Adds usage contribution tracking for group entities. Unlike

s/usage contribution/utilization/

> 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

s/usage/utilization/

> 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>
> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> ---
> kernel/sched/debug.c | 2 ++
> kernel/sched/fair.c | 3 +++
> 2 files changed, 5 insertions(+)
>
> diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
> index f384452..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
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 3a91ae6..a171e1b 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -2529,6 +2529,9 @@ 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;
> }

What happened to the update of se->avg.utilization_avg_contrib in
__synchronize_entity_decay()? It seems to have disapperead after v7.
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