Re: [PATCH v3 4/5] sched/pelt: Add a new runnable average signal

From: Dietmar Eggemann
Date: Thu Feb 20 2020 - 10:05:17 EST


On 19/02/2020 13:55, Vincent Guittot wrote:
> Now that runnable_load_avg has been removed, we can replace it by a new
> signal that will highlight the runnable pressure on a cfs_rq. This signal
> track the waiting time of tasks on rq and can help to better define the
> state of rqs.
>
> At now, only util_avg is used to define the state of a rq:
> A rq with more that around 80% of utilization and more than 1 tasks is
> considered as overloaded.

Don't we make the distinction of overutilized and overloaded?

update_sg_lb_stats(), SG_OVERUTILIZED and SG_OVERLOAD

[...]

> @@ -310,13 +325,14 @@ int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq)
> * util_sum = cpu_scale * load_sum
> * runnable_sum = util_sum
> *
> - * load_avg is not supported and meaningless.
> + * load_avg and runnable_load_avg are not supported and meaningless.

Nit pick:

s/runnable_load_avg/runnable_avg

[...]

> + * load_avg and runnable_load_avg are not supported and meaningless.
> *
> */
>
> int update_dl_rq_load_avg(u64 now, struct rq *rq, int running)

[...]

> - * load_avg is not supported and meaningless.
> + * load_avg and runnable_load_avg are not supported and meaningless.
> *
> */
>
> @@ -389,9 +406,11 @@ int update_irq_load_avg(struct rq *rq, u64 running)

[...]