Re: [PATCH 1/2] sched/fair: optimization of update_blocked_averages()

From: Peter Zijlstra
Date: Fri Feb 08 2019 - 10:40:25 EST



Argh head hurts!!

On Wed, Feb 06, 2019 at 05:14:21PM +0100, Vincent Guittot wrote:
> @@ -4438,6 +4450,10 @@ static int tg_unthrottle_up(struct task_group *tg, void *data)
> /* adjust cfs_rq_clock_task() */
> cfs_rq->throttled_clock_task_time += rq_clock_task(rq) -
> cfs_rq->throttled_clock_task;
> +
> + /* Add cfs_rq with already running entity in the list */
> + if (cfs_rq->nr_running >= 1)
> + list_add_leaf_cfs_rq(cfs_rq);
> }
>
> return 0;

Do we want the below to go with the above change?

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 38d4669aa2ef..0bd80a891025 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4536,6 +4536,8 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
/* update hierarchical throttle state */
walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);

+ assert_list_leaf_cfs_rq(rq);
+
if (!cfs_rq->load.weight)
return;