Re: [PATCH v2 1/5] sched/fair: Reorder enqueue/dequeue_task_fair path

From: Dietmar Eggemann
Date: Tue Feb 18 2020 - 07:38:25 EST

On 14/02/2020 16:27, Vincent Guittot wrote:
> The walk through the cgroup hierarchy during the enqueue/dequeue of a task
> is split in 2 distinct parts for throttled cfs_rq without any added value
> but making code less readable.
> Change the code ordering such that everything related to a cfs_rq
> (throttled or not) will be done in the same loop.
> In addition, the same steps ordering is used when updating a cfs_rq:
> - update_load_avg
> - update_cfs_group
> - update *h_nr_running

Is this code change really necessary? You pay with two extra goto's. We
still have the two for_each_sched_entity(se)'s because of 'if
(se->on_rq); break;'.