Re: [PATCH 2/9] sched/fair: Add new cfs_rq.h_nr_enqueued

[Peter Zijlstra]

On Thu, Nov 28, 2024 at 10:27:43AM +0100, Vincent Guittot wrote:
> With delayed dequeued feature, a sleeping sched_entity remains enqueued
> in the rq until its lag has elapsed. As a result, it stays also visible
> in the statistics that are used to balance the system and in particular
> the field h_nr_running when the sched_entity is associated to a task.
> 
> Create a new h_nr_enqueued that tracks all enqueued tasks and restore the
> behavior of h_nr_running i.e. tracking the number of fair tasks that want
> to run.

Isn't h_nr_enqueued := h_nr_running - h_nr_delayed ? Does it really make
sense to have another variable that is so trivially computable?

Also naming; h_nr_enqueued isn't really adequate I feel, because the
whole problem is that the delayed tasks are still very much enqueued.