Re: [PATCH] sched/fair: Fix se_is_idle() for !FAIR_GROUP_SCHED

[Vincent Guittot]

On Wed, 8 Sept 2021 at 22:40, Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> wrote:
>
> se_is_idle() unconditionally returns 0 for !FAIR_GROUP_SCHED.
>
> Check whether the task is SCHED_IDLE instead so buddies aren't set for
> such tasks, as was the behavior before 304000390f88.
>
> Fixes: 304000390f88 ("sched: Cgroup SCHED_IDLE support")
> Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>

Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>

> ---
>  kernel/sched/fair.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index ff69f245b939..8b22665bc18e 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -497,7 +497,7 @@ static int cfs_rq_is_idle(struct cfs_rq *cfs_rq)
>
>  static int se_is_idle(struct sched_entity *se)
>  {
> -       return 0;
> +       return task_has_idle_policy(task_of(se));
>  }
>
>  #endif /* CONFIG_FAIR_GROUP_SCHED */
>
> base-commit: ac08b1c68d1b1ed3cebb218fc3ea2c07484eb07d
> --
> 2.32.0
>