Re: [PATCH 4/4] sched/fair: Rework/fix task_h_load()

[Vincent Guittot]

On Wed, 2 Sept 2026 at 12:37, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Wed, Sep 02, 2026 at 10:13:01AM +0200, Peter Zijlstra wrote:
>
> > Let me go and try and reproduce.
>
> Different physical machine.. *splat*, virtual machine it lives. Argh I
> hate computers.
>
> Anyway, confirmed on physical machine that triggered it, the blow seems
> to cure things. I'll fold it in.
>
> ---
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -15287,9 +15287,6 @@ static void set_next_task_fair(struct rq
>                         weight = __calc_prop_weight(cfs_rq, se, weight);
>         }
>
> -       for_each_sched_entity_bl(se, cfs_rq)
> -               update_cfs_rq_h_load(group_cfs_rq(se), se, cfs_rq);
> -
>         if (throttled)
>                 task_throttle_setup_work(p);
>
> @@ -15309,11 +15306,15 @@ static void set_next_task_fair(struct rq
>                  */
>                 list_move(&se->group_node, &rq->cfs_tasks);
>         }
> -       if (!first)
> -               return;
>
>         WARN_ON_ONCE(se->sched_delayed);
>
> +       for_each_sched_entity_bl(se, cfs_rq)
> +               update_cfs_rq_h_load(group_cfs_rq(se), se, cfs_rq);
> +

should work too

> +       if (!first)
> +               return;
> +
>         if (hrtick_enabled_fair(rq))
>                 hrtick_start_fair(rq, p);
>
>
>