Re: [PATCH v3] sched/fair: Fix fault in reweight_entity

[Tadeusz Struk <tadeusz.struk@xxxxxxxxxx>]

On 1/26/22 05:53, Dietmar Eggemann wrote:
> Can we then not get rid of `bool update_load` parameter of
> set_load_weight() completely?
>
> @@ -1214,8 +1214,9 @@ int tg_nop(struct task_group *tg, void *data)
>   }
>   #endif
>   
> -static void set_load_weight(struct task_struct *p, bool update_load)
> +static void set_load_weight(struct task_struct *p)
>   {
> +       int task_new = READ_ONCE(p->__state) & TASK_NEW;
>          int prio = p->static_prio - MAX_RT_PRIO;
>          struct load_weight *load = &p->se.load;
>   
> @@ -1232,7 +1233,7 @@ static void set_load_weight(struct task_struct *p, bool update_load)
>           * SCHED_OTHER tasks have to update their load when changing their
>           * weight
>           */
> -       if (update_load && p->sched_class == &fair_sched_class) {
> +       if (!task_new && p->sched_class == &fair_sched_class) {
>                  reweight_task(p, prio);
>          } else {
>                  load->weight = scale_load(sched_prio_to_weight[prio]);

That will also work. Let's agree on the best way to fix it.
Peter, what's your preference?

--
Thanks,
Tadeusz