Re: [PATCH 2/6 v2] sched/eevdf: Take into account current's lag when updating slice protection

[K Prateek Nayak]

Hello Vincent,

On 6/15/2026 9:54 PM, Vincent Guittot wrote:
> @@ -1083,6 +1083,7 @@ struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
>   */
>  static inline void set_protect_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
>  {
> +	u64 vruntime = min_vruntime(se->vruntime, avg_vruntime(cfs_rq));

set_protect_slice() is only called for set_next_entity(... first = true)
which has to come from the pick where the entity has to be eligible and
behind the avg_vruntime(cfs_rq) right?

Is there a case where se->vruntime is ahead of the average here that
I'm missing?

>  	u64 slice = normalized_sysctl_sched_base_slice;
>  	u64 vprot = se->deadline;
>  
> @@ -1090,8 +1091,8 @@ static inline void set_protect_slice(struct cfs_rq *cfs_rq, struct sched_entity
>  		slice = cfs_rq_min_slice(cfs_rq);
>  
>  	slice = min(slice, se->slice);
> -	if (slice != se->slice)
> -		vprot = min_vruntime(vprot, se->vruntime + calc_delta_fair(slice, se));
> +	if (vruntime != se->vruntime || slice != se->slice)
> +		vprot = min_vruntime(vprot, vruntime + calc_delta_fair(slice, se));
>  
>  	se->vprot = vprot;
>  }
-- 
Thanks and Regards,
Prateek