Re: [PATCH v2] sched/task_group: Re-layout structure to reduce false sharing

[Tim Chen]

On Mon, 2023-06-26 at 15:52 +0800, Chen Yu wrote:
> 
>  
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index ec7b3e0a2b20..067f1310bad2 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -1958,8 +1958,10 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
>  #endif
>  
>  #ifdef CONFIG_RT_GROUP_SCHED
> -	p->rt.rt_rq  = tg->rt_rq[cpu];
> -	p->rt.parent = tg->rt_se[cpu];
> +	if (p->sched_class = &rt_sched_class) {
> +		p->rt.rt_rq  = tg->rt_rq[cpu];
> +		p->rt.parent = tg->rt_se[cpu];
> +	}

If we avoid the assignment for non-rt task, do you see it further improves
c2c bounce?

Tim