Re: [PATCH 23/34] sched_ext: Implement hierarchical bypass mode

[Andrea Righi]

Hi Tejun,

On Wed, Mar 04, 2026 at 12:01:08PM -1000, Tejun Heo wrote:
...
> @@ -4471,14 +4527,35 @@ static void enable_bypass_dsp(struct scx_sched *sch)
>  		return;
>  
>  	/*
> -	 * The LB timer will stop running if bypass_arm_depth is 0. Increment
> -	 * before starting the LB timer.
> +	 * When a sub-sched bypasses, its tasks are queued on the bypass DSQs of
> +	 * the nearest non-bypassing ancestor or root. As enable_bypass_dsp() is
> +	 * called iff @sch is not already bypassed due to an ancestor bypassing,
> +	 * we can assume that the parent is not bypassing and thus will be the
> +	 * host of the bypass DSQs.
> +	 *
> +	 * While the situation may change in the future, the following
> +	 * guarantees that the nearest non-bypassing ancestor or root has bypass
> +	 * dispatch enabled while a descendant is bypassing, which is all that's
> +	 * required.
> +	 *
> +	 * bypass_dsp_enabled() test is used to detemrine whether to enter the

Nit: s/detemrine/determine/

Thanks,
-Andrea