Re: [PATCH 08/17] sched_ext: Block proxy donors across scheduler transitions

[Tejun Heo <tj@kernel.org>]

Hello,

On Sun, Aug 16, 2026 at 07:35:06PM +0200, Andrea Righi wrote:
> @@ -11295,6 +11295,15 @@ sched_change_begin(struct task_struct *p, const struct sched_class *next_class,
>  		flags |= DEQUEUE_NOCLOCK;
>  	}
>  
> +	/*
> +	 * Don't carry retained proxy state across scheduling class changes.
> +	 * Compatible RT/DL PI transitions could preserve the session so that a
> +	 * boosted donor continues proxy-executing its lock owner. Defining which
> +	 * class transitions can safely retain that state is left for future work.
> +	 */
> +	if ((flags & DEQUEUE_CLASS) && next_class != p->sched_class)
> +		sched_proxy_block_task(rq, p);
> +

I suppose this prevents RT PI propagation through existing proxy execution
chain regardless of sched class in use? That sounds pretty convoluted and
overlapping anyway but John does this look okay to you?

Thanks.

-- 
tejun