Re: [PATCH v7] sched_ext: idle: Refresh idle masks during idle-to-idle transitions

[Tejun Heo]

Hello,

On Fri, Jan 10, 2025 at 10:23:21PM +0100, Andrea Righi wrote:
...
> +	/*
> +	 * Update the idle masks:
> +	 * - for real idle transitions (do_notify == true)
> +	 * - for idle-to-idle transitions (indicated by the previous task
> +	 *   being the idle thread, managed by pick_task_idle())
> +	 *
> +	 * Skip updating idle masks if the previous task is not the idle
> +	 * thread, since set_next_task_idle() has already handled it when
> +	 * transitioning from a task to the idle thread (calling this
> +	 * function with do_notify == true).
> +	 *
> +	 * In this way we can avoid updating the idle masks twice,
> +	 * unnecessarily.
> +	 */
> +	if (do_notify || is_idle_task(rq->curr))
> +		update_idle_masks(cpu, idle);

Sorry about the multiple nitpicks but wouldn't it be better to have the
static_key test before dynamic tests? I'd move scx_builtin_idle_enabled test
out of update_idle_masks() and put that in front of other tests here. Also,
maybe name the function update_builtin_idle() to stay consistent with the
static_key name? Otherwise looks good to me.

Thanks.

-- 
tejun