Re: [PATCH 3/4] workqueue: Tag bound workers with KTHREAD_IS_PER_CPU

[Valentin Schneider]

On 12/01/21 15:43, Peter Zijlstra wrote:
> @@ -4919,8 +4922,10 @@ static void unbind_workers(int cpu)
>
>               raw_spin_unlock_irq(&pool->lock);
>
> -		for_each_pool_worker(worker, pool)
> +		for_each_pool_worker(worker, pool) {
> +			kthread_set_per_cpu(worker->task, false);
>                       WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_possible_mask) < 0);
> +		}

Doesn't this supersede patch 1? With patch 4 on top, the BALANCE_PUSH
stuff should start resetting the affinity of the kworkers for which we
are removing the IS_PER_CPU flag.

It's the only nit I have, the rest looks good to me so:

Reviewed-by: Valentin Schneider <valentin.schneider@xxxxxxx>

I'll go frob that sched_cpu_dying() warning.