Re: Workqueues splat due to ending up on wrong CPU

[Peter Zijlstra]

On Tue, Dec 03, 2019 at 10:55:21AM +0100, Peter Zijlstra wrote:
> @@ -1100,6 +1099,12 @@ void cpuhp_online_idle(enum cpuhp_state state)
>  	if (state != CPUHP_AP_ONLINE_IDLE)
>  		return;
>  
> +	/*
> +	 * Unpark the stopper thread before we start the idle thread; this

s/thread/loop/, _this_ is the idle thread :-)

> +	 * ensures the stopper is always available.
> +	 */
> +	stop_machine_unpark(smp_processor_id());
> +
>  	st->state = CPUHP_AP_ONLINE_IDLE;
>  	complete_ap_thread(st, true);
>  }