Re: [RFC][PATCH 4/7] smp: Optimize send_call_function_single_ipi()

[Frederic Weisbecker]

On Tue, May 26, 2020 at 06:11:01PM +0200, Peter Zijlstra wrote:
> +void flush_smp_call_function_from_idle(void)
> +{
> +	unsigned long flags;
> +
> +	if (llist_empty(this_cpu_ptr(&call_single_queue)))
> +		return;

Now it seems weird that sched_ttwu_pending() didn't have that
llist_empty() optimization. The ordering should allow it.

Anyway,

Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>