Re: [PATCH 07/10] sched: Migrate sched to use new tick dependency mask model

[Chris Metcalf <cmetcalf@ezchip.com>]

On 07/23/2015 12:42 PM, Frederic Weisbecker wrote:
> +static inline void sched_update_tick_dependency(struct rq *rq)
> +{
> +	int cpu;
> +
> +	if (!tick_nohz_full_enabled())
> +		return;
> +
> +	cpu = cpu_of(rq);
> +
> +	if (!tick_nohz_full_cpu(rq->cpu))
> +		return;
> +
> +	if (sched_can_stop_tick(rq))
> +		tick_nohz_clear_tick_dependency_cpu(TICK_SCHED_BIT, cpu);
> +	else
> +		tick_nohz_set_tick_dependency_cpu(TICK_SCHED_BIT, cpu);
> +}

Is it worth asserting that the rq is locked at this point? Presumably 
that's a requirement so that the cpu can't change out from under you.
-- 
Chris Metcalf, EZChip Semiconductor
http://www.ezchip.com