Re: [PATCH v9 06/10] time: tick-sched: Split tick_nohz_stop_sched_tick()

[Frederic Weisbecker]

On Wed, Apr 04, 2018 at 10:41:13AM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> 
> In order to address the issue with short idle duration predictions
> by the idle governor after the scheduler tick has been stopped, split
> tick_nohz_stop_sched_tick() into two separate routines, one computing
> the time to the next timer event and the other simply stopping the
> tick when the time to the next timer event is known.
> 
> Prepare these two routines to be called separately, as one of them
> will be called by the idle governor in the cpuidle_select() code
> path after subsequent changes.
> 
> Update the former callers of tick_nohz_stop_sched_tick() to use
> the new routines, tick_nohz_next_event() and tick_nohz_stop_tick(),
> instead of it and move the updates of the sleep_length field in
> struct tick_sched into __tick_nohz_idle_stop_tick() as it doesn't
> need to be updated anywhere else.
> 
> There should be no intentional visible changes in functionality
> resulting from this change.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>

Thanks! And sorry for the slow reviews, the changes are sensitive
and I want to make sure we are not breaking some subtlety.