Re: [PATCH] cpuidle: menu: Retain tick when shallow state is selected

[leo . yan]

On Wed, Aug 22, 2018 at 08:02:00PM +0800, Leo Yan wrote:

[...]

> > +			if (!tick_nohz_tick_stopped()) {
> > +				/*
> > +				 * If the state selected so far is shallow,
> > +				 * waking up early won't hurt, so retain the
> > +				 * tick in that case and let the governor run
> > +				 * again in the next iteration of the loop.
> > +				 */
> > +				expected_interval = drv->states[idx].target_residency;
> > +				break;
> > +			}
> > +
> 
> This is reliable, how we can rely on a shallow idle state target
> residency to decide if need to stop a tick or not?

s/This is reliable/This isn't reliable

> 
> >  			/*
> >  			 * If the state selected so far is shallow and this
> >  			 * state's target residency matches the time till the
> >