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

[...]

quoted

+			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

quoted

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