SurfaceFlinger: tune number of buffers for low activity layers
Tune number of buffers indicating whether a layer is low activity
or not to 2 accommodate more cases of low activity layers.
Bug: 140948091
Test: 1) Set the static wallpaper
2) Go to Settings->About Phone -> scroll all the way down
3) Move device to Zone1 and launch settings page
4) Move device to Non Zone1 without touch and wait for 1-2 secs and observe
Change-Id: I6a06fa4945843a8d991463c30cb0e6db68f99365
diff --git a/services/surfaceflinger/Scheduler/LayerInfo.h b/services/surfaceflinger/Scheduler/LayerInfo.h
index a733781..17afdda 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.h
+++ b/services/surfaceflinger/Scheduler/LayerInfo.h
@@ -109,7 +109,7 @@
bool isLowActivityLayer() const {
// We want to make sure that we received more than two frames from the layer
// in order to check low activity.
- if (mElements.size() < 2) {
+ if (mElements.size() < scheduler::LOW_ACTIVITY_BUFFERS + 1) {
return false;
}
@@ -118,7 +118,8 @@
// Check the frame before last to determine whether there is low activity.
// If that frame is older than LOW_ACTIVITY_EPSILON_NS, the layer is sending
// infrequent updates.
- if (mElements.at(mElements.size() - 2) < obsoleteEpsilon) {
+ if (mElements.at(mElements.size() - (scheduler::LOW_ACTIVITY_BUFFERS + 1)) <
+ obsoleteEpsilon) {
return true;
}
diff --git a/services/surfaceflinger/Scheduler/SchedulerUtils.h b/services/surfaceflinger/Scheduler/SchedulerUtils.h
index ced1899..ac10f83 100644
--- a/services/surfaceflinger/Scheduler/SchedulerUtils.h
+++ b/services/surfaceflinger/Scheduler/SchedulerUtils.h
@@ -42,9 +42,11 @@
// or waiting idle in messaging app, when cursor is blinking.
static constexpr std::chrono::nanoseconds OBSOLETE_TIME_EPSILON_NS = 1200ms;
-// Layer is considered low activity if the buffers come more than LOW_ACTIVITY_EPSILON_NS
-// apart. This is helping SF to vote for lower refresh rates when there is not activity
+// Layer is considered low activity if the LOW_ACTIVITY_BUFFERS buffers come more than
+// LOW_ACTIVITY_EPSILON_NS apart.
+// This is helping SF to vote for lower refresh rates when there is not activity
// in screen.
+static constexpr int LOW_ACTIVITY_BUFFERS = 2;
static constexpr std::chrono::nanoseconds LOW_ACTIVITY_EPSILON_NS = 250ms;
// Calculates the statistical mean (average) in the data structure (array, vector). The