Merge "SurfaceFlinger: tune number of buffers for low activity layers" into qt-qpr1-dev (dd08ee7c) · Commits · e / os / platform_frameworks_native

services/surfaceflinger/Scheduler/LayerInfo.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -109,7 +109,7 @@ class LayerInfo {
		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 @@ class LayerInfo {
		// 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;
		}

+4 −2

Original line number	Diff line number	Diff line
		@@ -42,9 +42,11 @@ static constexpr uint32_t HWC2_SCREEN_OFF_CONFIG_ID = 0xffffffff;
		// 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