Merge "SF: increase precision in VSyncPredictor" into rvc-dev am: dc9cc4def7 (ed4b9623) · Commits · e / os / platform_frameworks_native

services/surfaceflinger/Scheduler/VSyncPredictor.cpp

+3 −3

services/surfaceflinger/tests/unittests/VSyncPredictorTest.cpp

+45 −3

Original line number	Original line	Diff line number	Diff line
	@@ -204,7 +204,7 @@ TEST_F(VSyncPredictorTest, againstOutliersDiscontinuous_500hzLowVariance) {
	};		};
	auto idealPeriod = 2000000;		auto idealPeriod = 2000000;
	auto expectedPeriod = 1999892;		auto expectedPeriod = 1999892;
	auto expectedIntercept = 175409;		auto expectedIntercept = 86342;

	tracker.setPeriod(idealPeriod);		tracker.setPeriod(idealPeriod);
	for (auto const& timestamp : simulatedVsyncs) {		for (auto const& timestamp : simulatedVsyncs) {
	@@ -335,8 +335,8 @@ TEST_F(VSyncPredictorTest, doesNotPredictBeforeTimePointWithHigherIntercept) {
	158929706370359,		158929706370359,
	};		};
	auto const idealPeriod = 11111111;		auto const idealPeriod = 11111111;
	auto const expectedPeriod = 11113500;		auto const expectedPeriod = 11113919;
	auto const expectedIntercept = -395335;		auto const expectedIntercept = -1195945;

	tracker.setPeriod(idealPeriod);		tracker.setPeriod(idealPeriod);
	for (auto const& timestamp : simulatedVsyncs) {		for (auto const& timestamp : simulatedVsyncs) {
	@@ -355,6 +355,32 @@ TEST_F(VSyncPredictorTest, doesNotPredictBeforeTimePointWithHigherIntercept) {
	EXPECT_THAT(prediction, Ge(timePoint));		EXPECT_THAT(prediction, Ge(timePoint));
	}		}

			// See b/151146131
			TEST_F(VSyncPredictorTest, hasEnoughPrecision) {
			VSyncPredictor tracker{mPeriod, 20, kMinimumSamplesForPrediction, kOutlierTolerancePercent};
			std::vector<nsecs_t> const simulatedVsyncs{840873348817, 840890049444, 840906762675,
			840923581635, 840940161584, 840956868096,
			840973702473, 840990256277, 841007116851,
			841023722530, 841040452167, 841057073002,
			841073800920, 841090474360, 841107278632,
			841123898634, 841140750875, 841157287127,
			841591357014, 840856664232

			};
			auto const idealPeriod = 16666666;
			auto const expectedPeriod = 16698426;
			auto const expectedIntercept = 58055;

			tracker.setPeriod(idealPeriod);
			for (auto const& timestamp : simulatedVsyncs) {
			tracker.addVsyncTimestamp(timestamp);
			}

			auto [slope, intercept] = tracker.getVSyncPredictionModel();
			EXPECT_THAT(slope, IsCloseTo(expectedPeriod, mMaxRoundingError));
			EXPECT_THAT(intercept, IsCloseTo(expectedIntercept, mMaxRoundingError));
			}

	TEST_F(VSyncPredictorTest, resetsWhenInstructed) {		TEST_F(VSyncPredictorTest, resetsWhenInstructed) {
	auto const idealPeriod = 10000;		auto const idealPeriod = 10000;
	auto const realPeriod = 10500;		auto const realPeriod = 10500;
	@@ -390,6 +416,22 @@ TEST_F(VSyncPredictorTest, slopeAlwaysValid) {
	}		}
	}		}

			constexpr nsecs_t operator""_years(unsigned long long years) noexcept {
			using namespace std::chrono_literals;
			return years * 365 * 24 * 3600 *
			std::chrono::duration_cast<std::chrono::nanoseconds>(1s).count();
			}
			TEST_F(VSyncPredictorTest, aPhoneThatHasBeenAroundAWhileCanStillComputePeriod) {
			constexpr nsecs_t timeBase = 100_years;

			for (auto i = 0; i < kHistorySize; i++) {
			tracker.addVsyncTimestamp(timeBase + i * mPeriod);
			}
			auto [slope, intercept] = tracker.getVSyncPredictionModel();
			EXPECT_THAT(slope, IsCloseTo(mPeriod, mMaxRoundingError));
			EXPECT_THAT(intercept, Eq(0));
			}

	} // namespace android::scheduler		} // namespace android::scheduler

	// TODO(b/129481165): remove the #pragma below and fix conversion issues		// TODO(b/129481165): remove the #pragma below and fix conversion issues

Original line number	Original line	Diff line number	Diff line
	@@ -115,10 +115,10 @@ bool VSyncPredictor::addVsyncTimestamp(nsecs_t timestamp) {
	auto it = mRateMap.find(mIdealPeriod);		auto it = mRateMap.find(mIdealPeriod);
	auto const currentPeriod = std::get<0>(it->second);		auto const currentPeriod = std::get<0>(it->second);
	// TODO (b/144707443): its important that there's some precision in the mean of the ordinals		// TODO (b/144707443): its important that there's some precision in the mean of the ordinals
	// for the intercept calculation, so scale the ordinals by 10 to continue		// for the intercept calculation, so scale the ordinals by 1000 to continue
	// fixed point calculation. Explore expanding		// fixed point calculation. Explore expanding
	// scheduler::utils::calculate_mean to have a fixed point fractional part.		// scheduler::utils::calculate_mean to have a fixed point fractional part.
	static constexpr int kScalingFactor = 10;		static constexpr int64_t kScalingFactor = 1000;

	for (auto i = 0u; i < mTimestamps.size(); i++) {		for (auto i = 0u; i < mTimestamps.size(); i++) {
	traceInt64If("VSP-ts", mTimestamps[i]);		traceInt64If("VSP-ts", mTimestamps[i]);
	@@ -147,7 +147,7 @@ bool VSyncPredictor::addVsyncTimestamp(nsecs_t timestamp) {
	return false;		return false;
	}		}

	nsecs_t const anticipatedPeriod = top / bottom * kScalingFactor;		nsecs_t const anticipatedPeriod = top * kScalingFactor / bottom;
	nsecs_t const intercept = meanTS - (anticipatedPeriod * meanOrdinal / kScalingFactor);		nsecs_t const intercept = meanTS - (anticipatedPeriod * meanOrdinal / kScalingFactor);

	auto const percent = std::abs(anticipatedPeriod - mIdealPeriod) * kMaxPercent / mIdealPeriod;		auto const percent = std::abs(anticipatedPeriod - mIdealPeriod) * kMaxPercent / mIdealPeriod;