commit 04eb8e0ba24ca4c5d5741cdfbb5c6bbfc5c2c8b9
author Jerry Chang <chenghsiuchang@google.com> Wed Nov 15 08:06:07 2023 +0000
committer Jerry Chang <chenghsiuchang@google.com> Thu Nov 23 08:45:02 2023 +0000
tree dbac2975a4fdca57abd5a04aa9e52534da212aa1
parent 43881b0fa27a23422041337c89d95098a2d4b618

SF: update consistent criteria for heuristic refresh rate calculation

Enlarge the consistent criteria to apply heuristic logic for more cases.
To prevent introducing oscillation, this makes sure to only select a
valid know refresh rate if all the frametime in the layer history have
the same nearest known refresh rate.

Bug: 299201319
Test: presubmit
Change-Id: Ie317f7fe337c84c2c7314069cba1bd02a147bf6b

services/surfaceflinger/Scheduler/LayerInfo.cpp

diff --git a/services/surfaceflinger/Scheduler/LayerInfo.cpp b/services/surfaceflinger/Scheduler/LayerInfo.cpp
index bf3a7bc..8ee4ebb 100644
--- a/services/surfaceflinger/Scheduler/LayerInfo.cpp
+++ b/services/surfaceflinger/Scheduler/LayerInfo.cpp
@@ -276,17 +276,16 @@
 
     if (const auto averageFrameTime = calculateAverageFrameTime()) {
         const auto refreshRate = Fps::fromPeriodNsecs(*averageFrameTime);
-        const bool refreshRateConsistent = mRefreshRateHistory.add(refreshRate, now);
-        if (refreshRateConsistent) {
-            const auto knownRefreshRate = selector.findClosestKnownFrameRate(refreshRate);
+        const auto closestKnownRefreshRate = mRefreshRateHistory.add(refreshRate, now, selector);
+        if (closestKnownRefreshRate.isValid()) {
             using fps_approx_ops::operator!=;
 
             // To avoid oscillation, use the last calculated refresh rate if it is close enough.
             if (std::abs(mLastRefreshRate.calculated.getValue() - refreshRate.getValue()) >
                         MARGIN &&
-                mLastRefreshRate.reported != knownRefreshRate) {
+                mLastRefreshRate.reported != closestKnownRefreshRate) {
                 mLastRefreshRate.calculated = refreshRate;
-                mLastRefreshRate.reported = knownRefreshRate;
+                mLastRefreshRate.reported = closestKnownRefreshRate;
             }
 
             ALOGV("%s %s rounded to nearest known frame rate %s", mName.c_str(),
@@ -432,7 +431,8 @@
     mRefreshRates.clear();
 }
 
-bool LayerInfo::RefreshRateHistory::add(Fps refreshRate, nsecs_t now) {
+Fps LayerInfo::RefreshRateHistory::add(Fps refreshRate, nsecs_t now,
+                                       const RefreshRateSelector& selector) {
     mRefreshRates.push_back({refreshRate, now});
     while (mRefreshRates.size() >= HISTORY_SIZE ||
            now - mRefreshRates.front().timestamp > HISTORY_DURATION.count()) {
@@ -447,11 +447,11 @@
         ATRACE_INT(mHeuristicTraceTagData->average.c_str(), refreshRate.getIntValue());
     }
 
-    return isConsistent();
+    return selectRefreshRate(selector);
 }
 
-bool LayerInfo::RefreshRateHistory::isConsistent() const {
-    if (mRefreshRates.empty()) return true;
+Fps LayerInfo::RefreshRateHistory::selectRefreshRate(const RefreshRateSelector& selector) const {
+    if (mRefreshRates.empty()) return Fps();
 
     const auto [min, max] =
             std::minmax_element(mRefreshRates.begin(), mRefreshRates.end(),
@@ -459,8 +459,19 @@
                                     return isStrictlyLess(lhs.refreshRate, rhs.refreshRate);
                                 });
 
-    const bool consistent =
-            max->refreshRate.getValue() - min->refreshRate.getValue() < MARGIN_CONSISTENT_FPS;
+    const auto maxClosestRate = selector.findClosestKnownFrameRate(max->refreshRate);
+    const bool consistent = [&](Fps maxFps, Fps minFps) {
+        if (FlagManager::getInstance().use_known_refresh_rate_for_fps_consistency()) {
+            if (maxFps.getValue() - minFps.getValue() <
+                MARGIN_CONSISTENT_FPS_FOR_CLOSEST_REFRESH_RATE) {
+                const auto minClosestRate = selector.findClosestKnownFrameRate(minFps);
+                using fps_approx_ops::operator==;
+                return maxClosestRate == minClosestRate;
+            }
+            return false;
+        }
+        return maxFps.getValue() - minFps.getValue() < MARGIN_CONSISTENT_FPS;
+    }(max->refreshRate, min->refreshRate);
 
     if (CC_UNLIKELY(sTraceEnabled)) {
         if (!mHeuristicTraceTagData.has_value()) {
@@ -472,7 +483,7 @@
         ATRACE_INT(mHeuristicTraceTagData->consistent.c_str(), consistent);
     }
 
-    return consistent;
+    return consistent ? maxClosestRate : Fps();
 }
 
 FrameRateCompatibility LayerInfo::FrameRate::convertCompatibility(int8_t compatibility) {