SF: Do not trace FrameTimeline before start

Filter FrameTimeline events for frames started before the trace started.

Bug: 364194637
Test: manual
Flag: com.android.graphics.surfaceflinger.flags.filter_frames_before_trace_starts
Change-Id: I9185f384f306eddab1afc2ea9d7901dd70d2f1a2

6 files changed, 209 insertions, 104 deletions

diff --git a/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp b/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp
index 2311360ce9..47b811b721 100644
--- a/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp
+++ b/services/surfaceflinger/FrameTimeline/FrameTimeline.cpp
@@ -38,6 +38,8 @@ using base::StringAppendF;
 using FrameTimelineEvent = perfetto::protos::pbzero::FrameTimelineEvent;
 using FrameTimelineDataSource = impl::FrameTimeline::FrameTimelineDataSource;
 
+namespace {
+
 void dumpTable(std::string& result, TimelineItem predictions, TimelineItem actuals,
                const std::string& indent, PredictionState predictionState, nsecs_t baseTime) {
     StringAppendF(&result, "%s", indent.c_str());
@@ -319,6 +321,16 @@ nsecs_t getMinTime(PredictionState predictionState, TimelineItem predictions,
     return minTime;
 }
 
+bool shouldTraceForDataSource(const FrameTimelineDataSource::TraceContext& ctx, nsecs_t timestamp) {
+    if (auto ds = ctx.GetDataSourceLocked(); ds && ds->getStartTime() > timestamp) {
+        return false;
+    }
+
+    return true;
+}
+
+} // namespace
+
 int64_t TraceCookieCounter::getCookieForTracing() {
     return ++mTraceCookie;
 }
@@ -726,15 +738,24 @@ void SurfaceFrame::onCommitNotComposited(Fps refreshRate, Fps displayFrameRender
     classifyJankLocked(JankType::None, refreshRate, displayFrameRenderRate, nullptr);
 }
 
-void SurfaceFrame::tracePredictions(int64_t displayFrameToken, nsecs_t monoBootOffset) const {
+void SurfaceFrame::tracePredictions(int64_t displayFrameToken, nsecs_t monoBootOffset,
+                                    bool filterFramesBeforeTraceStarts) const {
     int64_t expectedTimelineCookie = mTraceCookieCounter.getCookieForTracing();
+    bool traced = false;
 
     // Expected timeline start
     FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+        const auto timestamp = mPredictions.startTime;
+        if (filterFramesBeforeTraceStarts && !shouldTraceForDataSource(ctx, timestamp)) {
+            // Do not trace packets started before tracing starts.
+            return;
+        }
+        traced = true;
+
         std::scoped_lock lock(mMutex);
         auto packet = ctx.NewTracePacket();
         packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        packet->set_timestamp(static_cast<uint64_t>(mPredictions.startTime + monoBootOffset));
+        packet->set_timestamp(static_cast<uint64_t>(timestamp + monoBootOffset));
 
         auto* event = packet->set_frame_timeline_event();
         auto* expectedSurfaceFrameStartEvent = event->set_expected_surface_frame_start();
@@ -748,42 +769,54 @@ void SurfaceFrame::tracePredictions(int64_t displayFrameToken, nsecs_t monoBootO
         expectedSurfaceFrameStartEvent->set_layer_name(mDebugName);
     });
 
-    // Expected timeline end
-    FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
-        std::scoped_lock lock(mMutex);
-        auto packet = ctx.NewTracePacket();
-        packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        packet->set_timestamp(static_cast<uint64_t>(mPredictions.endTime + monoBootOffset));
+    if (traced) {
+        // Expected timeline end
+        FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+            std::scoped_lock lock(mMutex);
+            auto packet = ctx.NewTracePacket();
+            packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
+            packet->set_timestamp(static_cast<uint64_t>(mPredictions.endTime + monoBootOffset));
 
-        auto* event = packet->set_frame_timeline_event();
-        auto* expectedSurfaceFrameEndEvent = event->set_frame_end();
+            auto* event = packet->set_frame_timeline_event();
+            auto* expectedSurfaceFrameEndEvent = event->set_frame_end();
 
-        expectedSurfaceFrameEndEvent->set_cookie(expectedTimelineCookie);
-    });
+            expectedSurfaceFrameEndEvent->set_cookie(expectedTimelineCookie);
+        });
+    }
 }
 
-void SurfaceFrame::traceActuals(int64_t displayFrameToken, nsecs_t monoBootOffset) const {
+void SurfaceFrame::traceActuals(int64_t displayFrameToken, nsecs_t monoBootOffset,
+                                bool filterFramesBeforeTraceStarts) const {
     int64_t actualTimelineCookie = mTraceCookieCounter.getCookieForTracing();
+    bool traced = false;
 
     // Actual timeline start
     FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+        const auto timestamp = [&]() {
+            std::scoped_lock lock(mMutex);
+            // Actual start time is not yet available, so use expected start instead
+            if (mPredictionState == PredictionState::Expired) {
+                // If prediction is expired, we can't use the predicted start time. Instead, just
+                // use a start time a little earlier than the end time so that we have some info
+                // about this frame in the trace.
+                nsecs_t endTime =
+                        (mPresentState == PresentState::Dropped ? mDropTime : mActuals.endTime);
+                return endTime - kPredictionExpiredStartTimeDelta;
+            }
+
+            return mActuals.startTime == 0 ? mPredictions.startTime : mActuals.startTime;
+        }();
+
+        if (filterFramesBeforeTraceStarts && !shouldTraceForDataSource(ctx, timestamp)) {
+            // Do not trace packets started before tracing starts.
+            return;
+        }
+        traced = true;
+
         std::scoped_lock lock(mMutex);
         auto packet = ctx.NewTracePacket();
         packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        // Actual start time is not yet available, so use expected start instead
-        if (mPredictionState == PredictionState::Expired) {
-            // If prediction is expired, we can't use the predicted start time. Instead, just use a
-            // start time a little earlier than the end time so that we have some info about this
-            // frame in the trace.
-            nsecs_t endTime =
-                    (mPresentState == PresentState::Dropped ? mDropTime : mActuals.endTime);
-            const auto timestamp = endTime - kPredictionExpiredStartTimeDelta;
-            packet->set_timestamp(static_cast<uint64_t>(timestamp + monoBootOffset));
-        } else {
-            const auto timestamp =
-                    mActuals.startTime == 0 ? mPredictions.startTime : mActuals.startTime;
-            packet->set_timestamp(static_cast<uint64_t>(timestamp + monoBootOffset));
-        }
+        packet->set_timestamp(static_cast<uint64_t>(timestamp + monoBootOffset));
 
         auto* event = packet->set_frame_timeline_event();
         auto* actualSurfaceFrameStartEvent = event->set_actual_surface_frame_start();
@@ -812,28 +845,31 @@ void SurfaceFrame::traceActuals(int64_t displayFrameToken, nsecs_t monoBootOffse
         actualSurfaceFrameStartEvent->set_jank_severity_type(toProto(mJankSeverityType));
     });
 
-    // Actual timeline end
-    FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
-        std::scoped_lock lock(mMutex);
-        auto packet = ctx.NewTracePacket();
-        packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        if (mPresentState == PresentState::Dropped) {
-            packet->set_timestamp(static_cast<uint64_t>(mDropTime + monoBootOffset));
-        } else {
-            packet->set_timestamp(static_cast<uint64_t>(mActuals.endTime + monoBootOffset));
-        }
+    if (traced) {
+        // Actual timeline end
+        FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+            std::scoped_lock lock(mMutex);
+            auto packet = ctx.NewTracePacket();
+            packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
+            if (mPresentState == PresentState::Dropped) {
+                packet->set_timestamp(static_cast<uint64_t>(mDropTime + monoBootOffset));
+            } else {
+                packet->set_timestamp(static_cast<uint64_t>(mActuals.endTime + monoBootOffset));
+            }
 
-        auto* event = packet->set_frame_timeline_event();
-        auto* actualSurfaceFrameEndEvent = event->set_frame_end();
+            auto* event = packet->set_frame_timeline_event();
+            auto* actualSurfaceFrameEndEvent = event->set_frame_end();
 
-        actualSurfaceFrameEndEvent->set_cookie(actualTimelineCookie);
-    });
+            actualSurfaceFrameEndEvent->set_cookie(actualTimelineCookie);
+        });
+    }
 }
 
 /**
  * TODO(b/178637512): add inputEventId to the perfetto trace.
  */
-void SurfaceFrame::trace(int64_t displayFrameToken, nsecs_t monoBootOffset) const {
+void SurfaceFrame::trace(int64_t displayFrameToken, nsecs_t monoBootOffset,
+                         bool filterFramesBeforeTraceStarts) const {
     if (mToken == FrameTimelineInfo::INVALID_VSYNC_ID ||
         displayFrameToken == FrameTimelineInfo::INVALID_VSYNC_ID) {
         // No packets can be traced with a missing token.
@@ -842,9 +878,9 @@ void SurfaceFrame::trace(int64_t displayFrameToken, nsecs_t monoBootOffset) cons
     if (getPredictionState() != PredictionState::Expired) {
         // Expired predictions have zeroed timestamps. This cannot be used in any meaningful way in
         // a trace.
-        tracePredictions(displayFrameToken, monoBootOffset);
+        tracePredictions(displayFrameToken, monoBootOffset, filterFramesBeforeTraceStarts);
     }
-    traceActuals(displayFrameToken, monoBootOffset);
+    traceActuals(displayFrameToken, monoBootOffset, filterFramesBeforeTraceStarts);
 }
 
 namespace impl {
@@ -870,8 +906,12 @@ std::optional<TimelineItem> TokenManager::getPredictionsForToken(int64_t token)
 }
 
 FrameTimeline::FrameTimeline(std::shared_ptr<TimeStats> timeStats, pid_t surfaceFlingerPid,
-                             JankClassificationThresholds thresholds, bool useBootTimeClock)
+                             JankClassificationThresholds thresholds, bool useBootTimeClock,
+                             bool filterFramesBeforeTraceStarts)
       : mUseBootTimeClock(useBootTimeClock),
+        mFilterFramesBeforeTraceStarts(
+                FlagManager::getInstance().filter_frames_before_trace_starts() &&
+                filterFramesBeforeTraceStarts),
         mMaxDisplayFrames(kDefaultMaxDisplayFrames),
         mTimeStats(std::move(timeStats)),
         mSurfaceFlingerPid(surfaceFlingerPid),
@@ -1154,16 +1194,23 @@ void FrameTimeline::DisplayFrame::onCommitNotComposited() {
     }
 }
 
-void FrameTimeline::DisplayFrame::tracePredictions(pid_t surfaceFlingerPid,
-                                                   nsecs_t monoBootOffset) const {
+void FrameTimeline::DisplayFrame::tracePredictions(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
+                                                   bool filterFramesBeforeTraceStarts) const {
     int64_t expectedTimelineCookie = mTraceCookieCounter.getCookieForTracing();
+    bool traced = false;
 
     // Expected timeline start
     FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+        const auto timestamp = mSurfaceFlingerPredictions.startTime;
+        if (filterFramesBeforeTraceStarts && !shouldTraceForDataSource(ctx, timestamp)) {
+            // Do not trace packets started before tracing starts.
+            return;
+        }
+        traced = true;
+
         auto packet = ctx.NewTracePacket();
         packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        packet->set_timestamp(
-                static_cast<uint64_t>(mSurfaceFlingerPredictions.startTime + monoBootOffset));
+        packet->set_timestamp(static_cast<uint64_t>(timestamp + monoBootOffset));
 
         auto* event = packet->set_frame_timeline_event();
         auto* expectedDisplayFrameStartEvent = event->set_expected_display_frame_start();
@@ -1174,22 +1221,25 @@ void FrameTimeline::DisplayFrame::tracePredictions(pid_t surfaceFlingerPid,
         expectedDisplayFrameStartEvent->set_pid(surfaceFlingerPid);
     });
 
-    // Expected timeline end
-    FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
-        auto packet = ctx.NewTracePacket();
-        packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        packet->set_timestamp(
-                static_cast<uint64_t>(mSurfaceFlingerPredictions.endTime + monoBootOffset));
+    if (traced) {
+        // Expected timeline end
+        FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+            auto packet = ctx.NewTracePacket();
+            packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
+            packet->set_timestamp(
+                    static_cast<uint64_t>(mSurfaceFlingerPredictions.endTime + monoBootOffset));
 
-        auto* event = packet->set_frame_timeline_event();
-        auto* expectedDisplayFrameEndEvent = event->set_frame_end();
+            auto* event = packet->set_frame_timeline_event();
+            auto* expectedDisplayFrameEndEvent = event->set_frame_end();
 
-        expectedDisplayFrameEndEvent->set_cookie(expectedTimelineCookie);
-    });
+            expectedDisplayFrameEndEvent->set_cookie(expectedTimelineCookie);
+        });
+    }
 }
 
 void FrameTimeline::DisplayFrame::addSkippedFrame(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
-                                                  nsecs_t previousPredictionPresentTime) const {
+                                                  nsecs_t previousPredictionPresentTime,
+                                                  bool filterFramesBeforeTraceStarts) const {
     nsecs_t skippedFrameStartTime = 0, skippedFramePresentTime = 0;
     const constexpr float kThresh = 0.5f;
     const constexpr float kRange = 1.5f;
@@ -1215,9 +1265,17 @@ void FrameTimeline::DisplayFrame::addSkippedFrame(pid_t surfaceFlingerPid, nsecs
     // add slice
     if (skippedFrameStartTime != 0 && skippedFramePresentTime != 0) {
         int64_t actualTimelineCookie = mTraceCookieCounter.getCookieForTracing();
+        bool traced = false;
 
         // Actual timeline start
         FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+            if (filterFramesBeforeTraceStarts &&
+                !shouldTraceForDataSource(ctx, skippedFrameStartTime)) {
+                // Do not trace packets started before tracing starts.
+                return;
+            }
+            traced = true;
+
             auto packet = ctx.NewTracePacket();
             packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
             packet->set_timestamp(static_cast<uint64_t>(skippedFrameStartTime + monoBootOffset));
@@ -1238,30 +1296,40 @@ void FrameTimeline::DisplayFrame::addSkippedFrame(pid_t surfaceFlingerPid, nsecs
             actualDisplayFrameStartEvent->set_jank_severity_type(toProto(JankSeverityType::None));
         });
 
-        // Actual timeline end
-        FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
-            auto packet = ctx.NewTracePacket();
-            packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-            packet->set_timestamp(static_cast<uint64_t>(skippedFramePresentTime + monoBootOffset));
+        if (traced) {
+            // Actual timeline end
+            FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+                auto packet = ctx.NewTracePacket();
+                packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
+                packet->set_timestamp(
+                        static_cast<uint64_t>(skippedFramePresentTime + monoBootOffset));
 
-            auto* event = packet->set_frame_timeline_event();
-            auto* actualDisplayFrameEndEvent = event->set_frame_end();
+                auto* event = packet->set_frame_timeline_event();
+                auto* actualDisplayFrameEndEvent = event->set_frame_end();
 
-            actualDisplayFrameEndEvent->set_cookie(actualTimelineCookie);
-        });
+                actualDisplayFrameEndEvent->set_cookie(actualTimelineCookie);
+            });
+        }
     }
 }
 
-void FrameTimeline::DisplayFrame::traceActuals(pid_t surfaceFlingerPid,
-                                               nsecs_t monoBootOffset) const {
+void FrameTimeline::DisplayFrame::traceActuals(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
+                                               bool filterFramesBeforeTraceStarts) const {
     int64_t actualTimelineCookie = mTraceCookieCounter.getCookieForTracing();
+    bool traced = false;
 
     // Actual timeline start
     FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+        const auto timestamp = mSurfaceFlingerActuals.startTime;
+        if (filterFramesBeforeTraceStarts && !shouldTraceForDataSource(ctx, timestamp)) {
+            // Do not trace packets started before tracing starts.
+            return;
+        }
+        traced = true;
+
         auto packet = ctx.NewTracePacket();
         packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        packet->set_timestamp(
-                static_cast<uint64_t>(mSurfaceFlingerActuals.startTime + monoBootOffset));
+        packet->set_timestamp(static_cast<uint64_t>(timestamp + monoBootOffset));
 
         auto* event = packet->set_frame_timeline_event();
         auto* actualDisplayFrameStartEvent = event->set_actual_display_frame_start();
@@ -1280,22 +1348,25 @@ void FrameTimeline::DisplayFrame::traceActuals(pid_t surfaceFlingerPid,
         actualDisplayFrameStartEvent->set_jank_severity_type(toProto(mJankSeverityType));
     });
 
-    // Actual timeline end
-    FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
-        auto packet = ctx.NewTracePacket();
-        packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
-        packet->set_timestamp(
-                static_cast<uint64_t>(mSurfaceFlingerActuals.presentTime + monoBootOffset));
+    if (traced) {
+        // Actual timeline end
+        FrameTimelineDataSource::Trace([&](FrameTimelineDataSource::TraceContext ctx) {
+            auto packet = ctx.NewTracePacket();
+            packet->set_timestamp_clock_id(perfetto::protos::pbzero::BUILTIN_CLOCK_BOOTTIME);
+            packet->set_timestamp(
+                    static_cast<uint64_t>(mSurfaceFlingerActuals.presentTime + monoBootOffset));
 
-        auto* event = packet->set_frame_timeline_event();
-        auto* actualDisplayFrameEndEvent = event->set_frame_end();
+            auto* event = packet->set_frame_timeline_event();
+            auto* actualDisplayFrameEndEvent = event->set_frame_end();
 
-        actualDisplayFrameEndEvent->set_cookie(actualTimelineCookie);
-    });
+            actualDisplayFrameEndEvent->set_cookie(actualTimelineCookie);
+        });
+    }
 }
 
 nsecs_t FrameTimeline::DisplayFrame::trace(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
-                                           nsecs_t previousPredictionPresentTime) const {
+                                           nsecs_t previousPredictionPresentTime,
+                                           bool filterFramesBeforeTraceStarts) const {
     if (mSurfaceFrames.empty()) {
         // We don't want to trace display frames without any surface frames updates as this cannot
         // be janky
@@ -1311,16 +1382,17 @@ nsecs_t FrameTimeline::DisplayFrame::trace(pid_t surfaceFlingerPid, nsecs_t mono
     if (mPredictionState == PredictionState::Valid) {
         // Expired and unknown predictions have zeroed timestamps. This cannot be used in any
         // meaningful way in a trace.
-        tracePredictions(surfaceFlingerPid, monoBootOffset);
+        tracePredictions(surfaceFlingerPid, monoBootOffset, filterFramesBeforeTraceStarts);
     }
-    traceActuals(surfaceFlingerPid, monoBootOffset);
+    traceActuals(surfaceFlingerPid, monoBootOffset, filterFramesBeforeTraceStarts);
 
     for (auto& surfaceFrame : mSurfaceFrames) {
-        surfaceFrame->trace(mToken, monoBootOffset);
+        surfaceFrame->trace(mToken, monoBootOffset, filterFramesBeforeTraceStarts);
     }
 
     if (FlagManager::getInstance().add_sf_skipped_frames_to_trace()) {
-        addSkippedFrame(surfaceFlingerPid, monoBootOffset, previousPredictionPresentTime);
+        addSkippedFrame(surfaceFlingerPid, monoBootOffset, previousPredictionPresentTime,
+                        filterFramesBeforeTraceStarts);
     }
     return mSurfaceFlingerPredictions.presentTime;
 }
@@ -1414,8 +1486,9 @@ void FrameTimeline::flushPendingPresentFences() {
         const nsecs_t signalTime = Fence::SIGNAL_TIME_INVALID;
         auto& displayFrame = pendingPresentFence.second;
         displayFrame->onPresent(signalTime, mPreviousActualPresentTime);
-        mPreviousPredictionPresentTime = displayFrame->trace(mSurfaceFlingerPid, monoBootOffset,
-                                                             mPreviousPredictionPresentTime);
+        mPreviousPredictionPresentTime =
+                displayFrame->trace(mSurfaceFlingerPid, monoBootOffset,
+                                    mPreviousPredictionPresentTime, mFilterFramesBeforeTraceStarts);
         mPendingPresentFences.erase(mPendingPresentFences.begin());
     }
 
@@ -1431,8 +1504,9 @@ void FrameTimeline::flushPendingPresentFences() {
 
         auto& displayFrame = pendingPresentFence.second;
         displayFrame->onPresent(signalTime, mPreviousActualPresentTime);
-        mPreviousPredictionPresentTime = displayFrame->trace(mSurfaceFlingerPid, monoBootOffset,
-                                                             mPreviousPredictionPresentTime);
+        mPreviousPredictionPresentTime =
+                displayFrame->trace(mSurfaceFlingerPid, monoBootOffset,
+                                    mPreviousPredictionPresentTime, mFilterFramesBeforeTraceStarts);
         mPreviousActualPresentTime = signalTime;
 
         mPendingPresentFences.erase(mPendingPresentFences.begin() + static_cast<int>(i));
diff --git a/services/surfaceflinger/FrameTimeline/FrameTimeline.h b/services/surfaceflinger/FrameTimeline/FrameTimeline.h
index 94cfcb40b9..cffb61ee10 100644
--- a/services/surfaceflinger/FrameTimeline/FrameTimeline.h
+++ b/services/surfaceflinger/FrameTimeline/FrameTimeline.h
@@ -214,7 +214,8 @@ public:
     // enabled. The displayFrameToken is needed to link the SurfaceFrame to the corresponding
     // DisplayFrame at the trace processor side. monoBootOffset is the difference
     // between SYSTEM_TIME_BOOTTIME and SYSTEM_TIME_MONOTONIC.
-    void trace(int64_t displayFrameToken, nsecs_t monoBootOffset) const;
+    void trace(int64_t displayFrameToken, nsecs_t monoBootOffset,
+               bool filterFramesBeforeTraceStarts) const;
 
     // Getter functions used only by FrameTimelineTests and SurfaceFrame internally
     TimelineItem getActuals() const;
@@ -234,8 +235,10 @@ public:
             std::chrono::duration_cast<std::chrono::nanoseconds>(2ms).count();
 
 private:
-    void tracePredictions(int64_t displayFrameToken, nsecs_t monoBootOffset) const;
-    void traceActuals(int64_t displayFrameToken, nsecs_t monoBootOffset) const;
+    void tracePredictions(int64_t displayFrameToken, nsecs_t monoBootOffset,
+                          bool filterFramesBeforeTraceStarts) const;
+    void traceActuals(int64_t displayFrameToken, nsecs_t monoBootOffset,
+                      bool filterFramesBeforeTraceStarts) const;
     void classifyJankLocked(int32_t displayFrameJankType, const Fps& refreshRate,
                             Fps displayFrameRenderRate, nsecs_t* outDeadlineDelta) REQUIRES(mMutex);
 
@@ -367,9 +370,15 @@ private:
 class FrameTimeline : public android::frametimeline::FrameTimeline {
 public:
     class FrameTimelineDataSource : public perfetto::DataSource<FrameTimelineDataSource> {
-        void OnSetup(const SetupArgs&) override{};
-        void OnStart(const StartArgs&) override{};
-        void OnStop(const StopArgs&) override{};
+    public:
+        nsecs_t getStartTime() const { return mTraceStartTime; }
+
+    private:
+        void OnSetup(const SetupArgs&) override {};
+        void OnStart(const StartArgs&) override { mTraceStartTime = systemTime(); };
+        void OnStop(const StopArgs&) override {};
+
+        nsecs_t mTraceStartTime = 0;
     };
 
     /*
@@ -390,7 +399,8 @@ public:
         // is enabled. monoBootOffset is the difference between SYSTEM_TIME_BOOTTIME
         // and SYSTEM_TIME_MONOTONIC.
         nsecs_t trace(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
-                      nsecs_t previousPredictionPresentTime) const;
+                      nsecs_t previousPredictionPresentTime,
+                      bool filterFramesBeforeTraceStarts) const;
         // Sets the token, vsyncPeriod, predictions and SF start time.
         void onSfWakeUp(int64_t token, Fps refreshRate, Fps renderRate,
                         std::optional<TimelineItem> predictions, nsecs_t wakeUpTime);
@@ -424,10 +434,13 @@ public:
 
     private:
         void dump(std::string& result, nsecs_t baseTime) const;
-        void tracePredictions(pid_t surfaceFlingerPid, nsecs_t monoBootOffset) const;
-        void traceActuals(pid_t surfaceFlingerPid, nsecs_t monoBootOffset) const;
+        void tracePredictions(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
+                              bool filterFramesBeforeTraceStarts) const;
+        void traceActuals(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
+                          bool filterFramesBeforeTraceStarts) const;
         void addSkippedFrame(pid_t surfaceFlingerPid, nsecs_t monoBootOffset,
-                             nsecs_t previousActualPresentTime) const;
+                             nsecs_t previousActualPresentTime,
+                             bool filterFramesBeforeTraceStarts) const;
         void classifyJank(nsecs_t& deadlineDelta, nsecs_t& deltaToVsync,
                           nsecs_t previousPresentTime);
 
@@ -471,7 +484,8 @@ public:
     };
 
     FrameTimeline(std::shared_ptr<TimeStats> timeStats, pid_t surfaceFlingerPid,
-                  JankClassificationThresholds thresholds = {}, bool useBootTimeClock = true);
+                  JankClassificationThresholds thresholds = {}, bool useBootTimeClock = true,
+                  bool filterFramesBeforeTraceStarts = true);
     ~FrameTimeline() = default;
 
     frametimeline::TokenManager* getTokenManager() override { return &mTokenManager; }
@@ -516,6 +530,7 @@ private:
     TraceCookieCounter mTraceCookieCounter;
     mutable std::mutex mMutex;
     const bool mUseBootTimeClock;
+    const bool mFilterFramesBeforeTraceStarts;
     uint32_t mMaxDisplayFrames;
     std::shared_ptr<TimeStats> mTimeStats;
     const pid_t mSurfaceFlingerPid;
diff --git a/services/surfaceflinger/common/FlagManager.cpp b/services/surfaceflinger/common/FlagManager.cpp
index 08412cb8e4..12d6138675 100644
--- a/services/surfaceflinger/common/FlagManager.cpp
+++ b/services/surfaceflinger/common/FlagManager.cpp
@@ -143,6 +143,7 @@ void FlagManager::dump(std::string& result) const {
     DUMP_READ_ONLY_FLAG(ce_fence_promise);
     DUMP_READ_ONLY_FLAG(idle_screen_refresh_rate_timeout);
     DUMP_READ_ONLY_FLAG(graphite_renderengine);
+    DUMP_READ_ONLY_FLAG(filter_frames_before_trace_starts);
     DUMP_READ_ONLY_FLAG(latch_unsignaled_with_auto_refresh_changed);
     DUMP_READ_ONLY_FLAG(deprecate_vsync_sf);
     DUMP_READ_ONLY_FLAG(allow_n_vsyncs_in_targeter);
@@ -248,6 +249,7 @@ FLAG_MANAGER_READ_ONLY_FLAG(vrr_bugfix_24q4, "");
 FLAG_MANAGER_READ_ONLY_FLAG(vrr_bugfix_dropped_frame, "")
 FLAG_MANAGER_READ_ONLY_FLAG(ce_fence_promise, "");
 FLAG_MANAGER_READ_ONLY_FLAG(graphite_renderengine, "debug.renderengine.graphite")
+FLAG_MANAGER_READ_ONLY_FLAG(filter_frames_before_trace_starts, "")
 FLAG_MANAGER_READ_ONLY_FLAG(latch_unsignaled_with_auto_refresh_changed, "");
 FLAG_MANAGER_READ_ONLY_FLAG(deprecate_vsync_sf, "");
 FLAG_MANAGER_READ_ONLY_FLAG(allow_n_vsyncs_in_targeter, "");
diff --git a/services/surfaceflinger/common/include/common/FlagManager.h b/services/surfaceflinger/common/include/common/FlagManager.h
index ab0ea3bdaa..a1be19421b 100644
--- a/services/surfaceflinger/common/include/common/FlagManager.h
+++ b/services/surfaceflinger/common/include/common/FlagManager.h
@@ -81,6 +81,7 @@ public:
     bool ce_fence_promise() const;
     bool idle_screen_refresh_rate_timeout() const;
     bool graphite_renderengine() const;
+    bool filter_frames_before_trace_starts() const;
     bool latch_unsignaled_with_auto_refresh_changed() const;
     bool deprecate_vsync_sf() const;
     bool allow_n_vsyncs_in_targeter() const;
diff --git a/services/surfaceflinger/surfaceflinger_flags_new.aconfig b/services/surfaceflinger/surfaceflinger_flags_new.aconfig
index fcfeaccee7..102e2b643c 100644
--- a/services/surfaceflinger/surfaceflinger_flags_new.aconfig
+++ b/services/surfaceflinger/surfaceflinger_flags_new.aconfig
@@ -66,6 +66,17 @@ flag {
 } # detached_mirror
 
 flag {
+  name: "filter_frames_before_trace_starts"
+  namespace: "core_graphics"
+  description: "Do not trace FrameTimeline events for frames started before the trace started"
+  bug: "364194637"
+  is_fixed_read_only: true
+  metadata {
+    purpose: PURPOSE_BUGFIX
+  }
+} # filter_frames_before_trace_starts
+
+flag {
   name: "flush_buffer_slots_to_uncache"
   namespace: "core_graphics"
   description: "Flush DisplayCommands for disabled displays in order to uncache requested buffers."
diff --git a/services/surfaceflinger/tests/unittests/FrameTimelineTest.cpp b/services/surfaceflinger/tests/unittests/FrameTimelineTest.cpp
index 9be0fc38b3..0dfbd6185e 100644
--- a/services/surfaceflinger/tests/unittests/FrameTimelineTest.cpp
+++ b/services/surfaceflinger/tests/unittests/FrameTimelineTest.cpp
@@ -84,9 +84,11 @@ public:
 
     void SetUp() override {
         constexpr bool kUseBootTimeClock = true;
+        constexpr bool kFilterFramesBeforeTraceStarts = false;
         mTimeStats = std::make_shared<mock::TimeStats>();
         mFrameTimeline = std::make_unique<impl::FrameTimeline>(mTimeStats, kSurfaceFlingerPid,
-                                                               kTestThresholds, !kUseBootTimeClock);
+                                                               kTestThresholds, !kUseBootTimeClock,
+                                                               kFilterFramesBeforeTraceStarts);
         mFrameTimeline->registerDataSource();
         mTokenManager = &mFrameTimeline->mTokenManager;
         mTraceCookieCounter = &mFrameTimeline->mTraceCookieCounter;