diff --git a/services/surfaceflinger/Scheduler/MessageQueue.cpp b/services/surfaceflinger/Scheduler/MessageQueue.cpp
index 9b04497..dec8f59 100644
--- a/services/surfaceflinger/Scheduler/MessageQueue.cpp
+++ b/services/surfaceflinger/Scheduler/MessageQueue.cpp
@@ -17,12 +17,12 @@
 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 
 #include <binder/IPCThreadState.h>
-
+#include <gui/DisplayEventReceiver.h>
 #include <utils/Log.h>
 #include <utils/Timers.h>
 #include <utils/threads.h>
 
-#include <gui/DisplayEventReceiver.h>
+#include <scheduler/interface/ICompositor.h>
 
 #include "EventThread.h"
 #include "FrameTimeline.h"
diff --git a/services/surfaceflinger/Scheduler/MessageQueue.h b/services/surfaceflinger/Scheduler/MessageQueue.h
index ad0ea72..0d59337 100644
--- a/services/surfaceflinger/Scheduler/MessageQueue.h
+++ b/services/surfaceflinger/Scheduler/MessageQueue.h
@@ -37,15 +37,7 @@
 
 namespace android {
 
-struct ICompositor {
-    virtual void configure() = 0;
-    virtual bool commit(TimePoint frameTime, VsyncId, TimePoint expectedVsyncTime) = 0;
-    virtual void composite(TimePoint frameTime, VsyncId) = 0;
-    virtual void sample() = 0;
-
-protected:
-    ~ICompositor() = default;
-};
+struct ICompositor;
 
 template <typename F>
 class Task : public MessageHandler {
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 1fc1519..1e97f35 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -34,6 +34,8 @@
 #include <utils/Trace.h>
 
 #include <FrameTimeline/FrameTimeline.h>
+#include <scheduler/interface/ICompositor.h>
+
 #include <algorithm>
 #include <cinttypes>
 #include <cstdint>
diff --git a/services/surfaceflinger/Scheduler/include/scheduler/interface/CompositionCoverage.h b/services/surfaceflinger/Scheduler/include/scheduler/interface/CompositionCoverage.h
new file mode 100644
index 0000000..3d0f1a9
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/include/scheduler/interface/CompositionCoverage.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <cstdint>
+
+#include <ftl/flags.h>
+
+namespace android {
+
+// Whether composition was covered by HWC and/or GPU.
+enum class CompositionCoverage : std::uint8_t {
+    Hwc = 1 << 0,
+
+    // Mutually exclusive: The composition either used the GPU, or reused a buffer that had been
+    // composited on the GPU.
+    Gpu = 1 << 1,
+    GpuReuse = 1 << 2,
+};
+
+using CompositionCoverageFlags = ftl::Flags<CompositionCoverage>;
+
+} // namespace android
diff --git a/services/surfaceflinger/Scheduler/include/scheduler/interface/ICompositor.h b/services/surfaceflinger/Scheduler/include/scheduler/interface/ICompositor.h
new file mode 100644
index 0000000..cc41925
--- /dev/null
+++ b/services/surfaceflinger/Scheduler/include/scheduler/interface/ICompositor.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <scheduler/Time.h>
+#include <scheduler/VsyncId.h>
+
+namespace android {
+
+struct ICompositor {
+    // Configures physical displays, processing hotplug and/or mode setting via the Composer HAL.
+    virtual void configure() = 0;
+
+    // Commits transactions for layers and displays. Returns whether any state has been invalidated,
+    // i.e. whether a frame should be composited for each display.
+    virtual bool commit(TimePoint frameTime, VsyncId, TimePoint expectedVsyncTime) = 0;
+
+    // Composites a frame for each display. CompositionEngine performs GPU and/or HAL composition
+    // via RenderEngine and the Composer HAL, respectively.
+    virtual void composite(TimePoint frameTime, VsyncId) = 0;
+
+    // Samples the composited frame via RegionSamplingThread.
+    virtual void sample() = 0;
+
+protected:
+    ~ICompositor() = default;
+};
+
+} // namespace android
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 7d0dc93..0dc8b05 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -408,15 +408,8 @@
 
     mDebugFlashDelay = base::GetUintProperty("debug.sf.showupdates"s, 0u);
 
-    // DDMS debugging deprecated (b/120782499)
-    property_get("debug.sf.ddms", value, "0");
-    int debugDdms = atoi(value);
-    ALOGI_IF(debugDdms, "DDMS debugging not supported");
-
-    property_get("debug.sf.enable_gl_backpressure", value, "1");
-    mPropagateBackpressureClientComposition = atoi(value);
-    ALOGI_IF(mPropagateBackpressureClientComposition,
-             "Enabling backpressure propagation for Client Composition");
+    mBackpressureGpuComposition = base::GetBoolProperty("debug.sf.enable_gl_backpressure"s, true);
+    ALOGI_IF(mBackpressureGpuComposition, "Enabling backpressure for GPU composition");
 
     property_get("ro.surface_flinger.supports_background_blur", value, "0");
     bool supportsBlurs = atoi(value);
@@ -2155,11 +2148,11 @@
     const Period vsyncPeriod = mScheduler->getVsyncSchedule().period();
     const FenceTimePtr& previousPresentFence = getPreviousPresentFence(frameTime, vsyncPeriod);
 
-    // When Backpressure propagation is enabled we want to give a small grace period
+    // When backpressure propagation is enabled, we want to give a small grace period of 1ms
     // for the present fence to fire instead of just giving up on this frame to handle cases
     // where present fence is just about to get signaled.
-    const int graceTimeForPresentFenceMs =
-            (mPropagateBackpressureClientComposition || !mHadClientComposition) ? 1 : 0;
+    const int graceTimeForPresentFenceMs = static_cast<int>(
+            mBackpressureGpuComposition || !mCompositionCoverage.test(CompositionCoverage::Gpu));
 
     // Pending frames may trigger backpressure propagation.
     const TracedOrdinal<bool> framePending = {"PrevFramePending",
@@ -2182,9 +2175,14 @@
                                                       (lastScheduledPresentTime.ns() <
                                                        previousPresentTime - frameMissedSlop))};
     const TracedOrdinal<bool> hwcFrameMissed = {"PrevHwcFrameMissed",
-                                                mHadDeviceComposition && frameMissed};
+                                                frameMissed &&
+                                                        mCompositionCoverage.test(
+                                                                CompositionCoverage::Hwc)};
+
     const TracedOrdinal<bool> gpuFrameMissed = {"PrevGpuFrameMissed",
-                                                mHadClientComposition && frameMissed};
+                                                frameMissed &&
+                                                        mCompositionCoverage.test(
+                                                                CompositionCoverage::Gpu)};
 
     if (frameMissed) {
         mFrameMissedCount++;
@@ -2222,7 +2220,7 @@
     }
 
     if (framePending) {
-        if ((hwcFrameMissed && !gpuFrameMissed) || mPropagateBackpressureClientComposition) {
+        if (mBackpressureGpuComposition || (hwcFrameMissed && !gpuFrameMissed)) {
             scheduleCommit(FrameHint::kNone);
             return false;
         }
@@ -2459,29 +2457,43 @@
 
     postComposition(presentTime);
 
-    const bool prevFrameHadClientComposition = mHadClientComposition;
+    const bool hadGpuComposited = mCompositionCoverage.test(CompositionCoverage::Gpu);
+    mCompositionCoverage.clear();
 
-    mHadClientComposition = mHadDeviceComposition = mReusedClientComposition = false;
     TimeStats::ClientCompositionRecord clientCompositionRecord;
     for (const auto& [_, display] : displays) {
         const auto& state = display->getCompositionDisplay()->getState();
-        mHadClientComposition |= state.usesClientComposition && !state.reusedClientComposition;
-        mHadDeviceComposition |= state.usesDeviceComposition;
-        mReusedClientComposition |= state.reusedClientComposition;
+
+        if (state.usesDeviceComposition) {
+            mCompositionCoverage |= CompositionCoverage::Hwc;
+        }
+
+        if (state.reusedClientComposition) {
+            mCompositionCoverage |= CompositionCoverage::GpuReuse;
+        } else if (state.usesClientComposition) {
+            mCompositionCoverage |= CompositionCoverage::Gpu;
+        }
+
         clientCompositionRecord.predicted |=
                 (state.strategyPrediction != CompositionStrategyPredictionState::DISABLED);
         clientCompositionRecord.predictionSucceeded |=
                 (state.strategyPrediction == CompositionStrategyPredictionState::SUCCESS);
     }
 
-    clientCompositionRecord.hadClientComposition = mHadClientComposition;
-    clientCompositionRecord.reused = mReusedClientComposition;
-    clientCompositionRecord.changed = prevFrameHadClientComposition != mHadClientComposition;
+    const bool hasGpuComposited = mCompositionCoverage.test(CompositionCoverage::Gpu);
+
+    clientCompositionRecord.hadClientComposition = hasGpuComposited;
+    clientCompositionRecord.reused = mCompositionCoverage.test(CompositionCoverage::GpuReuse);
+    clientCompositionRecord.changed = hadGpuComposited != hasGpuComposited;
+
     mTimeStats->pushCompositionStrategyState(clientCompositionRecord);
 
-    // TODO: b/160583065 Enable skip validation when SF caches all client composition layers
-    const bool usedGpuComposition = mHadClientComposition || mReusedClientComposition;
-    mScheduler->modulateVsync(&VsyncModulator::onDisplayRefresh, usedGpuComposition);
+    using namespace ftl::flag_operators;
+
+    // TODO(b/160583065): Enable skip validation when SF caches all client composition layers.
+    const bool hasGpuUseOrReuse =
+            mCompositionCoverage.any(CompositionCoverage::Gpu | CompositionCoverage::GpuReuse);
+    mScheduler->modulateVsync(&VsyncModulator::onDisplayRefresh, hasGpuUseOrReuse);
 
     mLayersWithQueuedFrames.clear();
     if (mLayerTracingEnabled && mLayerTracing.flagIsSet(LayerTracing::TRACE_COMPOSITION)) {
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 207dfe2..ed09c3f 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -57,6 +57,8 @@
 #include <scheduler/PresentLatencyTracker.h>
 #include <scheduler/Time.h>
 #include <scheduler/TransactionSchedule.h>
+#include <scheduler/interface/CompositionCoverage.h>
+#include <scheduler/interface/ICompositor.h>
 #include <ui/FenceResult.h>
 
 #include "Display/DisplayMap.h"
@@ -606,19 +608,9 @@
     void onComposerHalVsyncIdle(hal::HWDisplayId) override;
 
     // ICompositor overrides:
-
-    // Configures physical displays, processing hotplug and/or mode setting via the Composer HAL.
     void configure() override;
-
-    // Commits transactions for layers and displays. Returns whether any state has been invalidated,
-    // i.e. whether a frame should be composited for each display.
     bool commit(TimePoint frameTime, VsyncId, TimePoint expectedVsyncTime) override;
-
-    // Composites a frame for each display. CompositionEngine performs GPU and/or HAL composition
-    // via RenderEngine and the Composer HAL, respectively.
     void composite(TimePoint frameTime, VsyncId) override;
-
-    // Samples the composited frame via RegionSamplingThread.
     void sample() override;
 
     // ISchedulerCallback overrides:
@@ -1158,17 +1150,6 @@
     // Tracks layers that need to update a display's dirty region.
     std::vector<sp<Layer>> mLayersPendingRefresh;
 
-    // True if in the previous frame at least one layer was composed via the GPU.
-    bool mHadClientComposition = false;
-    // True if in the previous frame at least one layer was composed via HW Composer.
-    // Note that it is possible for a frame to be composed via both client and device
-    // composition, for example in the case of overlays.
-    bool mHadDeviceComposition = false;
-    // True if in the previous frame, the client composition was skipped by reusing the buffer
-    // used in a previous composition. This can happed if the client composition requests
-    // did not change.
-    bool mReusedClientComposition = false;
-
     BootStage mBootStage = BootStage::BOOTLOADER;
 
     struct HotplugEvent {
@@ -1204,7 +1185,7 @@
     std::atomic_bool mForceFullDamage = false;
 
     bool mLayerCachingEnabled = false;
-    bool mPropagateBackpressureClientComposition = false;
+    bool mBackpressureGpuComposition = false;
 
     LayerTracing mLayerTracing{*this};
     bool mLayerTracingEnabled = false;
@@ -1268,6 +1249,9 @@
     std::atomic<int> mNumTrustedPresentationListeners = 0;
 
     std::unique_ptr<compositionengine::CompositionEngine> mCompositionEngine;
+
+    CompositionCoverageFlags mCompositionCoverage;
+
     // mMaxRenderTargetSize is only set once in init() so it doesn't need to be protected by
     // any mutex.
     size_t mMaxRenderTargetSize{1};
diff --git a/services/surfaceflinger/tests/unittests/TestableScheduler.h b/services/surfaceflinger/tests/unittests/TestableScheduler.h
index 0cbfa63..74885d8 100644
--- a/services/surfaceflinger/tests/unittests/TestableScheduler.h
+++ b/services/surfaceflinger/tests/unittests/TestableScheduler.h
@@ -16,11 +16,12 @@
 
 #pragma once
 
-#include <Scheduler/Scheduler.h>
 #include <ftl/fake_guard.h>
 #include <gmock/gmock.h>
 #include <gui/ISurfaceComposer.h>
 
+#include <scheduler/interface/ICompositor.h>
+
 #include "Scheduler/EventThread.h"
 #include "Scheduler/LayerHistory.h"
 #include "Scheduler/Scheduler.h"