diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index d6f0824..5c5c5bb 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -40,6 +40,7 @@
 #include <media/audiohal/DevicesFactoryHalInterface.h>
 #include <media/audiohal/EffectsFactoryHalInterface.h>
 #include <media/AudioParameter.h>
+#include <media/MediaMetricsItem.h>
 #include <media/TypeConverter.h>
 #include <memunreachable/memunreachable.h>
 #include <utils/String16.h>
@@ -198,6 +199,11 @@
     std::vector<pid_t> halPids;
     mDevicesFactoryHal->getHalPids(&halPids);
     TimeCheck::setAudioHalPids(halPids);
+
+    // Notify that we have started (also called when audioserver service restarts)
+    mediametrics::LogItem(mMetricsId)
+        .set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_CTOR)
+        .record();
 }
 
 void AudioFlinger::onFirstRef()
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index d4e0ae2..a16fa94 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -952,6 +952,8 @@
     SimpleLog  mRejectedSetParameterLog;
     SimpleLog  mAppSetParameterLog;
     SimpleLog  mSystemSetParameterLog;
+
+    static inline constexpr const char *mMetricsId = AMEDIAMETRICS_KEY_AUDIO_FLINGER;
 };
 
 #undef INCLUDING_FROM_AUDIOFLINGER_H
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 87b72fb..7b14050 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -24,6 +24,7 @@
 #include <math.h>
 #include <fcntl.h>
 #include <memory>
+#include <sstream>
 #include <string>
 #include <linux/futex.h>
 #include <sys/stat.h>
@@ -212,6 +213,28 @@
 
 // ----------------------------------------------------------------------------
 
+// TODO: move all toString helpers to audio.h
+// under  #ifdef __cplusplus #endif
+static std::string patchSinksToString(const struct audio_patch *patch)
+{
+    std::stringstream ss;
+    for (size_t i = 0; i < patch->num_sinks; ++i) {
+        ss << "(" << toString(patch->sinks[i].ext.device.type)
+            << ", " << patch->sinks[i].ext.device.address << ")";
+    }
+    return ss.str();
+}
+
+static std::string patchSourcesToString(const struct audio_patch *patch)
+{
+    std::stringstream ss;
+    for (size_t i = 0; i < patch->num_sources; ++i) {
+        ss << "(" << toString(patch->sources[i].ext.device.type)
+            << ", " << patch->sources[i].ext.device.address << ")";
+    }
+    return ss.str();
+}
+
 static pthread_once_t sFastTrackMultiplierOnce = PTHREAD_ONCE_INIT;
 
 static void sFastTrackMultiplierInit()
@@ -466,6 +489,7 @@
     :   Thread(false /*canCallJava*/),
         mType(type),
         mAudioFlinger(audioFlinger),
+        mMetricsId(std::string(AMEDIAMETRICS_KEY_PREFIX_AUDIO_THREAD) + std::to_string(id)),
         // mSampleRate, mFrameCount, mChannelMask, mChannelCount, mFrameSize, mFormat, mBufferSize
         // are set by PlaybackThread::readOutputParameters_l() or
         // RecordThread::readInputParameters_l()
@@ -477,6 +501,13 @@
         mSystemReady(systemReady),
         mSignalPending(false)
 {
+    mediametrics::LogItem(mMetricsId)
+        .setPid(getpid())
+        .set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_CTOR)
+        .set(AMEDIAMETRICS_PROP_TYPE, threadTypeToString(type))
+        .set(AMEDIAMETRICS_PROP_THREADID, id)
+        .record();
+
     memset(&mPatch, 0, sizeof(struct audio_patch));
 }
 
@@ -493,6 +524,10 @@
     }
 
     sendStatistics(true /* force */);
+
+    mediametrics::LogItem(mMetricsId)
+        .set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_DTOR)
+        .record();
 }
 
 status_t AudioFlinger::ThreadBase::readyToRun()
@@ -2794,6 +2829,30 @@
         mAudioFlinger->moveEffectChain_l(effectChains[i]->sessionId(),
             this/* srcThread */, this/* dstThread */);
     }
+
+    audio_output_flags_t flags = mOutput != nullptr ? mOutput->flags : AUDIO_OUTPUT_FLAG_NONE;
+    mediametrics::LogItem item(mMetricsId);
+    item.set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_READPARAMETERS)
+        .set(AMEDIAMETRICS_PROP_ENCODING, formatToString(mFormat).c_str())
+        .set(AMEDIAMETRICS_PROP_SAMPLERATE, (int32_t)mSampleRate)
+        .set(AMEDIAMETRICS_PROP_CHANNELMASK, (int32_t)mChannelMask)
+        .set(AMEDIAMETRICS_PROP_CHANNELCOUNT, (int32_t)mChannelCount)
+        .set(AMEDIAMETRICS_PROP_FRAMECOUNT, (int32_t)mNormalFrameCount)
+        .set(AMEDIAMETRICS_PROP_FLAGS, toString(flags).c_str())
+        .set(AMEDIAMETRICS_PROP_PREFIX_HAPTIC AMEDIAMETRICS_PROP_CHANNELMASK,
+                (int32_t)mHapticChannelMask)
+        .set(AMEDIAMETRICS_PROP_PREFIX_HAPTIC AMEDIAMETRICS_PROP_CHANNELCOUNT,
+                (int32_t)mHapticChannelCount)
+        .set(AMEDIAMETRICS_PROP_PREFIX_HAL    AMEDIAMETRICS_PROP_ENCODING,
+                formatToString(mHALFormat).c_str())
+        .set(AMEDIAMETRICS_PROP_PREFIX_HAL    AMEDIAMETRICS_PROP_FRAMECOUNT,
+                (int32_t)mFrameCount) // sic - added HAL
+        ;
+    uint32_t latencyMs;
+    if (mOutput->stream->getLatency(&latencyMs) == NO_ERROR) {
+        item.set(AMEDIAMETRICS_PROP_PREFIX_HAL AMEDIAMETRICS_PROP_LATENCYMS, (double)latencyMs);
+    }
+    item.record();
 }
 
 void AudioFlinger::PlaybackThread::updateMetadata_l()
@@ -3870,6 +3929,11 @@
 
                         const int32_t throttleMs = (int32_t)mHalfBufferMs - deltaMs;
                         if ((signed)mHalfBufferMs >= throttleMs && throttleMs > 0) {
+                            mediametrics::LogItem(mMetricsId)
+                                // ms units always double
+                                .set(AMEDIAMETRICS_PROP_THROTTLEMS, (double)throttleMs)
+                                .record();
+
                             usleep(throttleMs * 1000);
                             // notify of throttle start on verbose log
                             ALOGV_IF(mThreadThrottleEndMs == mThreadThrottleTimeMs,
@@ -4142,6 +4206,11 @@
         status = mOutput->stream->setParameters(param.toString());
         *handle = AUDIO_PATCH_HANDLE_NONE;
     }
+    mediametrics::LogItem(mMetricsId)
+        .set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_CREATEAUDIOPATCH)
+        .set(AMEDIAMETRICS_PROP_OUTPUTDEVICES, patchSinksToString(patch).c_str())
+        .record();
+
     if (configChanged) {
         sendIoConfigEvent_l(AUDIO_OUTPUT_CONFIG_CHANGED);
     }
@@ -4683,19 +4752,29 @@
     // DeferredOperations handles statistics after setting mixerStatus.
     class DeferredOperations {
     public:
-        DeferredOperations(mixer_state *mixerStatus)
-            : mMixerStatus(mixerStatus) { }
+        DeferredOperations(mixer_state *mixerStatus, const std::string &metricsId)
+            : mMixerStatus(mixerStatus)
+            , mMetricsId(metricsId) {}
 
         // when leaving scope, tally frames properly.
         ~DeferredOperations() {
             // Tally underrun frames only if we are actually mixing (MIXER_TRACKS_READY)
             // because that is when the underrun occurs.
             // We do not distinguish between FastTracks and NormalTracks here.
-            if (*mMixerStatus == MIXER_TRACKS_READY) {
+            if (*mMixerStatus == MIXER_TRACKS_READY && mUnderrunFrames.size() > 0) {
+                mediametrics::LogItem item(mMetricsId);
+
+                item.set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_UNDERRUN);
                 for (const auto &underrun : mUnderrunFrames) {
                     underrun.first->mAudioTrackServerProxy->tallyUnderrunFrames(
                             underrun.second);
+
+                    item.set(std::string("[" AMEDIAMETRICS_KEY_PREFIX_AUDIO_TRACK)
+                            + std::to_string(underrun.first->portId())
+                            + "]" AMEDIAMETRICS_PROP_UNDERRUN,
+                            (int32_t)underrun.second);
                 }
+                item.record();
             }
         }
 
@@ -4708,8 +4787,10 @@
 
     private:
         const mixer_state * const mMixerStatus;
+        const std::string& mMetricsId;
         std::vector<std::pair<sp<Track>, size_t>> mUnderrunFrames;
-    } deferredOperations(&mixerStatus); // implicit nested scope for variable capture
+    } deferredOperations(&mixerStatus, mMetricsId);
+    // implicit nested scope for variable capture
 
     bool noFastHapticTrack = true;
     for (size_t i=0 ; i<count ; i++) {
@@ -5187,11 +5268,20 @@
                     mixerStatus != MIXER_TRACKS_ENABLED) {
                 mixerStatus = MIXER_TRACKS_READY;
             }
+
+            // Enable the next few lines to instrument a test for underrun log handling.
+            // TODO: Remove when we have a better way of testing the underrun log.
+#if 0
+            static int i;
+            if ((++i & 0xf) == 0) {
+                deferredOperations.tallyUnderrunFrames(track, 10 /* underrunFrames */);
+            }
+#endif
         } else {
             size_t underrunFrames = 0;
             if (framesReady < desiredFrames && !track->isStopped() && !track->isPaused()) {
-                ALOGV("track(%d) underrun,  framesReady(%zu) < framesDesired(%zd)",
-                        trackId, framesReady, desiredFrames);
+                ALOGV("track(%d) underrun, track state %s  framesReady(%zu) < framesDesired(%zd)",
+                        trackId, track->getTrackStateAsString(), framesReady, desiredFrames);
                 underrunFrames = desiredFrames;
             }
             deferredOperations.tallyUnderrunFrames(track, underrunFrames);
@@ -8404,6 +8494,12 @@
         mPatch = *patch;
     }
 
+    mediametrics::LogItem(mMetricsId)
+        .set(AMEDIAMETRICS_PROP_EVENT, AMEDIAMETRICS_PROP_EVENT_VALUE_CREATEAUDIOPATCH)
+        .set(AMEDIAMETRICS_PROP_INPUTDEVICES, patchSourcesToString(patch).c_str())
+        .set(AMEDIAMETRICS_PROP_SOURCE, toString(mAudioSource).c_str())
+        .record();
+
     return status;
 }
 
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index f1adc23..b0eb75d 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -523,6 +523,7 @@
                 Condition               mWaitWorkCV;
 
                 const sp<AudioFlinger>  mAudioFlinger;
+                const std::string       mMetricsId;
 
                 // updated by PlaybackThread::readOutputParameters_l() or
                 // RecordThread::readInputParameters_l()
diff --git a/services/audioflinger/TrackBase.h b/services/audioflinger/TrackBase.h
index 91dbfa4..e39b944 100644
--- a/services/audioflinger/TrackBase.h
+++ b/services/audioflinger/TrackBase.h
@@ -69,7 +69,8 @@
                                 bool isOut,
                                 alloc_type alloc = ALLOC_CBLK,
                                 track_type type = TYPE_DEFAULT,
-                                audio_port_handle_t portId = AUDIO_PORT_HANDLE_NONE);
+                                audio_port_handle_t portId = AUDIO_PORT_HANDLE_NONE,
+                                std::string metricsId = {});
     virtual             ~TrackBase();
     virtual status_t    initCheck() const;
 
@@ -94,7 +95,14 @@
             bool        isPatchTrack() const { return (mType == TYPE_PATCH); }
             bool        isExternalTrack() const { return !isOutputTrack() && !isPatchTrack(); }
 
-    virtual void        invalidate() { mIsInvalid = true; }
+    virtual void        invalidate() {
+                            if (mIsInvalid) return;
+                            mediametrics::LogItem(mMetricsId)
+                                .set(AMEDIAMETRICS_PROP_EVENT,
+                                     AMEDIAMETRICS_PROP_EVENT_VALUE_INVALIDATE)
+                                .record();
+                            mIsInvalid = true;
+                        }
             bool        isInvalid() const { return mIsInvalid; }
 
             void        terminate() { mTerminated = true; }
@@ -353,6 +361,14 @@
     audio_port_handle_t mPortId; // unique ID for this track used by audio policy
     bool                mIsInvalid; // non-resettable latch, set by invalidate()
 
+    // It typically takes 5 threadloop mix iterations for latency to stabilize.
+    static inline constexpr int32_t LOG_START_COUNTDOWN = 8;
+    int32_t             mLogStartCountdown = 0;
+    int64_t             mLogStartTimeNs = 0;
+    int64_t             mLogStartFrames = 0;
+
+    const std::string   mMetricsId;
+
     bool                mServerLatencySupported = false;
     std::atomic<bool>   mServerLatencyFromTrack{}; // latency from track or server timestamp.
     std::atomic<double> mServerLatencyMs{};        // last latency pushed from server thread.
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index 2437202..23d8329 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -80,7 +80,8 @@
             bool isOut,
             alloc_type alloc,
             track_type type,
-            audio_port_handle_t portId)
+            audio_port_handle_t portId,
+            std::string metricsId)
     :   RefBase(),
         mThread(thread),
         mClient(client),
@@ -105,6 +106,7 @@
         mThreadIoHandle(thread ? thread->id() : AUDIO_IO_HANDLE_NONE),
         mPortId(portId),
         mIsInvalid(false),
+        mMetricsId(std::move(metricsId)),
         mCreatorPid(creatorPid)
 {
     const uid_t callingUid = IPCThreadState::self()->getCallingUid();
@@ -519,7 +521,9 @@
                   (sharedBuffer != 0) ? sharedBuffer->size() : bufferSize,
                   sessionId, creatorPid, uid, true /*isOut*/,
                   (type == TYPE_PATCH) ? ( buffer == NULL ? ALLOC_LOCAL : ALLOC_NONE) : ALLOC_CBLK,
-                  type, portId),
+                  type,
+                  portId,
+                  std::string(AMEDIAMETRICS_KEY_PREFIX_AUDIO_TRACK) + std::to_string(portId)),
     mFillingUpStatus(FS_INVALID),
     // mRetryCount initialized later when needed
     mSharedBuffer(sharedBuffer),
@@ -596,6 +600,14 @@
         mExternalVibration = new os::ExternalVibration(
                 mUid, "" /* pkg */, mAttr, mAudioVibrationController);
     }
+
+    // Once this item is logged by the server, the client can add properties.
+    mediametrics::LogItem(mMetricsId)
+        .setPid(creatorPid)
+        .setUid(uid)
+        .set(AMEDIAMETRICS_PROP_EVENT,
+                AMEDIAMETRICS_PROP_PREFIX_SERVER AMEDIAMETRICS_PROP_EVENT_VALUE_CTOR)
+        .record();
 }
 
 AudioFlinger::PlaybackThread::Track::~Track()
@@ -966,6 +978,14 @@
             }
         }
 
+        // Audio timing metrics are computed a few mix cycles after starting.
+        {
+            mLogStartCountdown = LOG_START_COUNTDOWN;
+            mLogStartTimeNs = systemTime();
+            mLogStartFrames = mAudioTrackServerProxy->getTimestamp()
+                    .mPosition[ExtendedTimestamp::LOCATION_SERVER];
+        }
+
         if (status == NO_ERROR || status == ALREADY_EXISTS) {
             // for streaming tracks, remove the buffer read stop limit.
             mAudioTrackServerProxy->start();
@@ -1497,6 +1517,28 @@
 
     mServerLatencyFromTrack.store(useTrackTimestamp);
     mServerLatencyMs.store(latencyMs);
+
+    if (mLogStartCountdown > 0) {
+        if (--mLogStartCountdown == 0) {
+            // startup is the difference in times for the current timestamp and our start
+            double startUpMs =
+                    (local.mTimeNs[ExtendedTimestamp::LOCATION_SERVER] - mLogStartTimeNs) * 1e-6;
+            // adjust for frames played.
+            startUpMs -= (local.mPosition[ExtendedTimestamp::LOCATION_SERVER] - mLogStartFrames)
+                      * 1e3 / mSampleRate;
+            ALOGV("%s: logging localTime:%lld, startTime:%lld"
+                  "  localPosition:%lld, startPosition:%lld",
+                    __func__,
+                    (long long)local.mTimeNs[ExtendedTimestamp::LOCATION_SERVER],
+                    (long long)mLogStartTimeNs,
+                    (long long)local.mPosition[ExtendedTimestamp::LOCATION_SERVER],
+                    (long long)mLogStartFrames);
+            mediametrics::LogItem(mMetricsId)
+                .set(AMEDIAMETRICS_PROP_LATENCYMS, latencyMs)
+                .set(AMEDIAMETRICS_PROP_STARTUPMS, startUpMs)
+                .record();
+        }
+    }
 }
 
 binder::Status AudioFlinger::PlaybackThread::Track::AudioVibrationController::mute(
@@ -2071,7 +2113,8 @@
                   (type == TYPE_DEFAULT) ?
                           ((flags & AUDIO_INPUT_FLAG_FAST) ? ALLOC_PIPE : ALLOC_CBLK) :
                           ((buffer == NULL) ? ALLOC_LOCAL : ALLOC_NONE),
-                  type, portId),
+                  type, portId,
+                  std::string(AMEDIAMETRICS_KEY_PREFIX_AUDIO_RECORD) + std::to_string(portId)),
         mOverflow(false),
         mFramesToDrop(0),
         mResamplerBufferProvider(NULL), // initialize in case of early constructor exit
@@ -2117,6 +2160,13 @@
             + "_" + std::to_string(mId)
             + "_R");
 #endif
+
+    // Once this item is logged by the server, the client can add properties.
+    mediametrics::LogItem(mMetricsId)
+        .setPid(creatorPid)
+        .setUid(uid)
+        .set(AMEDIAMETRICS_PROP_EVENT, "server." AMEDIAMETRICS_PROP_EVENT_VALUE_CTOR)
+        .record();
 }
 
 AudioFlinger::RecordThread::RecordTrack::~RecordTrack()