diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index fca840b..75b4e4c 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -58,6 +58,8 @@
 #include <media/LinearMap.h>
 #include <media/VolumeShaper.h>
 
+#include <audio_utils/SimpleLog.h>
+
 #include "FastCapture.h"
 #include "FastMixer.h"
 #include <media/nbaio/NBAIO.h>
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 54e07c0..3b1edec 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -699,17 +699,29 @@
             SetParameterConfigEventData *data = (SetParameterConfigEventData *)event->mData.get();
             if (checkForNewParameter_l(data->mKeyValuePairs, event->mStatus)) {
                 configChanged = true;
+                mLocalLog.log("CFG_EVENT_SET_PARAMETER: (%s) configuration changed",
+                        data->mKeyValuePairs.string());
             }
         } break;
         case CFG_EVENT_CREATE_AUDIO_PATCH: {
+            const audio_devices_t oldDevice = getDevice();
             CreateAudioPatchConfigEventData *data =
                                             (CreateAudioPatchConfigEventData *)event->mData.get();
             event->mStatus = createAudioPatch_l(&data->mPatch, &data->mHandle);
+            const audio_devices_t newDevice = getDevice();
+            mLocalLog.log("CFG_EVENT_CREATE_AUDIO_PATCH: old device %#x (%s) new device %#x (%s)",
+                    (unsigned)oldDevice, devicesToString(oldDevice).c_str(),
+                    (unsigned)newDevice, devicesToString(newDevice).c_str());
         } break;
         case CFG_EVENT_RELEASE_AUDIO_PATCH: {
+            const audio_devices_t oldDevice = getDevice();
             ReleaseAudioPatchConfigEventData *data =
                                             (ReleaseAudioPatchConfigEventData *)event->mData.get();
             event->mStatus = releaseAudioPatch_l(data->mHandle);
+            const audio_devices_t newDevice = getDevice();
+            mLocalLog.log("CFG_EVENT_RELEASE_AUDIO_PATCH: old device %#x (%s) new device %#x (%s)",
+                    (unsigned)oldDevice, devicesToString(oldDevice).c_str(),
+                    (unsigned)newDevice, devicesToString(newDevice).c_str());
         } break;
         default:
             ALOG_ASSERT(false, "processConfigEvents_l() unknown event type %d", event->mType);
@@ -826,6 +838,7 @@
     } else {
         dprintf(fd, " none\n");
     }
+    // Note: output device may be used by capture threads for effects such as AEC.
     dprintf(fd, "  Output device: %#x (%s)\n", mOutDevice, devicesToString(mOutDevice).c_str());
     dprintf(fd, "  Input device: %#x (%s)\n", mInDevice, devicesToString(mInDevice).c_str());
     dprintf(fd, "  Audio source: %d (%s)\n", mAudioSource, sourceToString(mAudioSource));
@@ -1694,7 +1707,8 @@
     dumpInternals(fd, args);
     dumpTracks(fd, args);
     dumpEffectChains(fd, args);
-    mLocalLog.dump(fd, args, "  " /* prefix */);
+    dprintf(fd, "  Local log:\n");
+    mLocalLog.dump(fd, "   " /* prefix */, 40 /* lines */);
 }
 
 void AudioFlinger::PlaybackThread::dumpTracks(int fd, const Vector<String16>& args __unused)
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 422eeb5..8270e74 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -288,6 +288,9 @@
                 bool        standby() const { return mStandby; }
                 audio_devices_t outDevice() const { return mOutDevice; }
                 audio_devices_t inDevice() const { return mInDevice; }
+                audio_devices_t getDevice() const { return isOutput() ? mOutDevice : mInDevice; }
+
+    virtual     bool        isOutput() const = 0;
 
     virtual     sp<StreamHalInterface> stream() const = 0;
 
@@ -575,6 +578,8 @@
                     int                 mLastActiveTracksGeneration;
                     wp<T>               mLatestActiveTrack; // latest track added to ActiveTracks
                 };
+
+                SimpleLog mLocalLog;
 };
 
 class VolumeInterface {
@@ -760,6 +765,8 @@
                 // Return the asynchronous signal wait time.
     virtual     int64_t     computeWaitTimeNs_l() const { return INT64_MAX; }
 
+    virtual     bool        isOutput() const override { return true; }
+
 protected:
     // updated by readOutputParameters_l()
     size_t                          mNormalFrameCount;  // normal mixer and effects
@@ -971,80 +978,6 @@
     static const size_t     kFastMixerLogSize = 4 * 1024;
     sp<NBLog::Writer>       mFastMixerNBLogWriter;
 
-    // Do not call from a sched_fifo thread as it uses a system time call
-    // and obtains a local mutex.
-    class LocalLog {
-    public:
-        void log(const char *fmt, ...) {
-            va_list val;
-            va_start(val, fmt);
-
-            // format to buffer
-            char buffer[512];
-            int length = vsnprintf(buffer, sizeof(buffer), fmt, val);
-            if (length >= (signed)sizeof(buffer)) {
-                length = sizeof(buffer) - 1;
-            }
-
-            // strip out trailing newline
-            while (length > 0 && buffer[length - 1] == '\n') {
-                buffer[--length] = 0;
-            }
-
-            // store in circular array
-            AutoMutex _l(mLock);
-            mLog.emplace_back(
-                    std::make_pair(systemTime(SYSTEM_TIME_REALTIME), std::string(buffer)));
-            if (mLog.size() > kLogSize) {
-                mLog.pop_front();
-            }
-
-            va_end(val);
-        }
-
-        void dump(int fd, const Vector<String16>& args, const char *prefix = "") {
-            if (!AudioFlinger::dumpTryLock(mLock)) return; // a local lock, shouldn't happen
-            if (mLog.size() > 0) {
-                bool dumpAll = false;
-                for (const auto &arg : args) {
-                    if (arg == String16("--locallog")) {
-                        dumpAll = true;
-                    }
-                }
-
-                dprintf(fd, "Local Log:\n");
-                auto it = mLog.begin();
-                if (!dumpAll) {
-                    const size_t lines =
-                            (size_t)property_get_int32("audio.locallog.lines", kLogPrint);
-                    if (mLog.size() > lines) {
-                        it += (mLog.size() - lines);
-                    }
-                }
-                for (; it != mLog.end(); ++it) {
-                    const int64_t ns = it->first;
-                    const int ns_per_sec = 1000000000;
-                    const time_t sec = ns / ns_per_sec;
-                    struct tm tm;
-                    localtime_r(&sec, &tm);
-
-                    dprintf(fd, "%s%02d-%02d %02d:%02d:%02d.%03d %s\n",
-                            prefix,
-                            tm.tm_mon + 1, // localtime_r uses months in 0 - 11 range
-                            tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
-                            (int)(ns % ns_per_sec / 1000000),
-                            it->second.c_str());
-                }
-            }
-            mLock.unlock();
-        }
-
-    private:
-        Mutex mLock;
-        static const size_t kLogSize = 256; // full history
-        static const size_t kLogPrint = 32; // default print history
-        std::deque<std::pair<int64_t, std::string>> mLog;
-    } mLocalLog;
 
 public:
     virtual     bool        hasFastMixer() const = 0;
@@ -1446,6 +1379,7 @@
                             ThreadBase::acquireWakeLock_l();
                             mActiveTracks.updatePowerState(this, true /* force */);
                         }
+    virtual bool        isOutput() const override { return false; }
 
 private:
             // Enter standby if not already in standby, and set mStandby flag
@@ -1587,8 +1521,6 @@
     virtual     void        dumpInternals(int fd, const Vector<String16>& args);
                 void        dumpTracks(int fd, const Vector<String16>& args);
 
-    virtual     bool        isOutput() const = 0;
-
  protected:
 
                 audio_attributes_t      mAttr;
@@ -1636,7 +1568,7 @@
 
     virtual     void        dumpInternals(int fd, const Vector<String16>& args);
 
-    virtual     bool        isOutput() const { return true; }
+    virtual     bool        isOutput() const override { return true; }
 
 protected:
 
@@ -1660,7 +1592,7 @@
 
                 AudioStreamIn* clearInput();
 
-    virtual     bool           isOutput() const { return false; }
+    virtual     bool           isOutput() const override { return false; }
 
 protected: