diff --git a/res/values/strings.xml b/res/values/strings.xml
index 92a3a9de899..056af6b060c 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -3576,8 +3576,14 @@
     <string name="wait_for_debugger_summary">Debugged application waits for debugger to
             attach before executing</string>
 
-    <!-- Preference category for user interface debugging development settings. [CHAR LIMIT=25] -->
-    <string name="debug_ui_category">User interface</string>
+    <!-- Preference category for input debugging development settings. [CHAR LIMIT=25] -->
+    <string name="debug_input_category">Input</string>
+
+    <!-- Preference category for drawing debugging development settings. [CHAR LIMIT=25] -->
+    <string name="debug_drawing_category">Drawing</string>
+
+    <!-- Preference category for monitoring debugging development settings. [CHAR LIMIT=25] -->
+    <string name="debug_monitoring_category">Monitoring</string>
 
     <!-- UI debug setting: always enable strict mode? [CHAR LIMIT=25] -->
     <string name="strict_mode">Strict mode enabled</string>
@@ -3595,20 +3601,32 @@
     <!-- UI debug setting: show touches location summary [CHAR LIMIT=50] -->
     <string name="show_touches_summary">Show visual feedback for touches</string>
 
-    <!-- UI debug setting: show where screen updates happen? [CHAR LIMIT=25] -->
-    <string name="show_screen_updates">Show screen updates</string>
-    <!-- UI debug setting: show screen updates summary [CHAR LIMIT=50] -->
-    <string name="show_screen_updates_summary">Flash areas of screen when they update</string>
+    <!-- UI debug setting: show where surface updates happen? [CHAR LIMIT=25] -->
+    <string name="show_screen_updates">Show surface updates</string>
+    <!-- UI debug setting: show surface updates summary [CHAR LIMIT=50] -->
+    <string name="show_screen_updates_summary">Flash entire window surfaces when they update</string>
 
-    <!-- UI debug setting: show where screen updates happen with GPU rendering? [CHAR LIMIT=25] -->
-    <string name="show_hw_screen_updates">Show GPU screen updates</string>
+    <!-- UI debug setting: show where window updates happen with GPU rendering? [CHAR LIMIT=25] -->
+    <string name="show_hw_screen_updates">Show GPU view updates</string>
     <!-- UI debug setting: show GPU rendering screen updates summary [CHAR LIMIT=50] -->
-    <string name="show_hw_screen_updates_summary">Flash areas of screen when they update with the GPU</string>
+    <string name="show_hw_screen_updates_summary">Flash views inside windows when drawn with the GPU</string>
 
     <!-- UI debug setting: disable use of overlays? [CHAR LIMIT=25] -->
-    <string name="disable_overlays">Disable overlays</string>
+    <string name="disable_overlays">Disable HW overlays</string>
     <!-- UI debug setting: disable use of overlays summary [CHAR LIMIT=50] -->
-    <string name="disable_overlays_summary">Don\'t use overlays for screen compositing</string>
+    <string name="disable_overlays_summary">Always use GPU for screen compositing</string>
+
+    <!-- UI debug setting: enable low-level traces? [CHAR LIMIT=25] -->
+    <string name="enable_traces_title">Enable traces</string>
+    <!-- UI debug setting: title for dialog to enable low-level traces [CHAR LIMIT=25] -->
+    <string name="enable_traces_dialog_title">Select enabled traces</string>
+
+    <!-- UI debug setting: enable low-level traces, none enabled summary [CHAR LIMIT=NONE] -->
+    <string name="enable_traces_summary_none">No traces currently enabled</string>
+    <!-- UI debug setting: enable low-level traces, some number enabled summary [CHAR LIMIT=NONE] -->
+    <string name="enable_traces_summary_num"><xliff:g id="num">%1$d</xliff:g> traces currently enabled</string>
+    <!-- UI debug setting: enable low-level traces, all enabled summary [CHAR LIMIT=NONE] -->
+    <string name="enable_traces_summary_all">All traces currently enabled</string>
 
     <!-- UI debug setting: show layout bounds information [CHAR LIMIT=25] -->
     <string name="debug_layout">Show layout bounds</string>
@@ -3623,7 +3641,7 @@
     <!-- UI debug setting: force hardware acceleration to render apps [CHAR LIMIT=25] -->
     <string name="force_hw_ui">Force GPU rendering</string>
     <!-- UI debug setting: force hardware acceleration summary [CHAR LIMIT=50] -->
-    <string name="force_hw_ui_summary">Use 2D hardware acceleration in applications</string>
+    <string name="force_hw_ui_summary">Force use of GPU for 2d drawing</string>
 
     <!-- UI debug setting: profile time taken by hardware acceleration to render apps [CHAR LIMIT=25] -->
     <string name="track_frame_time">Profile GPU rendering</string>
diff --git a/res/xml/development_prefs.xml b/res/xml/development_prefs.xml
index ab8aad3d292..f33dd38cd53 100644
--- a/res/xml/development_prefs.xml
+++ b/res/xml/development_prefs.xml
@@ -70,58 +70,38 @@
 
     </PreferenceCategory>
 
-    <PreferenceCategory android:key="debug_ui_category"
-            android:title="@string/debug_ui_category">
-
-        <CheckBoxPreference
-            android:key="strict_mode"
-            android:title="@string/strict_mode"
-            android:summary="@string/strict_mode_summary"/>
-
-        <CheckBoxPreference
-            android:key="pointer_location"
-            android:title="@string/pointer_location"
-            android:summary="@string/pointer_location_summary"/>
+    <PreferenceCategory android:key="debug_input_category"
+            android:title="@string/debug_input_category">
 
         <CheckBoxPreference
             android:key="show_touches"
             android:title="@string/show_touches"
             android:summary="@string/show_touches_summary"/>
 
+        <CheckBoxPreference
+            android:key="pointer_location"
+            android:title="@string/pointer_location"
+            android:summary="@string/pointer_location_summary"/>
+
+    </PreferenceCategory>
+
+    <PreferenceCategory android:key="debug_drawing_category"
+            android:title="@string/debug_drawing_category">
+
         <CheckBoxPreference
             android:key="debug_layout"
             android:title="@string/debug_layout"
             android:summary="@string/debug_layout_summary"/>
 
-        <CheckBoxPreference
-            android:key="show_screen_updates"
-            android:title="@string/show_screen_updates"
-            android:summary="@string/show_screen_updates_summary"/>
-
-        <CheckBoxPreference
-            android:key="disable_overlays"
-            android:title="@string/disable_overlays"
-            android:summary="@string/disable_overlays_summary"/>
-
-        <CheckBoxPreference
-            android:key="show_cpu_usage"
-            android:title="@string/show_cpu_usage"
-            android:summary="@string/show_cpu_usage_summary"/>
-
-        <CheckBoxPreference
-            android:key="force_hw_ui"
-            android:title="@string/force_hw_ui"
-            android:summary="@string/force_hw_ui_summary"/>
-
         <CheckBoxPreference
             android:key="show_hw_screen_udpates"
             android:title="@string/show_hw_screen_updates"
             android:summary="@string/show_hw_screen_updates_summary"/>
 
         <CheckBoxPreference
-            android:key="track_frame_time"
-            android:title="@string/track_frame_time"
-            android:summary="@string/track_frame_time_summary"/>
+            android:key="show_screen_updates"
+            android:title="@string/show_screen_updates"
+            android:summary="@string/show_screen_updates_summary"/>
 
         <ListPreference
             android:key="window_animation_scale"
@@ -144,6 +124,41 @@
             android:entries="@array/animator_duration_scale_entries"
             android:entryValues="@array/animator_duration_scale_values" />
 
+        <CheckBoxPreference
+            android:key="disable_overlays"
+            android:title="@string/disable_overlays"
+            android:summary="@string/disable_overlays_summary"/>
+
+        <CheckBoxPreference
+            android:key="force_hw_ui"
+            android:title="@string/force_hw_ui"
+            android:summary="@string/force_hw_ui_summary"/>
+
+    </PreferenceCategory>
+
+    <PreferenceCategory android:key="debug_monitoring_category"
+            android:title="@string/debug_monitoring_category">
+
+        <CheckBoxPreference
+            android:key="strict_mode"
+            android:title="@string/strict_mode"
+            android:summary="@string/strict_mode_summary"/>
+
+        <CheckBoxPreference
+            android:key="show_cpu_usage"
+            android:title="@string/show_cpu_usage"
+            android:summary="@string/show_cpu_usage_summary"/>
+
+        <CheckBoxPreference
+            android:key="track_frame_time"
+            android:title="@string/track_frame_time"
+            android:summary="@string/track_frame_time_summary"/>
+
+        <MultiCheckPreference
+            android:key="enable_traces"
+            android:title="@string/enable_traces_title"
+            android:dialogTitle="@string/enable_traces_dialog_title" />
+
     </PreferenceCategory>
 
     <PreferenceCategory android:key="debug_applications_category"
diff --git a/src/com/android/settings/DevelopmentSettings.java b/src/com/android/settings/DevelopmentSettings.java
index d32cbc75404..49695e886bb 100644
--- a/src/com/android/settings/DevelopmentSettings.java
+++ b/src/com/android/settings/DevelopmentSettings.java
@@ -40,8 +40,10 @@ import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.StrictMode;
 import android.os.SystemProperties;
+import android.os.Trace;
 import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
+import android.preference.MultiCheckPreference;
 import android.preference.Preference;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceScreen;
@@ -88,6 +90,8 @@ public class DevelopmentSettings extends PreferenceFragment
     private static final String TRANSITION_ANIMATION_SCALE_KEY = "transition_animation_scale";
     private static final String ANIMATOR_DURATION_SCALE_KEY = "animator_duration_scale";
 
+    private static final String ENABLE_TRACES_KEY = "enable_traces";
+
     private static final String IMMEDIATELY_DESTROY_ACTIVITIES_KEY
             = "immediately_destroy_activities";
     private static final String APP_PROCESS_LIMIT_KEY = "app_process_limit";
@@ -101,6 +105,7 @@ public class DevelopmentSettings extends PreferenceFragment
 
     private Switch mEnabledSwitch;
     private boolean mLastEnabledState;
+    private boolean mHaveDebugSettings;
 
     private CheckBoxPreference mEnableAdb;
     private CheckBoxPreference mKeepScreenOn;
@@ -124,6 +129,7 @@ public class DevelopmentSettings extends PreferenceFragment
     private ListPreference mWindowAnimationScale;
     private ListPreference mTransitionAnimationScale;
     private ListPreference mAnimatorDurationScale;
+    private MultiCheckPreference mEnableTracesPref;
 
     private CheckBoxPreference mImmediatelyDestroyActivities;
     private ListPreference mAppProcessLimit;
@@ -177,6 +183,15 @@ public class DevelopmentSettings extends PreferenceFragment
         mAnimatorDurationScale = (ListPreference) findPreference(ANIMATOR_DURATION_SCALE_KEY);
         mAllPrefs.add(mAnimatorDurationScale);
         mAnimatorDurationScale.setOnPreferenceChangeListener(this);
+        mEnableTracesPref = (MultiCheckPreference)findPreference(ENABLE_TRACES_KEY);
+        String[] traceValues = new String[Trace.TRACE_TAGS.length];
+        for (int i=Trace.TRACE_FLAGS_START_BIT; i<traceValues.length; i++) {
+            traceValues[i] = Integer.toString(1<<i);
+        }
+        mEnableTracesPref.setEntries(Trace.TRACE_TAGS);
+        mEnableTracesPref.setEntryValues(traceValues);
+        mAllPrefs.add(mEnableTracesPref);
+        mEnableTracesPref.setOnPreferenceChangeListener(this);
 
         mImmediatelyDestroyActivities = (CheckBoxPreference) findPreference(
                 IMMEDIATELY_DESTROY_ACTIVITIES_KEY);
@@ -275,15 +290,32 @@ public class DevelopmentSettings extends PreferenceFragment
                 Settings.Secure.DEVELOPMENT_SETTINGS_ENABLED, 0) != 0;
         mEnabledSwitch.setChecked(mLastEnabledState);
         setPrefsEnabledState(mLastEnabledState);
+
+        if (mHaveDebugSettings && !mLastEnabledState) {
+            // Overall debugging is disabled, but there are some debug
+            // settings that are enabled.  This is an invalid state.  Switch
+            // to debug settings being enabled, so the user knows there is
+            // stuff enabled and can turn it all off if they want.
+            Settings.Secure.putInt(getActivity().getContentResolver(),
+                    Settings.Secure.DEVELOPMENT_SETTINGS_ENABLED, 1);
+            mLastEnabledState = true;
+            setPrefsEnabledState(mLastEnabledState);
+        }
+    }
+
+    void updateCheckBox(CheckBoxPreference checkBox, boolean value) {
+        checkBox.setChecked(value);
+        mHaveDebugSettings |= value;
     }
 
     private void updateAllOptions() {
         final ContentResolver cr = getActivity().getContentResolver();
-        mEnableAdb.setChecked(Settings.Secure.getInt(cr,
+        mHaveDebugSettings = false;
+        updateCheckBox(mEnableAdb, Settings.Secure.getInt(cr,
                 Settings.Secure.ADB_ENABLED, 0) != 0);
-        mKeepScreenOn.setChecked(Settings.System.getInt(cr,
+        updateCheckBox(mKeepScreenOn, Settings.System.getInt(cr,
                 Settings.System.STAY_ON_WHILE_PLUGGED_IN, 0) != 0);
-        mAllowMockLocation.setChecked(Settings.Secure.getInt(cr,
+        updateCheckBox(mAllowMockLocation, Settings.Secure.getInt(cr,
                 Settings.Secure.ALLOW_MOCK_LOCATION, 0) != 0);
         updateHdcpValues();
         updatePasswordSummary();
@@ -298,6 +330,7 @@ public class DevelopmentSettings extends PreferenceFragment
         updateShowHwScreenUpdatesOptions();
         updateDebugLayoutOptions();
         updateAnimationScaleOptions();
+        updateEnableTracesOptions();
         updateImmediatelyDestroyActivitiesOptions();
         updateAppProcessLimitOptions();
         updateShowAllANRsOptions();
@@ -315,7 +348,9 @@ public class DevelopmentSettings extends PreferenceFragment
         writeAnimationScaleOption(0, mWindowAnimationScale, null);
         writeAnimationScaleOption(1, mTransitionAnimationScale, null);
         writeAnimationScaleOption(2, mAnimatorDurationScale, null);
+        writeEnableTracesOptions(0);
         writeAppProcessLimitOptions(null);
+        mHaveDebugSettings = false;
         updateAllOptions();
     }
 
@@ -369,7 +404,7 @@ public class DevelopmentSettings extends PreferenceFragment
     private void updateDebuggerOptions() {
         mDebugApp = Settings.System.getString(
                 getActivity().getContentResolver(), Settings.System.DEBUG_APP);
-        mWaitForDebugger.setChecked(Settings.System.getInt(
+        updateCheckBox(mWaitForDebugger, Settings.System.getInt(
                 getActivity().getContentResolver(), Settings.System.WAIT_FOR_DEBUGGER, 0) != 0);
         if (mDebugApp != null && mDebugApp.length() > 0) {
             String label;
@@ -383,6 +418,7 @@ public class DevelopmentSettings extends PreferenceFragment
             }
             mDebugAppPref.setSummary(getResources().getString(R.string.debug_app_set, label));
             mWaitForDebugger.setEnabled(true);
+            mHaveDebugSettings = true;
         } else {
             mDebugAppPref.setSummary(getResources().getString(R.string.debug_app_not_set));
             mWaitForDebugger.setEnabled(false);
@@ -411,7 +447,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateStrictModeVisualOptions() {
-        mStrictMode.setChecked(currentStrictModeActiveIndex() == 1);
+        updateCheckBox(mStrictMode, currentStrictModeActiveIndex() == 1);
     }
 
     private void writePointerLocationOptions() {
@@ -420,7 +456,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updatePointerLocationOptions() {
-        mPointerLocation.setChecked(Settings.System.getInt(getActivity().getContentResolver(),
+        updateCheckBox(mPointerLocation, Settings.System.getInt(getActivity().getContentResolver(),
                 Settings.System.POINTER_LOCATION, 0) != 0);
     }
 
@@ -430,7 +466,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateShowTouchesOptions() {
-        mShowTouches.setChecked(Settings.System.getInt(getActivity().getContentResolver(),
+        updateCheckBox(mShowTouches, Settings.System.getInt(getActivity().getContentResolver(),
                 Settings.System.SHOW_TOUCHES, 0) != 0);
     }
 
@@ -448,11 +484,11 @@ public class DevelopmentSettings extends PreferenceFragment
                 @SuppressWarnings("unused")
                 int enableGL = reply.readInt();
                 int showUpdates = reply.readInt();
-                mShowScreenUpdates.setChecked(showUpdates != 0);
+                updateCheckBox(mShowScreenUpdates, showUpdates != 0);
                 @SuppressWarnings("unused")
                 int showBackground = reply.readInt();
                 int disableOverlays = reply.readInt();
-                mDisableOverlays.setChecked(disableOverlays != 0);
+                updateCheckBox(mDisableOverlays, disableOverlays != 0);
                 reply.recycle();
                 data.recycle();
             }
@@ -495,7 +531,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateHardwareUiOptions() {
-        mForceHardwareUi.setChecked(SystemProperties.getBoolean(HARDWARE_UI_PROPERTY, false));
+        updateCheckBox(mForceHardwareUi, SystemProperties.getBoolean(HARDWARE_UI_PROPERTY, false));
     }
     
     private void writeHardwareUiOptions() {
@@ -503,7 +539,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateTrackFrameTimeOptions() {
-        mTrackFrameTime.setChecked(
+        updateCheckBox(mTrackFrameTime,
                 SystemProperties.getBoolean(HardwareRenderer.PROFILE_PROPERTY, false));
     }
 
@@ -513,7 +549,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateShowHwScreenUpdatesOptions() {
-        mShowHwScreenUpdates.setChecked(
+        updateCheckBox(mShowHwScreenUpdates,
                 SystemProperties.getBoolean(HardwareRenderer.DEBUG_DIRTY_REGIONS_PROPERTY, false));
     }
 
@@ -523,7 +559,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateDebugLayoutOptions() {
-        mDebugLayout.setChecked(
+        updateCheckBox(mDebugLayout,
                 SystemProperties.getBoolean(View.DEBUG_LAYOUT_PROPERTY, false));
     }
 
@@ -533,7 +569,7 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateCpuUsageOptions() {
-        mShowCpuUsage.setChecked(Settings.System.getInt(getActivity().getContentResolver(),
+        updateCheckBox(mShowCpuUsage, Settings.System.getInt(getActivity().getContentResolver(),
                 Settings.System.SHOW_PROCESSES, 0) != 0);
     }
     
@@ -559,13 +595,16 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateImmediatelyDestroyActivitiesOptions() {
-        mImmediatelyDestroyActivities.setChecked(Settings.System.getInt(
+        updateCheckBox(mImmediatelyDestroyActivities, Settings.System.getInt(
             getActivity().getContentResolver(), Settings.System.ALWAYS_FINISH_ACTIVITIES, 0) != 0);
     }
 
     private void updateAnimationScaleValue(int which, ListPreference pref) {
         try {
             float scale = mWindowManager.getAnimationScale(which);
+            if (scale != 1) {
+                mHaveDebugSettings = true;
+            }
             CharSequence[] values = pref.getEntryValues();
             for (int i=0; i<values.length; i++) {
                 float val = Float.parseFloat(values[i].toString());
@@ -603,6 +642,9 @@ public class DevelopmentSettings extends PreferenceFragment
             for (int i=0; i<values.length; i++) {
                 int val = Integer.parseInt(values[i].toString());
                 if (val >= limit) {
+                    if (i != 0) {
+                        mHaveDebugSettings = true;
+                    }
                     mAppProcessLimit.setValueIndex(i);
                     mAppProcessLimit.setSummary(mAppProcessLimit.getEntries()[i]);
                     return;
@@ -630,10 +672,51 @@ public class DevelopmentSettings extends PreferenceFragment
     }
 
     private void updateShowAllANRsOptions() {
-        mShowAllANRs.setChecked(Settings.Secure.getInt(
+        updateCheckBox(mShowAllANRs, Settings.Secure.getInt(
             getActivity().getContentResolver(), Settings.Secure.ANR_SHOW_BACKGROUND, 0) != 0);
     }
 
+    private void updateEnableTracesOptions() {
+        String strValue = SystemProperties.get(Trace.PROPERTY_TRACE_TAG_ENABLEFLAGS);
+        long flags = SystemProperties.getLong(Trace.PROPERTY_TRACE_TAG_ENABLEFLAGS, 0);
+        String[] values = mEnableTracesPref.getEntryValues();
+        int numSet = 0;
+        for (int i=Trace.TRACE_FLAGS_START_BIT; i<values.length; i++) {
+            boolean set = (flags&(1<<i)) != 0;
+            mEnableTracesPref.setValue(i-Trace.TRACE_FLAGS_START_BIT, set);
+            if (set) {
+                numSet++;
+            }
+        }
+        if (numSet == 0) {
+            mEnableTracesPref.setSummary(R.string.enable_traces_summary_none);
+        } else if (numSet == values.length) {
+            mHaveDebugSettings = true;
+            mEnableTracesPref.setSummary(R.string.enable_traces_summary_all);
+        } else {
+            mHaveDebugSettings = true;
+            mEnableTracesPref.setSummary(getString(R.string.enable_traces_summary_num, numSet));
+        }
+    }
+
+    private void writeEnableTracesOptions() {
+        long value = 0;
+        String[] values = mEnableTracesPref.getEntryValues();
+        for (int i=Trace.TRACE_FLAGS_START_BIT; i<values.length; i++) {
+            if (mEnableTracesPref.getValue(i-Trace.TRACE_FLAGS_START_BIT)) {
+                value |= 1<<i;
+            }
+        }
+        writeEnableTracesOptions(value);
+        // Make sure summary is updated.
+        updateEnableTracesOptions();
+    }
+
+    private void writeEnableTracesOptions(long value) {
+        SystemProperties.set(Trace.PROPERTY_TRACE_TAG_ENABLEFLAGS,
+                "0x" + Long.toString(value, 16));
+    }
+
     @Override
     public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
         if (buttonView == mEnabledSwitch) {
@@ -754,6 +837,9 @@ public class DevelopmentSettings extends PreferenceFragment
         } else if (preference == mAnimatorDurationScale) {
             writeAnimationScaleOption(2, mAnimatorDurationScale, newValue);
             return true;
+        } else if (preference == mEnableTracesPref) {
+            writeEnableTracesOptions();
+            return true;
         } else if (preference == mAppProcessLimit) {
             writeAppProcessLimitOptions(newValue);
             return true;