am: Increase dropbox buffer size to 256KB (from 128KB)

Minor changes for dumping stack traces:
- Print the native traces right after foreground/persistent apps
- Also include mediaserver, sdcard, and surfaceflinger in traces

Bug: 11321322
Change-Id: Ic09b7da316a5f197dda0ac3bde06f75574cc2166

2 files changed, 21 insertions, 14 deletions

diff --git a/services/java/com/android/server/Watchdog.java b/services/java/com/android/server/Watchdog.java
index 616090e..dfffd2e 100644
--- a/services/java/com/android/server/Watchdog.java
+++ b/services/java/com/android/server/Watchdog.java
@@ -60,7 +60,8 @@ public class Watchdog extends Thread {
 
     static final int TIME_TO_WAIT = DB ? 5*1000 : 30*1000;
 
-    static final String[] NATIVE_STACKS_OF_INTEREST = new String[] {
+    // Which native processes to dump into dropbox's stack traces
+    public static final String[] NATIVE_STACKS_OF_INTEREST = new String[] {
         "/system/bin/mediaserver",
         "/system/bin/sdcard",
         "/system/bin/surfaceflinger"
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 3ba9098..e7ddd80 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -21,6 +21,7 @@ import static com.android.internal.util.XmlUtils.readIntAttribute;
 import static com.android.internal.util.XmlUtils.readLongAttribute;
 import static com.android.internal.util.XmlUtils.writeIntAttribute;
 import static com.android.internal.util.XmlUtils.writeLongAttribute;
+import static com.android.server.Watchdog.NATIVE_STACKS_OF_INTEREST;
 import static org.xmlpull.v1.XmlPullParser.END_DOCUMENT;
 import static org.xmlpull.v1.XmlPullParser.START_TAG;
 
@@ -322,6 +323,9 @@ public final class ActivityManagerService extends ActivityManagerNative
 
     static final String[] EMPTY_STRING_ARRAY = new String[0];
 
+    // How many bytes to write into the dropbox log before truncating
+    static final int DROPBOX_MAX_SIZE = 256 * 1024;
+
     /** Run all ActivityStacks through this */
     ActivityStackSupervisor mStackSupervisor;
 
@@ -3687,7 +3691,17 @@ public final class ActivityManagerService extends ActivityManagerNative
                 }
             }
 
-            // Next measure CPU usage.
+            // Next collect the stacks of the native pids
+            if (nativeProcs != null) {
+                int[] pids = Process.getPidsForCommands(nativeProcs);
+                if (pids != null) {
+                    for (int pid : pids) {
+                        Debug.dumpNativeBacktraceToFile(pid, tracesPath);
+                    }
+                }
+            }
+
+            // Lastly, measure CPU usage.
             if (processCpuTracker != null) {
                 processCpuTracker.init();
                 System.gc();
@@ -3719,19 +3733,9 @@ public final class ActivityManagerService extends ActivityManagerNative
                     }
                 }
             }
-
         } finally {
             observer.stopWatching();
         }
-
-        if (nativeProcs != null) {
-            int[] pids = Process.getPidsForCommands(nativeProcs);
-            if (pids != null) {
-                for (int pid : pids) {
-                    Debug.dumpNativeBacktraceToFile(pid, tracesPath);
-                }
-            }
-        }
     }
 
     final void logAppTooSlow(ProcessRecord app, long startTime, String msg) {
@@ -3895,7 +3899,8 @@ public final class ActivityManagerService extends ActivityManagerNative
 
         final ProcessCpuTracker processCpuTracker = new ProcessCpuTracker(true);
 
-        File tracesFile = dumpStackTraces(true, firstPids, processCpuTracker, lastPids, null);
+        File tracesFile = dumpStackTraces(true, firstPids, processCpuTracker, lastPids,
+                NATIVE_STACKS_OF_INTEREST);
 
         String cpuInfo = null;
         if (MONITOR_CPU_USAGE) {
@@ -9820,7 +9825,8 @@ public final class ActivityManagerService extends ActivityManagerNative
                 }
                 if (logFile != null) {
                     try {
-                        sb.append(FileUtils.readTextFile(logFile, 128 * 1024, "\n\n[[TRUNCATED]]"));
+                        sb.append(FileUtils.readTextFile(logFile, DROPBOX_MAX_SIZE,
+                                    "\n\n[[TRUNCATED]]"));
                     } catch (IOException e) {
                         Slog.e(TAG, "Error reading " + logFile, e);
                     }