am 418af932: am 05db19bc: Merge "trigger kernel blocked stack trace on system server watchdog" into jb-mr1.1-dev

* commit '418af9323fcb2363636bf4072c230a8adebfcc86':
  trigger kernel blocked stack trace on system server watchdog

1 files changed, 12 insertions, 0 deletions

diff --git a/services/java/com/android/server/Watchdog.java b/services/java/com/android/server/Watchdog.java
index 8bbf923adaea..b2a8ad834dc4 100644
--- a/services/java/com/android/server/Watchdog.java
+++ b/services/java/com/android/server/Watchdog.java
@@ -39,6 +39,8 @@ import android.util.Log;
 import android.util.Slog;
 
 import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Calendar;
 
@@ -439,6 +441,16 @@ public class Watchdog extends Thread {
                 dumpKernelStackTraces();
             }
 
+            // Trigger the kernel to dump all blocked threads to the kernel log
+            try {
+                FileWriter sysrq_trigger = new FileWriter("/proc/sysrq-trigger");
+                sysrq_trigger.write("w");
+                sysrq_trigger.close();
+            } catch (IOException e) {
+                Slog.e(TAG, "Failed to write to /proc/sysrq-trigger");
+                Slog.e(TAG, e.getMessage());
+            }
+
             // Try to add the error to the dropbox, but assuming that the ActivityManager
             // itself may be deadlocked.  (which has happened, causing this statement to
             // deadlock and the watchdog as a whole to be ineffective)