From cf4b2542fae9d6c5d3788c6a935824094fb1c1ea Mon Sep 17 00:00:00 2001
From: Yusuke Sato <yusukes@google.com>
Date: Wed, 17 Jun 2015 00:21:28 -0700
Subject: [PATCH] Trace Process.killProcessGroup calls in server/am/

to make it easier to find boot time regressions like 21813611
and 21861473.

Process.killProcessGroup is a blocking call and usually takes
about 50ms to finish on a recent device even when the process
group contains only one process. Since Process.killProcessGroup
tends to be called in a loop, the function can be a bottleneck.

Bug: 21813611
Change-Id: I9c1727c0c0b321a30c96321198cc02f438496ded
---
 .../server/am/ActivityManagerService.java        | 16 +++++++++++-----
 .../com/android/server/am/ProcessRecord.java     |  3 +++
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 667abb64b4a54..946397550f980 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -2747,13 +2747,19 @@ public final class ActivityManagerService extends ActivityManagerNative
         return index;
     }
 
+    private static void killProcessGroup(int uid, int pid) {
+        Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "killProcessGroup");
+        Process.killProcessGroup(uid, pid);
+        Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
+    }
+
     final void removeLruProcessLocked(ProcessRecord app) {
         int lrui = mLruProcesses.lastIndexOf(app);
         if (lrui >= 0) {
             if (!app.killed) {
                 Slog.wtfStack(TAG, "Removing process that hasn't been killed: " + app);
                 Process.killProcessQuiet(app.pid);
-                Process.killProcessGroup(app.info.uid, app.pid);
+                killProcessGroup(app.info.uid, app.pid);
             }
             if (lrui <= mLruProcessActivityStart) {
                 mLruProcessActivityStart--;
@@ -3118,7 +3124,7 @@ public final class ActivityManagerService extends ActivityManagerNative
             // clean it up now.
             if (DEBUG_PROCESSES || DEBUG_CLEANUP) Slog.v(TAG_PROCESSES, "App died: " + app);
             checkTime(startTime, "startProcess: bad proc running, killing");
-            Process.killProcessGroup(app.info.uid, app.pid);
+            killProcessGroup(app.info.uid, app.pid);
             handleAppDiedLocked(app, true, true);
             checkTime(startTime, "startProcess: done killing old proc");
         }
@@ -4604,7 +4610,7 @@ public final class ActivityManagerService extends ActivityManagerNative
             if (!fromBinderDied) {
                 Process.killProcessQuiet(pid);
             }
-            Process.killProcessGroup(app.info.uid, pid);
+            killProcessGroup(app.info.uid, pid);
             app.killed = true;
         }
 
@@ -5927,7 +5933,7 @@ public final class ActivityManagerService extends ActivityManagerNative
             EventLog.writeEvent(EventLogTags.AM_DROP_PROCESS, pid);
             if (pid > 0 && pid != MY_PID) {
                 Process.killProcessQuiet(pid);
-                //TODO: Process.killProcessGroup(app.info.uid, pid);
+                //TODO: killProcessGroup(app.info.uid, pid);
             } else {
                 try {
                     thread.scheduleExit();
@@ -12390,7 +12396,7 @@ public final class ActivityManagerService extends ActivityManagerNative
                             } else {
                                 // Huh.
                                 Process.killProcess(pid);
-                                Process.killProcessGroup(uid, pid);
+                                killProcessGroup(uid, pid);
                             }
                         }
                         return;
diff --git a/services/core/java/com/android/server/am/ProcessRecord.java b/services/core/java/com/android/server/am/ProcessRecord.java
index 3acd3a387bcca..bd31a218f4c1f 100644
--- a/services/core/java/com/android/server/am/ProcessRecord.java
+++ b/services/core/java/com/android/server/am/ProcessRecord.java
@@ -40,6 +40,7 @@ import android.os.Bundle;
 import android.os.IBinder;
 import android.os.Process;
 import android.os.SystemClock;
+import android.os.Trace;
 import android.os.UserHandle;
 import android.util.ArrayMap;
 import android.util.PrintWriterPrinter;
@@ -536,6 +537,7 @@ final class ProcessRecord {
 
     void kill(String reason, boolean noisy) {
         if (!killedByAm) {
+            Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "kill");
             if (noisy) {
                 Slog.i(TAG, "Killing " + toShortString() + " (adj " + setAdj + "): " + reason);
             }
@@ -546,6 +548,7 @@ final class ProcessRecord {
                 killed = true;
                 killedByAm = true;
             }
+            Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
         }
     }