From 6a4b7680ccb809b49af5c258d89f61b97769ddf8 Mon Sep 17 00:00:00 2001
From: Marco Ballesio <balejs@google.com>
Date: Wed, 29 Jul 2020 09:13:53 -0700
Subject: [PATCH] Ensure CachedAppOptimizerThread cpuset

CachedAppOptimizerThread isn't started until the device config is
downloaded from the Phenotype server, but CachedAppOptimizer.init() is
called at device boot.

Configure the system-background cpuset for CachedOptimizerThread at
creation, then set it again when the thread is started, to ensure
priorities aren't modified by ActivityManager.

Test: flashed/wiped the device and verified no optimizer thread was
present until wifi connection, then verified that the thread cpuset was
system-background once created. Rebooted the device again and verified
that the optimizer thread was system-background cpuset again.
Bug: 149610535

Change-Id: I310f234552320f95bd7e05053084425a3fcc6dcf
---
 .../android/server/am/CachedAppOptimizer.java    | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/services/core/java/com/android/server/am/CachedAppOptimizer.java b/services/core/java/com/android/server/am/CachedAppOptimizer.java
index 43e3a04ad0329..d9fde0f6728a8 100644
--- a/services/core/java/com/android/server/am/CachedAppOptimizer.java
+++ b/services/core/java/com/android/server/am/CachedAppOptimizer.java
@@ -16,8 +16,6 @@
 
 package com.android.server.am;
 
-import static android.os.Process.THREAD_PRIORITY_FOREGROUND;
-
 import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_COMPACTION;
 import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_FREEZER;
 import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM;
@@ -256,7 +254,7 @@ public final class CachedAppOptimizer {
             ProcessDependencies processDependencies) {
         mAm = am;
         mCachedAppOptimizerThread = new ServiceThread("CachedAppOptimizerThread",
-            THREAD_PRIORITY_FOREGROUND, true);
+            Process.THREAD_GROUP_SYSTEM, true);
         mProcStateThrottle = new HashSet<>();
         mProcessDependencies = processDependencies;
         mTestCallback = callback;
@@ -280,8 +278,6 @@ public final class CachedAppOptimizer {
             updateProcStateThrottle();
             updateUseFreezer();
         }
-        Process.setThreadGroupAndCpuset(mCachedAppOptimizerThread.getThreadId(),
-                Process.THREAD_GROUP_SYSTEM);
     }
 
     /**
@@ -411,12 +407,15 @@ public final class CachedAppOptimizer {
         mUseCompaction = DeviceConfig.getBoolean(DeviceConfig.NAMESPACE_ACTIVITY_MANAGER,
                     KEY_USE_COMPACTION, DEFAULT_USE_COMPACTION);
 
-        if (mUseCompaction) {
+        if (mUseCompaction && mCompactionHandler == null) {
             if (!mCachedAppOptimizerThread.isAlive()) {
                 mCachedAppOptimizerThread.start();
             }
 
             mCompactionHandler = new MemCompactionHandler();
+
+            Process.setThreadGroupAndCpuset(mCachedAppOptimizerThread.getThreadId(),
+                    Process.THREAD_GROUP_SYSTEM);
         }
     }
 
@@ -470,13 +469,16 @@ public final class CachedAppOptimizer {
             mUseFreezer = isFreezerSupported();
         }
 
-        if (mUseFreezer) {
+        if (mUseFreezer && mFreezeHandler == null) {
             Slog.d(TAG_AM, "Freezer enabled");
             if (!mCachedAppOptimizerThread.isAlive()) {
                 mCachedAppOptimizerThread.start();
             }
 
             mFreezeHandler = new FreezeHandler();
+
+            Process.setThreadGroupAndCpuset(mCachedAppOptimizerThread.getThreadId(),
+                    Process.THREAD_GROUP_SYSTEM);
         }
     }