ActivityManagerService: reroute lmkd atoms logging

- Added support to subscribe for a lmkd LMK_ASYNC_EVENT_STAT event
- Added processing LMK_KILL_OCCURRED and LMK_STATE_CHANGED packets
  with logging to statsd
- Added statsd auto-generated code wrapping the statsd logging

Bug: 184698933
Test: lmkd_unit_test - test check_for_oom tests lmkd message send to AMS
Test: statsd_testdrive 51 54 to inspect statsd logged atoms data
Change-Id: I69ef1a9daa5532244a15665bff06d0ad6b370869
Merged-In: I69ef1a9daa5532244a15665bff06d0ad6b370869

services/core/java/com/android/server/am/LmkdConnection.java

@@ -43,8 +43,12 @@ import java.nio.ByteBuffer;
 public class LmkdConnection {
     private static final String TAG = TAG_WITH_CLASS_NAME ? "LmkdConnection" : TAG_AM;
 
-    // lmkd reply max size in bytes
+    /**
-    private static final int LMKD_REPLY_MAX_SIZE = 12;
+     * Max LMKD reply packet length in bytes
+     * Used to hold the data for the statsd atoms logging
+     * Must be in sync with statslog.h
+     */
+    private static final int LMKD_REPLY_MAX_SIZE = 214;
 
     // connection listener interface
     interface LmkdConnectionListener {

services/core/java/com/android/server/am/LmkdStatsReporter.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.am;
+
+import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM;
+import static com.android.server.am.ActivityManagerDebugConfig.TAG_WITH_CLASS_NAME;
+
+import android.util.Slog;
+
+import com.android.internal.util.FrameworkStatsLog;
+
+import java.io.ByteArrayInputStream;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+/**
+ * Activity manager communication with lmkd data handling and statsd atom logging
+ */
+public final class LmkdStatsReporter {
+
+    static final String TAG = TAG_WITH_CLASS_NAME ? "LmkdStatsReporter" : TAG_AM;
+
+    public static final int KILL_OCCURRED_MSG_SIZE = 80;
+    public static final int STATE_CHANGED_MSG_SIZE = 8;
+
+    private static final int PRESSURE_AFTER_KILL = 0;
+    private static final int NOT_RESPONDING = 1;
+    private static final int LOW_SWAP_AND_THRASHING = 2;
+    private static final int LOW_MEM_AND_SWAP = 3;
+    private static final int LOW_MEM_AND_THRASHING = 4;
+    private static final int DIRECT_RECL_AND_THRASHING = 5;
+    private static final int LOW_MEM_AND_SWAP_UTIL = 6;
+
+    /**
+     * Processes the LMK_KILL_OCCURRED packet data
+     * Logs the event when LMKD kills a process to reduce memory pressure.
+     * Code: LMK_KILL_OCCURRED = 51
+     */
+    public static void logKillOccurred(ByteBuffer dataReceived) {
+        DataInputStream inputData = new DataInputStream(
+                new ByteArrayInputStream(dataReceived.array()));
+
+        try {
+            //read first int which denotes the message type
+            final int msgType = inputData.readInt();
+            final long pgFault = inputData.readLong();
+            final long pgMajFault = inputData.readLong();
+            final long rssInBytes = inputData.readLong();
+            final long cacheInBytes = inputData.readLong();
+            final long swapInBytes = inputData.readLong();
+            final long processStartTimeNS = inputData.readLong();
+            final int uid = inputData.readInt();
+            final int oomScore = inputData.readInt();
+            final int minOomScore = inputData.readInt();
+            final int freeMemKb = inputData.readInt();
+            final int freeSwapKb = inputData.readInt();
+            final int killReason = inputData.readInt();
+            final String procName = inputData.readUTF();
+
+            FrameworkStatsLog.write(FrameworkStatsLog.LMK_KILL_OCCURRED, uid, procName, oomScore,
+                    pgFault, pgMajFault, rssInBytes, cacheInBytes, swapInBytes, processStartTimeNS,
+                    minOomScore, freeMemKb, freeSwapKb, mapKillReason(killReason));
+        } catch (IOException e) {
+            Slog.e(TAG, "Invalid buffer data. Failed to log LMK_KILL_OCCURRED");
+            return;
+        }
+    }
+
+    /**
+     * Processes the LMK_STATE_CHANGED packet
+     * Logs the change in LMKD state which is used as start/stop boundaries for logging
+     * LMK_KILL_OCCURRED event.
+     * Code: LMK_STATE_CHANGED = 54
+     */
+    public static void logStateChanged(int state) {
+        FrameworkStatsLog.write(FrameworkStatsLog.LMK_STATE_CHANGED, state);
+    }
+
+    private static int mapKillReason(int reason) {
+        switch (reason) {
+            case PRESSURE_AFTER_KILL:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__PRESSURE_AFTER_KILL;
+            case NOT_RESPONDING:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__NOT_RESPONDING;
+            case LOW_SWAP_AND_THRASHING:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__LOW_SWAP_AND_THRASHING;
+            case LOW_MEM_AND_SWAP:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__LOW_MEM_AND_SWAP;
+            case LOW_MEM_AND_THRASHING:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__LOW_MEM_AND_THRASHING;
+            case DIRECT_RECL_AND_THRASHING:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__DIRECT_RECL_AND_THRASHING;
+            case LOW_MEM_AND_SWAP_UTIL:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__LOW_MEM_AND_SWAP_UTIL;
+            default:
+                return FrameworkStatsLog.LMK_KILL_OCCURRED__REASON__UNKNOWN;
+        }
+    }
+}

services/core/java/com/android/server/am/ProcessList.java

@@ -316,18 +316,25 @@ public final class ProcessList {
     // LMK_GETKILLCNT
     // LMK_SUBSCRIBE
     // LMK_PROCKILL
+    // LMK_UPDATE_PROPS
+    // LMK_KILL_OCCURRED
+    // LMK_STATE_CHANGED
     static final byte LMK_TARGET = 0;
     static final byte LMK_PROCPRIO = 1;
     static final byte LMK_PROCREMOVE = 2;
     static final byte LMK_PROCPURGE = 3;
     static final byte LMK_GETKILLCNT = 4;
     static final byte LMK_SUBSCRIBE = 5;
-    static final byte LMK_PROCKILL = 6; // Note: this is an unsolicated command
+    static final byte LMK_PROCKILL = 6; // Note: this is an unsolicited command
+    static final byte LMK_UPDATE_PROPS = 7;
+    static final byte LMK_KILL_OCCURRED = 8; // Msg to subscribed clients on kill occurred event
+    static final byte LMK_STATE_CHANGED = 9; // Msg to subscribed clients on state changed
 
     // Low Memory Killer Daemon command codes.
     // These must be kept in sync with async_event_type definitions in lmkd.h
     //
     static final int LMK_ASYNC_EVENT_KILL = 0;
+    static final int LMK_ASYNC_EVENT_STAT = 1;
 
     // lmkd reconnect delay in msecs
     private static final long LMKD_RECONNECT_DELAY_MS = 1000;
@@ -781,6 +788,7 @@ public final class ProcessList {
                             if (receivedLen < 4) {
                                 return false;
                             }
+
                             switch (dataReceived.getInt(0)) {
                                 case LMK_PROCKILL:
                                     if (receivedLen != 12) {
@@ -789,6 +797,20 @@ public final class ProcessList {
                                     mAppExitInfoTracker.scheduleNoteLmkdProcKilled(
                                             dataReceived.getInt(4), dataReceived.getInt(8));
                                     return true;
+                                case LMK_KILL_OCCURRED:
+                                    if (receivedLen < LmkdStatsReporter.KILL_OCCURRED_MSG_SIZE) {
+                                        return false;
+                                    }
+                                    dataReceived.position(4);
+                                    LmkdStatsReporter.logKillOccurred(dataReceived);
+                                    return true;
+                                case LMK_STATE_CHANGED:
+                                    if (receivedLen != LmkdStatsReporter.STATE_CHANGED_MSG_SIZE) {
+                                        return false;
+                                    }
+                                    LmkdStatsReporter.logStateChanged(
+                                            dataReceived.getInt(4));
+                                    return true;
                                 default:
                                     return false;
                             }
@@ -1433,6 +1455,12 @@ public final class ProcessList {
             buf.putInt(LMK_SUBSCRIBE);
             buf.putInt(LMK_ASYNC_EVENT_KILL);
             ostream.write(buf.array(), 0, buf.position());
+
+            // Subscribe for stats event notifications
+            buf = ByteBuffer.allocate(4 * 2);
+            buf.putInt(LMK_SUBSCRIBE);
+            buf.putInt(LMK_ASYNC_EVENT_STAT);
+            ostream.write(buf.array(), 0, buf.position());
         } catch (IOException ex) {
             return false;
         }