diff --git a/cmds/statsd/src/atoms.proto b/cmds/statsd/src/atoms.proto
index 7ddb783..1c7eb41 100644
--- a/cmds/statsd/src/atoms.proto
+++ b/cmds/statsd/src/atoms.proto
@@ -4746,6 +4746,12 @@
 
   // The process state at the time of compaction.
   optional android.app.ProcessStateEnum process_state = 16 [default = PROCESS_STATE_UNKNOWN];
+
+  // Free ZRAM in kilobytes before compaction.
+  optional int64 before_zram_free_kilobytes = 17;
+
+  // Free ZRAM in kilobytes after compaction.
+  optional int64 after_zram_free_kilobytes = 18;
 }
 
 /**
diff --git a/core/java/android/os/Debug.java b/core/java/android/os/Debug.java
index aba81af..149ef54 100644
--- a/core/java/android/os/Debug.java
+++ b/core/java/android/os/Debug.java
@@ -2439,4 +2439,11 @@
             VMDebug.attachAgent(library + "=" + options, classLoader);
         }
     }
+
+    /**
+     * Return the current free ZRAM usage in kilobytes.
+     *
+     * @hide
+     */
+    public static native long getZramFreeKb();
 }
diff --git a/core/jni/android_os_Debug.cpp b/core/jni/android_os_Debug.cpp
index e9035ed..195fe58 100644
--- a/core/jni/android_os_Debug.cpp
+++ b/core/jni/android_os_Debug.cpp
@@ -737,6 +737,25 @@
     return env->NewStringUTF(s.c_str());
 }
 
+static jlong android_os_Debug_getFreeZramKb(JNIEnv* env, jobject clazz) {
+
+    jlong zramFreeKb = 0;
+
+    std::string status_path = android::base::StringPrintf("/proc/meminfo");
+    UniqueFile file = MakeUniqueFile(status_path.c_str(), "re");
+
+    char line[256];
+    while (file != nullptr && fgets(line, sizeof(line), file.get())) {
+        jlong v;
+        if (sscanf(line, "SwapFree: %" SCNd64 " kB", &v) == 1) {
+            zramFreeKb = v;
+            break;
+        }
+    }
+
+    return zramFreeKb;
+}
+
 /*
  * JNI registration.
  */
@@ -778,6 +797,8 @@
             (void*)android_os_Debug_dumpNativeBacktraceToFileTimeout },
     { "getUnreachableMemory", "(IZ)Ljava/lang/String;",
             (void*)android_os_Debug_getUnreachableMemory },
+    { "getZramFreeKb", "()J",
+            (void*)android_os_Debug_getFreeZramKb },
 };
 
 int register_android_os_Debug(JNIEnv *env)
diff --git a/services/core/java/com/android/server/am/AppCompactor.java b/services/core/java/com/android/server/am/AppCompactor.java
index c7e4fc7..17ffd9c 100644
--- a/services/core/java/com/android/server/am/AppCompactor.java
+++ b/services/core/java/com/android/server/am/AppCompactor.java
@@ -28,6 +28,7 @@
 
 import android.app.ActivityManager;
 import android.app.ActivityThread;
+import android.os.Debug;
 import android.os.Handler;
 import android.os.Message;
 import android.os.Process;
@@ -410,6 +411,7 @@
                         Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "Compact "
                                 + ((pendingAction == COMPACT_PROCESS_SOME) ? "some" : "full")
                                 + ": " + name);
+                        long zramFreeKbBefore = Debug.getZramFreeKb();
                         long[] rssBefore = Process.getRss(pid);
                         FileOutputStream fos = new FileOutputStream("/proc/" + pid + "/reclaim");
                         fos.write(action.getBytes());
@@ -417,10 +419,12 @@
                         long[] rssAfter = Process.getRss(pid);
                         long end = SystemClock.uptimeMillis();
                         long time = end - start;
+                        long zramFreeKbAfter = Debug.getZramFreeKb();
                         EventLog.writeEvent(EventLogTags.AM_COMPACT, pid, name, action,
                                 rssBefore[0], rssBefore[1], rssBefore[2], rssBefore[3],
                                 rssAfter[0], rssAfter[1], rssAfter[2], rssAfter[3], time,
-                                lastCompactAction, lastCompactTime, msg.arg1, msg.arg2);
+                                lastCompactAction, lastCompactTime, msg.arg1, msg.arg2,
+                                zramFreeKbBefore, zramFreeKbAfter);
                         // Note that as above not taking mPhenoTypeFlagLock here to avoid locking
                         // on every single compaction for a flag that will seldom change and the
                         // impact of reading the wrong value here is low.
@@ -429,7 +433,8 @@
                                     rssBefore[0], rssBefore[1], rssBefore[2], rssBefore[3],
                                     rssAfter[0], rssAfter[1], rssAfter[2], rssAfter[3], time,
                                     lastCompactAction, lastCompactTime, msg.arg1,
-                                    ActivityManager.processStateAmToProto(msg.arg2));
+                                    ActivityManager.processStateAmToProto(msg.arg2),
+                                    zramFreeKbBefore, zramFreeKbAfter);
                         }
                         synchronized (mAm) {
                             proc.lastCompactTime = end;
diff --git a/services/core/java/com/android/server/am/EventLogTags.logtags b/services/core/java/com/android/server/am/EventLogTags.logtags
index a71f6af..4b12e43 100644
--- a/services/core/java/com/android/server/am/EventLogTags.logtags
+++ b/services/core/java/com/android/server/am/EventLogTags.logtags
@@ -138,4 +138,4 @@
 30061 am_remove_task (Task ID|1|5), (Stack ID|1|5)
 
 # The task is being compacted
-30063 am_compact (Pid|1|5),(Process Name|3),(Action|3),(BeforeRssTotal|2|2),(BeforeRssFile|2|2),(BeforeRssAnon|2|2),(BeforeRssSwap|2|2),(AfterRssTotal|2|2),(AfterRssFile|2|2),(AfterRssAnon|2|2),(AfterRssSwap|2|2),(Time|2|3),(LastAction|1|2),(LastActionTimestamp|2|3),(setAdj|1|2),(procState|1|2)
+30063 am_compact (Pid|1|5),(Process Name|3),(Action|3),(BeforeRssTotal|2|2),(BeforeRssFile|2|2),(BeforeRssAnon|2|2),(BeforeRssSwap|2|2),(AfterRssTotal|2|2),(AfterRssFile|2|2),(AfterRssAnon|2|2),(AfterRssSwap|2|2),(Time|2|3),(LastAction|1|2),(LastActionTimestamp|2|3),(setAdj|1|2),(procState|1|2),(BeforeZRAMFree|2|2),(AfterZRAMFree|2|2)