diff --git a/services/core/java/com/android/server/wm/ActivityTaskSupervisor.java b/services/core/java/com/android/server/wm/ActivityTaskSupervisor.java
index 7c5f059fb89a4..c8b7d982fa0ee 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskSupervisor.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskSupervisor.java
@@ -2049,6 +2049,16 @@ public class ActivityTaskSupervisor implements RecentTasks.Callbacks {
 
         // Update the current top activity.
         mTopResumedActivity = topRootTask.getTopResumedActivity();
+        // Update process state if there is no activity state change (e.g. focus change between
+        // multi-window mode activities) to make sure that the current top has top oom-adj.
+        // If the previous top is null, there should be activity state change from it, Then the
+        // process state should also have been updated so no need to update again.
+        if (mTopResumedActivity != null && prevTopActivity != null) {
+            if (mTopResumedActivity.app != null) {
+                mTopResumedActivity.app.addToPendingTop();
+            }
+            mService.updateOomAdj();
+        }
         scheduleTopResumedActivityStateIfNeeded();
 
         mService.updateTopApp(mTopResumedActivity);
diff --git a/services/core/java/com/android/server/wm/WindowProcessController.java b/services/core/java/com/android/server/wm/WindowProcessController.java
index 81878e3ef229c..1cfbe07d3f168 100644
--- a/services/core/java/com/android/server/wm/WindowProcessController.java
+++ b/services/core/java/com/android/server/wm/WindowProcessController.java
@@ -1110,7 +1110,7 @@ public class WindowProcessController extends ConfigurationContainer<Configuratio
     void updateProcessInfo(boolean updateServiceConnectionActivities, boolean activityChange,
             boolean updateOomAdj, boolean addPendingTopUid) {
         if (addPendingTopUid) {
-            mAtm.mAmInternal.addPendingTopUid(mUid, mPid);
+            addToPendingTop();
         }
         if (updateOomAdj) {
             prepareOomAdjustment();
@@ -1121,6 +1121,11 @@ public class WindowProcessController extends ConfigurationContainer<Configuratio
         mAtm.mH.sendMessage(m);
     }
 
+    /** Makes the process have top state before oom-adj is computed from a posted message. */
+    void addToPendingTop() {
+        mAtm.mAmInternal.addPendingTopUid(mUid, mPid);
+    }
+
     void updateServiceConnectionActivities() {
         // Posting on handler so WM lock isn't held when we call into AM.
         mAtm.mH.sendMessage(PooledLambda.obtainMessage(
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityTaskSupervisorTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityTaskSupervisorTests.java
index a34586bb2e8aa..66da2a6318685 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityTaskSupervisorTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityTaskSupervisorTests.java
@@ -19,6 +19,7 @@ package com.android.server.wm;
 import static android.app.ActivityManager.START_DELIVERED_TO_TOP;
 import static android.app.ActivityManager.START_TASK_TO_FRONT;
 import static android.app.ITaskStackListener.FORCED_RESIZEABLE_REASON_SECONDARY_DISPLAY;
+import static android.app.WindowConfiguration.WINDOWING_MODE_MULTI_WINDOW;
 
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn;
 import static com.android.dx.mockito.inline.extended.ExtendedMockito.never;
@@ -36,6 +37,7 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.clearInvocations;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.timeout;
 
@@ -265,6 +267,30 @@ public class ActivityTaskSupervisorTests extends WindowTestsBase {
         assertThat(allowedOnUntrusted).isFalse();
     }
 
+    /**
+     * Verifies that process state will be updated with pending top without activity state change.
+     * E.g. switch focus between resumed activities in multi-window mode.
+     */
+    @Test
+    public void testUpdatePendingTopForTopResumed() {
+        final Task task1 = new TaskBuilder(mSupervisor)
+                .setWindowingMode(WINDOWING_MODE_MULTI_WINDOW).build();
+        final ActivityRecord activity1 = new ActivityBuilder(mAtm)
+                .setTask(task1).setUid(ActivityBuilder.DEFAULT_FAKE_UID + 1).build();
+        task1.setResumedActivity(activity1, "test");
+
+        final ActivityRecord activity2 = new TaskBuilder(mSupervisor)
+                .setWindowingMode(WINDOWING_MODE_MULTI_WINDOW)
+                .setCreateActivity(true).build().getTopMostActivity();
+        activity2.getTask().setResumedActivity(activity2, "test");
+
+        mAtm.mAmInternal.deletePendingTopUid(activity1.getUid());
+        clearInvocations(mAtm);
+        activity1.moveFocusableActivityToTop("test");
+        assertTrue(mAtm.mAmInternal.isPendingTopUid(activity1.getUid()));
+        verify(mAtm).updateOomAdj();
+    }
+
     /**
      * We need to launch home again after user unlocked for those displays that do not have
      * encryption aware home app.