diff --git a/src/tests/GC/Scenarios/THDChaos/livingobject.cs b/src/tests/GC/Scenarios/THDChaos/livingobject.cs
index d88dd0c4fb0595..e01b0b06aa4bd4 100644
--- a/src/tests/GC/Scenarios/THDChaos/livingobject.cs
+++ b/src/tests/GC/Scenarios/THDChaos/livingobject.cs
@@ -24,7 +24,7 @@ public void ThreadStart( )
         {
             // console synchronization Console.SetOut(TextWriter.Synchronized(Console.Out));
 
-            if( iCounter%100 == 0)
+            if( Volatile.Read( ref iCounter )%100 == 0)
             {
                 Console.Out.WriteLine( iCounter + " number of threads has been started" );
             }
@@ -43,9 +43,9 @@ public void ThreadStart( )
             MethodContainer[ 0 ] = ( byte ) 1;
             MethodContainer[ MethodContainer.Length - 1 ] = ( byte ) 1;
 
-            IncreatCount( );
-
-            if( LivingObject.iCounter < ThdChaos.iThrd )
+            // Atomically reserve a thread creation slot before starting a successor thread,
+            // so that no more than ThdChaos.iThrd successor threads are ever created.
+            if( IncreatCount( ) <= ThdChaos.iThrd )
             {
                 Thread Mv_Thread = new Thread( new ThreadStart (this.ThreadStart) );
                 Mv_Thread.Start( );
@@ -54,12 +54,9 @@ public void ThreadStart( )
         }
 
 
-        public void IncreatCount()
+        public int IncreatCount()
         {
-            lock(this)
-            {
-                iCounter += 1;
-            }
+            return Interlocked.Increment( ref iCounter );
         }
 
     }
diff --git a/src/tests/GC/Scenarios/THDChaos/thdchaos.cs b/src/tests/GC/Scenarios/THDChaos/thdchaos.cs
index 44fa03c9837f96..6df7f458cfb721 100644
--- a/src/tests/GC/Scenarios/THDChaos/thdchaos.cs
+++ b/src/tests/GC/Scenarios/THDChaos/thdchaos.cs
@@ -12,6 +12,7 @@ namespace DefaultNamespace {
     using System.Threading;
     using System;
     using System.IO;
+    using System.Runtime.InteropServices;
     using TestLibrary;
 
     public class ThdChaos
@@ -40,6 +41,13 @@ public static int Main( System.String [] Args )
                 iThrd = 20;
             }
 
+            // 32-bit Arm has a limited address space, creating too many threads at once
+            // can exhaust it and result in OutOfMemoryException.
+            if( RuntimeInformation.ProcessArchitecture == Architecture.Arm && iThrd > 5 )
+            {
+                iThrd = 5;
+            }
+
             ThdChaos Mv_ThdChaos = new ThdChaos();
             MasterThread Mv_Thread = new MasterThread( iThrd );
             return 100;