diff a/test/hotspot/jtreg/runtime/testlibrary/ClassUnloadCommon.java b/test/hotspot/jtreg/runtime/testlibrary/ClassUnloadCommon.java
--- a/test/hotspot/jtreg/runtime/testlibrary/ClassUnloadCommon.java
+++ b/test/hotspot/jtreg/runtime/testlibrary/ClassUnloadCommon.java
@@ -60,11 +60,11 @@
         l = null;
         dummy = null;
     }
 
     public static void triggerUnloading() {
-        allocateMemory(16 * 1024); // yg size is 8m with cms[[keep?]], force young collection
+        allocateMemory(16 * 1024); // force young collection
         System.gc();
     }
 
     /**
      * Creates a class loader that loads classes from {@code ${test.class.path}}