8049831: Metadata Full GCs are not triggered when CMSClassUnloadingEnabled is turned off

Reviewed-by: brutisso, tschatzl, ehelin, jmasa, dfazunen

src/share/vm/gc_implementation/shared/vmGCOperations.cpp

 /*
- * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -211,10 +211,12 @@ void VM_GenCollectFull::doit() {
 
 bool VM_CollectForMetadataAllocation::initiate_concurrent_GC() {
 #if INCLUDE_ALL_GCS
-  if (UseConcMarkSweepGC || UseG1GC) {
   if (UseConcMarkSweepGC && CMSClassUnloadingEnabled) {
     MetaspaceGC::set_should_concurrent_collect(true);
-    } else if (UseG1GC) {
+    return true;
+  }
+
+  if (UseG1GC) {
     G1CollectedHeap* g1h = G1CollectedHeap::heap();
     g1h->g1_policy()->set_initiate_conc_mark_if_possible();
 
@@ -228,11 +230,10 @@ bool VM_CollectForMetadataAllocation::initiate_concurrent_GC() {
       double pause_target = g1h->g1_policy()->max_pause_time_ms();
       g1h->do_collection_pause_at_safepoint(pause_target);
     }
-    }
-
     return true;
   }
 #endif
+
   return false;
 }
 

test/TEST.groups

@@ -169,6 +169,7 @@ compact1 = \
 #
 needs_full_vm_compact1 = \
   runtime/NMT \
+  gc/class_unloading/TestCMSClassUnloadingDisabledHWM.java \
   gc/g1/TestRegionAlignment.java \
   gc/g1/TestShrinkToOneRegion.java \
   gc/metaspace/G1AddMetaspaceDependency.java \