8264649: runtime/InternalApi/ThreadCpuTimesDeadlock.java crash in fastdebug C2 with -XX:-UseTLAB

Reviewed-by: thartmann, kvn

Author: Hui Shi

src/hotspot/share/opto/phaseX.cpp

@@ -1481,6 +1481,9 @@ void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
   temp->init_req(0,nn);     // Add a use to nn to prevent him from dying
   remove_dead_node( old );
   temp->del_req(0);         // Yank bogus edge
+  if (nn != NULL && nn->outcnt() == 0) {
+    _worklist.push(nn);
+  }
 #ifndef PRODUCT
   if( VerifyIterativeGVN ) {
     for ( int i = 0; i < _verify_window_size; i++ ) {

test/hotspot/jtreg/runtime/InternalApi/ThreadCpuTimesDeadlock.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2021, 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
@@ -30,6 +30,15 @@
  * @run main/othervm -XX:+UsePerfData -Xmx128m ThreadCpuTimesDeadlock
  */
 
+/*
+ * @test
+ * @bug 8264649
+ * @summary OSR compiled method crash when UseTLAB is off
+ * @requires vm.debug
+ * @modules java.management/sun.management
+ * @run main/othervm -XX:-UseTLAB -XX:+UsePerfData -Xmx128m ThreadCpuTimesDeadlock
+ */
+
 import java.lang.management.ManagementFactory;
 import javax.management.JMException;
 import javax.management.MBeanServer;