--- old/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp	2014-11-07 17:32:36.833000000 -0500
+++ new/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp	2014-11-07 17:32:36.757000000 -0500
@@ -42,8 +42,12 @@
 void VM_CMS_Operation::acquire_pending_list_lock() {
   // The caller may block while communicating
   // with the SLT thread in order to acquire/release the PLL.
-  ConcurrentMarkSweepThread::slt()->
-    manipulatePLL(SurrogateLockerThread::acquirePLL);
+  SurrogateLockerThread* slt = ConcurrentMarkSweepThread::slt();
+  if (slt != NULL) {
+    slt->manipulatePLL(SurrogateLockerThread::acquirePLL);
+  } else {
+    SurrogateLockerThread::report_missing_slt();
+  }
 }
 
 void VM_CMS_Operation::release_and_notify_pending_list_lock() {
--- old/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp	2014-11-07 17:32:37.288000000 -0500
+++ new/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp	2014-11-07 17:32:37.211000000 -0500
@@ -213,8 +213,12 @@
   assert(_needs_pll, "don't call this otherwise");
   // The caller may block while communicating
   // with the SLT thread in order to acquire/release the PLL.
-  ConcurrentMarkThread::slt()->
-    manipulatePLL(SurrogateLockerThread::acquirePLL);
+  SurrogateLockerThread* slt = ConcurrentMarkThread::slt();
+  if (slt != NULL) {
+    slt->manipulatePLL(SurrogateLockerThread::acquirePLL);
+  } else {
+    SurrogateLockerThread::report_missing_slt();
+  }
 }
 
 void VM_CGC_Operation::release_and_notify_pending_list_lock() {
--- old/src/share/vm/gc_implementation/shared/concurrentGCThread.cpp	2014-11-07 17:32:37.702000000 -0500
+++ new/src/share/vm/gc_implementation/shared/concurrentGCThread.cpp	2014-11-07 17:32:37.625000000 -0500
@@ -138,6 +138,13 @@
   return res;
 }
 
+void SurrogateLockerThread::report_missing_slt() {
+  vm_exit_during_initialization(
+    "GC before GC support fully initialized: "
+    "SLT is needed but has not yet been created.");
+  ShouldNotReachHere();
+}
+
 void SurrogateLockerThread::manipulatePLL(SLT_msg_type msg) {
   MutexLockerEx x(&_monitor, Mutex::_no_safepoint_check_flag);
   assert(_buffer == empty, "Should be empty");
--- old/src/share/vm/gc_implementation/shared/concurrentGCThread.hpp	2014-11-07 17:32:38.132000000 -0500
+++ new/src/share/vm/gc_implementation/shared/concurrentGCThread.hpp	2014-11-07 17:32:38.055000000 -0500
@@ -93,6 +93,9 @@
  public:
   static SurrogateLockerThread* make(TRAPS);
 
+  // Terminate VM with error message that SLT needed but not yet created.
+  static void report_missing_slt();
+
   SurrogateLockerThread();
 
   bool is_hidden_from_external_view() const     { return true; }
--- old/src/share/vm/runtime/interfaceSupport.cpp	2014-11-07 17:32:38.561000000 -0500
+++ new/src/share/vm/runtime/interfaceSupport.cpp	2014-11-07 17:32:38.485000000 -0500
@@ -87,7 +87,7 @@
   // Short-circuit any possible re-entrant gc-a-lot attempt
   if (thread->skip_gcalot()) return;
 
-  if (is_init_completed()) {
+  if (Threads::is_vm_complete()) {
 
     if (++_fullgc_alot_invocation < FullGCALotStart) {
       return;
--- /dev/null	2014-11-07 13:36:26.372000000 -0500
+++ new/test/gc/TestScavengeALot_CMS.java	2014-11-07 17:32:38.886000000 -0500
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/**
+ * @test
+ * @bug 8062036
+ * @summary  ConcurrentMarkThread::slt may be invoked before ConcurrentMarkThread::makeSurrogateLockerThread causing intermittent crashes
+ *
+ * @key gc
+ * @requires vm.gc == "ConcMarkSweep" | vm.gc == "null"
+ * @run main/othervm -XX:+UseConcMarkSweepGC -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockExperimentalVMOptions -XX:+ScavengeALot -XX:SurvivorAlignmentInBytes=2k -Xmx10m TestScavengeALot_CMS
+ */
+
+public class TestScavengeALot_CMS {
+    public static void main(String[] args) throws Exception {
+        System.out.println("Initialization complete.");
+    }
+}
--- /dev/null	2014-11-07 13:36:26.372000000 -0500
+++ new/test/gc/TestScavengeALot_G1.java	2014-11-07 17:32:39.273000000 -0500
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/**
+ * @test
+ * @bug 8062036
+ * @summary  ConcurrentMarkThread::slt may be invoked before ConcurrentMarkThread::makeSurrogateLockerThread causing intermittent crashes
+ *
+ * @key gc
+ * @requires vm.gc == "G1" | vm.gc == "null"
+ * @run main/othervm -XX:+UseG1GC -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockExperimentalVMOptions -XX:+ScavengeALot -XX:SurvivorAlignmentInBytes=2k -Xmx10m TestScavengeALot_G1
+ */
+
+public class TestScavengeALot_G1 {
+    public static void main(String[] args) throws Exception {
+        System.out.println("Initialization complete.");
+    }
+}