--- old/src/share/vm/classfile/systemDictionary.cpp	2015-10-30 18:24:03.340762269 -0400
+++ new/src/share/vm/classfile/systemDictionary.cpp	2015-10-30 18:24:02.918928806 -0400
@@ -23,6 +23,7 @@
  */
 
 #include "precompiled.hpp"
+#include "classfile/backtrace.hpp"
 #include "classfile/classLoaderData.inline.hpp"
 #include "classfile/dictionary.hpp"
 #include "classfile/javaClasses.inline.hpp"
@@ -1708,6 +1709,9 @@
   VerifySDReachableAndLiveClosure cl(is_alive);
   dictionary()->oops_do(&cl);
 #endif
+
+  // Unload deallocated backtraces
+  BacktraceList::unlink(is_alive);
   return unloading_occurred;
 }
 
@@ -1721,6 +1725,11 @@
 
   // Visit extra methods
   invoke_method_table()->oops_do(strong);
+
+  // BacktraceList are weak roots
+  if (weak != NULL) {
+    BacktraceList::oops_do(weak);
+  }
 }
 
 void SystemDictionary::oops_do(OopClosure* f) {
@@ -1733,6 +1742,9 @@
 
   // Visit extra methods
   invoke_method_table()->oops_do(f);
+
+  // BacktraceList are weak roots
+  BacktraceList::oops_do(f);
 }
 
 // Extended Class redefinition support.