--- old/jdk/src/java.base/share/classes/java/lang/Throwable.java	2015-11-09 17:14:53.000000000 -0800
+++ new/jdk/src/java.base/share/classes/java/lang/Throwable.java	2015-11-09 17:14:53.000000000 -0800
@@ -24,6 +24,8 @@
  */
 
 package java.lang;
+import sun.misc.VM;
+
 import  java.io.*;
 import  java.util.*;
 
@@ -778,7 +780,11 @@
     public synchronized Throwable fillInStackTrace() {
         if (stackTrace != null ||
             backtrace != null /* Out of protocol state */ ) {
-            fillInStackTrace(0);
+            if (backtrace == null && StackStreamFactory.useStackTrace(this)) {
+                backtrace = StackStreamFactory.makeStackTrace(this);
+            } else {
+                fillInStackTrace(0);
+            }
             stackTrace = UNASSIGNED_STACK;
         }
         return this;
@@ -819,10 +825,14 @@
         // backtrace if this is the first call to this method
         if (stackTrace == UNASSIGNED_STACK ||
             (stackTrace == null && backtrace != null) /* Out of protocol state */) {
-            int depth = getStackTraceDepth();
-            stackTrace = new StackTraceElement[depth];
-            for (int i=0; i < depth; i++)
-                stackTrace[i] = getStackTraceElement(i);
+            if (backtrace instanceof StackStreamFactory.StackTrace) {
+                stackTrace = ((StackStreamFactory.StackTrace)backtrace).getStackTraceElements();
+            } else {
+                int depth = getStackTraceDepth();
+                stackTrace = new StackTraceElement[depth];
+                for (int i = 0; i < depth; i++)
+                    stackTrace[i] = getStackTraceElement(i);
+            }
         } else if (stackTrace == null) {
             return UNASSIGNED_STACK;
         }