--- a/hotspot/src/share/vm/ci/ciEnv.cpp	Wed Nov 06 06:51:24 2013 -0800
+++ b/hotspot/src/share/vm/ci/ciEnv.cpp	Fri Nov 08 01:13:11 2013 -0800
@@ -935,7 +935,9 @@
 
     // Prevent SystemDictionary::add_to_hierarchy from running
     // and invalidating our dependencies until we install this method.
+    // No safepoints are allowed. Otherwise, class redefinition can occur in between.
     MutexLocker ml(Compile_lock);
+    No_Safepoint_Verifier nsv;
 
     // Change in Jvmti state may invalidate compilation.
     if (!failing() &&
@@ -1001,16 +1003,6 @@
     // Free codeBlobs
     code_buffer->free_blob();
 
-    // stress test 6243940 by immediately making the method
-    // non-entrant behind the system's back. This has serious
-    // side effects on the code cache and is not meant for
-    // general stress testing
-    if (nm != NULL && StressNonEntrant) {
-      MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
-      NativeJump::patch_verified_entry(nm->entry_point(), nm->verified_entry_point(),
-                  SharedRuntime::get_handle_wrong_method_stub());
-    }
-
     if (nm == NULL) {
       // The CodeCache is full.  Print out warning and disable compilation.
       record_failure("code cache is full");
@@ -1036,11 +1028,11 @@
             char *method_name = method->name_and_sig_as_C_string();
             tty->print_cr("Replacing method %s", method_name);
           }
-          if (old != NULL ) {
+          if (old != NULL) {
             old->make_not_entrant();
           }
         }
-        if (TraceNMethodInstalls ) {
+        if (TraceNMethodInstalls) {
           ResourceMark rm;
           char *method_name = method->name_and_sig_as_C_string();
           ttyLocker ttyl;
@@ -1051,7 +1043,7 @@
         // Allow the code to be executed
         method->set_code(method, nm);
       } else {
-        if (TraceNMethodInstalls ) {
+        if (TraceNMethodInstalls) {
           ResourceMark rm;
           char *method_name = method->name_and_sig_as_C_string();
           ttyLocker ttyl;
@@ -1061,7 +1053,6 @@
                         entry_bci);
         }
         method->method_holder()->add_osr_nmethod(nm);
-
       }
     }
   }