Put code flushing behind flag - defaults to false....

src/heap.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 587 matching lines @@
 
   for (int i = 0; i < gc_prologue_callbacks_.length(); ++i) {
     if (gc_type & gc_prologue_callbacks_[i].gc_type) {
       gc_prologue_callbacks_[i].callback(gc_type, kNoGCCallbackFlags);
     }
   }
 
   EnsureFromSpaceIsCommitted();
 
   if (collector == MARK_COMPACTOR) {
-    // Flush all potentially unused code.
-    FlushCode();
+    if (FLAG_flush_code) {
+      // Flush all potentially unused code.
+      FlushCode();
+    }
 
     // Perform mark-sweep with optional compaction.
     MarkCompact(tracer);
 
     int old_gen_size = PromotedSpaceSize();
     old_gen_promotion_limit_ =
         old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3);
     old_gen_allocation_limit_ =
         old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2);
     old_gen_exhausted_ = false;
@@ skipping 4118 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal