New flag --stress-compaction

src/v8.cc

 // Copyright 2011 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 198 matching lines @@
   if (!CPU::SupportsCrankshaft()) {
     use_crankshaft_ = false;
   }
 
   RuntimeProfiler::GlobalSetup();
 
   // Peephole optimization might interfere with deoptimization.
   FLAG_peephole_optimization = !use_crankshaft_;
 
   ElementsAccessor::InitializeOncePerProcess();
+
+  if (FLAG_stress_compaction) {
+    FLAG_force_marking_deque_overflows = true;
+    FLAG_gc_global = true;
+    FLAG_max_new_space_size = (1 << (kPageSizeBits - 10)) * 2;
+  }
 }
 
 } }  // namespace v8::internal