Introduce a flag to change the new space growth factor

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 5041 matching lines @@
             "semi-space size of %d MB\n",
             max_semi_space_size_ / MB);
       }
     } else {
       target_semispace_size_ = target_semispace_size;
     }
   }
 
   target_semispace_size_ = Max(initial_semispace_size_, target_semispace_size_);
 
+  if (FLAG_semi_space_growth_factor < 2) {
+    FLAG_semi_space_growth_factor = 2;
+  }
+
   // The old generation is paged and needs at least one page for each space.
   int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1;
   max_old_generation_size_ =
       Max(static_cast<intptr_t>(paged_space_count * Page::kPageSize),
           max_old_generation_size_);
 
   // We rely on being able to allocate new arrays in paged spaces.
   DCHECK(Page::kMaxRegularHeapObjectSize >=
          (JSArray::kSize +
           FixedArray::SizeFor(JSObject::kInitialMaxFastElementArray) +
@@ skipping 1236 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal