Start with a maximally large new space reservation

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 65b3bed357d00153cbbaa65dcf9dc000532d4737..d5d0dd9bc199e24cae244c2109693d9311dd28f2 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -59,7 +59,7 @@ Heap::Heap()
       // be a multiple of Page::kPageSize.
       reserved_semispace_size_(8 * (kPointerSize / 4) * MB),
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
-      initial_semispace_size_(Page::kPageSize),
+      initial_semispace_size_(8 * (kPointerSize / 4) * MB),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
       max_executable_size_(256ul * (kPointerSize / 4) * MB),
       // Variables set based on semispace_size_ and old_generation_size_ in
@@ -139,7 +139,8 @@ Heap::Heap()
 // V8 with snapshots and a non-default max semispace size is much
 // easier if you can define it as part of the build environment.
 #if defined(V8_MAX_SEMISPACE_SIZE)
-  max_semi_space_size_ = reserved_semispace_size_ = V8_MAX_SEMISPACE_SIZE;
+  initial_semispace_size_ = max_semi_space_size_ = reserved_semispace_size_ =
+      V8_MAX_SEMISPACE_SIZE;
 #endif
 
   // Ensure old_generation_size_ is a multiple of kPageSize.
@@ -4939,9 +4940,12 @@ bool Heap::ConfigureHeap(int max_semi_space_size, int max_old_space_size,
     } else {
       initial_semispace_size_ = initial_semispace_size;
     }
+    initial_semispace_size_ =
+        Min(initial_semispace_size_, max_semi_space_size_);
+  } else {
+    initial_semispace_size_ = max_semi_space_size_;
   }
 
-  initial_semispace_size_ = Min(initial_semispace_size_, max_semi_space_size_);
 
   // 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;