Make newspace semispaces be single page-sized memory chunks.

src/heap.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 66 matching lines @@
 #elif defined(V8_TARGET_ARCH_X64)
       reserved_semispace_size_(16*MB),
       max_semispace_size_(16*MB),
       initial_semispace_size_(1*MB),
       max_old_generation_size_(1*GB),
       max_executable_size_(256*MB),
       code_range_size_(512*MB),
 #else
       reserved_semispace_size_(4*MB),
       max_semispace_size_(4*MB),
-      initial_semispace_size_(512*KB),
+      initial_semispace_size_(1*MB),
       max_old_generation_size_(512*MB),
       max_executable_size_(128*MB),
       code_range_size_(0),
 #endif
 // Variables set based on semispace_size_ and old_generation_size_ in
 // ConfigureHeap (survived_since_last_expansion_, external_allocation_limit_)
 // Will be 4 * reserved_semispace_size_ to ensure that young
 // generation can be aligned to its size.
       survived_since_last_expansion_(0),
       always_allocate_scope_depth_(0),
@@ skipping 4539 matching lines @@
 
 
 // TODO(1236194): Since the heap size is configurable on the command line
 // and through the API, we should gracefully handle the case that the heap
 // size is not big enough to fit all the initial objects.
 bool Heap::ConfigureHeap(intptr_t max_semispace_size,
                          intptr_t max_old_gen_size,
                          intptr_t max_executable_size) {
   if (HasBeenSetup()) return false;
 
-  if (max_semispace_size > 0) max_semispace_size_ = max_semispace_size;
+  if (max_semispace_size > 0) {
+    if (max_semispace_size < Page::kPageSize) {
+      max_semispace_size = Page::kPageSize;
+    }
+    max_semispace_size_ = max_semispace_size;
+  }
 
   if (Snapshot::IsEnabled()) {
     // If we are using a snapshot we always reserve the default amount
     // of memory for each semispace because code in the snapshot has
     // write-barrier code that relies on the size and alignment of new
     // space.  We therefore cannot use a larger max semispace size
     // than the default reserved semispace size.
     if (max_semispace_size_ > reserved_semispace_size_) {
       max_semispace_size_ = reserved_semispace_size_;
     }
@@ skipping 1227 matching lines @@
 }
 
 
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 } }  // namespace v8::internal