Grow old generation slower on low-memory devices.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 00e513ba880daa3fb9158af71cf57d6a91d1ace7..f2e9321a7a47087f84b567a57ccd1639908c259f 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -81,6 +81,7 @@ Heap::Heap()
 // Will be 4 * reserved_semispace_size_ to ensure that young
 // generation can be aligned to its size.
       maximum_committed_(0),
+      old_generation_growing_factor_(4),
       survived_since_last_expansion_(0),
       sweep_generation_(0),
       always_allocate_scope_depth_(0),
@@ -5952,6 +5953,12 @@ bool Heap::ConfigureHeap(int max_semispace_size,
 
   code_range_size_ = code_range_size;
 
+  // We set the old generation growing factor to 2 to grow the heap slower on
+  // low memory devices.
+  if (max_old_generation_size_ <= 256 * MB) {

[Michael Starzinger, 2014/04/15 12:11:50]

I personally am fine with hard-coding this constant. But I am not sure how much
this duplicates "magic constants" between embedders and V8. I am deferring to
Ross' opinion about this.

[rmcilroy, 2014/04/15 12:43:01]

I'm fine with this being hard-coded as well, but could we extract a constant
somewhere for the 256MB and use it both here and in
ResourceConstraints::ConfigureDefaultS? That way, if we decide to change the
heap size of a low-mem device it will change both places. 

[Hannes Payer (out of office), 2014/04/16 07:53:01]

Done.

[Hannes Payer (out of office), 2014/04/16 07:53:01]

Done.

+    old_generation_growing_factor_ = 2;
+  }
+
   configured_ = true;
   return true;
 }