Changed the expansion of new space to depend on how much has survived scaveng...

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 2150)
+++ src/heap.cc	(working copy)
@@ -79,9 +79,9 @@
 
 // semispace_size_ should be a power of 2 and old_generation_size_ should be
 // a multiple of Page::kPageSize.
-int Heap::semispace_size_  = 2*MB;
+int Heap::semispace_size_  = 8*MB;
 int Heap::old_generation_size_ = 512*MB;
-int Heap::initial_semispace_size_ = 256*KB;
+int Heap::initial_semispace_size_ = 512*KB;
 
 GCCallback Heap::global_gc_prologue_callback_ = NULL;
 GCCallback Heap::global_gc_epilogue_callback_ = NULL;
@@ -90,9 +90,8 @@
 // ConfigureHeap.
 int Heap::young_generation_size_ = 0;  // Will be 2 * semispace_size_.
 
-// Double the new space after this many scavenge collections.
-int Heap::new_space_growth_limit_ = 8;
-int Heap::scavenge_count_ = 0;
+int Heap::survived_since_last_expansion_ = 0;
+
 Heap::HeapState Heap::gc_state_ = NOT_IN_GC;
 
 int Heap::mc_count_ = 0;
@@ -421,7 +420,7 @@
     old_gen_promotion_limit_ =
         old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3);
     old_gen_allocation_limit_ =
-        old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 3);
+        old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2);
     old_gen_exhausted_ = false;
 
     // If we have used the mark-compact collector to collect the new
@@ -624,16 +623,17 @@
   // Implements Cheney's copying algorithm
   LOG(ResourceEvent("scavenge", "begin"));
 
-  scavenge_count_++;
+  // Used for updating survived_since_last_expansion_ at function end.
+  int survived_watermark = PromotedSpaceSize();
+
   if (new_space_.Capacity() < new_space_.MaximumCapacity() &&
-      scavenge_count_ > new_space_growth_limit_) {
-    // Double the size of the new space, and double the limit.  The next
-    // doubling attempt will occur after the current new_space_growth_limit_
-    // more collections.
+      survived_since_last_expansion_ > new_space_.Capacity()) {
+    // Double the size of new space if there is room to grow and enough
+    // data has survived scavenge since the last expansion.
     // TODO(1240712): NewSpace::Double has a return value which is
     // ignored here.
     new_space_.Double();
-    new_space_growth_limit_ *= 2;
+    survived_since_last_expansion_ = 0;
   }
 
   // Flip the semispaces.  After flipping, to space is empty, from space has
@@ -737,6 +737,10 @@
   // Set age mark.
   new_space_.set_age_mark(new_space_.top());
 
+  // Update how much has survivived scavenge.

[Kasper Lund, 2009/06/12 11:04:45]

survivived -> survived

+  survived_since_last_expansion_ +=
+      PromotedSpaceSize() + new_space_.Size() - survived_watermark;

[Kasper Lund, 2009/06/12 11:04:45]

Maybe reorder these to make it (crystal) clear that you're adding
new_space_.Size() and the promoted space growth to the last expansion variable.

+
   LOG(ResourceEvent("scavenge", "end"));
 
   gc_state_ = NOT_IN_GC;