Make idle notification cleanup less aggressive. Do not clean up on...

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 5979)
+++ src/heap.cc	(working copy)
@@ -3757,14 +3757,21 @@
   static const int kIdlesBeforeScavenge = 4;
   static const int kIdlesBeforeMarkSweep = 7;
   static const int kIdlesBeforeMarkCompact = 8;
+  static const int kMaxIdleCount = 9;
+  static const int kGCsBetweenCleanup = 4;
   static int number_idle_notifications = 0;
   static int last_gc_count = gc_count_;
 
   bool uncommit = true;
   bool finished = false;
 
-  if (last_gc_count == gc_count_) {
-    number_idle_notifications++;
+  // Reset the number of idle notifications received when a number of
+  // GCs have taken place. This allows another round of cleanup based
+  // on idle notifications if enough work has been carried out to
+  // provoke a number of garbage collections.
+  if (gc_count_ < last_gc_count + kGCsBetweenCleanup) {
+    number_idle_notifications =
+        Min(number_idle_notifications + 1, kMaxIdleCount);
   } else {
     number_idle_notifications = 0;
     last_gc_count = gc_count_;
@@ -3779,7 +3786,6 @@
     }
     new_space_.Shrink();
     last_gc_count = gc_count_;
-
   } else if (number_idle_notifications == kIdlesBeforeMarkSweep) {
     // Before doing the mark-sweep collections we clear the
     // compilation cache to avoid hanging on to source code and
@@ -3794,7 +3800,6 @@
     CollectAllGarbage(true);
     new_space_.Shrink();
     last_gc_count = gc_count_;
-    number_idle_notifications = 0;
     finished = true;
 
   } else if (contexts_disposed_ > 0) {
@@ -3813,6 +3818,11 @@
       number_idle_notifications = 0;
       uncommit = false;
     }
+  } else if (number_idle_notifications > kIdlesBeforeMarkCompact) {
+    // If we have received more than kIdlesBeforeMarkCompact idle
+    // notifications we do not perform any cleanup because we don't
+    // expect to gain much by doing so.
+    finished = true;
   }
 
   // Make sure that we have no pending context disposals and