Use an upper bound for marking time estimation in idle notification.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/571913003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23954 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap/gc-idle-time-handler-unittest.cc

@@ -32,8 +32,8 @@ class GCIdleTimeHandlerTest : public ::testing::Test {
   }
 
   static const size_t kSizeOfObjects = 100 * MB;
-  static const size_t kMarkCompactSpeed = 100 * KB;
-  static const size_t kMarkingSpeed = 100 * KB;
+  static const size_t kMarkCompactSpeed = 200 * KB;
+  static const size_t kMarkingSpeed = 200 * KB;
 
  private:
   GCIdleTimeHandler handler_;
@@ -87,7 +87,7 @@ TEST(GCIdleTimeHandler, EstimateMarkCompactTimeInitial) {
 
 TEST(GCIdleTimeHandler, EstimateMarkCompactTimeNonZero) {
   size_t size = 100 * MB;
-  size_t speed = 10 * KB;
+  size_t speed = 1 * MB;
   size_t time = GCIdleTimeHandler::EstimateMarkCompactTime(size, speed);
   EXPECT_EQ(size / speed, time);
 }

src/heap/gc-idle-time-handler.cc

@@ -10,7 +10,7 @@ namespace v8 {
 namespace internal {
 
 const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
-const size_t GCIdleTimeHandler::kMaxMarkCompactTimeInMs = 1000000;
+const size_t GCIdleTimeHandler::kMaxMarkCompactTimeInMs = 1000;
 const size_t GCIdleTimeHandler::kMinTimeForFinalizeSweeping = 100;
 const int GCIdleTimeHandler::kMaxMarkCompactsInIdleRound = 7;
 const int GCIdleTimeHandler::kIdleScavengeThreshold = 5;
@@ -78,9 +78,10 @@ GCIdleTimeAction GCIdleTimeHandler::Compute(size_t idle_time_in_ms,
     }
   }
   if (heap_state.incremental_marking_stopped) {
-    if (idle_time_in_ms >= EstimateMarkCompactTime(
-                               heap_state.size_of_objects,
-                               heap_state.mark_compact_speed_in_bytes_per_ms) ||
+    size_t estimated_time_in_ms =
+        EstimateMarkCompactTime(heap_state.size_of_objects,
+                                heap_state.mark_compact_speed_in_bytes_per_ms);
+    if (idle_time_in_ms >= estimated_time_in_ms ||
         (heap_state.size_of_objects < kSmallHeapSize &&
          heap_state.contexts_disposed > 0)) {
       // If there are no more than two GCs left in this idle round and we are