Re-land: Distinguish beween final incremental mark-compact and full mark-compact event in IdleNotif…

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

Index: src/heap/gc-idle-time-handler.cc
diff --git a/src/heap/gc-idle-time-handler.cc b/src/heap/gc-idle-time-handler.cc
index 4103b78a348c81e3be0b60b030a04d107eaa4ea1..730d2bb2568888ca8208e875c0ab6587cab101b1 100644
--- a/src/heap/gc-idle-time-handler.cc
+++ b/src/heap/gc-idle-time-handler.cc
@@ -11,6 +11,7 @@ namespace internal {
 
 const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
 const size_t GCIdleTimeHandler::kMaxMarkCompactTimeInMs = 1000;
+const size_t GCIdleTimeHandler::kMaxFinalIncrementalMarkCompactTimeInMs = 1000;
 const size_t GCIdleTimeHandler::kMinTimeForFinalizeSweeping = 100;
 const int GCIdleTimeHandler::kMaxMarkCompactsInIdleRound = 7;
 const int GCIdleTimeHandler::kIdleScavengeThreshold = 5;
@@ -84,8 +85,7 @@ size_t GCIdleTimeHandler::EstimateMarkingStepSize(
 size_t GCIdleTimeHandler::EstimateMarkCompactTime(
     size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms) {
   // TODO(hpayer): Be more precise about the type of mark-compact event. It
-  // makes a huge difference if it is incremental or non-incremental and if
-  // compaction is happening.
+  // makes a huge difference if compaction is happening.
   if (mark_compact_speed_in_bytes_per_ms == 0) {
     mark_compact_speed_in_bytes_per_ms = kInitialConservativeMarkCompactSpeed;
   }
@@ -94,6 +94,19 @@ size_t GCIdleTimeHandler::EstimateMarkCompactTime(
 }
 
 
+size_t GCIdleTimeHandler::EstimateFinalIncrementalMarkCompactTime(
+    size_t size_of_objects,
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
+  if (final_incremental_mark_compact_speed_in_bytes_per_ms == 0) {
+    final_incremental_mark_compact_speed_in_bytes_per_ms =
+        kInitialConservativeFinalIncrementalMarkCompactSpeed;
+  }
+  size_t result =
+      size_of_objects / final_incremental_mark_compact_speed_in_bytes_per_ms;
+  return Min(result, kMaxFinalIncrementalMarkCompactTimeInMs);
+}
+
+
 bool GCIdleTimeHandler::ShouldDoScavenge(
     size_t idle_time_in_ms, size_t new_space_size, size_t used_new_space_size,
     size_t scavenge_speed_in_bytes_per_ms,
@@ -149,6 +162,16 @@ bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
 }
 
 
+bool GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
+    size_t idle_time_in_ms, size_t size_of_objects,
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
+  return idle_time_in_ms >=
+         EstimateFinalIncrementalMarkCompactTime(
+             size_of_objects,
+             final_incremental_mark_compact_speed_in_bytes_per_ms);
+}
+
+
 // The following logic is implemented by the controller:
 // (1) If we don't have any idle time, do nothing, unless a context was
 // disposed, incremental marking is stopped, and the heap is small. Then do