Shrink new space and uncommit from space in idle notification during long idle times.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index e9379ac5658c9653cb21023f180d567a2364c068..8dad5b755d3c7d8aae4eda456914feba27b1b463 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -130,7 +130,6 @@ Heap::Heap()
       store_buffer_(this),
       marking_(this),
       incremental_marking_(this),
-      gc_count_at_last_idle_gc_(0),
       full_codegen_bytes_generated_(0),
       crankshaft_codegen_bytes_generated_(0),
       gcs_since_last_deopt_(0),
@@ -4504,17 +4503,8 @@ void Heap::MakeHeapIterable() {
 }
 
 
-void Heap::IdleMarkCompact(const char* message) {
-  bool uncommit = false;
-  if (gc_count_at_last_idle_gc_ == gc_count_) {
-    // No GC since the last full GC, the mutator is probably not active.
-    isolate_->compilation_cache()->Clear();
-    uncommit = true;
-  }
-  CollectAllGarbage(kReduceMemoryFootprintMask, message);
-  gc_idle_time_handler_.NotifyIdleMarkCompact();
-  gc_count_at_last_idle_gc_ = gc_count_;
-  if (uncommit) {
+void Heap::ReduceNewSpaceSize(bool long_idle_time) {
+  if (long_idle_time) {
     new_space_.Shrink();
     UncommitFromSpace();
   }
@@ -4522,7 +4512,7 @@ void Heap::IdleMarkCompact(const char* message) {
 
 
 bool Heap::TryFinalizeIdleIncrementalMarking(
-    double idle_time_in_ms, size_t size_of_objects,
+    bool long_idle_time, double idle_time_in_ms, size_t size_of_objects,
     size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
   if (FLAG_overapproximate_weak_closure &&
       (incremental_marking()->IsReadyToOverApproximateWeakClosure() ||
@@ -4539,6 +4529,7 @@ bool Heap::TryFinalizeIdleIncrementalMarking(
                   static_cast<size_t>(idle_time_in_ms), size_of_objects,
                   final_incremental_mark_compact_speed_in_bytes_per_ms))) {
     CollectAllGarbage(kNoGCFlags, "idle notification: finalize incremental");
+    ReduceNewSpaceSize(long_idle_time);
     return true;
   }
   return false;
@@ -4567,6 +4558,8 @@ bool Heap::IdleNotification(double deadline_in_seconds) {
   HistogramTimerScope idle_notification_scope(
       isolate_->counters()->gc_idle_notification());
   double idle_time_in_ms = deadline_in_ms - MonotonicallyIncreasingTimeInMs();
+  bool long_idle_time = static_cast<size_t>(idle_time_in_ms) >
+                        GCIdleTimeHandler::kMaxFrameRenderingIdleTime;
 
   GCIdleTimeHandler::HeapState heap_state;
   heap_state.contexts_disposed = contexts_disposed_;
@@ -4576,8 +4569,7 @@ bool Heap::IdleNotification(double deadline_in_seconds) {
   heap_state.incremental_marking_stopped = incremental_marking()->IsStopped();
   // TODO(ulan): Start incremental marking only for large heaps.
   intptr_t limit = old_generation_allocation_limit_;
-  if (static_cast<size_t>(idle_time_in_ms) >
-      GCIdleTimeHandler::kMaxFrameRenderingIdleTime) {
+  if (long_idle_time) {
     limit = idle_old_generation_allocation_limit_;
   }
 
@@ -4632,24 +4624,28 @@ bool Heap::IdleNotification(double deadline_in_seconds) {
                !mark_compact_collector_.marking_deque()->IsEmpty());
       if (remaining_idle_time_in_ms > 0.0) {
         action.additional_work = TryFinalizeIdleIncrementalMarking(
-            remaining_idle_time_in_ms, heap_state.size_of_objects,
+            long_idle_time, remaining_idle_time_in_ms,
+            heap_state.size_of_objects,
             heap_state.final_incremental_mark_compact_speed_in_bytes_per_ms);
       }
       break;
     }
     case DO_FULL_GC: {
+      if (long_idle_time) isolate_->compilation_cache()->Clear();

[ulan, 2015/04/28 10:26:47]

Seems too aggressive. This should happen only if mutator is idle for a long
time.

[Hannes Payer (out of office), 2015/04/28 11:11:12]

Done, guarded again with the gc count. But warning: we don't trigger this path
often. This should be fixed with the new idle memory phase.

       if (contexts_disposed_) {
         HistogramTimerScope scope(isolate_->counters()->gc_context());
         CollectAllGarbage(kNoGCFlags, "idle notification: contexts disposed");
-        gc_idle_time_handler_.NotifyIdleMarkCompact();
-        gc_count_at_last_idle_gc_ = gc_count_;
       } else {
-        IdleMarkCompact("idle notification: finalize idle round");
+        CollectAllGarbage(kReduceMemoryFootprintMask,
+                          "idle notification: finalize idle round");
       }
+      ReduceNewSpaceSize(long_idle_time);
+      gc_idle_time_handler_.NotifyIdleMarkCompact();
       break;
     }
     case DO_SCAVENGE:
       CollectGarbage(NEW_SPACE, "idle notification: scavenge");
+      ReduceNewSpaceSize(idle_time_in_ms);
       break;
     case DO_FINALIZE_SWEEPING:
       mark_compact_collector()->EnsureSweepingCompleted();