[heap] MinorMC: Parallel marking

Bug: chromium:651354
Change-Id: I9df2ca542112f04787987bda67657fc4015787b5
Reviewed-on: https://chromium-review.googlesource.com/506152
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45363}

src/flag-definitions.h

@@ -671,6 +671,10 @@ DEFINE_BOOL(incremental_marking_wrappers, true,
             "use incremental marking for marking wrappers")
 DEFINE_BOOL(concurrent_marking, V8_CONCURRENT_MARKING, "use concurrent marking")
 DEFINE_BOOL(trace_concurrent_marking, false, "trace concurrent marking")
+DEFINE_BOOL(minor_mc_parallel_marking, true,
+            "use parallel marking for the young generation")
+DEFINE_BOOL(trace_minor_mc_parallel_marking, false,
+            "trace parallel marking for the young generation")
 DEFINE_INT(min_progress_during_incremental_marking_finalization, 32,
            "keep finalizing incremental marking as long as we discover at "
            "least this many unmarked objects")
@@ -1300,6 +1304,7 @@ DEFINE_BOOL(single_threaded, false, "disable the use of background tasks")
 DEFINE_NEG_IMPLICATION(single_threaded, concurrent_recompilation)
 DEFINE_NEG_IMPLICATION(single_threaded, concurrent_marking)
 DEFINE_NEG_IMPLICATION(single_threaded, concurrent_sweeping)
+DEFINE_NEG_IMPLICATION(single_threaded, minor_mc_parallel_marking)
 DEFINE_NEG_IMPLICATION(single_threaded, parallel_compaction)
 DEFINE_NEG_IMPLICATION(single_threaded, parallel_pointer_update)
 DEFINE_NEG_IMPLICATION(single_threaded, concurrent_store_buffer)

src/heap/gc-tracer.cc

@@ -531,8 +531,8 @@ void GCTracer::PrintNVP() const {
           "finish_sweeping=%.2f "
           "mark=%.2f "
           "mark.identify_global_handles=%.2f "
+          "mark.seed=%.2f "
           "mark.roots=%.2f "
-          "mark.old_to_new=%.2f "
           "mark.weak=%.2f "
           "mark.global_handles=%.2f "
           "clear=%.2f "
@@ -552,8 +552,8 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MINOR_MC_SWEEPING],
           current_.scopes[Scope::MINOR_MC_MARK],
           current_.scopes[Scope::MINOR_MC_MARK_IDENTIFY_GLOBAL_HANDLES],
+          current_.scopes[Scope::MINOR_MC_MARK_SEED],
           current_.scopes[Scope::MINOR_MC_MARK_ROOTS],
-          current_.scopes[Scope::MINOR_MC_MARK_OLD_TO_NEW_POINTERS],
           current_.scopes[Scope::MINOR_MC_MARK_WEAK],
           current_.scopes[Scope::MINOR_MC_MARK_GLOBAL_HANDLES],
           current_.scopes[Scope::MINOR_MC_CLEAR],

src/heap/gc-tracer.h

@@ -101,7 +101,7 @@ enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
   F(MINOR_MC_MARK)                                    \
   F(MINOR_MC_MARK_GLOBAL_HANDLES)                     \
   F(MINOR_MC_MARK_IDENTIFY_GLOBAL_HANDLES)            \
-  F(MINOR_MC_MARK_OLD_TO_NEW_POINTERS)                \
+  F(MINOR_MC_MARK_SEED)                               \
   F(MINOR_MC_MARK_ROOTS)                              \
   F(MINOR_MC_MARK_WEAK)                               \
   F(MINOR_MC_MARKING_DEQUE)                           \

src/heap/mark-compact.h

@@ -360,14 +360,29 @@ class MinorMarkCompactCollector final : public MarkCompactCollectorBase {
   void CleanupSweepToIteratePages();
 
  private:
+  class RootMarkingVisitorSeedOnly;
   class RootMarkingVisitor;
 
-  inline MarkingDeque* marking_deque() { return &marking_deque_; }
+  static const int kNumMarkers = 4;
+  static const int kMainMarker = 0;
+
+  inline MarkingDeque* marking_deque(int index) {
+    DCHECK_LT(index, kNumMarkers);
+    return marking_deque_[index];
+  }
+
+  inline YoungGenerationMarkingVisitor* marking_visitor(int index) {
+    DCHECK_LT(index, kNumMarkers);
+    return marking_visitor_[index];
+  }
 
   SlotCallbackResult CheckAndMarkObject(Heap* heap, Address slot_address);
   void MarkLiveObjects() override;
+  void MarkRootSetInParallel();
   void ProcessMarkingDeque() override;
   void EmptyMarkingDeque() override;
+  void EmptySpecificMarkingDeque(MarkingDeque* marking_deque,
+                                 YoungGenerationMarkingVisitor* visitor);
   void ClearNonLiveReferences() override;
 
   void EvacuatePrologue() override;
@@ -376,12 +391,16 @@ class MinorMarkCompactCollector final : public MarkCompactCollectorBase {
   void EvacuatePagesInParallel() override;
   void UpdatePointersAfterEvacuation() override;
 
-  MarkingDeque marking_deque_;
-  YoungGenerationMarkingVisitor* marking_visitor_;
+  int NumberOfMarkingTasks();
+
+  MarkingDeque* marking_deque_[kNumMarkers];
+  YoungGenerationMarkingVisitor* marking_visitor_[kNumMarkers];
   base::Semaphore page_parallel_job_semaphore_;
   List<Page*> new_space_evacuation_pages_;
   std::vector<Page*> sweep_to_iterate_pages_;
 
+  friend class MarkYoungGenerationJobTraits;
+  friend class YoungGenerationMarkingTask;
   friend class YoungGenerationMarkingVisitor;
 };