8137022: Concurrent refinement thread adjustment and (de-)activation …

…suboptimal

8155996: Improve concurrent refinement green zone control
8134303: Introduce -XX:-G1UseConcRefinement

Reviewed-by: sjohanss, tschatzl, iwalulya, ayang

src/hotspot/share/gc/g1/g1Analytics.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -82,6 +82,7 @@ G1Analytics::G1Analytics(const G1Predictions* predictor) :
     _mixed_rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
     _concurrent_refine_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
     _dirtied_cards_rate_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
+    _dirtied_cards_in_thread_buffers_seq(new TruncatedSeq(TruncatedSeqLength)),
     _young_card_scan_to_merge_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
     _mixed_card_scan_to_merge_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
     _young_cost_per_card_scan_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
@@ -172,6 +173,10 @@ void G1Analytics::report_dirtied_cards_rate_ms(double cards_per_ms) {
   _dirtied_cards_rate_ms_seq->add(cards_per_ms);
 }
 
+void G1Analytics::report_dirtied_cards_in_thread_buffers(size_t cards) {
+  _dirtied_cards_in_thread_buffers_seq->add(double(cards));
+}
+
 void G1Analytics::report_cost_per_card_scan_ms(double cost_per_card_ms, bool for_young_only_phase) {
   if  (for_young_only_phase) {
     _young_cost_per_card_scan_ms_seq->add(cost_per_card_ms);
@@ -256,6 +261,10 @@ double G1Analytics::predict_dirtied_cards_rate_ms() const {
   return predict_zero_bounded(_dirtied_cards_rate_ms_seq);
 }
 
+size_t G1Analytics::predict_dirtied_cards_in_thread_buffers() const {
+  return predict_size(_dirtied_cards_in_thread_buffers_seq);
+}
+
 size_t G1Analytics::predict_scan_card_num(size_t rs_length, bool for_young_only_phase) const {
   if (for_young_only_phase || !enough_samples_available(_mixed_card_scan_to_merge_ratio_seq)) {
     return (size_t)(rs_length * predict_in_unit_interval(_young_card_scan_to_merge_ratio_seq));

src/hotspot/share/gc/g1/g1Analytics.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,6 +49,7 @@ class G1Analytics: public CHeapObj<mtGC> {
   TruncatedSeq* _mixed_rs_length_diff_seq;
   TruncatedSeq* _concurrent_refine_rate_ms_seq;
   TruncatedSeq* _dirtied_cards_rate_ms_seq;
+  TruncatedSeq* _dirtied_cards_in_thread_buffers_seq;
   // The ratio between the number of scanned cards and actually merged cards, for
   // young-only and mixed gcs.
   TruncatedSeq* _young_card_scan_to_merge_ratio_seq;
@@ -126,6 +127,7 @@ class G1Analytics: public CHeapObj<mtGC> {
   void report_alloc_rate_ms(double alloc_rate);
   void report_concurrent_refine_rate_ms(double cards_per_ms);
   void report_dirtied_cards_rate_ms(double cards_per_ms);
+  void report_dirtied_cards_in_thread_buffers(size_t num_cards);
   void report_cost_per_card_scan_ms(double cost_per_remset_card_ms, bool for_young_only_phase);
   void report_cost_per_card_merge_ms(double cost_per_card_ms, bool for_young_only_phase);
   void report_card_scan_to_merge_ratio(double cards_per_entry_ratio, bool for_young_only_phase);
@@ -142,6 +144,7 @@ class G1Analytics: public CHeapObj<mtGC> {
 
   double predict_concurrent_refine_rate_ms() const;
   double predict_dirtied_cards_rate_ms() const;
+  size_t predict_dirtied_cards_in_thread_buffers() const;
 
   // Predict how many of the given remembered set of length rs_length will add to
   // the number of total cards scanned.

src/hotspot/share/gc/g1/g1Arguments.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2022, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -177,7 +177,13 @@ void G1Arguments::initialize() {
     FLAG_SET_ERGO(ParallelGCThreads, 1);
   }
 
-  if (FLAG_IS_DEFAULT(G1ConcRefinementThreads)) {
+  if (!G1UseConcRefinement) {
+    if (!FLAG_IS_DEFAULT(G1ConcRefinementThreads)) {
+      log_warning(gc, ergo)("Ignoring -XX:G1ConcRefinementThreads "
+                            "because of -XX:-G1UseConcRefinement");
+    }
+    FLAG_SET_DEFAULT(G1ConcRefinementThreads, 0);
+  } else if (FLAG_IS_DEFAULT(G1ConcRefinementThreads)) {
     FLAG_SET_ERGO(G1ConcRefinementThreads, ParallelGCThreads);
   }
 

src/hotspot/share/gc/g1/g1CollectedHeap.cpp

@@ -1533,7 +1533,7 @@ G1RegionToSpaceMapper* G1CollectedHeap::create_aux_memory_mapper(const char* des
 
 jint G1CollectedHeap::initialize_concurrent_refinement() {
   jint ecode = JNI_OK;
-  _cr = G1ConcurrentRefine::create(&ecode);
+  _cr = G1ConcurrentRefine::create(policy(), &ecode);
   return ecode;
 }
 
@@ -1713,9 +1713,6 @@ jint G1CollectedHeap::initialize() {
     return ecode;
   }
 
-  // Initialize and schedule sampling task on service thread.
-  _rem_set->initialize_sampling_task(service_thread());
-
   // Create and schedule the periodic gc task on the service thread.
   _periodic_gc_task = new G1PeriodicGCTask("Periodic GC Task");
   _service_thread->register_task(_periodic_gc_task);