8228388: Add information about dirty/skipped card for Merge HCC in G1 log

Collect and print informatio about the number of processed cards during the Merge HCC phase to improve log output.

Reviewed-by: kbarrett, sangheki

Author: Thomas Schatzl

src/hotspot/share/gc/g1/g1GCPhaseTimes.cpp

@@ -86,8 +86,14 @@ G1GCPhaseTimes::G1GCPhaseTimes(STWGCTimer* gc_timer, uint max_gc_threads) :
   _gc_par_phases[MergeLB] = new WorkerDataArray<double>(max_gc_threads, "Log Buffers (ms):");
   if (G1HotCardCache::default_use_cache()) {
     _gc_par_phases[MergeHCC] = new WorkerDataArray<double>(max_gc_threads, "Hot Card Cache (ms):");
+    _merge_hcc_dirty_cards = new WorkerDataArray<size_t>(max_gc_threads, "Dirty Cards:");
+    _gc_par_phases[MergeHCC]->link_thread_work_items(_merge_hcc_dirty_cards, MergeHCCDirtyCards);
+    _merge_hcc_skipped_cards = new WorkerDataArray<size_t>(max_gc_threads, "Skipped Cards:");
+    _gc_par_phases[MergeHCC]->link_thread_work_items(_merge_hcc_skipped_cards, MergeHCCSkippedCards);
   } else {
     _gc_par_phases[MergeHCC] = NULL;
+    _merge_hcc_dirty_cards = NULL;
+    _merge_hcc_skipped_cards = NULL;
   }
   _gc_par_phases[ScanHR] = new WorkerDataArray<double>(max_gc_threads, "Scan Heap Roots (ms):");
   _gc_par_phases[OptScanHR] = new WorkerDataArray<double>(max_gc_threads, "Optional Scan Heap Roots (ms):");

src/hotspot/share/gc/g1/g1GCPhaseTimes.hpp

@@ -100,6 +100,11 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
     ScanHRUsedMemory
   };
 
+  enum GCMergeHCCWorkItems {
+    MergeHCCDirtyCards,
+    MergeHCCSkippedCards
+  };
+
   enum GCMergeLBWorkItems {
     MergeLBProcessedBuffers,
     MergeLBDirtyCards,
@@ -121,6 +126,9 @@ class G1GCPhaseTimes : public CHeapObj<mtGC> {
   WorkerDataArray<size_t>* _merge_rs_merged_fine;
   WorkerDataArray<size_t>* _merge_rs_merged_coarse;
 
+  WorkerDataArray<size_t>* _merge_hcc_dirty_cards;
+  WorkerDataArray<size_t>* _merge_hcc_skipped_cards;
+
   WorkerDataArray<size_t>* _merge_lb_processed_buffers;
   WorkerDataArray<size_t>* _merge_lb_dirty_cards;
   WorkerDataArray<size_t>* _merge_lb_skipped_cards;

src/hotspot/share/gc/g1/g1RemSet.cpp

@@ -1147,6 +1147,9 @@ class G1MergeHeapRootsTask : public AbstractGangTask {
       G1GCParPhaseTimesTracker x(p, G1GCPhaseTimes::MergeHCC, worker_id);
       G1MergeLogBufferCardsClosure cl(g1h, _scan_state);
       g1h->iterate_hcc_closure(&cl, worker_id);
+
+      p->record_thread_work_item(G1GCPhaseTimes::MergeHCC, worker_id, cl.cards_dirty(), G1GCPhaseTimes::MergeHCCDirtyCards);
+      p->record_thread_work_item(G1GCPhaseTimes::MergeHCC, worker_id, cl.cards_skipped(), G1GCPhaseTimes::MergeHCCSkippedCards);
     }
 
     // Now apply the closure to all remaining log entries.

test/hotspot/jtreg/gc/g1/TestNoUseHCC.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2019, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package gc.g1;
+
+/*
+ * @test TestNoUseHCC
+ * @summary Check that G1 survives a GC without HCC enabled
+ * @requires vm.gc.G1
+ * @key gc
+ * @modules java.base/jdk.internal.misc
+ * @library /test/lib
+ * @build sun.hotspot.WhiteBox
+ * @run driver ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -Xlog:gc+phases=debug -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:+UseG1GC -Xmx64M -XX:G1ConcRSLogCacheSize=0 gc.g1.TestNoUseHCC
+ */
+
+import sun.hotspot.WhiteBox;
+
+public class TestNoUseHCC {
+
+    private static final WhiteBox WB = WhiteBox.getWhiteBox();
+
+    public static void main(String [] args) {
+        WB.youngGC();
+    }
+}
+