changeset 4919:03ecf4784ddd

8014078: G1: improve remembered set summary information by providing per region type information Summary: Add memory consumption breakdown on a per region type in the G1 remembered set summary statistics. This simplifies remembered set memory consumption analysis. Reviewed-by: brutisso
author tschatzl
date Thu, 19 Dec 2013 09:22:30 +0100
parents 4923cab3640c
children f6c3b2632e00
files src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp src/share/vm/gc_implementation/g1/g1RemSet.cpp src/share/vm/gc_implementation/g1/g1RemSet.hpp src/share/vm/gc_implementation/g1/g1RemSetSummary.cpp test/gc/g1/TestSummarizeRSetStats.java test/gc/g1/TestSummarizeRSetStatsPerRegion.java test/gc/g1/TestSummarizeRSetStatsTools.java
diffstat 7 files changed, 429 insertions(+), 183 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Dec 19 09:22:30 2013 +0100
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Dec 19 09:22:30 2013 +0100
@@ -3704,6 +3704,11 @@
   AllocationProfiler::iterate_since_last_gc();
   // Fill TLAB's and such
   ensure_parsability(true);
+
+  if (G1SummarizeRSetStats && (G1SummarizeRSetStatsPeriod > 0) &&
+      (total_collections() % G1SummarizeRSetStatsPeriod == 0)) {
+    g1_rem_set()->print_periodic_summary_info("Before GC RS summary");
+  }
 }
 
 void G1CollectedHeap::gc_epilogue(bool full /* Ignored */) {
@@ -3712,7 +3717,7 @@
       (G1SummarizeRSetStatsPeriod > 0) &&
       // we are at the end of the GC. Total collections has already been increased.
       ((total_collections() - 1) % G1SummarizeRSetStatsPeriod == 0)) {
-    g1_rem_set()->print_periodic_summary_info();
+    g1_rem_set()->print_periodic_summary_info("After GC RS summary");
   }
 
   // FIXME: what is this about?
--- a/src/share/vm/gc_implementation/g1/g1RemSet.cpp	Thu Dec 19 09:22:30 2013 +0100
+++ b/src/share/vm/gc_implementation/g1/g1RemSet.cpp	Thu Dec 19 09:22:30 2013 +0100
@@ -734,12 +734,12 @@
   return has_refs_into_cset;
 }
 
-void G1RemSet::print_periodic_summary_info() {
+void G1RemSet::print_periodic_summary_info(const char* header) {
   G1RemSetSummary current;
   current.initialize(this, n_workers());
 
   _prev_period_summary.subtract_from(&current);
-  print_summary_info(&_prev_period_summary);
+  print_summary_info(&_prev_period_summary, header);
 
   _prev_period_summary.set(&current);
 }
--- a/src/share/vm/gc_implementation/g1/g1RemSet.hpp	Thu Dec 19 09:22:30 2013 +0100
+++ b/src/share/vm/gc_implementation/g1/g1RemSet.hpp	Thu Dec 19 09:22:30 2013 +0100
@@ -145,7 +145,7 @@
   virtual void print_summary_info();
 
   // Print accumulated summary info from the last time called.
-  virtual void print_periodic_summary_info();
+  virtual void print_periodic_summary_info(const char* header);
 
   // Prepare remembered set for verification.
   virtual void prepare_for_verify();
--- a/src/share/vm/gc_implementation/g1/g1RemSetSummary.cpp	Thu Dec 19 09:22:30 2013 +0100
+++ b/src/share/vm/gc_implementation/g1/g1RemSetSummary.cpp	Thu Dec 19 09:22:30 2013 +0100
@@ -125,25 +125,115 @@
   _sampling_thread_vtime = other->sampling_thread_vtime() - _sampling_thread_vtime;
 }
 
+static double percent_of(size_t numerator, size_t denominator) {
+  if (denominator != 0) {
+    return (double)numerator / denominator * 100.0f;
+  } else {
+    return 0.0f;
+  }
+}
+
+static size_t round_to_K(size_t value) {
+  return value / K;
+}
+
+class RegionTypeCounter VALUE_OBJ_CLASS_SPEC {
+private:
+  const char* _name;
+
+  size_t _rs_mem_size;
+  size_t _cards_occupied;
+  size_t _amount;
+
+  size_t _code_root_mem_size;
+  size_t _code_root_elems;
+
+  double rs_mem_size_percent_of(size_t total) {
+    return percent_of(_rs_mem_size, total);
+  }
+
+  double cards_occupied_percent_of(size_t total) {
+    return percent_of(_cards_occupied, total);
+  }
+
+  double code_root_mem_size_percent_of(size_t total) {
+    return percent_of(_code_root_mem_size, total);
+  }
+
+  double code_root_elems_percent_of(size_t total) {
+    return percent_of(_code_root_elems, total);
+  }
+
+  size_t amount() const { return _amount; }
+
+public:
+
+  RegionTypeCounter(const char* name) : _name(name), _rs_mem_size(0), _cards_occupied(0),
+    _amount(0), _code_root_mem_size(0), _code_root_elems(0) { }
+
+  void add(size_t rs_mem_size, size_t cards_occupied, size_t code_root_mem_size,
+    size_t code_root_elems) {
+    _rs_mem_size += rs_mem_size;
+    _cards_occupied += cards_occupied;
+    _code_root_mem_size += code_root_mem_size;
+    _code_root_elems += code_root_elems;
+    _amount++;
+  }
+
+  size_t rs_mem_size() const { return _rs_mem_size; }
+  size_t cards_occupied() const { return _cards_occupied; }
+
+  size_t code_root_mem_size() const { return _code_root_mem_size; }
+  size_t code_root_elems() const { return _code_root_elems; }
+
+  void print_rs_mem_info_on(outputStream * out, size_t total) {
+    out->print_cr("    %8dK (%5.1f%%) by %zd %s regions", round_to_K(rs_mem_size()), rs_mem_size_percent_of(total), amount(), _name);
+  }
+
+  void print_cards_occupied_info_on(outputStream * out, size_t total) {
+    out->print_cr("     %8d (%5.1f%%) entries by %zd %s regions", cards_occupied(), cards_occupied_percent_of(total), amount(), _name);
+  }
+
+  void print_code_root_mem_info_on(outputStream * out, size_t total) {
+    out->print_cr("    %8dK (%5.1f%%) by %zd %s regions", round_to_K(code_root_mem_size()), code_root_mem_size_percent_of(total), amount(), _name);
+  }
+
+  void print_code_root_elems_info_on(outputStream * out, size_t total) {
+    out->print_cr("     %8d (%5.1f%%) elements by %zd %s regions", code_root_elems(), code_root_elems_percent_of(total), amount(), _name);
+  }
+};
+
+
 class HRRSStatsIter: public HeapRegionClosure {
-  size_t _occupied;
+private:
+  RegionTypeCounter _young;
+  RegionTypeCounter _humonguous;
+  RegionTypeCounter _free;
+  RegionTypeCounter _old;
+  RegionTypeCounter _all;
 
-  size_t _total_rs_mem_sz;
   size_t _max_rs_mem_sz;
   HeapRegion* _max_rs_mem_sz_region;
 
-  size_t _total_code_root_mem_sz;
+  size_t total_rs_mem_sz() const            { return _all.rs_mem_size(); }
+  size_t total_cards_occupied() const       { return _all.cards_occupied(); }
+
+  size_t max_rs_mem_sz() const              { return _max_rs_mem_sz; }
+  HeapRegion* max_rs_mem_sz_region() const  { return _max_rs_mem_sz_region; }
+
   size_t _max_code_root_mem_sz;
   HeapRegion* _max_code_root_mem_sz_region;
+
+  size_t total_code_root_mem_sz() const     { return _all.code_root_mem_size(); }
+  size_t total_code_root_elems() const      { return _all.code_root_elems(); }
+
+  size_t max_code_root_mem_sz() const       { return _max_code_root_mem_sz; }
+  HeapRegion* max_code_root_mem_sz_region() const { return _max_code_root_mem_sz_region; }
+
 public:
-  HRRSStatsIter() :
-    _occupied(0),
-    _total_rs_mem_sz(0),
-    _max_rs_mem_sz(0),
-    _max_rs_mem_sz_region(NULL),
-    _total_code_root_mem_sz(0),
-    _max_code_root_mem_sz(0),
-    _max_code_root_mem_sz_region(NULL)
+  HRRSStatsIter() : _all("All"), _young("Young"), _humonguous("Humonguous"),
+    _free("Free"), _old("Old"), _max_code_root_mem_sz_region(NULL), _max_rs_mem_sz_region(NULL),
+    _max_rs_mem_sz(0), _max_code_root_mem_sz(0)
   {}
 
   bool doHeapRegion(HeapRegion* r) {
@@ -156,46 +246,95 @@
       _max_rs_mem_sz = rs_mem_sz;
       _max_rs_mem_sz_region = r;
     }
-    _total_rs_mem_sz += rs_mem_sz;
-
+    size_t occupied_cards = hrrs->occupied();
     size_t code_root_mem_sz = hrrs->strong_code_roots_mem_size();
-    if (code_root_mem_sz > _max_code_root_mem_sz) {
-      _max_code_root_mem_sz = code_root_mem_sz;
+    if (code_root_mem_sz > max_code_root_mem_sz()) {
       _max_code_root_mem_sz_region = r;
     }
-    _total_code_root_mem_sz += code_root_mem_sz;
+    size_t code_root_elems = hrrs->strong_code_roots_list_length();
 
-    size_t occ = hrrs->occupied();
-    _occupied += occ;
+    RegionTypeCounter* current = NULL;
+    if (r->is_young()) {
+      current = &_young;
+    } else if (r->isHumongous()) {
+      current = &_humonguous;
+    } else if (r->is_empty()) {
+      current = &_free;
+    } else {
+      current = &_old;
+    }
+    current->add(rs_mem_sz, occupied_cards, code_root_mem_sz, code_root_elems);
+    _all.add(rs_mem_sz, occupied_cards, code_root_mem_sz, code_root_elems);
+
     return false;
   }
-  size_t total_rs_mem_sz() { return _total_rs_mem_sz; }
-  size_t max_rs_mem_sz() { return _max_rs_mem_sz; }
-  HeapRegion* max_rs_mem_sz_region() { return _max_rs_mem_sz_region; }
-  size_t total_code_root_mem_sz() { return _total_code_root_mem_sz; }
-  size_t max_code_root_mem_sz() { return _max_code_root_mem_sz; }
-  HeapRegion* max_code_root_mem_sz_region() { return _max_code_root_mem_sz_region; }
-  size_t occupied() { return _occupied; }
+
+  void print_summary_on(outputStream* out) {
+    RegionTypeCounter* counters[] = { &_young, &_humonguous, &_free, &_old, NULL };
+
+    out->print_cr("\n Current rem set statistics");
+    out->print_cr("  Total per region rem sets sizes = "SIZE_FORMAT"K."
+                  " Max = "SIZE_FORMAT"K.",
+                  round_to_K(total_rs_mem_sz()), round_to_K(max_rs_mem_sz()));
+    for (RegionTypeCounter** current = &counters[0]; *current != NULL; current++) {
+      (*current)->print_rs_mem_info_on(out, total_rs_mem_sz());
+    }
+
+    out->print_cr("   Static structures = "SIZE_FORMAT"K,"
+                  " free_lists = "SIZE_FORMAT"K.",
+                  round_to_K(HeapRegionRemSet::static_mem_size()),
+                  round_to_K(HeapRegionRemSet::fl_mem_size()));
+
+    out->print_cr("    "SIZE_FORMAT" occupied cards represented.",
+                  total_cards_occupied());
+    for (RegionTypeCounter** current = &counters[0]; *current != NULL; current++) {
+      (*current)->print_cards_occupied_info_on(out, total_cards_occupied());
+    }
+
+    // Largest sized rem set region statistics
+    HeapRegionRemSet* rem_set = max_rs_mem_sz_region()->rem_set();
+    out->print_cr("    Region with largest rem set = "HR_FORMAT", "
+                  "size = "SIZE_FORMAT "K, occupied = "SIZE_FORMAT"K.",
+                  HR_FORMAT_PARAMS(max_rs_mem_sz_region()),
+                  round_to_K(rem_set->mem_size()),
+                  round_to_K(rem_set->occupied()));
+
+    // Strong code root statistics
+    HeapRegionRemSet* max_code_root_rem_set = max_code_root_mem_sz_region()->rem_set();
+    out->print_cr("  Total heap region code root sets sizes = "SIZE_FORMAT"K."
+                  "  Max = "SIZE_FORMAT"K.",
+                  round_to_K(total_code_root_mem_sz()),
+                  round_to_K(max_code_root_rem_set->strong_code_roots_mem_size()));
+    for (RegionTypeCounter** current = &counters[0]; *current != NULL; current++) {
+      (*current)->print_code_root_mem_info_on(out, total_code_root_mem_sz());
+    }
+
+    out->print_cr("    "SIZE_FORMAT" code roots represented.",
+                  total_code_root_elems());
+    for (RegionTypeCounter** current = &counters[0]; *current != NULL; current++) {
+      (*current)->print_code_root_elems_info_on(out, total_code_root_elems());
+    }
+
+    out->print_cr("    Region with largest amount of code roots = "HR_FORMAT", "
+                  "size = "SIZE_FORMAT "K, num_elems = "SIZE_FORMAT".",
+                  HR_FORMAT_PARAMS(max_code_root_mem_sz_region()),
+                  round_to_K(max_code_root_rem_set->strong_code_roots_mem_size()),
+                  round_to_K(max_code_root_rem_set->strong_code_roots_list_length()));
+  }
 };
 
-double calc_percentage(size_t numerator, size_t denominator) {
-  if (denominator != 0) {
-    return (double)numerator / denominator * 100.0;
-  } else {
-    return 0.0f;
-  }
-}
-
 void G1RemSetSummary::print_on(outputStream* out) {
-  out->print_cr("\n Concurrent RS processed "SIZE_FORMAT" cards",
+  out->print_cr("\n Recent concurrent refinement statistics");
+  out->print_cr("  Processed "SIZE_FORMAT" cards",
                 num_concurrent_refined_cards());
   out->print_cr("  Of %d completed buffers:", num_processed_buf_total());
   out->print_cr("     %8d (%5.1f%%) by concurrent RS threads.",
                 num_processed_buf_total(),
-                calc_percentage(num_processed_buf_rs_threads(), num_processed_buf_total()));
+                percent_of(num_processed_buf_rs_threads(), num_processed_buf_total()));
   out->print_cr("     %8d (%5.1f%%) by mutator threads.",
                 num_processed_buf_mutator(),
-                calc_percentage(num_processed_buf_mutator(), num_processed_buf_total()));
+                percent_of(num_processed_buf_mutator(), num_processed_buf_total()));
+  out->print_cr("  Did %d coarsenings.", num_coarsenings());
   out->print_cr("  Concurrent RS threads times (s)");
   out->print("     ");
   for (uint i = 0; i < _num_vtimes; i++) {
@@ -207,33 +346,5 @@
 
   HRRSStatsIter blk;
   G1CollectedHeap::heap()->heap_region_iterate(&blk);
-  // RemSet stats
-  out->print_cr("  Total heap region rem set sizes = "SIZE_FORMAT"K."
-                "  Max = "SIZE_FORMAT"K.",
-                blk.total_rs_mem_sz()/K, blk.max_rs_mem_sz()/K);
-  out->print_cr("  Static structures = "SIZE_FORMAT"K,"
-                " free_lists = "SIZE_FORMAT"K.",
-                HeapRegionRemSet::static_mem_size() / K,
-                HeapRegionRemSet::fl_mem_size() / K);
-  out->print_cr("    "SIZE_FORMAT" occupied cards represented.",
-                blk.occupied());
-  HeapRegion* max_rs_mem_sz_region = blk.max_rs_mem_sz_region();
-  HeapRegionRemSet* max_rs_rem_set = max_rs_mem_sz_region->rem_set();
-  out->print_cr("    Max size region = "HR_FORMAT", "
-                "size = "SIZE_FORMAT "K, occupied = "SIZE_FORMAT"K.",
-                HR_FORMAT_PARAMS(max_rs_mem_sz_region),
-                (max_rs_rem_set->mem_size() + K - 1)/K,
-                (max_rs_rem_set->occupied() + K - 1)/K);
-  out->print_cr("    Did %d coarsenings.", num_coarsenings());
-  // Strong code root stats
-  out->print_cr("  Total heap region code-root set sizes = "SIZE_FORMAT"K."
-                "  Max = "SIZE_FORMAT"K.",
-                blk.total_code_root_mem_sz()/K, blk.max_code_root_mem_sz()/K);
-  HeapRegion* max_code_root_mem_sz_region = blk.max_code_root_mem_sz_region();
-  HeapRegionRemSet* max_code_root_rem_set = max_code_root_mem_sz_region->rem_set();
-  out->print_cr("    Max size region = "HR_FORMAT", "
-                "size = "SIZE_FORMAT "K, num_elems = "SIZE_FORMAT".",
-                HR_FORMAT_PARAMS(max_code_root_mem_sz_region),
-                (max_code_root_rem_set->strong_code_roots_mem_size() + K - 1)/K,
-                (max_code_root_rem_set->strong_code_roots_list_length()));
+  blk.print_summary_on(out);
 }
--- a/test/gc/g1/TestSummarizeRSetStats.java	Thu Dec 19 09:22:30 2013 +0100
+++ b/test/gc/g1/TestSummarizeRSetStats.java	Thu Dec 19 09:22:30 2013 +0100
@@ -25,140 +25,61 @@
  * @test TestSummarizeRSetStats.java
  * @bug 8013895
  * @library /testlibrary
- * @build TestSummarizeRSetStats
+ * @build TestSummarizeRSetStatsTools TestSummarizeRSetStats
  * @summary Verify output of -XX:+G1SummarizeRSetStats
  * @run main TestSummarizeRSetStats
  *
  * Test the output of G1SummarizeRSetStats in conjunction with G1SummarizeRSetStatsPeriod.
  */
 
-import com.oracle.java.testlibrary.*;
-import java.lang.Thread;
-import java.util.ArrayList;
-import java.util.Arrays;
-
-class RunSystemGCs {
-    // 4M size, both are directly allocated into the old gen
-    static Object[] largeObject1 = new Object[1024 * 1024];
-    static Object[] largeObject2 = new Object[1024 * 1024];
-
-    static int[] temp;
-
-    public static void main(String[] args) {
-        // create some cross-references between these objects
-        for (int i = 0; i < largeObject1.length; i++) {
-            largeObject1[i] = largeObject2;
-        }
-
-        for (int i = 0; i < largeObject2.length; i++) {
-            largeObject2[i] = largeObject1;
-        }
-
-        int numGCs = Integer.parseInt(args[0]);
-
-        if (numGCs > 0) {
-            // try to force a minor collection: the young gen is 4M, the
-            // amount of data allocated below is roughly that (4*1024*1024 +
-            // some header data)
-            for (int i = 0; i < 1024 ; i++) {
-                temp = new int[1024];
-            }
-        }
-
-        for (int i = 0; i < numGCs - 1; i++) {
-            System.gc();
-        }
-    }
-}
-
 public class TestSummarizeRSetStats {
 
-    public static String runTest(String[] additionalArgs, int numGCs) throws Exception {
-        ArrayList<String> finalargs = new ArrayList<String>();
-        String[] defaultArgs = new String[] {
-            "-XX:+UseG1GC",
-            "-Xmn4m",
-            "-Xmx20m",
-            "-XX:InitiatingHeapOccupancyPercent=100", // we don't want the additional GCs due to initial marking
-            "-XX:+PrintGC",
-            "-XX:+UnlockDiagnosticVMOptions",
-            "-XX:G1HeapRegionSize=1M",
-        };
-
-        finalargs.addAll(Arrays.asList(defaultArgs));
-
-        if (additionalArgs != null) {
-            finalargs.addAll(Arrays.asList(additionalArgs));
-        }
-
-        finalargs.add(RunSystemGCs.class.getName());
-        finalargs.add(String.valueOf(numGCs));
-
-        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
-            finalargs.toArray(new String[0]));
-        OutputAnalyzer output = new OutputAnalyzer(pb.start());
-
-        output.shouldHaveExitValue(0);
-
-        String result = output.getStdout();
-        return result;
-    }
-
-    private static void expectStatistics(String result, int expectedCumulative, int expectedPeriodic) throws Exception {
-        int actualTotal = result.split("Concurrent RS processed").length - 1;
-        int actualCumulative = result.split("Cumulative RS summary").length - 1;
-
-        if (expectedCumulative != actualCumulative) {
-            throw new Exception("Incorrect amount of RSet summaries at the end. Expected " + expectedCumulative + ", got " + actualCumulative);
-        }
-
-        if (expectedPeriodic != (actualTotal - actualCumulative)) {
-            throw new Exception("Incorrect amount of per-period RSet summaries at the end. Expected " + expectedPeriodic + ", got " + (actualTotal - actualCumulative));
-        }
-    }
-
     public static void main(String[] args) throws Exception {
         String result;
 
-        // no RSet statistics output
-        result = runTest(null, 0);
-        expectStatistics(result, 0, 0);
+        if (!TestSummarizeRSetStatsTools.testingG1GC()) {
+            return;
+        }
 
-        // no RSet statistics output
-        result = runTest(null, 2);
-        expectStatistics(result, 0, 0);
+        // no remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(null, 0);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 0, 0);
 
-        // no RSet statistics output
-        result = runTest(new String[] { "-XX:G1SummarizeRSetStatsPeriod=1" }, 3);
-        expectStatistics(result, 0, 0);
+        // no remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(null, 2);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 0, 0);
 
-        // single RSet statistics output at the end
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats" }, 0);
-        expectStatistics(result, 1, 0);
+        // no remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:G1SummarizeRSetStatsPeriod=1" }, 3);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 0, 0);
 
-        // single RSet statistics output at the end
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats" }, 2);
-        expectStatistics(result, 1, 0);
+        // single remembered set summary output at the end
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats" }, 0);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 0);
 
-        // single RSet statistics output
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 0);
-        expectStatistics(result, 1, 0);
+        // single remembered set summary output at the end
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats" }, 2);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 0);
 
-        // two times RSet statistics output
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 1);
-        expectStatistics(result, 1, 1);
+        // single remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 0);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 0);
 
-        // four times RSet statistics output
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 3);
-        expectStatistics(result, 1, 3);
+        // two times remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 1);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 2);
 
-        // three times RSet statistics output
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=2" }, 3);
-        expectStatistics(result, 1, 2);
+        // four times remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 3);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 6);
 
-        // single RSet statistics output
-        result = runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=100" }, 3);
-        expectStatistics(result, 1, 1);
+        // three times remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=2" }, 3);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 4);
+
+        // single remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=100" }, 3);
+        TestSummarizeRSetStatsTools.expectRSetSummaries(result, 1, 2);
     }
 }
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/gc/g1/TestSummarizeRSetStatsPerRegion.java	Thu Dec 19 09:22:30 2013 +0100
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2013, 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.
+ */
+
+/*
+ * @test TestSummarizeRSetStatsPerRegion.java
+ * @bug 8014078
+ * @library /testlibrary
+ * @build TestSummarizeRSetStatsTools TestSummarizeRSetStatsPerRegion
+ * @summary Verify output of -XX:+G1SummarizeRSetStats in regards to per-region type output
+ * @run main TestSummarizeRSetStatsPerRegion
+ */
+
+import com.oracle.java.testlibrary.*;
+import java.lang.Thread;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+public class TestSummarizeRSetStatsPerRegion {
+
+    public static void main(String[] args) throws Exception {
+        String result;
+
+        if (!TestSummarizeRSetStatsTools.testingG1GC()) {
+            return;
+        }
+
+        // single remembered set summary output at the end
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats" }, 0);
+        TestSummarizeRSetStatsTools.expectPerRegionRSetSummaries(result, 1, 0);
+
+        // two times remembered set summary output
+        result = TestSummarizeRSetStatsTools.runTest(new String[] { "-XX:+G1SummarizeRSetStats", "-XX:G1SummarizeRSetStatsPeriod=1" }, 1);
+        TestSummarizeRSetStatsTools.expectPerRegionRSetSummaries(result, 1, 2);
+    }
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/gc/g1/TestSummarizeRSetStatsTools.java	Thu Dec 19 09:22:30 2013 +0100
@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2013, 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.
+ */
+
+/*
+ * Common helpers for TestSummarizeRSetStats* tests
+ */
+
+import sun.management.ManagementFactoryHelper;
+import com.sun.management.HotSpotDiagnosticMXBean;
+import com.sun.management.VMOption;
+
+import com.oracle.java.testlibrary.*;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.lang.Thread;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+class VerifySummaryOutput {
+    // 4M size, both are directly allocated into the old gen
+    static Object[] largeObject1 = new Object[1024 * 1024];
+    static Object[] largeObject2 = new Object[1024 * 1024];
+
+    static int[] temp;
+
+    public static void main(String[] args) {
+        // create some cross-references between these objects
+        for (int i = 0; i < largeObject1.length; i++) {
+            largeObject1[i] = largeObject2;
+        }
+
+        for (int i = 0; i < largeObject2.length; i++) {
+            largeObject2[i] = largeObject1;
+        }
+
+        int numGCs = Integer.parseInt(args[0]);
+
+        if (numGCs > 0) {
+            // try to force a minor collection: the young gen is 4M, the
+            // amount of data allocated below is roughly that (4*1024*1024 +
+            // some header data)
+            for (int i = 0; i < 1024 ; i++) {
+                temp = new int[1024];
+            }
+        }
+
+        for (int i = 0; i < numGCs - 1; i++) {
+            System.gc();
+        }
+    }
+}
+
+public class TestSummarizeRSetStatsTools {
+
+    // the VM is currently run using G1GC, i.e. trying to test G1 functionality.
+    public static boolean testingG1GC() {
+        HotSpotDiagnosticMXBean diagnostic = ManagementFactoryHelper.getDiagnosticMXBean();
+
+        VMOption option = diagnostic.getVMOption("UseG1GC");
+        if (option.getValue().equals("false")) {
+          System.out.println("Skipping this test. It is only a G1 test.");
+          return false;
+        }
+        return true;
+    }
+
+    public static String runTest(String[] additionalArgs, int numGCs) throws Exception {
+        ArrayList<String> finalargs = new ArrayList<String>();
+        String[] defaultArgs = new String[] {
+            "-XX:+UseG1GC",
+            "-XX:+UseCompressedOops",
+            "-Xmn4m",
+            "-Xmx20m",
+            "-XX:InitiatingHeapOccupancyPercent=100", // we don't want the additional GCs due to initial marking
+            "-XX:+PrintGC",
+            "-XX:+UnlockDiagnosticVMOptions",
+            "-XX:G1HeapRegionSize=1M",
+        };
+
+        finalargs.addAll(Arrays.asList(defaultArgs));
+
+        if (additionalArgs != null) {
+            finalargs.addAll(Arrays.asList(additionalArgs));
+        }
+
+        finalargs.add(VerifySummaryOutput.class.getName());
+        finalargs.add(String.valueOf(numGCs));
+
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+            finalargs.toArray(new String[0]));
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+        output.shouldHaveExitValue(0);
+
+        String result = output.getStdout();
+        return result;
+    }
+
+    private static void checkCounts(int expected, int actual, String which) throws Exception {
+        if (expected != actual) {
+            throw new Exception("RSet summaries mention " + which + " regions an incorrect number of times. Expected " + expected + ", got " + actual);
+        }
+    }
+
+    public static void expectPerRegionRSetSummaries(String result, int expectedCumulative, int expectedPeriodic) throws Exception {
+        expectRSetSummaries(result, expectedCumulative, expectedPeriodic);
+        int actualYoung = result.split("Young regions").length - 1;
+        int actualHumonguous = result.split("Humonguous regions").length - 1;
+        int actualFree = result.split("Free regions").length - 1;
+        int actualOther = result.split("Old regions").length - 1;
+
+        // the strings we check for above are printed four times per summary
+        int expectedPerRegionTypeInfo = (expectedCumulative + expectedPeriodic) * 4;
+
+        checkCounts(expectedPerRegionTypeInfo, actualYoung, "Young");
+        checkCounts(expectedPerRegionTypeInfo, actualHumonguous, "Humonguous");
+        checkCounts(expectedPerRegionTypeInfo, actualFree, "Free");
+        checkCounts(expectedPerRegionTypeInfo, actualOther, "Old");
+    }
+
+    public static void expectRSetSummaries(String result, int expectedCumulative, int expectedPeriodic) throws Exception {
+        int actualTotal = result.split("concurrent refinement").length - 1;
+        int actualCumulative = result.split("Cumulative RS summary").length - 1;
+
+        if (expectedCumulative != actualCumulative) {
+            throw new Exception("Incorrect amount of RSet summaries at the end. Expected " + expectedCumulative + ", got " + actualCumulative);
+        }
+
+        if (expectedPeriodic != (actualTotal - actualCumulative)) {
+            throw new Exception("Incorrect amount of per-period RSet summaries at the end. Expected " + expectedPeriodic + ", got " + (actualTotal - actualCumulative));
+        }
+    }
+}
+