7027766: G1: introduce flag to dump the liveness information per region at the end of marking

Repurpose the existing flag G1PrintRegionLivenessInfo to print out the liveness distribution across the regions in the heap at the end of marking.

Reviewed-by: iveresov, jwilhelm

hotspot/src/share/vm/gc_implementation/g1/collectionSetChooser.cpp

@@ -262,38 +262,17 @@ CollectionSetChooser::sortMarkedHeapRegions() {
   for (int i = 0; i < _numMarkedRegions; i++) {
     assert(_markedRegions.at(i) != NULL, "Should be true by sorting!");
     _markedRegions.at(i)->set_sort_index(i);
-    if (G1PrintRegionLivenessInfo > 0) {
+  }
-      if (i == 0) gclog_or_tty->print_cr("Sorted marked regions:");
+  if (G1PrintRegionLivenessInfo) {
-      if (i < G1PrintRegionLivenessInfo ||
+    G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Sorting");
-          (_numMarkedRegions-i) < G1PrintRegionLivenessInfo) {
+    for (int i = 0; i < _numMarkedRegions; ++i) {
-        HeapRegion* hr = _markedRegions.at(i);
+      HeapRegion* r = _markedRegions.at(i);
-        size_t u = hr->used();
+      cl.doHeapRegion(r);
-        gclog_or_tty->print_cr("  Region %d: %d used, %d max live, %5.2f%%.",
-                      i, u, hr->max_live_bytes(),
-                      100.0*(float)hr->max_live_bytes()/(float)u);
-      }
     }
   }
-  if (G1PolicyVerbose > 1)
-    printSortedHeapRegions();
   assert(verify(), "should now be sorted");
 }
 
-void
-printHeapRegion(HeapRegion *hr) {
-  if (hr->isHumongous())
-    gclog_or_tty->print("H: ");
-  if (hr->in_collection_set())
-    gclog_or_tty->print("CS: ");
-  gclog_or_tty->print_cr("Region " PTR_FORMAT " (%s%s) "
-                         "[" PTR_FORMAT ", " PTR_FORMAT"] "
-                         "Used: " SIZE_FORMAT "K, garbage: " SIZE_FORMAT "K.",
-                         hr, hr->is_young() ? "Y " : "  ",
-                         hr->is_marked()? "M1" : "M0",
-                         hr->bottom(), hr->end(),
-                         hr->used()/K, hr->garbage_bytes()/K);
-}
-
 void
 CollectionSetChooser::addMarkedHeapRegion(HeapRegion* hr) {
   assert(!hr->isHumongous(),
@@ -351,27 +330,9 @@ CollectionSetChooser::clearMarkedHeapRegions(){
 
 void
 CollectionSetChooser::updateAfterFullCollection() {
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
   clearMarkedHeapRegions();
 }
 
-void
-CollectionSetChooser::printSortedHeapRegions() {
-  gclog_or_tty->print_cr("Printing %d Heap Regions sorted by amount of known garbage",
-                _numMarkedRegions);
-
-  DEBUG_ONLY(int marked_count = 0;)
-  for (int i = 0; i < _markedRegions.length(); i++) {
-    HeapRegion* r = _markedRegions.at(i);
-    if (r != NULL) {
-      printHeapRegion(r);
-      DEBUG_ONLY(marked_count++;)
-    }
-  }
-  assert(marked_count == _numMarkedRegions, "must be");
-  gclog_or_tty->print_cr("Done sorted heap region print");
-}
-
 void CollectionSetChooser::removeRegion(HeapRegion *hr) {
   int si = hr->sort_index();
   assert(si == -1 || hr->is_marked(), "Sort index not valid.");

hotspot/src/share/vm/gc_implementation/g1/collectionSetChooser.hpp

@@ -100,8 +100,6 @@ public:
 
   CollectionSetChooser();
 
-  void printSortedHeapRegions();
-
   void sortMarkedHeapRegions();
   void fillCache();
   bool addRegionToCache(void);

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp

@@ -1204,7 +1204,6 @@ void ConcurrentMark::checkpointRootsFinal(bool clear_all_soft_refs) {
   g1p->record_concurrent_mark_remark_end();
 }
 
-
 #define CARD_BM_TEST_MODE 0
 
 class CalcLiveObjectsClosure: public HeapRegionClosure {
@@ -1726,6 +1725,11 @@ void ConcurrentMark::cleanup() {
   }
   _total_counting_time += this_final_counting_time;
 
+  if (G1PrintRegionLivenessInfo) {
+    G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Marking");
+    _g1h->heap_region_iterate(&cl);
+  }
+
   // Install newly created mark bitMap as "prev".
   swapMarkBitMaps();
 
@@ -4423,3 +4427,175 @@ CMTask::CMTask(int task_id,
 
   _marking_step_diffs_ms.add(0.5);
 }
+
+// These are formatting macros that are used below to ensure
+// consistent formatting. The *_H_* versions are used to format the
+// header for a particular value and they should be kept consistent
+// with the corresponding macro. Also note that most of the macros add
+// the necessary white space (as a prefix) which makes them a bit
+// easier to compose.
+
+// All the output lines are prefixed with this string to be able to
+// identify them easily in a large log file.
+#define G1PPRL_LINE_PREFIX            "###"
+
+#define G1PPRL_ADDR_BASE_FORMAT    " "PTR_FORMAT"-"PTR_FORMAT
+#ifdef _LP64
+#define G1PPRL_ADDR_BASE_H_FORMAT  " %37s"
+#else // _LP64
+#define G1PPRL_ADDR_BASE_H_FORMAT  " %21s"
+#endif // _LP64
+
+// For per-region info
+#define G1PPRL_TYPE_FORMAT            "   %-4s"
+#define G1PPRL_TYPE_H_FORMAT          "   %4s"
+#define G1PPRL_BYTE_FORMAT            "  "SIZE_FORMAT_W(9)
+#define G1PPRL_BYTE_H_FORMAT          "  %9s"
+#define G1PPRL_DOUBLE_FORMAT          "  %14.1f"
+#define G1PPRL_DOUBLE_H_FORMAT        "  %14s"
+
+// For summary info
+#define G1PPRL_SUM_ADDR_FORMAT(tag)    "  "tag":"G1PPRL_ADDR_BASE_FORMAT
+#define G1PPRL_SUM_BYTE_FORMAT(tag)    "  "tag": "SIZE_FORMAT
+#define G1PPRL_SUM_MB_FORMAT(tag)      "  "tag": %1.2f MB"
+#define G1PPRL_SUM_MB_PERC_FORMAT(tag) G1PPRL_SUM_MB_FORMAT(tag)" / %1.2f %%"
+
+G1PrintRegionLivenessInfoClosure::
+G1PrintRegionLivenessInfoClosure(outputStream* out, const char* phase_name)
+  : _out(out),
+    _total_used_bytes(0), _total_capacity_bytes(0),
+    _total_prev_live_bytes(0), _total_next_live_bytes(0),
+    _hum_used_bytes(0), _hum_capacity_bytes(0),
+    _hum_prev_live_bytes(0), _hum_next_live_bytes(0) {
+  G1CollectedHeap* g1h = G1CollectedHeap::heap();
+  MemRegion g1_committed = g1h->g1_committed();
+  MemRegion g1_reserved = g1h->g1_reserved();
+  double now = os::elapsedTime();
+
+  // Print the header of the output.
+  _out->cr();
+  _out->print_cr(G1PPRL_LINE_PREFIX" PHASE %s @ %1.3f", phase_name, now);
+  _out->print_cr(G1PPRL_LINE_PREFIX" HEAP"
+                 G1PPRL_SUM_ADDR_FORMAT("committed")
+                 G1PPRL_SUM_ADDR_FORMAT("reserved")
+                 G1PPRL_SUM_BYTE_FORMAT("region-size"),
+                 g1_committed.start(), g1_committed.end(),
+                 g1_reserved.start(), g1_reserved.end(),
+                 HeapRegion::GrainBytes);
+  _out->print_cr(G1PPRL_LINE_PREFIX);
+  _out->print_cr(G1PPRL_LINE_PREFIX
+                 G1PPRL_TYPE_H_FORMAT
+                 G1PPRL_ADDR_BASE_H_FORMAT
+                 G1PPRL_BYTE_H_FORMAT
+                 G1PPRL_BYTE_H_FORMAT
+                 G1PPRL_BYTE_H_FORMAT
+                 G1PPRL_DOUBLE_H_FORMAT,
+                 "type", "address-range",
+                 "used", "prev-live", "next-live", "gc-eff");
+}
+
+// It takes as a parameter a reference to one of the _hum_* fields, it
+// deduces the corresponding value for a region in a humongous region
+// series (either the region size, or what's left if the _hum_* field
+// is < the region size), and updates the _hum_* field accordingly.
+size_t G1PrintRegionLivenessInfoClosure::get_hum_bytes(size_t* hum_bytes) {
+  size_t bytes = 0;
+  // The > 0 check is to deal with the prev and next live bytes which
+  // could be 0.
+  if (*hum_bytes > 0) {
+    bytes = MIN2((size_t) HeapRegion::GrainBytes, *hum_bytes);
+    *hum_bytes -= bytes;
+  }
+  return bytes;
+}
+
+// It deduces the values for a region in a humongous region series
+// from the _hum_* fields and updates those accordingly. It assumes
+// that that _hum_* fields have already been set up from the "starts
+// humongous" region and we visit the regions in address order.
+void G1PrintRegionLivenessInfoClosure::get_hum_bytes(size_t* used_bytes,
+                                                     size_t* capacity_bytes,
+                                                     size_t* prev_live_bytes,
+                                                     size_t* next_live_bytes) {
+  assert(_hum_used_bytes > 0 && _hum_capacity_bytes > 0, "pre-condition");
+  *used_bytes      = get_hum_bytes(&_hum_used_bytes);
+  *capacity_bytes  = get_hum_bytes(&_hum_capacity_bytes);
+  *prev_live_bytes = get_hum_bytes(&_hum_prev_live_bytes);
+  *next_live_bytes = get_hum_bytes(&_hum_next_live_bytes);
+}
+
+bool G1PrintRegionLivenessInfoClosure::doHeapRegion(HeapRegion* r) {
+  const char* type = "";
+  HeapWord* bottom       = r->bottom();
+  HeapWord* end          = r->end();
+  size_t capacity_bytes  = r->capacity();
+  size_t used_bytes      = r->used();
+  size_t prev_live_bytes = r->live_bytes();
+  size_t next_live_bytes = r->next_live_bytes();
+  double gc_eff          = r->gc_efficiency();
+  if (r->used() == 0) {
+    type = "FREE";
+  } else if (r->is_survivor()) {
+    type = "SURV";
+  } else if (r->is_young()) {
+    type = "EDEN";
+  } else if (r->startsHumongous()) {
+    type = "HUMS";
+
+    assert(_hum_used_bytes == 0 && _hum_capacity_bytes == 0 &&
+           _hum_prev_live_bytes == 0 && _hum_next_live_bytes == 0,
+           "they should have been zeroed after the last time we used them");
+    // Set up the _hum_* fields.
+    _hum_capacity_bytes  = capacity_bytes;
+    _hum_used_bytes      = used_bytes;
+    _hum_prev_live_bytes = prev_live_bytes;
+    _hum_next_live_bytes = next_live_bytes;
+    get_hum_bytes(&used_bytes, &capacity_bytes,
+                  &prev_live_bytes, &next_live_bytes);
+    end = bottom + HeapRegion::GrainWords;
+  } else if (r->continuesHumongous()) {
+    type = "HUMC";
+    get_hum_bytes(&used_bytes, &capacity_bytes,
+                  &prev_live_bytes, &next_live_bytes);
+    assert(end == bottom + HeapRegion::GrainWords, "invariant");
+  } else {
+    type = "OLD";
+  }
+
+  _total_used_bytes      += used_bytes;
+  _total_capacity_bytes  += capacity_bytes;
+  _total_prev_live_bytes += prev_live_bytes;
+  _total_next_live_bytes += next_live_bytes;
+
+  // Print a line for this particular region.
+  _out->print_cr(G1PPRL_LINE_PREFIX
+                 G1PPRL_TYPE_FORMAT
+                 G1PPRL_ADDR_BASE_FORMAT
+                 G1PPRL_BYTE_FORMAT
+                 G1PPRL_BYTE_FORMAT
+                 G1PPRL_BYTE_FORMAT
+                 G1PPRL_DOUBLE_FORMAT,
+                 type, bottom, end,
+                 used_bytes, prev_live_bytes, next_live_bytes, gc_eff);
+
+  return false;
+}
+
+G1PrintRegionLivenessInfoClosure::~G1PrintRegionLivenessInfoClosure() {
+  // Print the footer of the output.
+  _out->print_cr(G1PPRL_LINE_PREFIX);
+  _out->print_cr(G1PPRL_LINE_PREFIX
+                 " SUMMARY"
+                 G1PPRL_SUM_MB_FORMAT("capacity")
+                 G1PPRL_SUM_MB_PERC_FORMAT("used")
+                 G1PPRL_SUM_MB_PERC_FORMAT("prev-live")
+                 G1PPRL_SUM_MB_PERC_FORMAT("next-live"),
+                 bytes_to_mb(_total_capacity_bytes),
+                 bytes_to_mb(_total_used_bytes),
+                 perc(_total_used_bytes, _total_capacity_bytes),
+                 bytes_to_mb(_total_prev_live_bytes),
+                 perc(_total_prev_live_bytes, _total_capacity_bytes),
+                 bytes_to_mb(_total_next_live_bytes),
+                 perc(_total_next_live_bytes, _total_capacity_bytes));
+  _out->cr();
+}

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp

@@ -1149,4 +1149,54 @@ public:
 #endif // _MARKING_STATS_
 };
 
+// Class that's used to to print out per-region liveness
+// information. It's currently used at the end of marking and also
+// after we sort the old regions at the end of the cleanup operation.
+class G1PrintRegionLivenessInfoClosure: public HeapRegionClosure {
+private:
+  outputStream* _out;
+
+  // Accumulators for these values.
+  size_t _total_used_bytes;
+  size_t _total_capacity_bytes;
+  size_t _total_prev_live_bytes;
+  size_t _total_next_live_bytes;
+
+  // These are set up when we come across a "stars humongous" region
+  // (as this is where most of this information is stored, not in the
+  // subsequent "continues humongous" regions). After that, for every
+  // region in a given humongous region series we deduce the right
+  // values for it by simply subtracting the appropriate amount from
+  // these fields. All these values should reach 0 after we've visited
+  // the last region in the series.
+  size_t _hum_used_bytes;
+  size_t _hum_capacity_bytes;
+  size_t _hum_prev_live_bytes;
+  size_t _hum_next_live_bytes;
+
+  static double perc(size_t val, size_t total) {
+    if (total == 0) {
+      return 0.0;
+    } else {
+      return 100.0 * ((double) val / (double) total);
+    }
+  }
+
+  static double bytes_to_mb(size_t val) {
+    return (double) val / (double) M;
+  }
+
+  // See the .cpp file.
+  size_t get_hum_bytes(size_t* hum_bytes);
+  void get_hum_bytes(size_t* used_bytes, size_t* capacity_bytes,
+                     size_t* prev_live_bytes, size_t* next_live_bytes);
+
+public:
+  // The header and footer are printed in the constructor and
+  // destructor respectively.
+  G1PrintRegionLivenessInfoClosure(outputStream* out, const char* phase_name);
+  virtual bool doHeapRegion(HeapRegion* r);
+  ~G1PrintRegionLivenessInfoClosure();
+};
+
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARK_HPP

hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp

@@ -1057,7 +1057,13 @@ public:
     return _g1_reserved.contains(p);
   }
 
-  // Returns a MemRegion that corresponds to the space that  has been
+  // Returns a MemRegion that corresponds to the space that has been
+  // reserved for the heap
+  MemRegion g1_reserved() {
+    return _g1_reserved;
+  }
+
+  // Returns a MemRegion that corresponds to the space that has been
   // committed in the heap
   MemRegion g1_committed() {
     return _g1_committed;

hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp

@@ -138,9 +138,9 @@
   develop(bool, G1RSCountHisto, false,                                      \
           "If true, print a histogram of RS occupancies after each pause")  \
                                                                             \
-  develop(intx, G1PrintRegionLivenessInfo, 0,                               \
+  product(bool, G1PrintRegionLivenessInfo, false,                           \
-          "When > 0, print the occupancies of the <n> best and worst"       \
+          "Prints the liveness information for all regions in the heap "    \
-          "regions.")                                                       \
+          "at the end of a marking cycle.")                                 \
                                                                             \
   develop(bool, G1PrintParCleanupStats, false,                              \
           "When true, print extra stats about parallel cleanup.")           \

hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp

@@ -398,13 +398,16 @@ class HeapRegion: public G1OffsetTableContigSpace {
 
   // The number of bytes marked live in the region in the last marking phase.
   size_t marked_bytes()    { return _prev_marked_bytes; }
+  size_t live_bytes() {
+    return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes();
+  }
+
   // The number of bytes counted in the next marking.
   size_t next_marked_bytes() { return _next_marked_bytes; }
   // The number of bytes live wrt the next marking.
   size_t next_live_bytes() {
-    return (top() - next_top_at_mark_start())
+    return
-      * HeapWordSize
+      (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes();
-      + next_marked_bytes();
   }
 
   // A lower bound on the amount of garbage bytes in the region.