8008966: NPG: Inefficient Metaspace counter functions cause large young GC regressions

Reviewed-by: mgerdin, coleenp

hotspot/src/share/vm/classfile/classLoaderData.cpp

@@ -672,6 +672,8 @@ bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure) {
     dead->unload();
     data = data->next();
     // Remove from loader list.
+    // This class loader data will no longer be found
+    // in the ClassLoaderDataGraph.
     if (prev != NULL) {
       prev->set_next(data);
     } else {

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

@@ -1304,7 +1304,7 @@ bool G1CollectedHeap::do_collection(bool explicit_gc,
 
   print_heap_before_gc();
 
-  size_t metadata_prev_used = MetaspaceAux::used_in_bytes();
+  size_t metadata_prev_used = MetaspaceAux::allocated_used_bytes();
 
   HRSPhaseSetter x(HRSPhaseFullGC);
   verify_region_sets_optional();
@@ -1425,6 +1425,7 @@ bool G1CollectedHeap::do_collection(bool explicit_gc,
 
       // Delete metaspaces for unloaded class loaders and clean up loader_data graph
       ClassLoaderDataGraph::purge();
+    MetaspaceAux::verify_metrics();
 
       // Note: since we've just done a full GC, concurrent
       // marking is no longer active. Therefore we need not

hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp

@@ -177,7 +177,7 @@ bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
     size_t prev_used = heap->used();
 
     // Capture metadata size before collection for sizing.
-    size_t metadata_prev_used = MetaspaceAux::used_in_bytes();
+    size_t metadata_prev_used = MetaspaceAux::allocated_used_bytes();
 
     // For PrintGCDetails
     size_t old_gen_prev_used = old_gen->used_in_bytes();
@@ -238,6 +238,7 @@ bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
 
     // Delete metaspaces for unloaded class loaders and clean up loader_data graph
     ClassLoaderDataGraph::purge();
+    MetaspaceAux::verify_metrics();
 
     BiasedLocking::restore_marks();
     Threads::gc_epilogue();

hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp

@@ -891,7 +891,7 @@ public:
     _heap_used      = heap->used();
     _young_gen_used = heap->young_gen()->used_in_bytes();
     _old_gen_used   = heap->old_gen()->used_in_bytes();
-    _metadata_used  = MetaspaceAux::used_in_bytes();
+    _metadata_used  = MetaspaceAux::allocated_used_bytes();
   };
 
   size_t heap_used() const      { return _heap_used; }
@@ -1026,6 +1026,7 @@ void PSParallelCompact::post_compact()
 
   // Delete metaspaces for unloaded class loaders and clean up loader_data graph
   ClassLoaderDataGraph::purge();
+  MetaspaceAux::verify_metrics();
 
   Threads::gc_epilogue();
   CodeCache::gc_epilogue();

hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.cpp

@@ -225,7 +225,10 @@ void VM_CollectForMetadataAllocation::doit() {
         gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
       }
       heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
-      _result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
+      // After a GC try to allocate without expanding.  Could fail
+      // and expansion will be tried below.
+      _result =
+        _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
     }
     if (_result == NULL && !UseConcMarkSweepGC /* CMS already tried */) {
       // If still failing, allow the Metaspace to expand.

hotspot/src/share/vm/memory/filemap.cpp

@@ -238,8 +238,8 @@ void FileMapInfo::write_header() {
 
 void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {
   align_file_position();
-  size_t used = space->used_words(Metaspace::NonClassType) * BytesPerWord;
+  size_t used = space->used_bytes_slow(Metaspace::NonClassType);
-  size_t capacity = space->capacity_words(Metaspace::NonClassType) * BytesPerWord;
+  size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);
   struct FileMapInfo::FileMapHeader::space_info* si = &_header._space[i];
   write_region(i, (char*)space->bottom(), used, capacity, read_only, false);
 }

hotspot/src/share/vm/memory/genCollectedHeap.cpp

@@ -377,7 +377,7 @@ void GenCollectedHeap::do_collection(bool  full,
 
   ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
 
-  const size_t metadata_prev_used = MetaspaceAux::used_in_bytes();
+  const size_t metadata_prev_used = MetaspaceAux::allocated_used_bytes();
 
   print_heap_before_gc();
 
@@ -556,6 +556,7 @@ void GenCollectedHeap::do_collection(bool  full,
     if (complete) {
       // Delete metaspaces for unloaded class loaders and clean up loader_data graph
       ClassLoaderDataGraph::purge();
+      MetaspaceAux::verify_metrics();
       // Resize the metaspace capacity after full collections
       MetaspaceGC::compute_new_size();
       update_full_collections_completed();

hotspot/src/share/vm/memory/metaspace.cpp

@@ -47,7 +47,6 @@ typedef BinaryTreeDictionary<Metachunk, FreeList> ChunkTreeDictionary;
 // the free chunk lists
 const bool metaspace_slow_verify = false;
 
-
 // Parameters for stress mode testing
 const uint metadata_deallocate_a_lot_block = 10;
 const uint metadata_deallocate_a_lock_chunk = 3;
@@ -220,7 +219,6 @@ class ChunkManager VALUE_OBJ_CLASS_SPEC {
   void print_on(outputStream* st);
 };
 
-
 // Used to manage the free list of Metablocks (a block corresponds
 // to the allocation of a quantum of metadata).
 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
@@ -298,7 +296,7 @@ class VirtualSpaceNode : public CHeapObj<mtClass> {
   MemRegion* reserved() { return &_reserved; }
   VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
 
-  // Returns true if "word_size" is available in the virtual space
+  // Returns true if "word_size" is available in the VirtualSpace
   bool is_available(size_t word_size) { return _top + word_size <= end(); }
 
   MetaWord* top() const { return _top; }
@@ -313,6 +311,7 @@ class VirtualSpaceNode : public CHeapObj<mtClass> {
   // used and capacity in this single entry in the list
   size_t used_words_in_vs() const;
   size_t capacity_words_in_vs() const;
+  size_t free_words_in_vs() const;
 
   bool initialize();
 
@@ -449,6 +448,8 @@ class VirtualSpaceList : public CHeapObj<mtClass> {
   VirtualSpaceList(size_t word_size);
   VirtualSpaceList(ReservedSpace rs);
 
+  size_t free_bytes();
+
   Metachunk* get_new_chunk(size_t word_size,
                            size_t grow_chunks_by_words,
                            size_t medium_chunk_bunch);
@@ -579,7 +580,11 @@ class SpaceManager : public CHeapObj<mtClass> {
   bool has_small_chunk_limit() { return !vs_list()->is_class(); }
 
   // Sum of all space in allocated chunks
-  size_t _allocation_total;
+  size_t _allocated_blocks_words;
+
+  // Sum of all allocated chunks
+  size_t _allocated_chunks_words;
+  size_t _allocated_chunks_count;
 
   // Free lists of blocks are per SpaceManager since they
   // are assumed to be in chunks in use by the SpaceManager
@@ -635,12 +640,27 @@ class SpaceManager : public CHeapObj<mtClass> {
   size_t medium_chunk_size() { return (size_t) vs_list()->is_class() ? ClassMediumChunk : MediumChunk; }
   size_t medium_chunk_bunch() { return medium_chunk_size() * MediumChunkMultiple; }
 
-  size_t allocation_total() const { return _allocation_total; }
+  size_t allocated_blocks_words() const { return _allocated_blocks_words; }
-  void inc_allocation_total(size_t v) { Atomic::add_ptr(v, &_allocation_total); }
+  size_t allocated_blocks_bytes() const { return _allocated_blocks_words * BytesPerWord; }
+  size_t allocated_chunks_words() const { return _allocated_chunks_words; }
+  size_t allocated_chunks_count() const { return _allocated_chunks_count; }
+
   bool is_humongous(size_t word_size) { return word_size > medium_chunk_size(); }
 
   static Mutex* expand_lock() { return _expand_lock; }
 
+  // Increment the per Metaspace and global running sums for Metachunks
+  // by the given size.  This is used when a Metachunk to added to
+  // the in-use list.
+  void inc_size_metrics(size_t words);
+  // Increment the per Metaspace and global running sums Metablocks by the given
+  // size.  This is used when a Metablock is allocated.
+  void inc_used_metrics(size_t words);
+  // Delete the portion of the running sums for this SpaceManager. That is,
+  // the globals running sums for the Metachunks and Metablocks are
+  // decremented for all the Metachunks in-use by this SpaceManager.
+  void dec_total_from_size_metrics();
+
   // Set the sizes for the initial chunks.
   void get_initial_chunk_sizes(Metaspace::MetaspaceType type,
                                size_t* chunk_word_size,
@@ -686,7 +706,7 @@ class SpaceManager : public CHeapObj<mtClass> {
   void verify_chunk_size(Metachunk* chunk);
   NOT_PRODUCT(void mangle_freed_chunks();)
 #ifdef ASSERT
-  void verify_allocation_total();
+  void verify_allocated_blocks_words();
 #endif
 };
 
@@ -797,6 +817,9 @@ size_t VirtualSpaceNode::capacity_words_in_vs() const {
   return pointer_delta(end(), bottom(), sizeof(MetaWord));
 }
 
+size_t VirtualSpaceNode::free_words_in_vs() const {
+  return pointer_delta(end(), top(), sizeof(MetaWord));
+}
 
 // Allocates the chunk from the virtual space only.
 // This interface is also used internally for debugging.  Not all
@@ -1071,6 +1094,10 @@ VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
   link_vs(class_entry, rs.size()/BytesPerWord);
 }
 
+size_t VirtualSpaceList::free_bytes() {
+  return virtual_space_list()->free_words_in_vs() * BytesPerWord;
+}
+
 // Allocate another meta virtual space and add it to the list.
 bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
   assert_lock_strong(SpaceManager::expand_lock());
@@ -1211,9 +1238,9 @@ bool VirtualSpaceList::contains(const void *ptr) {
 //
 // After the GC the compute_new_size() for MetaspaceGC is called to
 // resize the capacity of the metaspaces.  The current implementation
-// is based on the flags MinMetaspaceFreeRatio and MaxHeapFreeRatio used
+// is based on the flags MinMetaspaceFreeRatio and MaxMetaspaceFreeRatio used
 // to resize the Java heap by some GC's.  New flags can be implemented
-// if really needed.  MinHeapFreeRatio is used to calculate how much
+// if really needed.  MinMetaspaceFreeRatio is used to calculate how much
 // free space is desirable in the metaspace capacity to decide how much
 // to increase the HWM.  MaxMetaspaceFreeRatio is used to decide how much
 // free space is desirable in the metaspace capacity before decreasing
@@ -1248,7 +1275,11 @@ size_t MetaspaceGC::delta_capacity_until_GC(size_t word_size) {
 }
 
 bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
+
+  size_t committed_capacity_bytes = MetaspaceAux::allocated_capacity_bytes();
   // If the user wants a limit, impose one.
+  size_t max_metaspace_size_bytes = MaxMetaspaceSize;
+  size_t metaspace_size_bytes = MetaspaceSize;
   if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) &&
       MetaspaceAux::reserved_in_bytes() >= MaxMetaspaceSize) {
     return false;
@@ -1260,57 +1291,48 @@ bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
 
   // If this is part of an allocation after a GC, expand
   // unconditionally.
-  if(MetaspaceGC::expand_after_GC()) {
+  if (MetaspaceGC::expand_after_GC()) {
     return true;
   }
 
-  size_t metaspace_size_words = MetaspaceSize / BytesPerWord;
+
 
   // If the capacity is below the minimum capacity, allow the
   // expansion.  Also set the high-water-mark (capacity_until_GC)
   // to that minimum capacity so that a GC will not be induced
   // until that minimum capacity is exceeded.
-  if (vsl->capacity_words_sum() < metaspace_size_words ||
+  if (committed_capacity_bytes < metaspace_size_bytes ||
       capacity_until_GC() == 0) {
-    set_capacity_until_GC(metaspace_size_words);
+    set_capacity_until_GC(metaspace_size_bytes);
     return true;
   } else {
-    if (vsl->capacity_words_sum() < capacity_until_GC()) {
+    if (committed_capacity_bytes < capacity_until_GC()) {
       return true;
     } else {
       if (TraceMetadataChunkAllocation && Verbose) {
         gclog_or_tty->print_cr("  allocation request size " SIZE_FORMAT
                         "  capacity_until_GC " SIZE_FORMAT
-                        "  capacity_words_sum " SIZE_FORMAT
+                        "  allocated_capacity_bytes " SIZE_FORMAT,
-                        "  used_words_sum " SIZE_FORMAT
-                        "  free chunks " SIZE_FORMAT
-                        "  free chunks count %d",
                         word_size,
                         capacity_until_GC(),
-                        vsl->capacity_words_sum(),
+                        MetaspaceAux::allocated_capacity_bytes());
-                        vsl->used_words_sum(),
-                        vsl->chunk_manager()->free_chunks_total(),
-                        vsl->chunk_manager()->free_chunks_count());
       }
       return false;
     }
   }
 }
 
-// Variables are in bytes
+
 
 void MetaspaceGC::compute_new_size() {
   assert(_shrink_factor <= 100, "invalid shrink factor");
   uint current_shrink_factor = _shrink_factor;
   _shrink_factor = 0;
 
-  VirtualSpaceList *vsl = Metaspace::space_list();
+  // Until a faster way of calculating the "used" quantity is implemented,
-
+  // use "capacity".
-  size_t capacity_after_gc = vsl->capacity_bytes_sum();
+  const size_t used_after_gc = MetaspaceAux::allocated_capacity_bytes();
-  // Check to see if these two can be calculated without walking the CLDG
+  const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC();
-  size_t used_after_gc = vsl->used_bytes_sum();
-  size_t capacity_until_GC = vsl->capacity_bytes_sum();
-  size_t free_after_gc = capacity_until_GC - used_after_gc;
 
   const double minimum_free_percentage = MinMetaspaceFreeRatio / 100.0;
   const double maximum_used_percentage = 1.0 - minimum_free_percentage;
@@ -1323,45 +1345,34 @@ void MetaspaceGC::compute_new_size() {
                                   MetaspaceSize);
 
   if (PrintGCDetails && Verbose) {
-    const double free_percentage = ((double)free_after_gc) / capacity_until_GC;
     gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
     gclog_or_tty->print_cr("  "
                   "  minimum_free_percentage: %6.2f"
                   "  maximum_used_percentage: %6.2f",
                   minimum_free_percentage,
                   maximum_used_percentage);
-    double d_free_after_gc = free_after_gc / (double) K;
     gclog_or_tty->print_cr("  "
-                  "   free_after_gc       : %6.1fK"
+                  "   used_after_gc       : %6.1fKB",
-                  "   used_after_gc       : %6.1fK"
+                  used_after_gc / (double) K);
-                  "   capacity_after_gc   : %6.1fK"
-                  "   metaspace HWM     : %6.1fK",
-                  free_after_gc / (double) K,
-                  used_after_gc / (double) K,
-                  capacity_after_gc / (double) K,
-                  capacity_until_GC / (double) K);
-    gclog_or_tty->print_cr("  "
-                  "   free_percentage: %6.2f",
-                  free_percentage);
   }
 
 
+  size_t shrink_bytes = 0;
   if (capacity_until_GC < minimum_desired_capacity) {
     // If we have less capacity below the metaspace HWM, then
     // increment the HWM.
     size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
     // Don't expand unless it's significant
     if (expand_bytes >= MinMetaspaceExpansion) {
-      size_t expand_words = expand_bytes / BytesPerWord;
+      MetaspaceGC::set_capacity_until_GC(capacity_until_GC + expand_bytes);
-      MetaspaceGC::inc_capacity_until_GC(expand_words);
     }
     if (PrintGCDetails && Verbose) {
-      size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
+      size_t new_capacity_until_GC = capacity_until_GC;
       gclog_or_tty->print_cr("    expanding:"
-                    "  minimum_desired_capacity: %6.1fK"
+                    "  minimum_desired_capacity: %6.1fKB"
-                    "  expand_words: %6.1fK"
+                    "  expand_bytes: %6.1fKB"
-                    "  MinMetaspaceExpansion: %6.1fK"
+                    "  MinMetaspaceExpansion: %6.1fKB"
-                    "  new metaspace HWM:  %6.1fK",
+                    "  new metaspace HWM:  %6.1fKB",
                     minimum_desired_capacity / (double) K,
                     expand_bytes / (double) K,
                     MinMetaspaceExpansion / (double) K,
@@ -1371,11 +1382,10 @@ void MetaspaceGC::compute_new_size() {
   }
 
   // No expansion, now see if we want to shrink
-  size_t shrink_words = 0;
   // We would never want to shrink more than this
-  size_t max_shrink_words = capacity_until_GC - minimum_desired_capacity;
+  size_t max_shrink_bytes = capacity_until_GC - minimum_desired_capacity;
-  assert(max_shrink_words >= 0, err_msg("max_shrink_words " SIZE_FORMAT,
+  assert(max_shrink_bytes >= 0, err_msg("max_shrink_bytes " SIZE_FORMAT,
-    max_shrink_words));
+    max_shrink_bytes));
 
   // Should shrinking be considered?
   if (MaxMetaspaceFreeRatio < 100) {
@@ -1385,17 +1395,15 @@ void MetaspaceGC::compute_new_size() {
     size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
     maximum_desired_capacity = MAX2(maximum_desired_capacity,
                                     MetaspaceSize);
-    if (PrintGC && Verbose) {
+    if (PrintGCDetails && Verbose) {
       gclog_or_tty->print_cr("  "
                              "  maximum_free_percentage: %6.2f"
                              "  minimum_used_percentage: %6.2f",
                              maximum_free_percentage,
                              minimum_used_percentage);
       gclog_or_tty->print_cr("  "
-                             "  capacity_until_GC: %6.1fK"
+                             "  minimum_desired_capacity: %6.1fKB"
-                             "  minimum_desired_capacity: %6.1fK"
+                             "  maximum_desired_capacity: %6.1fKB",
-                             "  maximum_desired_capacity: %6.1fK",
-                             capacity_until_GC / (double) K,
                              minimum_desired_capacity / (double) K,
                              maximum_desired_capacity / (double) K);
     }
@@ -1405,17 +1413,17 @@ void MetaspaceGC::compute_new_size() {
 
     if (capacity_until_GC > maximum_desired_capacity) {
       // Capacity too large, compute shrinking size
-      shrink_words = capacity_until_GC - maximum_desired_capacity;
+      shrink_bytes = capacity_until_GC - maximum_desired_capacity;
       // We don't want shrink all the way back to initSize if people call
       // System.gc(), because some programs do that between "phases" and then
       // we'd just have to grow the heap up again for the next phase.  So we
       // damp the shrinking: 0% on the first call, 10% on the second call, 40%
       // on the third call, and 100% by the fourth call.  But if we recompute
       // size without shrinking, it goes back to 0%.
-      shrink_words = shrink_words / 100 * current_shrink_factor;
+      shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
-      assert(shrink_words <= max_shrink_words,
+      assert(shrink_bytes <= max_shrink_bytes,
         err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
-          shrink_words, max_shrink_words));
+          shrink_bytes, max_shrink_bytes));
       if (current_shrink_factor == 0) {
         _shrink_factor = 10;
       } else {
@@ -1429,11 +1437,11 @@ void MetaspaceGC::compute_new_size() {
                       MetaspaceSize / (double) K,
                       maximum_desired_capacity / (double) K);
         gclog_or_tty->print_cr("  "
-                      "  shrink_words: %.1fK"
+                      "  shrink_bytes: %.1fK"
                       "  current_shrink_factor: %d"
                       "  new shrink factor: %d"
                       "  MinMetaspaceExpansion: %.1fK",
-                      shrink_words / (double) K,
+                      shrink_bytes / (double) K,
                       current_shrink_factor,
                       _shrink_factor,
                       MinMetaspaceExpansion / (double) K);
@@ -1441,23 +1449,11 @@ void MetaspaceGC::compute_new_size() {
     }
   }
 
-
   // Don't shrink unless it's significant
-  if (shrink_words >= MinMetaspaceExpansion) {
+  if (shrink_bytes >= MinMetaspaceExpansion &&
-    VirtualSpaceNode* csp = vsl->current_virtual_space();
+      ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
-    size_t available_to_shrink = csp->capacity_words_in_vs() -
+    MetaspaceGC::set_capacity_until_GC(capacity_until_GC - shrink_bytes);
-      csp->used_words_in_vs();
-    shrink_words = MIN2(shrink_words, available_to_shrink);
-    csp->shrink_by(shrink_words);
-    MetaspaceGC::dec_capacity_until_GC(shrink_words);
-    if (PrintGCDetails && Verbose) {
-      size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
-      gclog_or_tty->print_cr("  metaspace HWM: %.1fK", new_capacity_until_GC / (double) K);
-    }
   }
-  assert(used_after_gc <= vsl->capacity_bytes_sum(),
-         "sanity check");
-
 }
 
 // Metadebug methods
@@ -1860,18 +1856,28 @@ size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
 }
 
 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
-  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
+  // For CMS use "allocated_chunks_words()" which does not need the
-  size_t sum = 0;
+  // Metaspace lock.  For the other collectors sum over the
-  for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
+  // lists.  Use both methods as a check that "allocated_chunks_words()"
-    Metachunk* chunk = chunks_in_use(i);
+  // is correct.  That is, sum_capacity_in_chunks() is too expensive
-    while (chunk != NULL) {
+  // to use in the product and allocated_chunks_words() should be used
-      // Just changed this sum += chunk->capacity_word_size();
+  // but allow for  checking that allocated_chunks_words() returns the same
-      // sum += chunk->word_size() - Metachunk::overhead();
+  // value as sum_capacity_in_chunks_in_use() which is the definitive
-      sum += chunk->capacity_word_size();
+  // answer.
-      chunk = chunk->next();
+  if (UseConcMarkSweepGC) {
+    return allocated_chunks_words();
+  } else {
+    MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
+    size_t sum = 0;
+    for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
+      Metachunk* chunk = chunks_in_use(i);
+      while (chunk != NULL) {
+        sum += chunk->capacity_word_size();
+        chunk = chunk->next();
+      }
     }
-  }
   return sum;
+  }
 }
 
 size_t SpaceManager::sum_count_in_chunks_in_use() {
@@ -2029,12 +2035,44 @@ void SpaceManager::print_on(outputStream* st) const {
 SpaceManager::SpaceManager(Mutex* lock,
                            VirtualSpaceList* vs_list) :
   _vs_list(vs_list),
-  _allocation_total(0),
+  _allocated_blocks_words(0),
+  _allocated_chunks_words(0),
+  _allocated_chunks_count(0),
   _lock(lock)
 {
   initialize();
 }
 
+void SpaceManager::inc_size_metrics(size_t words) {
+  assert_lock_strong(SpaceManager::expand_lock());
+  // Total of allocated Metachunks and allocated Metachunks count
+  // for each SpaceManager
+  _allocated_chunks_words = _allocated_chunks_words + words;
+  _allocated_chunks_count++;
+  // Global total of capacity in allocated Metachunks
+  MetaspaceAux::inc_capacity(words);
+  // Global total of allocated Metablocks.
+  // used_words_slow() includes the overhead in each
+  // Metachunk so include it in the used when the
+  // Metachunk is first added (so only added once per
+  // Metachunk).
+  MetaspaceAux::inc_used(Metachunk::overhead());
+}
+
+void SpaceManager::inc_used_metrics(size_t words) {
+  // Add to the per SpaceManager total
+  Atomic::add_ptr(words, &_allocated_blocks_words);
+  // Add to the global total
+  MetaspaceAux::inc_used(words);
+}
+
+void SpaceManager::dec_total_from_size_metrics() {
+  MetaspaceAux::dec_capacity(allocated_chunks_words());
+  MetaspaceAux::dec_used(allocated_blocks_words());
+  // Also deduct the overhead per Metachunk
+  MetaspaceAux::dec_used(allocated_chunks_count() * Metachunk::overhead());
+}
+
 void SpaceManager::initialize() {
   Metadebug::init_allocation_fail_alot_count();
   for (ChunkIndex i = ZeroIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
@@ -2073,7 +2111,10 @@ void ChunkManager::return_chunks(ChunkIndex index, Metachunk* chunks) {
 
 SpaceManager::~SpaceManager() {
   // This call this->_lock which can't be done while holding expand_lock()
-  const size_t in_use_before = sum_capacity_in_chunks_in_use();
+  assert(sum_capacity_in_chunks_in_use() == allocated_chunks_words(),
+    err_msg("sum_capacity_in_chunks_in_use() " SIZE_FORMAT
+            " allocated_chunks_words() " SIZE_FORMAT,
+            sum_capacity_in_chunks_in_use(), allocated_chunks_words()));
 
   MutexLockerEx fcl(SpaceManager::expand_lock(),
                     Mutex::_no_safepoint_check_flag);
@@ -2082,6 +2123,8 @@ SpaceManager::~SpaceManager() {
 
   chunk_manager->slow_locked_verify();
 
+  dec_total_from_size_metrics();
+
   if (TraceMetadataChunkAllocation && Verbose) {
     gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
     locked_print_chunks_in_use_on(gclog_or_tty);
@@ -2092,7 +2135,7 @@ SpaceManager::~SpaceManager() {
 
   // Have to update before the chunks_in_use lists are emptied
   // below.
-  chunk_manager->inc_free_chunks_total(in_use_before,
+  chunk_manager->inc_free_chunks_total(allocated_chunks_words(),
                                        sum_count_in_chunks_in_use());
 
   // Add all the chunks in use by this space manager
@@ -2158,7 +2201,6 @@ SpaceManager::~SpaceManager() {
                      chunk_manager->humongous_dictionary()->total_count(),
                      chunk_size_name(HumongousIndex));
   }
-  set_chunks_in_use(HumongousIndex, NULL);
   chunk_manager->slow_locked_verify();
 }
 
@@ -2238,12 +2280,17 @@ void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
     assert(new_chunk->word_size() > medium_chunk_size(), "List inconsistency");
   }
 
+  // Add to the running sum of capacity
+  inc_size_metrics(new_chunk->word_size());
+
   assert(new_chunk->is_empty(), "Not ready for reuse");
   if (TraceMetadataChunkAllocation && Verbose) {
     gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
                         sum_count_in_chunks_in_use());
     new_chunk->print_on(gclog_or_tty);
-    vs_list()->chunk_manager()->locked_print_free_chunks(tty);
+    if (vs_list() != NULL) {
+      vs_list()->chunk_manager()->locked_print_free_chunks(tty);
+    }
   }
 }
 
@@ -2314,7 +2361,7 @@ MetaWord* SpaceManager::allocate_work(size_t word_size) {
   // of memory if this returns null.
   if (DumpSharedSpaces) {
     assert(current_chunk() != NULL, "should never happen");
-    inc_allocation_total(word_size);
+    inc_used_metrics(word_size);
     return current_chunk()->allocate(word_size); // caller handles null result
   }
   if (current_chunk() != NULL) {
@@ -2325,7 +2372,7 @@ MetaWord* SpaceManager::allocate_work(size_t word_size) {
     result = grow_and_allocate(word_size);
   }
   if (result > 0) {
-    inc_allocation_total(word_size);
+    inc_used_metrics(word_size);
     assert(result != (MetaWord*) chunks_in_use(MediumIndex),
            "Head of the list is being allocated");
   }
@@ -2359,20 +2406,14 @@ void SpaceManager::verify_chunk_size(Metachunk* chunk) {
 }
 
 #ifdef ASSERT
-void SpaceManager::verify_allocation_total() {
+void SpaceManager::verify_allocated_blocks_words() {
   // Verification is only guaranteed at a safepoint.
-  if (SafepointSynchronize::is_at_safepoint()) {
+  assert(SafepointSynchronize::is_at_safepoint() || !Universe::is_fully_initialized(),
-    gclog_or_tty->print_cr("Chunk " PTR_FORMAT " allocation_total " SIZE_FORMAT
+    "Verification can fail if the applications is running");
-                           " sum_used_in_chunks_in_use " SIZE_FORMAT,
+  assert(allocated_blocks_words() == sum_used_in_chunks_in_use(),
-                           this,
-                           allocation_total(),
-                           sum_used_in_chunks_in_use());
-  }
-  MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
-  assert(allocation_total() == sum_used_in_chunks_in_use(),
     err_msg("allocation total is not consistent " SIZE_FORMAT
             " vs " SIZE_FORMAT,
-            allocation_total(), sum_used_in_chunks_in_use()));
+            allocated_blocks_words(), sum_used_in_chunks_in_use()));
 }
 
 #endif
@@ -2428,14 +2469,65 @@ void SpaceManager::mangle_freed_chunks() {
 
 // MetaspaceAux
 
-size_t MetaspaceAux::used_in_bytes(Metaspace::MetadataType mdtype) {
+
+size_t MetaspaceAux::_allocated_capacity_words = 0;
+size_t MetaspaceAux::_allocated_used_words = 0;
+
+size_t MetaspaceAux::free_bytes() {
+  size_t result = 0;
+  if (Metaspace::class_space_list() != NULL) {
+    result = result + Metaspace::class_space_list()->free_bytes();
+  }
+  if (Metaspace::space_list() != NULL) {
+    result = result + Metaspace::space_list()->free_bytes();
+  }
+  return result;
+}
+
+void MetaspaceAux::dec_capacity(size_t words) {
+  assert_lock_strong(SpaceManager::expand_lock());
+  assert(words <= _allocated_capacity_words,
+    err_msg("About to decrement below 0: words " SIZE_FORMAT
+            " is greater than _allocated_capacity_words " SIZE_FORMAT,
+            words, _allocated_capacity_words));
+  _allocated_capacity_words = _allocated_capacity_words - words;
+}
+
+void MetaspaceAux::inc_capacity(size_t words) {
+  assert_lock_strong(SpaceManager::expand_lock());
+  // Needs to be atomic
+  _allocated_capacity_words = _allocated_capacity_words + words;
+}
+
+void MetaspaceAux::dec_used(size_t words) {
+  assert(words <= _allocated_used_words,
+    err_msg("About to decrement below 0: words " SIZE_FORMAT
+            " is greater than _allocated_used_words " SIZE_FORMAT,
+            words, _allocated_used_words));
+  // For CMS deallocation of the Metaspaces occurs during the
+  // sweep which is a concurrent phase.  Protection by the expand_lock()
+  // is not enough since allocation is on a per Metaspace basis
+  // and protected by the Metaspace lock.
+  jlong minus_words = (jlong) - (jlong) words;
+  Atomic::add_ptr(minus_words, &_allocated_used_words);
+}
+
+void MetaspaceAux::inc_used(size_t words) {
+  // _allocated_used_words tracks allocations for
+  // each piece of metadata.  Those allocations are
+  // generally done concurrently by different application
+  // threads so must be done atomically.
+  Atomic::add_ptr(words, &_allocated_used_words);
+}
+
+size_t MetaspaceAux::used_bytes_slow(Metaspace::MetadataType mdtype) {
   size_t used = 0;
   ClassLoaderDataGraphMetaspaceIterator iter;
   while (iter.repeat()) {
     Metaspace* msp = iter.get_next();
-    // Sum allocation_total for each metaspace
+    // Sum allocated_blocks_words for each metaspace
     if (msp != NULL) {
-      used += msp->used_words(mdtype);
+      used += msp->used_words_slow(mdtype);
     }
   }
   return used * BytesPerWord;
@@ -2453,13 +2545,15 @@ size_t MetaspaceAux::free_in_bytes(Metaspace::MetadataType mdtype) {
   return free * BytesPerWord;
 }
 
-size_t MetaspaceAux::capacity_in_bytes(Metaspace::MetadataType mdtype) {
+size_t MetaspaceAux::capacity_bytes_slow(Metaspace::MetadataType mdtype) {
-  size_t capacity = free_chunks_total(mdtype);
+  // Don't count the space in the freelists.  That space will be
+  // added to the capacity calculation as needed.
+  size_t capacity = 0;
   ClassLoaderDataGraphMetaspaceIterator iter;
   while (iter.repeat()) {
     Metaspace* msp = iter.get_next();
     if (msp != NULL) {
-      capacity += msp->capacity_words(mdtype);
+      capacity += msp->capacity_words_slow(mdtype);
     }
   }
   return capacity * BytesPerWord;
@@ -2486,23 +2580,30 @@ size_t MetaspaceAux::free_chunks_total_in_bytes(Metaspace::MetadataType mdtype)
   return free_chunks_total(mdtype) * BytesPerWord;
 }
 
+size_t MetaspaceAux::free_chunks_total() {
+  return free_chunks_total(Metaspace::ClassType) +
+         free_chunks_total(Metaspace::NonClassType);
+}
+
+size_t MetaspaceAux::free_chunks_total_in_bytes() {
+  return free_chunks_total() * BytesPerWord;
+}
+
 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
   gclog_or_tty->print(", [Metaspace:");
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print(" "  SIZE_FORMAT
                         "->" SIZE_FORMAT
-                        "("  SIZE_FORMAT "/" SIZE_FORMAT ")",
+                        "("  SIZE_FORMAT ")",
                         prev_metadata_used,
-                        used_in_bytes(),
+                        allocated_capacity_bytes(),
-                        capacity_in_bytes(),
                         reserved_in_bytes());
   } else {
     gclog_or_tty->print(" "  SIZE_FORMAT "K"
                         "->" SIZE_FORMAT "K"
-                        "("  SIZE_FORMAT "K/" SIZE_FORMAT "K)",
+                        "("  SIZE_FORMAT "K)",
                         prev_metadata_used / K,
-                        used_in_bytes()/ K,
+                        allocated_capacity_bytes() / K,
-                        capacity_in_bytes()/K,
                         reserved_in_bytes()/ K);
   }
 
@@ -2517,23 +2618,30 @@ void MetaspaceAux::print_on(outputStream* out) {
   out->print_cr(" Metaspace total "
                 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
                 " reserved " SIZE_FORMAT "K",
-                capacity_in_bytes()/K, used_in_bytes()/K, reserved_in_bytes()/K);
+                allocated_capacity_bytes()/K, allocated_used_bytes()/K, reserved_in_bytes()/K);
-  out->print_cr("  data space     "
+#if 0
-                SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
+// The calls to capacity_bytes_slow() and used_bytes_slow() cause
-                " reserved " SIZE_FORMAT "K",
+// lock ordering assertion failures with some collectors.  Do
-                capacity_in_bytes(nct)/K, used_in_bytes(nct)/K, reserved_in_bytes(nct)/K);
+// not include this code until the lock ordering is fixed.
-  out->print_cr("  class space    "
+  if (PrintGCDetails && Verbose) {
-                SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
+    out->print_cr("  data space     "
-                " reserved " SIZE_FORMAT "K",
+                  SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
-                capacity_in_bytes(ct)/K, used_in_bytes(ct)/K, reserved_in_bytes(ct)/K);
+                  " reserved " SIZE_FORMAT "K",
+                  capacity_bytes_slow(nct)/K, used_bytes_slow(nct)/K, reserved_in_bytes(nct)/K);
+    out->print_cr("  class space    "
+                  SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
+                  " reserved " SIZE_FORMAT "K",
+                  capacity_bytes_slow(ct)/K, used_bytes_slow(ct)/K, reserved_in_bytes(ct)/K);
+  }
+#endif
 }
 
 // Print information for class space and data space separately.
 // This is almost the same as above.
 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
   size_t free_chunks_capacity_bytes = free_chunks_total_in_bytes(mdtype);
-  size_t capacity_bytes = capacity_in_bytes(mdtype);
+  size_t capacity_bytes = capacity_bytes_slow(mdtype);
-  size_t used_bytes = used_in_bytes(mdtype);
+  size_t used_bytes = used_bytes_slow(mdtype);
   size_t free_bytes = free_in_bytes(mdtype);
   size_t used_and_free = used_bytes + free_bytes +
                            free_chunks_capacity_bytes;
@@ -2606,6 +2714,36 @@ void MetaspaceAux::verify_free_chunks() {
   Metaspace::class_space_list()->chunk_manager()->verify();
 }
 
+void MetaspaceAux::verify_capacity() {
+#ifdef ASSERT
+  size_t running_sum_capacity_bytes = allocated_capacity_bytes();
+  // For purposes of the running sum of used, verify against capacity
+  size_t capacity_in_use_bytes = capacity_bytes_slow();
+  assert(running_sum_capacity_bytes == capacity_in_use_bytes,
+    err_msg("allocated_capacity_words() * BytesPerWord " SIZE_FORMAT
+            " capacity_bytes_slow()" SIZE_FORMAT,
+            running_sum_capacity_bytes, capacity_in_use_bytes));
+#endif
+}
+
+void MetaspaceAux::verify_used() {
+#ifdef ASSERT
+  size_t running_sum_used_bytes = allocated_used_bytes();
+  // For purposes of the running sum of used, verify against capacity
+  size_t used_in_use_bytes = used_bytes_slow();
+  assert(allocated_used_bytes() == used_in_use_bytes,
+    err_msg("allocated_used_bytes() " SIZE_FORMAT
+            " used_bytes_slow()()" SIZE_FORMAT,
+            allocated_used_bytes(), used_in_use_bytes));
+#endif
+}
+
+void MetaspaceAux::verify_metrics() {
+  verify_capacity();
+  verify_used();
+}
+
+
 // Metaspace methods
 
 size_t Metaspace::_first_chunk_word_size = 0;
@@ -2755,8 +2893,8 @@ MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype)
   MetaWord* result;
   MetaspaceGC::set_expand_after_GC(true);
   size_t before_inc = MetaspaceGC::capacity_until_GC();
-  size_t delta_words = MetaspaceGC::delta_capacity_until_GC(word_size);
+  size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size) * BytesPerWord;
-  MetaspaceGC::inc_capacity_until_GC(delta_words);
+  MetaspaceGC::inc_capacity_until_GC(delta_bytes);
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
       " to " SIZE_FORMAT, before_inc, MetaspaceGC::capacity_until_GC());
@@ -2774,8 +2912,8 @@ char* Metaspace::bottom() const {
   return (char*)vsm()->current_chunk()->bottom();
 }
 
-size_t Metaspace::used_words(MetadataType mdtype) const {
+size_t Metaspace::used_words_slow(MetadataType mdtype) const {
-  // return vsm()->allocation_total();
+  // return vsm()->allocated_used_words();
   return mdtype == ClassType ? class_vsm()->sum_used_in_chunks_in_use() :
                                vsm()->sum_used_in_chunks_in_use();  // includes overhead!
 }
@@ -2790,11 +2928,19 @@ size_t Metaspace::free_words(MetadataType mdtype) const {
 // have been made. Don't include space in the global freelist and
 // in the space available in the dictionary which
 // is already counted in some chunk.
-size_t Metaspace::capacity_words(MetadataType mdtype) const {
+size_t Metaspace::capacity_words_slow(MetadataType mdtype) const {
   return mdtype == ClassType ? class_vsm()->sum_capacity_in_chunks_in_use() :
                                vsm()->sum_capacity_in_chunks_in_use();
 }
 
+size_t Metaspace::used_bytes_slow(MetadataType mdtype) const {
+  return used_words_slow(mdtype) * BytesPerWord;
+}
+
+size_t Metaspace::capacity_bytes_slow(MetadataType mdtype) const {
+  return capacity_words_slow(mdtype) * BytesPerWord;
+}
+
 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
   if (SafepointSynchronize::is_at_safepoint()) {
     assert(Thread::current()->is_VM_thread(), "should be the VM thread");
@@ -2921,10 +3067,6 @@ void Metaspace::verify() {
 }
 
 void Metaspace::dump(outputStream* const out) const {
-  if (UseMallocOnly) {
-    // Just print usage for now
-    out->print_cr("usage %d", used_words(Metaspace::NonClassType));
-  }
   out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
   vsm()->dump(out);
   out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());

hotspot/src/share/vm/memory/metaspace.hpp

@@ -111,6 +111,10 @@ class Metaspace : public CHeapObj<mtClass> {
   SpaceManager* _class_vsm;
   SpaceManager* class_vsm() const { return _class_vsm; }
 
+  // Allocate space for metadata of type mdtype. This is space
+  // within a Metachunk and is used by
+  //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
+  // which returns a Metablock.
   MetaWord* allocate(size_t word_size, MetadataType mdtype);
 
   // Virtual Space lists for both classes and other metadata
@@ -133,11 +137,14 @@ class Metaspace : public CHeapObj<mtClass> {
   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
 
   char*  bottom() const;
-  size_t used_words(MetadataType mdtype) const;
+  size_t used_words_slow(MetadataType mdtype) const;
   size_t free_words(MetadataType mdtype) const;
-  size_t capacity_words(MetadataType mdtype) const;
+  size_t capacity_words_slow(MetadataType mdtype) const;
   size_t waste_words(MetadataType mdtype) const;
 
+  size_t used_bytes_slow(MetadataType mdtype) const;
+  size_t capacity_bytes_slow(MetadataType mdtype) const;
+
   static Metablock* allocate(ClassLoaderData* loader_data, size_t size,
                             bool read_only, MetadataType mdtype, TRAPS);
   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
@@ -161,28 +168,81 @@ class Metaspace : public CHeapObj<mtClass> {
 class MetaspaceAux : AllStatic {
 
   // Statistics for class space and data space in metaspace.
-  static size_t used_in_bytes(Metaspace::MetadataType mdtype);
+
+  // These methods iterate over the classloader data graph
+  // for the given Metaspace type.  These are slow.
+  static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
   static size_t free_in_bytes(Metaspace::MetadataType mdtype);
-  static size_t capacity_in_bytes(Metaspace::MetadataType mdtype);
+  static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
+
+  // Iterates over the virtual space list.
   static size_t reserved_in_bytes(Metaspace::MetadataType mdtype);
 
   static size_t free_chunks_total(Metaspace::MetadataType mdtype);
   static size_t free_chunks_total_in_bytes(Metaspace::MetadataType mdtype);
 
  public:
-  // Total of space allocated to metadata in all Metaspaces
+  // Running sum of space in all Metachunks that has been
-  static size_t used_in_bytes() {
+  // allocated to a Metaspace.  This is used instead of
-    return used_in_bytes(Metaspace::ClassType) +
+  // iterating over all the classloaders
-           used_in_bytes(Metaspace::NonClassType);
+  static size_t _allocated_capacity_words;
+  // Running sum of space in all Metachunks that have
+  // are being used for metadata.
+  static size_t _allocated_used_words;
+
+ public:
+  // Decrement and increment _allocated_capacity_words
+  static void dec_capacity(size_t words);
+  static void inc_capacity(size_t words);
+
+  // Decrement and increment _allocated_used_words
+  static void dec_used(size_t words);
+  static void inc_used(size_t words);
+
+  // Total of space allocated to metadata in all Metaspaces.
+  // This sums the space used in each Metachunk by
+  // iterating over the classloader data graph
+  static size_t used_bytes_slow() {
+    return used_bytes_slow(Metaspace::ClassType) +
+           used_bytes_slow(Metaspace::NonClassType);
   }
 
-  // Total of available space in all Metaspaces
+  // Used by MetaspaceCounters
-  // Total of capacity allocated to all Metaspaces.  This includes
+  static size_t free_chunks_total();
-  // space in Metachunks not yet allocated and in the Metachunk
+  static size_t free_chunks_total_in_bytes();
-  // freelist.
+
-  static size_t capacity_in_bytes() {
+  static size_t allocated_capacity_words() {
-    return capacity_in_bytes(Metaspace::ClassType) +
+    return _allocated_capacity_words;
-           capacity_in_bytes(Metaspace::NonClassType);
+  }
+  static size_t allocated_capacity_bytes() {
+    return _allocated_capacity_words * BytesPerWord;
+  }
+
+  static size_t allocated_used_words() {
+    return _allocated_used_words;
+  }
+  static size_t allocated_used_bytes() {
+    return _allocated_used_words * BytesPerWord;
+  }
+
+  static size_t free_bytes();
+
+  // Total capacity in all Metaspaces
+  static size_t capacity_bytes_slow() {
+#ifdef PRODUCT
+    // Use allocated_capacity_bytes() in PRODUCT instead of this function.
+    guarantee(false, "Should not call capacity_bytes_slow() in the PRODUCT");
+#endif
+    size_t class_capacity = capacity_bytes_slow(Metaspace::ClassType);
+    size_t non_class_capacity = capacity_bytes_slow(Metaspace::NonClassType);
+    assert(allocated_capacity_bytes() == class_capacity + non_class_capacity,
+           err_msg("bad accounting: allocated_capacity_bytes() " SIZE_FORMAT
+             " class_capacity + non_class_capacity " SIZE_FORMAT
+             " class_capacity " SIZE_FORMAT " non_class_capacity " SIZE_FORMAT,
+             allocated_capacity_bytes(), class_capacity + non_class_capacity,
+             class_capacity, non_class_capacity));
+
+    return class_capacity + non_class_capacity;
   }
 
   // Total space reserved in all Metaspaces
@@ -201,6 +261,11 @@ class MetaspaceAux : AllStatic {
   static void print_waste(outputStream* out);
   static void dump(outputStream* out);
   static void verify_free_chunks();
+  // Checks that the values returned by allocated_capacity_bytes() and
+  // capacity_bytes_slow() are the same.
+  static void verify_capacity();
+  static void verify_used();
+  static void verify_metrics();
 };
 
 // Metaspace are deallocated when their class loader are GC'ed.
@@ -235,7 +300,6 @@ class MetaspaceGC : AllStatic {
  public:
 
   static size_t capacity_until_GC() { return _capacity_until_GC; }
-  static size_t capacity_until_GC_in_bytes() { return _capacity_until_GC * BytesPerWord; }
   static void inc_capacity_until_GC(size_t v) { _capacity_until_GC += v; }
   static void dec_capacity_until_GC(size_t v) {
     _capacity_until_GC = _capacity_until_GC > v ? _capacity_until_GC - v : 0;

hotspot/src/share/vm/memory/metaspaceCounters.cpp

@@ -29,6 +29,16 @@
 
 MetaspaceCounters* MetaspaceCounters::_metaspace_counters = NULL;
 
+size_t MetaspaceCounters::calc_total_capacity() {
+  // The total capacity is the sum of
+  //   1) capacity of Metachunks in use by all Metaspaces
+  //   2) unused space at the end of each Metachunk
+  //   3) space in the freelist
+  size_t total_capacity = MetaspaceAux::allocated_capacity_bytes()
+    + MetaspaceAux::free_bytes() + MetaspaceAux::free_chunks_total_in_bytes();
+  return total_capacity;
+}
+
 MetaspaceCounters::MetaspaceCounters() :
     _capacity(NULL),
     _used(NULL),
@@ -36,8 +46,8 @@ MetaspaceCounters::MetaspaceCounters() :
   if (UsePerfData) {
     size_t min_capacity = MetaspaceAux::min_chunk_size();
     size_t max_capacity = MetaspaceAux::reserved_in_bytes();
-    size_t curr_capacity = MetaspaceAux::capacity_in_bytes();
+    size_t curr_capacity = calc_total_capacity();
-    size_t used = MetaspaceAux::used_in_bytes();
+    size_t used = MetaspaceAux::allocated_used_bytes();
 
     initialize(min_capacity, max_capacity, curr_capacity, used);
   }
@@ -82,15 +92,13 @@ void MetaspaceCounters::initialize(size_t min_capacity,
 
 void MetaspaceCounters::update_capacity() {
   assert(UsePerfData, "Should not be called unless being used");
-  assert(_capacity != NULL, "Should be initialized");
+  size_t total_capacity = calc_total_capacity();
-  size_t capacity_in_bytes = MetaspaceAux::capacity_in_bytes();
+  _capacity->set_value(total_capacity);
-  _capacity->set_value(capacity_in_bytes);
 }
 
 void MetaspaceCounters::update_used() {
   assert(UsePerfData, "Should not be called unless being used");
-  assert(_used != NULL, "Should be initialized");
+  size_t used_in_bytes = MetaspaceAux::allocated_used_bytes();
-  size_t used_in_bytes = MetaspaceAux::used_in_bytes();
   _used->set_value(used_in_bytes);
 }
 

hotspot/src/share/vm/memory/metaspaceCounters.hpp

@@ -37,6 +37,7 @@ class MetaspaceCounters: public CHeapObj<mtClass> {
                   size_t max_capacity,
                   size_t curr_capacity,
                   size_t used);
+  size_t calc_total_capacity();
  public:
   MetaspaceCounters();
   ~MetaspaceCounters();

hotspot/src/share/vm/memory/metaspaceShared.cpp

@@ -376,18 +376,17 @@ void VM_PopulateDumpSharedSpace::doit() {
   const char* fmt = "%s space: %9d [ %4.1f%% of total] out of %9d bytes [%4.1f%% used] at " PTR_FORMAT;
   Metaspace* ro_space = _loader_data->ro_metaspace();
   Metaspace* rw_space = _loader_data->rw_metaspace();
-  const size_t BPW = BytesPerWord;
 
   // Allocated size of each space (may not be all occupied)
-  const size_t ro_alloced = ro_space->capacity_words(Metaspace::NonClassType) * BPW;
+  const size_t ro_alloced = ro_space->capacity_bytes_slow(Metaspace::NonClassType);
-  const size_t rw_alloced = rw_space->capacity_words(Metaspace::NonClassType) * BPW;
+  const size_t rw_alloced = rw_space->capacity_bytes_slow(Metaspace::NonClassType);
   const size_t md_alloced = md_end-md_low;
   const size_t mc_alloced = mc_end-mc_low;
   const size_t total_alloced = ro_alloced + rw_alloced + md_alloced + mc_alloced;
 
   // Occupied size of each space.
-  const size_t ro_bytes = ro_space->used_words(Metaspace::NonClassType) * BPW;
+  const size_t ro_bytes = ro_space->used_bytes_slow(Metaspace::NonClassType);
-  const size_t rw_bytes = rw_space->used_words(Metaspace::NonClassType) * BPW;
+  const size_t rw_bytes = rw_space->used_bytes_slow(Metaspace::NonClassType);
   const size_t md_bytes = size_t(md_top - md_low);
   const size_t mc_bytes = size_t(mc_top - mc_low);