Merge

.hgtags

@@ -381,3 +381,5 @@ a09fe9d1e016c285307507a5793bc4fa6215e9c9 hs25-b50
 566db1b0e6efca31f181456e54c8911d0192410d hs25-b51
 c81dd5393a5e333df7cb1f6621f5897ada6522b5 jdk8-b109
 58043478c26d4e8bf48700acea5f97aba8b417d4 hs25-b52
+6209b0ed51c086d4127bac0e086c8f326d1764d7 jdk8-b110
+562a3d356de67670b4172b82aca2d30743449e04 hs25-b53

agent/src/share/classes/sun/jvm/hotspot/memory/ProtectionDomainCacheEntry.java

+/*
+ * Copyright (c) 2001, 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.
+ *
+ */
+
+package sun.jvm.hotspot.memory;
+
+import java.util.*;
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.oops.*;
+import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.types.*;
+
+public class ProtectionDomainCacheEntry extends VMObject {
+  private static sun.jvm.hotspot.types.OopField protectionDomainField;
+
+  static {
+    VM.registerVMInitializedObserver(new Observer() {
+        public void update(Observable o, Object data) {
+          initialize(VM.getVM().getTypeDataBase());
+        }
+      });
+  }
+
+  private static synchronized void initialize(TypeDataBase db) {
+    Type type = db.lookupType("ProtectionDomainCacheEntry");
+    protectionDomainField = type.getOopField("_literal");
+  }
+
+  public ProtectionDomainCacheEntry(Address addr) {
+    super(addr);
+  }
+
+  public Oop protectionDomain() {
+    return VM.getVM().getObjectHeap().newOop(protectionDomainField.getValue(addr));
+  }
+}

agent/src/share/classes/sun/jvm/hotspot/memory/ProtectionDomainEntry.java

 /*
- * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 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
@@ -32,7 +32,7 @@ import sun.jvm.hotspot.types.*;
 
 public class ProtectionDomainEntry extends VMObject {
   private static AddressField nextField;
-  private static sun.jvm.hotspot.types.OopField protectionDomainField;
+  private static AddressField pdCacheField;
 
   static {
     VM.registerVMInitializedObserver(new Observer() {
@@ -46,7 +46,7 @@ public class ProtectionDomainEntry extends VMObject {
     Type type = db.lookupType("ProtectionDomainEntry");
 
     nextField = type.getAddressField("_next");
-    protectionDomainField = type.getOopField("_protection_domain");
+    pdCacheField = type.getAddressField("_pd_cache");
   }
 
   public ProtectionDomainEntry(Address addr) {
@@ -54,10 +54,12 @@ public class ProtectionDomainEntry extends VMObject {
   }
 
   public ProtectionDomainEntry next() {
-    return (ProtectionDomainEntry) VMObjectFactory.newObject(ProtectionDomainEntry.class, addr);
+    return (ProtectionDomainEntry) VMObjectFactory.newObject(ProtectionDomainEntry.class, nextField.getValue(addr));
   }
 
   public Oop protectionDomain() {
-    return VM.getVM().getObjectHeap().newOop(protectionDomainField.getValue(addr));
+    ProtectionDomainCacheEntry pd_cache = (ProtectionDomainCacheEntry)
+      VMObjectFactory.newObject(ProtectionDomainCacheEntry.class, pdCacheField.getValue(addr));
+    return pd_cache.protectionDomain();
   }
 }

make/hotspot_version

@@ -35,7 +35,7 @@ HOTSPOT_VM_COPYRIGHT=Copyright 2013
 
 HS_MAJOR_VER=25
 HS_MINOR_VER=0
-HS_BUILD_NUMBER=53
+HS_BUILD_NUMBER=54
 
 JDK_MAJOR_VER=1
 JDK_MINOR_VER=8

src/cpu/sparc/vm/c1_Runtime1_sparc.cpp

@@ -37,6 +37,9 @@
 #include "runtime/vframeArray.hpp"
 #include "utilities/macros.hpp"
 #include "vmreg_sparc.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
+#endif
 
 // Implementation of StubAssembler
 
@@ -912,7 +915,7 @@ OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
         Register tmp2 = G3_scratch;
         jbyte* byte_map_base = ((CardTableModRefBS*)bs)->byte_map_base;
 
-        Label not_already_dirty, restart, refill;
+        Label not_already_dirty, restart, refill, young_card;
 
 #ifdef _LP64
         __ srlx(addr, CardTableModRefBS::card_shift, addr);
@@ -924,9 +927,15 @@ OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
         __ set(rs, cardtable);         // cardtable := <card table base>
         __ ldub(addr, cardtable, tmp); // tmp := [addr + cardtable]
 
+        __ cmp_and_br_short(tmp, G1SATBCardTableModRefBS::g1_young_card_val(), Assembler::equal, Assembler::pt, young_card);
+
+        __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+        __ ldub(addr, cardtable, tmp); // tmp := [addr + cardtable]
+
         assert(CardTableModRefBS::dirty_card_val() == 0, "otherwise check this code");
         __ cmp_and_br_short(tmp, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);
 
+        __ bind(young_card);
         // We didn't take the branch, so we're already dirty: return.
         // Use return-from-leaf
         __ retl();

src/cpu/sparc/vm/macroAssembler_sparc.cpp

@@ -3752,7 +3752,7 @@ static void generate_dirty_card_log_enqueue(jbyte* byte_map_base) {
 #define __ masm.
   address start = __ pc();
 
-  Label not_already_dirty, restart, refill;
+  Label not_already_dirty, restart, refill, young_card;
 
 #ifdef _LP64
   __ srlx(O0, CardTableModRefBS::card_shift, O0);
@@ -3763,9 +3763,15 @@ static void generate_dirty_card_log_enqueue(jbyte* byte_map_base) {
   __ set(addrlit, O1); // O1 := <card table base>
   __ ldub(O0, O1, O2); // O2 := [O0 + O1]
 
+  __ cmp_and_br_short(O2, G1SATBCardTableModRefBS::g1_young_card_val(), Assembler::equal, Assembler::pt, young_card);
+
+  __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+  __ ldub(O0, O1, O2); // O2 := [O0 + O1]
+
   assert(CardTableModRefBS::dirty_card_val() == 0, "otherwise check this code");
   __ cmp_and_br_short(O2, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);
 
+  __ bind(young_card);
   // We didn't take the branch, so we're already dirty: return.
   // Use return-from-leaf
   __ retl();

src/cpu/x86/vm/c1_Runtime1_x86.cpp

@@ -38,6 +38,9 @@
 #include "runtime/vframeArray.hpp"
 #include "utilities/macros.hpp"
 #include "vmreg_x86.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
+#endif
 
 
 // Implementation of StubAssembler
@@ -1753,13 +1756,17 @@ OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
         __ leal(card_addr, __ as_Address(ArrayAddress(cardtable, index)));
 #endif
 
-        __ cmpb(Address(card_addr, 0), 0);
+        __ cmpb(Address(card_addr, 0), (int)G1SATBCardTableModRefBS::g1_young_card_val());
+        __ jcc(Assembler::equal, done);
+
+        __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+        __ cmpb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
         __ jcc(Assembler::equal, done);
 
         // storing region crossing non-NULL, card is clean.
         // dirty card and log.
 
-        __ movb(Address(card_addr, 0), 0);
+        __ movb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
 
         __ cmpl(queue_index, 0);
         __ jcc(Assembler::equal, runtime);

src/cpu/x86/vm/macroAssembler_x86.cpp

@@ -3389,13 +3389,18 @@ void MacroAssembler::g1_write_barrier_post(Register store_addr,
   const Register card_addr = tmp;
   lea(card_addr, as_Address(ArrayAddress(cardtable, index)));
 #endif
-  cmpb(Address(card_addr, 0), 0);
+  cmpb(Address(card_addr, 0), (int)G1SATBCardTableModRefBS::g1_young_card_val());
   jcc(Assembler::equal, done);
 
+  membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));
+  cmpb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
+  jcc(Assembler::equal, done);
+
+
   // storing a region crossing, non-NULL oop, card is clean.
   // dirty card and log.
 
-  movb(Address(card_addr, 0), 0);
+  movb(Address(card_addr, 0), (int)CardTableModRefBS::dirty_card_val());
 
   cmpl(queue_index, 0);
   jcc(Assembler::equal, runtime);

src/os/linux/vm/globals_linux.hpp

@@ -53,7 +53,7 @@
 // Defines Linux-specific default values. The flags are available on all
 // platforms, but they may have different default values on other platforms.
 //
-define_pd_global(bool, UseLargePages, true);
+define_pd_global(bool, UseLargePages, false);
 define_pd_global(bool, UseLargePagesIndividualAllocation, false);
 define_pd_global(bool, UseOSErrorReporting, false);
 define_pd_global(bool, UseThreadPriorities, true) ;

src/os/linux/vm/os_linux.cpp

@@ -3361,13 +3361,15 @@ bool os::Linux::setup_large_page_type(size_t page_size) {
   if (FLAG_IS_DEFAULT(UseHugeTLBFS) &&
       FLAG_IS_DEFAULT(UseSHM) &&
       FLAG_IS_DEFAULT(UseTransparentHugePages)) {
-    // If UseLargePages is specified on the command line try all methods,
-    // if it's default, then try only UseTransparentHugePages.
-    if (FLAG_IS_DEFAULT(UseLargePages)) {
-      UseTransparentHugePages = true;
-    } else {
-      UseHugeTLBFS = UseTransparentHugePages = UseSHM = true;
-    }
+
+    // The type of large pages has not been specified by the user.
+
+    // Try UseHugeTLBFS and then UseSHM.
+    UseHugeTLBFS = UseSHM = true;
+
+    // Don't try UseTransparentHugePages since there are known
+    // performance issues with it turned on. This might change in the future.
+    UseTransparentHugePages = false;
   }
 
   if (UseTransparentHugePages) {
@@ -3393,9 +3395,19 @@ bool os::Linux::setup_large_page_type(size_t page_size) {
 }
 
 void os::large_page_init() {
-  if (!UseLargePages) {
-    UseHugeTLBFS = false;
+  if (!UseLargePages &&
+      !UseTransparentHugePages &&
+      !UseHugeTLBFS &&
+      !UseSHM) {
+    // Not using large pages.
+    return;
+  }
+
+  if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) {
+    // The user explicitly turned off large pages.
+    // Ignore the rest of the large pages flags.
     UseTransparentHugePages = false;
+    UseHugeTLBFS = false;
     UseSHM = false;
     return;
   }

src/share/vm/classfile/dictionary.cpp

 /*
- * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 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
@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "classfile/dictionary.hpp"
 #include "classfile/systemDictionary.hpp"
+#include "memory/iterator.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
 #include "utilities/hashtable.inline.hpp"
@@ -38,17 +39,21 @@ Dictionary::Dictionary(int table_size)
   : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry)) {
   _current_class_index = 0;
   _current_class_entry = NULL;
+  _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
 };
 
 
-
 Dictionary::Dictionary(int table_size, HashtableBucket<mtClass>* t,
                        int number_of_entries)
   : TwoOopHashtable<Klass*, mtClass>(table_size, sizeof(DictionaryEntry), t, number_of_entries) {
   _current_class_index = 0;
   _current_class_entry = NULL;
+  _pd_cache_table = new ProtectionDomainCacheTable(defaultProtectionDomainCacheSize);
 };
 
+ProtectionDomainCacheEntry* Dictionary::cache_get(oop protection_domain) {
+  return _pd_cache_table->get(protection_domain);
+}
 
 DictionaryEntry* Dictionary::new_entry(unsigned int hash, Klass* klass,
                                        ClassLoaderData* loader_data) {
@@ -105,11 +110,12 @@ bool DictionaryEntry::contains_protection_domain(oop protection_domain) const {
 }
 
 
-void DictionaryEntry::add_protection_domain(oop protection_domain) {
+void DictionaryEntry::add_protection_domain(Dictionary* dict, oop protection_domain) {
   assert_locked_or_safepoint(SystemDictionary_lock);
   if (!contains_protection_domain(protection_domain)) {
+    ProtectionDomainCacheEntry* entry = dict->cache_get(protection_domain);
     ProtectionDomainEntry* new_head =
-                new ProtectionDomainEntry(protection_domain, _pd_set);
+                new ProtectionDomainEntry(entry, _pd_set);
     // Warning: Preserve store ordering.  The SystemDictionary is read
     //          without locks.  The new ProtectionDomainEntry must be
     //          complete before other threads can be allowed to see it
@@ -193,7 +199,10 @@ bool Dictionary::do_unloading() {
 
 
 void Dictionary::always_strong_oops_do(OopClosure* blk) {
-  // Follow all system classes and temporary placeholders in dictionary
+  // Follow all system classes and temporary placeholders in dictionary; only
+  // protection domain oops contain references into the heap. In a first
+  // pass over the system dictionary determine which need to be treated as
+  // strongly reachable and mark them as such.
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry *probe = bucket(index);
                           probe != NULL;
@@ -201,10 +210,13 @@ void Dictionary::always_strong_oops_do(OopClosure* blk) {
       Klass* e = probe->klass();
       ClassLoaderData* loader_data = probe->loader_data();
       if (is_strongly_reachable(loader_data, e)) {
-        probe->protection_domain_set_oops_do(blk);
+        probe->set_strongly_reachable();
       }
     }
   }
+  // Then iterate over the protection domain cache to apply the closure on the
+  // previously marked ones.
+  _pd_cache_table->always_strong_oops_do(blk);
 }
 
 
@@ -266,18 +278,12 @@ void Dictionary::classes_do(void f(Klass*, ClassLoaderData*)) {
   }
 }
 
-
 void Dictionary::oops_do(OopClosure* f) {
-  for (int index = 0; index < table_size(); index++) {
-    for (DictionaryEntry* probe = bucket(index);
-                          probe != NULL;
-                          probe = probe->next()) {
-      probe->protection_domain_set_oops_do(f);
-    }
-  }
+  // Only the protection domain oops contain references into the heap. Iterate
+  // over all of them.
+  _pd_cache_table->oops_do(f);
 }
 
-
 void Dictionary::methods_do(void f(Method*)) {
   for (int index = 0; index < table_size(); index++) {
     for (DictionaryEntry* probe = bucket(index);
@@ -292,6 +298,11 @@ void Dictionary::methods_do(void f(Method*)) {
   }
 }
 
+void Dictionary::unlink(BoolObjectClosure* is_alive) {
+  // Only the protection domain cache table may contain references to the heap
+  // that need to be unlinked.
+  _pd_cache_table->unlink(is_alive);
+}
 
 Klass* Dictionary::try_get_next_class() {
   while (true) {
@@ -306,7 +317,6 @@ Klass* Dictionary::try_get_next_class() {
   // never reached
 }
 
-
 // Add a loaded class to the system dictionary.
 // Readers of the SystemDictionary aren't always locked, so _buckets
 // is volatile. The store of the next field in the constructor is
@@ -396,7 +406,7 @@ void Dictionary::add_protection_domain(int index, unsigned int hash,
   assert(protection_domain() != NULL,
          "real protection domain should be present");
 
-  entry->add_protection_domain(protection_domain());
+  entry->add_protection_domain(this, protection_domain());
 
   assert(entry->contains_protection_domain(protection_domain()),
          "now protection domain should be present");
@@ -446,6 +456,146 @@ void Dictionary::reorder_dictionary() {
   }
 }
 
+ProtectionDomainCacheTable::ProtectionDomainCacheTable(int table_size)
+  : Hashtable<oop, mtClass>(table_size, sizeof(ProtectionDomainCacheEntry))
+{
+}
+
+void ProtectionDomainCacheTable::unlink(BoolObjectClosure* is_alive) {
+  assert(SafepointSynchronize::is_at_safepoint(), "must be");
+  for (int i = 0; i < table_size(); ++i) {
+    ProtectionDomainCacheEntry** p = bucket_addr(i);
+    ProtectionDomainCacheEntry* entry = bucket(i);
+    while (entry != NULL) {
+      if (is_alive->do_object_b(entry->literal())) {
+        p = entry->next_addr();
+      } else {
+        *p = entry->next();
+        free_entry(entry);
+      }
+      entry = *p;
+    }
+  }
+}
+
+void ProtectionDomainCacheTable::oops_do(OopClosure* f) {
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      probe->oops_do(f);
+    }
+  }
+}
+
+uint ProtectionDomainCacheTable::bucket_size() {
+  return sizeof(ProtectionDomainCacheEntry);
+}
+
+#ifndef PRODUCT
+void ProtectionDomainCacheTable::print() {
+  tty->print_cr("Protection domain cache table (table_size=%d, classes=%d)",
+                table_size(), number_of_entries());
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      probe->print();
+    }
+  }
+}
+
+void ProtectionDomainCacheEntry::print() {
+  tty->print_cr("entry "PTR_FORMAT" value "PTR_FORMAT" strongly_reachable %d next "PTR_FORMAT,
+                this, (void*)literal(), _strongly_reachable, next());
+}
+#endif
+
+void ProtectionDomainCacheTable::verify() {
+  int element_count = 0;
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      probe->verify();
+      element_count++;
+    }
+  }
+  guarantee(number_of_entries() == element_count,
+            "Verify of protection domain cache table failed");
+  debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
+}
+
+void ProtectionDomainCacheEntry::verify() {
+  guarantee(literal()->is_oop(), "must be an oop");
+}
+
+void ProtectionDomainCacheTable::always_strong_oops_do(OopClosure* f) {
+  // the caller marked the protection domain cache entries that we need to apply
+  // the closure on. Only process them.
+  for (int index = 0; index < table_size(); index++) {
+    for (ProtectionDomainCacheEntry* probe = bucket(index);
+                                     probe != NULL;
+                                     probe = probe->next()) {
+      if (probe->is_strongly_reachable()) {
+        probe->reset_strongly_reachable();
+        probe->oops_do(f);
+      }
+    }
+  }
+}
+
+ProtectionDomainCacheEntry* ProtectionDomainCacheTable::get(oop protection_domain) {
+  unsigned int hash = compute_hash(protection_domain);
+  int index = hash_to_index(hash);
+
+  ProtectionDomainCacheEntry* entry = find_entry(index, protection_domain);
+  if (entry == NULL) {
+    entry = add_entry(index, hash, protection_domain);
+  }
+  return entry;
+}
+
+ProtectionDomainCacheEntry* ProtectionDomainCacheTable::find_entry(int index, oop protection_domain) {
+  for (ProtectionDomainCacheEntry* e = bucket(index); e != NULL; e = e->next()) {
+    if (e->protection_domain() == protection_domain) {
+      return e;
+    }
+  }
+
+  return NULL;
+}
+
+ProtectionDomainCacheEntry* ProtectionDomainCacheTable::add_entry(int index, unsigned int hash, oop protection_domain) {
+  assert_locked_or_safepoint(SystemDictionary_lock);
+  assert(index == index_for(protection_domain), "incorrect index?");
+  assert(find_entry(index, protection_domain) == NULL, "no double entry");
+
+  ProtectionDomainCacheEntry* p = new_entry(hash, protection_domain);
+  Hashtable<oop, mtClass>::add_entry(index, p);
+  return p;
+}
+
+void ProtectionDomainCacheTable::free(ProtectionDomainCacheEntry* to_delete) {
+  unsigned int hash = compute_hash(to_delete->protection_domain());
+  int index = hash_to_index(hash);
+
+  ProtectionDomainCacheEntry** p = bucket_addr(index);
+  ProtectionDomainCacheEntry* entry = bucket(index);
+  while (true) {
+    assert(entry != NULL, "sanity");
+
+    if (entry == to_delete) {
+      *p = entry->next();
+      Hashtable<oop, mtClass>::free_entry(entry);
+      break;
+    } else {
+      p = entry->next_addr();
+      entry = *p;
+    }
+  }
+}
+
 SymbolPropertyTable::SymbolPropertyTable(int table_size)
   : Hashtable<Symbol*, mtSymbol>(table_size, sizeof(SymbolPropertyEntry))
 {
@@ -532,11 +682,13 @@ void Dictionary::print() {
       tty->cr();
     }
   }
+  tty->cr();
+  _pd_cache_table->print();
+  tty->cr();
 }
 
 #endif
 
-
 void Dictionary::verify() {
   guarantee(number_of_entries() >= 0, "Verify of system dictionary failed");
 
@@ -563,5 +715,7 @@ void Dictionary::verify() {
   guarantee(number_of_entries() == element_count,
             "Verify of system dictionary failed");
   debug_only(verify_lookup_length((double)number_of_entries() / table_size()));
+
+  _pd_cache_table->verify();
 }
 

src/share/vm/classfile/dictionary.hpp

@@ -27,11 +27,14 @@
 
 #include "classfile/systemDictionary.hpp"
 #include "oops/instanceKlass.hpp"
-#include "oops/oop.hpp"
+#include "oops/oop.inline.hpp"
 #include "utilities/hashtable.hpp"
 
 class DictionaryEntry;
 class PSPromotionManager;
+class ProtectionDomainCacheTable;
+class ProtectionDomainCacheEntry;
+class BoolObjectClosure;
 
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // The data structure for the system dictionary (and the shared system
@@ -45,6 +48,8 @@ private:
   // pointer to the current hash table entry.
   static DictionaryEntry*       _current_class_entry;
 
+  ProtectionDomainCacheTable*   _pd_cache_table;
+
   DictionaryEntry* get_entry(int index, unsigned int hash,
                              Symbol* name, ClassLoaderData* loader_data);
 
@@ -93,6 +98,7 @@ public:
 
   void methods_do(void f(Method*));
 
+  void unlink(BoolObjectClosure* is_alive);
 
   // Classes loaded by the bootstrap loader are always strongly reachable.
   // If we're not doing class unloading, all classes are strongly reachable.
@@ -118,6 +124,7 @@ public:
   // Sharing support
   void reorder_dictionary();
 
+  ProtectionDomainCacheEntry* cache_get(oop protection_domain);
 
 #ifndef PRODUCT
   void print();
@@ -126,21 +133,112 @@ public:
 };
 
 // The following classes can be in dictionary.cpp, but we need these
-// to be in header file so that SA's vmStructs can access.
+// to be in header file so that SA's vmStructs can access them.
+class ProtectionDomainCacheEntry : public HashtableEntry<oop, mtClass> {
+  friend class VMStructs;
+ private:
+  // Flag indicating whether this protection domain entry is strongly reachable.
+  // Used during iterating over the system dictionary to remember oops that need
+  // to be updated.
+  bool _strongly_reachable;
+ public:
+  oop protection_domain() { return literal(); }
+
+  void init() {
+    _strongly_reachable = false;
+  }
+
+  ProtectionDomainCacheEntry* next() {
+    return (ProtectionDomainCacheEntry*)HashtableEntry<oop, mtClass>::next();
+  }
+
+  ProtectionDomainCacheEntry** next_addr() {
+    return (ProtectionDomainCacheEntry**)HashtableEntry<oop, mtClass>::next_addr();
+  }
+
+  void oops_do(OopClosure* f) {
+    f->do_oop(literal_addr());
+  }
+
+  void set_strongly_reachable()   { _strongly_reachable = true; }
+  bool is_strongly_reachable()    { return _strongly_reachable; }
+  void reset_strongly_reachable() { _strongly_reachable = false; }
+
+  void print() PRODUCT_RETURN;
+  void verify();
+};
+
+// The ProtectionDomainCacheTable contains all protection domain oops. The system
+// dictionary entries reference its entries instead of having references to oops
+// directly.
+// This is used to speed up system dictionary iteration: the oops in the
+// protection domain are the only ones referring the Java heap. So when there is
+// need to update these, instead of going over every entry of the system dictionary,
+// we only need to iterate over this set.
+// The amount of different protection domains used is typically magnitudes smaller
+// than the number of system dictionary entries (loaded classes).
+class ProtectionDomainCacheTable : public Hashtable<oop, mtClass> {
+  friend class VMStructs;
+private:
+  ProtectionDomainCacheEntry* bucket(int i) {
+    return (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::bucket(i);
+  }
+
+  // The following method is not MT-safe and must be done under lock.
+  ProtectionDomainCacheEntry** bucket_addr(int i) {
+    return (ProtectionDomainCacheEntry**) Hashtable<oop, mtClass>::bucket_addr(i);
+  }
+
+  ProtectionDomainCacheEntry* new_entry(unsigned int hash, oop protection_domain) {
+    ProtectionDomainCacheEntry* entry = (ProtectionDomainCacheEntry*) Hashtable<oop, mtClass>::new_entry(hash, protection_domain);
+    entry->init();
+    return entry;
+  }
+
+  static unsigned int compute_hash(oop protection_domain) {
+    return (unsigned int)(protection_domain->identity_hash());
+  }
+
+  int index_for(oop protection_domain) {
+    return hash_to_index(compute_hash(protection_domain));
+  }
+
+  ProtectionDomainCacheEntry* add_entry(int index, unsigned int hash, oop protection_domain);
+  ProtectionDomainCacheEntry* find_entry(int index, oop protection_domain);
+
+public:
+
+  ProtectionDomainCacheTable(int table_size);
+
+  ProtectionDomainCacheEntry* get(oop protection_domain);
+  void free(ProtectionDomainCacheEntry* entry);
+
+  void unlink(BoolObjectClosure* cl);
+
+  // GC support
+  void oops_do(OopClosure* f);
+  void always_strong_oops_do(OopClosure* f);
+
+  static uint bucket_size();
+
+  void print() PRODUCT_RETURN;
+  void verify();
+};
+
 
 class ProtectionDomainEntry :public CHeapObj<mtClass> {
   friend class VMStructs;
  public:
   ProtectionDomainEntry* _next;
-  oop                    _protection_domain;
+  ProtectionDomainCacheEntry* _pd_cache;
 
-  ProtectionDomainEntry(oop protection_domain, ProtectionDomainEntry* next) {
-    _protection_domain = protection_domain;
-    _next              = next;
+  ProtectionDomainEntry(ProtectionDomainCacheEntry* pd_cache, ProtectionDomainEntry* next) {
+    _pd_cache = pd_cache;
+    _next     = next;
   }
 
   ProtectionDomainEntry* next() { return _next; }
-  oop protection_domain() { return _protection_domain; }
+  oop protection_domain() { return _pd_cache->protection_domain(); }
 };
 
 // An entry in the system dictionary, this describes a class as
@@ -151,6 +249,24 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
  private:
   // Contains the set of approved protection domains that can access
   // this system dictionary entry.
+  //
+  // This protection domain set is a set of tuples:
+  //
+  // (InstanceKlass C, initiating class loader ICL, Protection Domain PD)
+  //
+  // [Note that C.protection_domain(), which is stored in the java.lang.Class
+  // mirror of C, is NOT the same as PD]
+  //
+  // If such an entry (C, ICL, PD) exists in the table, it means that
+  // it is okay for a class Foo to reference C, where
+  //
+  //    Foo.protection_domain() == PD, and
+  //    Foo's defining class loader == ICL
+  //
+  // The usage of the PD set can be seen in SystemDictionary::validate_protection_domain()
+  // It is essentially a cache to avoid repeated Java up-calls to
+  // ClassLoader.checkPackageAccess().
+  //
   ProtectionDomainEntry* _pd_set;
   ClassLoaderData*       _loader_data;
 
@@ -158,7 +274,7 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
   // Tells whether a protection is in the approved set.
   bool contains_protection_domain(oop protection_domain) const;
   // Adds a protection domain to the approved set.
-  void add_protection_domain(oop protection_domain);
+  void add_protection_domain(Dictionary* dict, oop protection_domain);
 
   Klass* klass() const { return (Klass*)literal(); }
   Klass** klass_addr() { return (Klass**)literal_addr(); }
@@ -189,12 +305,11 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
          : contains_protection_domain(protection_domain());
   }
 
-
-  void protection_domain_set_oops_do(OopClosure* f) {
+  void set_strongly_reachable() {
     for (ProtectionDomainEntry* current = _pd_set;
                                 current != NULL;
                                 current = current->_next) {
-      f->do_oop(&(current->_protection_domain));
+      current->_pd_cache->set_strongly_reachable();
     }
   }
 
@@ -202,7 +317,7 @@ class DictionaryEntry : public HashtableEntry<Klass*, mtClass> {
     for (ProtectionDomainEntry* current = _pd_set;
                                 current != NULL;
                                 current = current->_next) {
-      current->_protection_domain->verify();
+      current->_pd_cache->protection_domain()->verify();
     }
   }
 

src/share/vm/classfile/systemDictionary.cpp

@@ -1697,6 +1697,24 @@ int SystemDictionary::calculate_systemdictionary_size(int classcount) {
   return newsize;
 }
 
+#ifdef ASSERT
+class VerifySDReachableAndLiveClosure : public OopClosure {
+private:
+  BoolObjectClosure* _is_alive;
+
+  template <class T> void do_oop_work(T* p) {
+    oop obj = oopDesc::load_decode_heap_oop(p);
+    guarantee(_is_alive->do_object_b(obj), "Oop in system dictionary must be live");
+  }
+
+public:
+  VerifySDReachableAndLiveClosure(BoolObjectClosure* is_alive) : OopClosure(), _is_alive(is_alive) { }
+
+  virtual void do_oop(oop* p)       { do_oop_work(p); }
+  virtual void do_oop(narrowOop* p) { do_oop_work(p); }
+};
+#endif
+
 // Assumes classes in the SystemDictionary are only unloaded at a safepoint
 // Note: anonymous classes are not in the SD.
 bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
@@ -1707,7 +1725,15 @@ bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive) {
     unloading_occurred = dictionary()->do_unloading();
     constraints()->purge_loader_constraints();
     resolution_errors()->purge_resolution_errors();
-}
+  }
+  // Oops referenced by the system dictionary may get unreachable independently
+  // of the class loader (eg. cached protection domain oops). So we need to
+  // explicitly unlink them here instead of in Dictionary::do_unloading.
+  dictionary()->unlink(is_alive);
+#ifdef ASSERT
+  VerifySDReachableAndLiveClosure cl(is_alive);
+  dictionary()->oops_do(&cl);
+#endif
   return unloading_occurred;
 }
 

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

@@ -6035,7 +6035,11 @@ void G1CollectedHeap::verify_dirty_region(HeapRegion* hr) {
   // is dirty.
   G1SATBCardTableModRefBS* ct_bs = g1_barrier_set();
   MemRegion mr(hr->bottom(), hr->pre_dummy_top());
-  ct_bs->verify_dirty_region(mr);
+  if (hr->is_young()) {
+    ct_bs->verify_g1_young_region(mr);
+  } else {
+    ct_bs->verify_dirty_region(mr);
+  }
 }
 
 void G1CollectedHeap::verify_dirty_young_list(HeapRegion* head) {

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

@@ -29,6 +29,7 @@
 #include "gc_implementation/g1/g1CollectedHeap.hpp"
 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
+#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "utilities/taskqueue.hpp"
 
@@ -134,7 +135,7 @@ G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
   assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
 
   MemRegion mr(start, end);
-  g1_barrier_set()->dirty(mr);
+  g1_barrier_set()->g1_mark_as_young(mr);
 }
 
 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {

src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp

@@ -319,10 +319,10 @@ G1CollectorPolicy::G1CollectorPolicy() :
 }
 
 void G1CollectorPolicy::initialize_flags() {
-  set_min_alignment(HeapRegion::GrainBytes);
+  _min_alignment = HeapRegion::GrainBytes;
   size_t card_table_alignment = GenRemSet::max_alignment_constraint(rem_set_name());
   size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
-  set_max_alignment(MAX3(card_table_alignment, min_alignment(), page_size));
+  _max_alignment = MAX3(card_table_alignment, _min_alignment, page_size);
   if (SurvivorRatio < 1) {
     vm_exit_during_initialization("Invalid survivor ratio specified");
   }

src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.cpp

@@ -70,6 +70,12 @@ bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
   if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
     return false;
   }
+
+  if  (val == g1_young_gen) {
+    // the card is for a young gen region. We don't need to keep track of all pointers into young
+    return false;
+  }
+
   // Cached bit can be installed either on a clean card or on a claimed card.
   jbyte new_val = val;
   if (val == clean_card_val()) {
@@ -85,6 +91,19 @@ bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
   return true;
 }
 
+void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
+  jbyte *const first = byte_for(mr.start());
+  jbyte *const last = byte_after(mr.last());
+
+  memset(first, g1_young_gen, last - first);
+}
+
+#ifndef PRODUCT
+void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
+  verify_region(mr, g1_young_gen,  true);
+}
+#endif
+
 G1SATBCardTableLoggingModRefBS::
 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
                                int max_covered_regions) :
@@ -97,7 +116,11 @@ G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
 void
 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
                                                      oop new_val) {
-  jbyte* byte = byte_for(field);
+  volatile jbyte* byte = byte_for(field);
+  if (*byte == g1_young_gen) {
+    return;
+  }
+  OrderAccess::storeload();
   if (*byte != dirty_card) {
     *byte = dirty_card;
     Thread* thr = Thread::current();
@@ -129,7 +152,7 @@ G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
 
 void
 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
-  jbyte* byte = byte_for(mr.start());
+  volatile jbyte* byte = byte_for(mr.start());
   jbyte* last_byte = byte_for(mr.last());
   Thread* thr = Thread::current();
   if (whole_heap) {
@@ -138,25 +161,35 @@ G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
       byte++;
     }
   } else {
-    // Enqueue if necessary.
-    if (thr->is_Java_thread()) {
-      JavaThread* jt = (JavaThread*)thr;
-      while (byte <= last_byte) {
-        if (*byte != dirty_card) {
-          *byte = dirty_card;
-          jt->dirty_card_queue().enqueue(byte);
+    // skip all consecutive young cards
+    for (; byte <= last_byte && *byte == g1_young_gen; byte++);
+
+    if (byte <= last_byte) {
+      OrderAccess::storeload();
+      // Enqueue if necessary.
+      if (thr->is_Java_thread()) {
+        JavaThread* jt = (JavaThread*)thr;
+        for (; byte <= last_byte; byte++) {
+          if (*byte == g1_young_gen) {
+            continue;
+          }
+          if (*byte != dirty_card) {
+            *byte = dirty_card;
+            jt->dirty_card_queue().enqueue(byte);
+          }
         }
-        byte++;
-      }
-    } else {
-      MutexLockerEx x(Shared_DirtyCardQ_lock,
-                      Mutex::_no_safepoint_check_flag);
-      while (byte <= last_byte) {
-        if (*byte != dirty_card) {
-          *byte = dirty_card;
-          _dcqs.shared_dirty_card_queue()->enqueue(byte);
+      } else {
+        MutexLockerEx x(Shared_DirtyCardQ_lock,
+                        Mutex::_no_safepoint_check_flag);
+        for (; byte <= last_byte; byte++) {
+          if (*byte == g1_young_gen) {
+            continue;
+          }
+          if (*byte != dirty_card) {
+            *byte = dirty_card;
+            _dcqs.shared_dirty_card_queue()->enqueue(byte);
+          }
         }
-        byte++;
       }
     }
   }

src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp

@@ -38,7 +38,14 @@ class DirtyCardQueueSet;
 // snapshot-at-the-beginning marking.
 
 class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS {
+protected:
+  enum G1CardValues {
+    g1_young_gen = CT_MR_BS_last_reserved << 1
+  };
+
 public:
+  static int g1_young_card_val()   { return g1_young_gen; }
+
   // Add "pre_val" to a set of objects that may have been disconnected from the
   // pre-marking object graph.
   static void enqueue(oop pre_val);
@@ -118,6 +125,9 @@ public:
       _byte_map[card_index] = val;
   }
 
+  void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
+  void g1_mark_as_young(const MemRegion& mr);
+
   bool mark_card_deferred(size_t card_index);
 
   bool is_card_deferred(size_t card_index) {

src/share/vm/gc_implementation/g1/ptrQueue.hpp

@@ -80,6 +80,10 @@ public:
 
   void reset() { if (_buf != NULL) _index = _sz; }
 
+  void enqueue(volatile void* ptr) {
+    enqueue((void*)(ptr));
+  }
+
   // Enqueues the given "obj".
   void enqueue(void* ptr) {
     if (!_active) return;

src/share/vm/gc_implementation/shared/vmGCOperations.hpp

@@ -214,9 +214,6 @@ class VM_CollectForMetadataAllocation: public VM_GC_Operation {
     : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true),
       _loader_data(loader_data), _size(size), _mdtype(mdtype), _result(NULL) {
   }
-  ~VM_CollectForMetadataAllocation()  {
-    MetaspaceGC::set_expand_after_GC(false);
-  }
   virtual VMOp_Type type() const { return VMOp_CollectForMetadataAllocation; }
   virtual void doit();
   MetaWord* result() const       { return _result; }

src/share/vm/gc_interface/collectedHeap.cpp

@@ -202,12 +202,6 @@ void CollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
       ShouldNotReachHere(); // Unexpected use of this function
   }
 }
-MetaWord* CollectedHeap::satisfy_failed_metadata_allocation(
-                                              ClassLoaderData* loader_data,
-                                              size_t size, Metaspace::MetadataType mdtype) {
-  return collector_policy()->satisfy_failed_metadata_allocation(loader_data, size, mdtype);
-}
-
 
 void CollectedHeap::pre_initialize() {
   // Used for ReduceInitialCardMarks (when COMPILER2 is used);

src/share/vm/gc_interface/collectedHeap.hpp

@@ -475,11 +475,6 @@ class CollectedHeap : public CHeapObj<mtInternal> {
   // the context of the vm thread.
   virtual void collect_as_vm_thread(GCCause::Cause cause);
 
-  // Callback from VM_CollectForMetadataAllocation operation.
-  MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
-                                               size_t size,
-                                               Metaspace::MetadataType mdtype);
-
   // Returns the barrier set for this heap
   BarrierSet* barrier_set() { return _barrier_set; }
 

src/share/vm/memory/collectorPolicy.cpp

@@ -47,85 +47,53 @@
 
 // CollectorPolicy methods.
 
-// Align down. If the aligning result in 0, return 'alignment'.
-static size_t restricted_align_down(size_t size, size_t alignment) {
-  return MAX2(alignment, align_size_down_(size, alignment));
-}
-
 void CollectorPolicy::initialize_flags() {
-  assert(max_alignment() >= min_alignment(),
-      err_msg("max_alignment: " SIZE_FORMAT " less than min_alignment: " SIZE_FORMAT,
-          max_alignment(), min_alignment()));
-  assert(max_alignment() % min_alignment() == 0,
-      err_msg("max_alignment: " SIZE_FORMAT " not aligned by min_alignment: " SIZE_FORMAT,
-          max_alignment(), min_alignment()));
+  assert(_max_alignment >= _min_alignment,
+         err_msg("max_alignment: " SIZE_FORMAT " less than min_alignment: " SIZE_FORMAT,
+                 _max_alignment, _min_alignment));
+  assert(_max_alignment % _min_alignment == 0,
+         err_msg("max_alignment: " SIZE_FORMAT " not aligned by min_alignment: " SIZE_FORMAT,
+                 _max_alignment, _min_alignment));
 
   if (MaxHeapSize < InitialHeapSize) {
     vm_exit_during_initialization("Incompatible initial and maximum heap sizes specified");
   }
 
-  // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
-  // override if MaxMetaspaceSize was set on the command line or not.
-  // This information is needed later to conform to the specification of the
-  // java.lang.management.MemoryUsage API.
-  //
-  // Ideally, we would be able to set the default value of MaxMetaspaceSize in
-  // globals.hpp to the aligned value, but this is not possible, since the
-  // alignment depends on other flags being parsed.
-  MaxMetaspaceSize = restricted_align_down(MaxMetaspaceSize, max_alignment());
-
-  if (MetaspaceSize > MaxMetaspaceSize) {
-    MetaspaceSize = MaxMetaspaceSize;
-  }
-
-  MetaspaceSize = restricted_align_down(MetaspaceSize, min_alignment());
-
-  assert(MetaspaceSize <= MaxMetaspaceSize, "Must be");
-
-  MinMetaspaceExpansion = restricted_align_down(MinMetaspaceExpansion, min_alignment());
-  MaxMetaspaceExpansion = restricted_align_down(MaxMetaspaceExpansion, min_alignment());
-
-  MinHeapDeltaBytes = align_size_up(MinHeapDeltaBytes, min_alignment());
-
-  assert(MetaspaceSize    % min_alignment() == 0, "metapace alignment");
-  assert(MaxMetaspaceSize % max_alignment() == 0, "maximum metaspace alignment");
-  if (MetaspaceSize < 256*K) {
-    vm_exit_during_initialization("Too small initial Metaspace size");
-  }
+  MinHeapDeltaBytes = align_size_up(MinHeapDeltaBytes, _min_alignment);
 }
 
 void CollectorPolicy::initialize_size_info() {
   // User inputs from -mx and ms must be aligned
-  set_min_heap_byte_size(align_size_up(Arguments::min_heap_size(), min_alignment()));
-  set_initial_heap_byte_size(align_size_up(InitialHeapSize, min_alignment()));
-  set_max_heap_byte_size(align_size_up(MaxHeapSize, max_alignment()));
+  _min_heap_byte_size = align_size_up(Arguments::min_heap_size(), _min_alignment);
+  _initial_heap_byte_size = align_size_up(InitialHeapSize, _min_alignment);
+  _max_heap_byte_size = align_size_up(MaxHeapSize, _max_alignment);
 
   // Check heap parameter properties
-  if (initial_heap_byte_size() < M) {
+  if (_initial_heap_byte_size < M) {
     vm_exit_during_initialization("Too small initial heap");
   }
   // Check heap parameter properties
-  if (min_heap_byte_size() < M) {
+  if (_min_heap_byte_size < M) {
     vm_exit_during_initialization("Too small minimum heap");
   }
-  if (initial_heap_byte_size() <= NewSize) {
+  if (_initial_heap_byte_size <= NewSize) {
      // make sure there is at least some room in old space
     vm_exit_during_initialization("Too small initial heap for new size specified");
   }
-  if (max_heap_byte_size() < min_heap_byte_size()) {
+  if (_max_heap_byte_size < _min_heap_byte_size) {
     vm_exit_during_initialization("Incompatible minimum and maximum heap sizes specified");
   }
-  if (initial_heap_byte_size() < min_heap_byte_size()) {
+  if (_initial_heap_byte_size < _min_heap_byte_size) {
     vm_exit_during_initialization("Incompatible minimum and initial heap sizes specified");
   }
-  if (max_heap_byte_size() < initial_heap_byte_size()) {
+  if (_max_heap_byte_size < _initial_heap_byte_size) {
     vm_exit_during_initialization("Incompatible initial and maximum heap sizes specified");
   }
 
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print_cr("Minimum heap " SIZE_FORMAT "  Initial heap "
       SIZE_FORMAT "  Maximum heap " SIZE_FORMAT,
-      min_heap_byte_size(), initial_heap_byte_size(), max_heap_byte_size());
+      _min_heap_byte_size, _initial_heap_byte_size, _max_heap_byte_size);
   }
 }
 
@@ -180,15 +148,15 @@ size_t CollectorPolicy::compute_max_alignment() {
 
 size_t GenCollectorPolicy::scale_by_NewRatio_aligned(size_t base_size) {
   size_t x = base_size / (NewRatio+1);
-  size_t new_gen_size = x > min_alignment() ?
-                     align_size_down(x, min_alignment()) :
-                     min_alignment();
+  size_t new_gen_size = x > _min_alignment ?
+                     align_size_down(x, _min_alignment) :
+                     _min_alignment;
   return new_gen_size;
 }
 
 size_t GenCollectorPolicy::bound_minus_alignment(size_t desired_size,
                                                  size_t maximum_size) {
-  size_t alignment = min_alignment();
+  size_t alignment = _min_alignment;
   size_t max_minus = maximum_size - alignment;
   return desired_size < max_minus ? desired_size : max_minus;
 }
@@ -207,8 +175,8 @@ void GenCollectorPolicy::initialize_size_policy(size_t init_eden_size,
 
 void GenCollectorPolicy::initialize_flags() {
   // All sizes must be multiples of the generation granularity.
-  set_min_alignment((uintx) Generation::GenGrain);
-  set_max_alignment(compute_max_alignment());
+  _min_alignment = (uintx) Generation::GenGrain;
+  _max_alignment = compute_max_alignment();
 
   CollectorPolicy::initialize_flags();
 
@@ -218,26 +186,26 @@ void GenCollectorPolicy::initialize_flags() {
   if (NewSize > MaxNewSize) {
     MaxNewSize = NewSize;
   }
-  NewSize = align_size_down(NewSize, min_alignment());
-  MaxNewSize = align_size_down(MaxNewSize, min_alignment());
+  NewSize = align_size_down(NewSize, _min_alignment);
+  MaxNewSize = align_size_down(MaxNewSize, _min_alignment);
 
   // Check validity of heap flags
-  assert(NewSize     % min_alignment() == 0, "eden space alignment");
-  assert(MaxNewSize  % min_alignment() == 0, "survivor space alignment");
+  assert(NewSize     % _min_alignment == 0, "eden space alignment");
+  assert(MaxNewSize  % _min_alignment == 0, "survivor space alignment");
 
-  if (NewSize < 3*min_alignment()) {
+  if (NewSize < 3 * _min_alignment) {
      // make sure there room for eden and two survivor spaces
     vm_exit_during_initialization("Too small new size specified");
   }
   if (SurvivorRatio < 1 || NewRatio < 1) {
-    vm_exit_during_initialization("Invalid heap ratio specified");
+    vm_exit_during_initialization("Invalid young gen ratio specified");
   }
 }
 
 void TwoGenerationCollectorPolicy::initialize_flags() {
   GenCollectorPolicy::initialize_flags();
 
-  OldSize = align_size_down(OldSize, min_alignment());
+  OldSize = align_size_down(OldSize, _min_alignment);
 
   if (FLAG_IS_CMDLINE(OldSize) && FLAG_IS_DEFAULT(NewSize)) {
     // NewRatio will be used later to set the young generation size so we use
@@ -246,11 +214,11 @@ void TwoGenerationCollectorPolicy::initialize_flags() {
     assert(NewRatio > 0, "NewRatio should have been set up earlier");
     size_t calculated_heapsize = (OldSize / NewRatio) * (NewRatio + 1);
 
-    calculated_heapsize = align_size_up(calculated_heapsize, max_alignment());
+    calculated_heapsize = align_size_up(calculated_heapsize, _max_alignment);
     MaxHeapSize = calculated_heapsize;
     InitialHeapSize = calculated_heapsize;
   }
-  MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
+  MaxHeapSize = align_size_up(MaxHeapSize, _max_alignment);
 
   // adjust max heap size if necessary
   if (NewSize + OldSize > MaxHeapSize) {
@@ -260,18 +228,18 @@ void TwoGenerationCollectorPolicy::initialize_flags() {
       uintx calculated_size = NewSize + OldSize;
       double shrink_factor = (double) MaxHeapSize / calculated_size;
       // align
-      NewSize = align_size_down((uintx) (NewSize * shrink_factor), min_alignment());
+      NewSize = align_size_down((uintx) (NewSize * shrink_factor), _min_alignment);
       // OldSize is already aligned because above we aligned MaxHeapSize to
-      // max_alignment(), and we just made sure that NewSize is aligned to
-      // min_alignment(). In initialize_flags() we verified that max_alignment()
-      // is a multiple of min_alignment().
+      // _max_alignment, and we just made sure that NewSize is aligned to
+      // _min_alignment. In initialize_flags() we verified that _max_alignment
+      // is a multiple of _min_alignment.
       OldSize = MaxHeapSize - NewSize;
     } else {
       MaxHeapSize = NewSize + OldSize;
     }
   }
   // need to do this again
-  MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
+  MaxHeapSize = align_size_up(MaxHeapSize, _max_alignment);
 
   // adjust max heap size if necessary
   if (NewSize + OldSize > MaxHeapSize) {
@@ -281,24 +249,24 @@ void TwoGenerationCollectorPolicy::initialize_flags() {
       uintx calculated_size = NewSize + OldSize;
       double shrink_factor = (double) MaxHeapSize / calculated_size;
       // align
-      NewSize = align_size_down((uintx) (NewSize * shrink_factor), min_alignment());
+      NewSize = align_size_down((uintx) (NewSize * shrink_factor), _min_alignment);
       // OldSize is already aligned because above we aligned MaxHeapSize to
-      // max_alignment(), and we just made sure that NewSize is aligned to
-      // min_alignment(). In initialize_flags() we verified that max_alignment()
-      // is a multiple of min_alignment().
+      // _max_alignment, and we just made sure that NewSize is aligned to
+      // _min_alignment. In initialize_flags() we verified that _max_alignment
+      // is a multiple of _min_alignment.
       OldSize = MaxHeapSize - NewSize;
     } else {
       MaxHeapSize = NewSize + OldSize;
     }
   }
   // need to do this again
-  MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
+  MaxHeapSize = align_size_up(MaxHeapSize, _max_alignment);
 
   always_do_update_barrier = UseConcMarkSweepGC;
 
   // Check validity of heap flags
-  assert(OldSize     % min_alignment() == 0, "old space alignment");
-  assert(MaxHeapSize % max_alignment() == 0, "maximum heap alignment");
+  assert(OldSize     % _min_alignment == 0, "old space alignment");
+  assert(MaxHeapSize % _max_alignment == 0, "maximum heap alignment");
 }
 
 // Values set on the command line win over any ergonomically
@@ -313,7 +281,7 @@ void TwoGenerationCollectorPolicy::initialize_flags() {
 void GenCollectorPolicy::initialize_size_info() {
   CollectorPolicy::initialize_size_info();
 
-  // min_alignment() is used for alignment within a generation.
+  // _min_alignment is used for alignment within a generation.
   // There is additional alignment done down stream for some
   // collectors that sometimes causes unwanted rounding up of
   // generations sizes.
@@ -322,18 +290,18 @@ void GenCollectorPolicy::initialize_size_info() {
 
   size_t max_new_size = 0;
   if (FLAG_IS_CMDLINE(MaxNewSize) || FLAG_IS_ERGO(MaxNewSize)) {
-    if (MaxNewSize < min_alignment()) {
-      max_new_size = min_alignment();
+    if (MaxNewSize < _min_alignment) {
+      max_new_size = _min_alignment;
     }
-    if (MaxNewSize >= max_heap_byte_size()) {
-      max_new_size = align_size_down(max_heap_byte_size() - min_alignment(),
-                                     min_alignment());
+    if (MaxNewSize >= _max_heap_byte_size) {
+      max_new_size = align_size_down(_max_heap_byte_size - _min_alignment,
+                                     _min_alignment);
       warning("MaxNewSize (" SIZE_FORMAT "k) is equal to or "
         "greater than the entire heap (" SIZE_FORMAT "k).  A "
         "new generation size of " SIZE_FORMAT "k will be used.",
-        MaxNewSize/K, max_heap_byte_size()/K, max_new_size/K);
+        MaxNewSize/K, _max_heap_byte_size/K, max_new_size/K);
     } else {
-      max_new_size = align_size_down(MaxNewSize, min_alignment());
+      max_new_size = align_size_down(MaxNewSize, _min_alignment);
     }
 
   // The case for FLAG_IS_ERGO(MaxNewSize) could be treated
@@ -351,7 +319,7 @@ void GenCollectorPolicy::initialize_size_info() {
   // just accept those choices.  The choices currently made are
   // not always "wise".
   } else {
-    max_new_size = scale_by_NewRatio_aligned(max_heap_byte_size());
+    max_new_size = scale_by_NewRatio_aligned(_max_heap_byte_size);
     // Bound the maximum size by NewSize below (since it historically
     // would have been NewSize and because the NewRatio calculation could
     // yield a size that is too small) and bound it by MaxNewSize above.
@@ -364,13 +332,13 @@ void GenCollectorPolicy::initialize_size_info() {
   // Given the maximum gen0 size, determine the initial and
   // minimum gen0 sizes.
 
-  if (max_heap_byte_size() == min_heap_byte_size()) {
+  if (_max_heap_byte_size == _min_heap_byte_size) {
     // The maximum and minimum heap sizes are the same so
     // the generations minimum and initial must be the
     // same as its maximum.
-    set_min_gen0_size(max_new_size);
-    set_initial_gen0_size(max_new_size);
-    set_max_gen0_size(max_new_size);
+    _min_gen0_size = max_new_size;
+    _initial_gen0_size = max_new_size;
+    _max_gen0_size = max_new_size;
   } else {
     size_t desired_new_size = 0;
     if (!FLAG_IS_DEFAULT(NewSize)) {
@@ -391,43 +359,37 @@ void GenCollectorPolicy::initialize_size_info() {
       // Use the default NewSize as the floor for these values.  If
       // NewRatio is overly large, the resulting sizes can be too
       // small.
-      _min_gen0_size = MAX2(scale_by_NewRatio_aligned(min_heap_byte_size()),
-                          NewSize);
+      _min_gen0_size = MAX2(scale_by_NewRatio_aligned(_min_heap_byte_size), NewSize);
       desired_new_size =
-        MAX2(scale_by_NewRatio_aligned(initial_heap_byte_size()),
-             NewSize);
+        MAX2(scale_by_NewRatio_aligned(_initial_heap_byte_size), NewSize);
     }
 
     assert(_min_gen0_size > 0, "Sanity check");
-    set_initial_gen0_size(desired_new_size);
-    set_max_gen0_size(max_new_size);
+    _initial_gen0_size = desired_new_size;
+    _max_gen0_size = max_new_size;
 
     // At this point the desirable initial and minimum sizes have been
     // determined without regard to the maximum sizes.
 
     // Bound the sizes by the corresponding overall heap sizes.
-    set_min_gen0_size(
-      bound_minus_alignment(_min_gen0_size, min_heap_byte_size()));
-    set_initial_gen0_size(
-      bound_minus_alignment(_initial_gen0_size, initial_heap_byte_size()));
-    set_max_gen0_size(
-      bound_minus_alignment(_max_gen0_size, max_heap_byte_size()));
+    _min_gen0_size = bound_minus_alignment(_min_gen0_size, _min_heap_byte_size);
+    _initial_gen0_size = bound_minus_alignment(_initial_gen0_size, _initial_heap_byte_size);
+    _max_gen0_size = bound_minus_alignment(_max_gen0_size, _max_heap_byte_size);
 
     // At this point all three sizes have been checked against the
     // maximum sizes but have not been checked for consistency
     // among the three.
 
     // Final check min <= initial <= max
-    set_min_gen0_size(MIN2(_min_gen0_size, _max_gen0_size));
-    set_initial_gen0_size(
-      MAX2(MIN2(_initial_gen0_size, _max_gen0_size), _min_gen0_size));
-    set_min_gen0_size(MIN2(_min_gen0_size, _initial_gen0_size));
+    _min_gen0_size = MIN2(_min_gen0_size, _max_gen0_size);
+    _initial_gen0_size = MAX2(MIN2(_initial_gen0_size, _max_gen0_size), _min_gen0_size);
+    _min_gen0_size = MIN2(_min_gen0_size, _initial_gen0_size);
   }
 
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print_cr("1: Minimum gen0 " SIZE_FORMAT "  Initial gen0 "
       SIZE_FORMAT "  Maximum gen0 " SIZE_FORMAT,
-      min_gen0_size(), initial_gen0_size(), max_gen0_size());
+      _min_gen0_size, _initial_gen0_size, _max_gen0_size);
   }
 }
 
@@ -447,19 +409,17 @@ bool TwoGenerationCollectorPolicy::adjust_gen0_sizes(size_t* gen0_size_ptr,
 
   if ((*gen1_size_ptr + *gen0_size_ptr) > heap_size) {
     if ((heap_size < (*gen0_size_ptr + min_gen1_size)) &&
-        (heap_size >= min_gen1_size + min_alignment())) {
+        (heap_size >= min_gen1_size + _min_alignment)) {
       // Adjust gen0 down to accommodate min_gen1_size
       *gen0_size_ptr = heap_size - min_gen1_size;
       *gen0_size_ptr =
-        MAX2((uintx)align_size_down(*gen0_size_ptr, min_alignment()),
-             min_alignment());
+        MAX2((uintx)align_size_down(*gen0_size_ptr, _min_alignment), _min_alignment);
       assert(*gen0_size_ptr > 0, "Min gen0 is too large");
       result = true;
     } else {
       *gen1_size_ptr = heap_size - *gen0_size_ptr;
       *gen1_size_ptr =
-        MAX2((uintx)align_size_down(*gen1_size_ptr, min_alignment()),
-                       min_alignment());
+        MAX2((uintx)align_size_down(*gen1_size_ptr, _min_alignment), _min_alignment);
     }
   }
   return result;
@@ -480,10 +440,9 @@ void TwoGenerationCollectorPolicy::initialize_size_info() {
   // The maximum gen1 size can be determined from the maximum gen0
   // and maximum heap size since no explicit flags exits
   // for setting the gen1 maximum.
-  _max_gen1_size = max_heap_byte_size() - _max_gen0_size;
+  _max_gen1_size = _max_heap_byte_size - _max_gen0_size;
   _max_gen1_size =
-    MAX2((uintx)align_size_down(_max_gen1_size, min_alignment()),
-         min_alignment());
+    MAX2((uintx)align_size_down(_max_gen1_size, _min_alignment), _min_alignment);
   // If no explicit command line flag has been set for the
   // gen1 size, use what is left for gen1.
   if (FLAG_IS_DEFAULT(OldSize) || FLAG_IS_ERGO(OldSize)) {
@@ -492,70 +451,66 @@ void TwoGenerationCollectorPolicy::initialize_size_info() {
     // with the overall heap size).  In either case make
     // the minimum, maximum and initial sizes consistent
     // with the gen0 sizes and the overall heap sizes.
-    assert(min_heap_byte_size() > _min_gen0_size,
+    assert(_min_heap_byte_size > _min_gen0_size,
       "gen0 has an unexpected minimum size");
-    set_min_gen1_size(min_heap_byte_size() - min_gen0_size());
-    set_min_gen1_size(
-      MAX2((uintx)align_size_down(_min_gen1_size, min_alignment()),
-           min_alignment()));
-    set_initial_gen1_size(initial_heap_byte_size() - initial_gen0_size());
-    set_initial_gen1_size(
-      MAX2((uintx)align_size_down(_initial_gen1_size, min_alignment()),
-           min_alignment()));
-
+    _min_gen1_size = _min_heap_byte_size - _min_gen0_size;
+    _min_gen1_size =
+      MAX2((uintx)align_size_down(_min_gen1_size, _min_alignment), _min_alignment);
+    _initial_gen1_size = _initial_heap_byte_size - _initial_gen0_size;
+    _initial_gen1_size =
+      MAX2((uintx)align_size_down(_initial_gen1_size, _min_alignment), _min_alignment);
   } else {
     // It's been explicitly set on the command line.  Use the
     // OldSize and then determine the consequences.
-    set_min_gen1_size(OldSize);
-    set_initial_gen1_size(OldSize);
+    _min_gen1_size = OldSize;
+    _initial_gen1_size = OldSize;
 
     // If the user has explicitly set an OldSize that is inconsistent
     // with other command line flags, issue a warning.
     // The generation minimums and the overall heap mimimum should
     // be within one heap alignment.
-    if ((_min_gen1_size + _min_gen0_size + min_alignment()) <
-           min_heap_byte_size()) {
+    if ((_min_gen1_size + _min_gen0_size + _min_alignment) < _min_heap_byte_size) {
       warning("Inconsistency between minimum heap size and minimum "
-          "generation sizes: using minimum heap = " SIZE_FORMAT,
-          min_heap_byte_size());
+              "generation sizes: using minimum heap = " SIZE_FORMAT,
+              _min_heap_byte_size);
     }
     if ((OldSize > _max_gen1_size)) {
       warning("Inconsistency between maximum heap size and maximum "
-          "generation sizes: using maximum heap = " SIZE_FORMAT
-          " -XX:OldSize flag is being ignored",
-          max_heap_byte_size());
+              "generation sizes: using maximum heap = " SIZE_FORMAT
+              " -XX:OldSize flag is being ignored",
+              _max_heap_byte_size);
     }
     // If there is an inconsistency between the OldSize and the minimum and/or
     // initial size of gen0, since OldSize was explicitly set, OldSize wins.
     if (adjust_gen0_sizes(&_min_gen0_size, &_min_gen1_size,
-                          min_heap_byte_size(), OldSize)) {
+                          _min_heap_byte_size, OldSize)) {
       if (PrintGCDetails && Verbose) {
         gclog_or_tty->print_cr("2: Minimum gen0 " SIZE_FORMAT "  Initial gen0 "
               SIZE_FORMAT "  Maximum gen0 " SIZE_FORMAT,
-              min_gen0_size(), initial_gen0_size(), max_gen0_size());
+              _min_gen0_size, _initial_gen0_size, _max_gen0_size);
       }
     }
     // Initial size
     if (adjust_gen0_sizes(&_initial_gen0_size, &_initial_gen1_size,
-                         initial_heap_byte_size(), OldSize)) {
+                          _initial_heap_byte_size, OldSize)) {
       if (PrintGCDetails && Verbose) {
         gclog_or_tty->print_cr("3: Minimum gen0 " SIZE_FORMAT "  Initial gen0 "
           SIZE_FORMAT "  Maximum gen0 " SIZE_FORMAT,
-          min_gen0_size(), initial_gen0_size(), max_gen0_size());
+          _min_gen0_size, _initial_gen0_size, _max_gen0_size);
       }
     }
   }
   // Enforce the maximum gen1 size.
-  set_min_gen1_size(MIN2(_min_gen1_size, _max_gen1_size));
+  _min_gen1_size = MIN2(_min_gen1_size, _max_gen1_size);
 
   // Check that min gen1 <= initial gen1 <= max gen1
-  set_initial_gen1_size(MAX2(_initial_gen1_size, _min_gen1_size));
-  set_initial_gen1_size(MIN2(_initial_gen1_size, _max_gen1_size));
+  _initial_gen1_size = MAX2(_initial_gen1_size, _min_gen1_size);
+  _initial_gen1_size = MIN2(_initial_gen1_size, _max_gen1_size);
 
   if (PrintGCDetails && Verbose) {
     gclog_or_tty->print_cr("Minimum gen1 " SIZE_FORMAT "  Initial gen1 "
       SIZE_FORMAT "  Maximum gen1 " SIZE_FORMAT,
-      min_gen1_size(), initial_gen1_size(), max_gen1_size());
+      _min_gen1_size, _initial_gen1_size, _max_gen1_size);
   }
 }
 

src/share/vm/memory/collectorPolicy.hpp

@@ -101,17 +101,12 @@ class CollectorPolicy : public CHeapObj<mtGC> {
   // Return maximum heap alignment that may be imposed by the policy
   static size_t compute_max_alignment();
 
-  void set_min_alignment(size_t align)         { _min_alignment = align; }
   size_t min_alignment()                       { return _min_alignment; }
-  void set_max_alignment(size_t align)         { _max_alignment = align; }
   size_t max_alignment()                       { return _max_alignment; }
 
   size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
-  void set_initial_heap_byte_size(size_t v) { _initial_heap_byte_size = v; }
   size_t max_heap_byte_size()     { return _max_heap_byte_size; }
-  void set_max_heap_byte_size(size_t v) { _max_heap_byte_size = v; }
   size_t min_heap_byte_size()     { return _min_heap_byte_size; }
-  void set_min_heap_byte_size(size_t v) { _min_heap_byte_size = v; }
 
   enum Name {
     CollectorPolicyKind,
@@ -248,12 +243,9 @@ class GenCollectorPolicy : public CollectorPolicy {
 
  public:
   // Accessors
-  size_t min_gen0_size() { return _min_gen0_size; }
-  void set_min_gen0_size(size_t v) { _min_gen0_size = v; }
+  size_t min_gen0_size()     { return _min_gen0_size; }
   size_t initial_gen0_size() { return _initial_gen0_size; }
-  void set_initial_gen0_size(size_t v) { _initial_gen0_size = v; }
-  size_t max_gen0_size() { return _max_gen0_size; }
-  void set_max_gen0_size(size_t v) { _max_gen0_size = v; }
+  size_t max_gen0_size()     { return _max_gen0_size; }
 
   virtual int number_of_generations() = 0;
 
@@ -302,12 +294,9 @@ class TwoGenerationCollectorPolicy : public GenCollectorPolicy {
 
  public:
   // Accessors
-  size_t min_gen1_size() { return _min_gen1_size; }
-  void set_min_gen1_size(size_t v) { _min_gen1_size = v; }
+  size_t min_gen1_size()     { return _min_gen1_size; }
   size_t initial_gen1_size() { return _initial_gen1_size; }
-  void set_initial_gen1_size(size_t v) { _initial_gen1_size = v; }
-  size_t max_gen1_size() { return _max_gen1_size; }
-  void set_max_gen1_size(size_t v) { _max_gen1_size = v; }
+  size_t max_gen1_size()     { return _max_gen1_size; }
 
   // Inherited methods
   TwoGenerationCollectorPolicy* as_two_generation_policy() { return this; }

src/share/vm/memory/filemap.hpp

@@ -26,6 +26,7 @@
 #define SHARE_VM_MEMORY_FILEMAP_HPP
 
 #include "memory/metaspaceShared.hpp"
+#include "memory/metaspace.hpp"
 
 // Layout of the file:
 //  header: dump of archive instance plus versioning info, datestamp, etc.

src/share/vm/memory/metaspace.cpp

@@ -29,17 +29,21 @@
 #include "memory/collectorPolicy.hpp"
 #include "memory/filemap.hpp"
 #include "memory/freeList.hpp"
+#include "memory/gcLocker.hpp"
 #include "memory/metablock.hpp"
 #include "memory/metachunk.hpp"
 #include "memory/metaspace.hpp"
 #include "memory/metaspaceShared.hpp"
 #include "memory/resourceArea.hpp"
 #include "memory/universe.hpp"
+#include "runtime/atomic.inline.hpp"
 #include "runtime/globals.hpp"
+#include "runtime/init.hpp"
 #include "runtime/java.hpp"
 #include "runtime/mutex.hpp"
 #include "runtime/orderAccess.hpp"
 #include "services/memTracker.hpp"
+#include "services/memoryService.hpp"
 #include "utilities/copy.hpp"
 #include "utilities/debug.hpp"
 
@@ -84,13 +88,7 @@ static ChunkIndex next_chunk_index(ChunkIndex i) {
   return (ChunkIndex) (i+1);
 }
 
-// Originally _capacity_until_GC was set to MetaspaceSize here but
-// the default MetaspaceSize before argument processing was being
-// used which was not the desired value.  See the code
-// in should_expand() to see how the initialization is handled
-// now.
-size_t MetaspaceGC::_capacity_until_GC = 0;
-bool MetaspaceGC::_expand_after_GC = false;
+volatile intptr_t MetaspaceGC::_capacity_until_GC = 0;
 uint MetaspaceGC::_shrink_factor = 0;
 bool MetaspaceGC::_should_concurrent_collect = false;
 
@@ -293,9 +291,10 @@ class VirtualSpaceNode : public CHeapObj<mtClass> {
   MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
 
   size_t reserved_words() const  { return _virtual_space.reserved_size() / BytesPerWord; }
-  size_t expanded_words() const  { return _virtual_space.committed_size() / BytesPerWord; }
   size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; }
 
+  bool is_pre_committed() const { return _virtual_space.special(); }
+
   // address of next available space in _virtual_space;
   // Accessors
   VirtualSpaceNode* next() { return _next; }
@@ -337,7 +336,7 @@ class VirtualSpaceNode : public CHeapObj<mtClass> {
 
   // Expands/shrinks the committed space in a virtual space.  Delegates
   // to Virtualspace
-  bool expand_by(size_t words, bool pre_touch = false);
+  bool expand_by(size_t min_words, size_t preferred_words);
 
   // In preparation for deleting this node, remove all the chunks
   // in the node from any freelist.
@@ -351,29 +350,64 @@ class VirtualSpaceNode : public CHeapObj<mtClass> {
   void print_on(outputStream* st) const;
 };
 
+#define assert_is_ptr_aligned(ptr, alignment) \
+  assert(is_ptr_aligned(ptr, alignment),      \
+    err_msg(PTR_FORMAT " is not aligned to "  \
+      SIZE_FORMAT, ptr, alignment))
+
+#define assert_is_size_aligned(size, alignment) \
+  assert(is_size_aligned(size, alignment),      \
+    err_msg(SIZE_FORMAT " is not aligned to "   \
+       SIZE_FORMAT, size, alignment))
+
+
+// Decide if large pages should be committed when the memory is reserved.
+static bool should_commit_large_pages_when_reserving(size_t bytes) {
+  if (UseLargePages && UseLargePagesInMetaspace && !os::can_commit_large_page_memory()) {
+    size_t words = bytes / BytesPerWord;
+    bool is_class = false; // We never reserve large pages for the class space.
+    if (MetaspaceGC::can_expand(words, is_class) &&
+        MetaspaceGC::allowed_expansion() >= words) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
   // byte_size is the size of the associated virtualspace.
-VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(), _container_count(0) {
-  // align up to vm allocation granularity
-  byte_size = align_size_up(byte_size, os::vm_allocation_granularity());
+VirtualSpaceNode::VirtualSpaceNode(size_t bytes) : _top(NULL), _next(NULL), _rs(), _container_count(0) {
+  assert_is_size_aligned(bytes, Metaspace::reserve_alignment());
 
   // This allocates memory with mmap.  For DumpSharedspaces, try to reserve
   // configurable address, generally at the top of the Java heap so other
   // memory addresses don't conflict.
   if (DumpSharedSpaces) {
-    char* shared_base = (char*)SharedBaseAddress;
-    _rs = ReservedSpace(byte_size, 0, false, shared_base, 0);
+    bool large_pages = false; // No large pages when dumping the CDS archive.
+    char* shared_base = (char*)align_ptr_up((char*)SharedBaseAddress, Metaspace::reserve_alignment());
+
+    _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages, shared_base, 0);
     if (_rs.is_reserved()) {
       assert(shared_base == 0 || _rs.base() == shared_base, "should match");
     } else {
       // Get a mmap region anywhere if the SharedBaseAddress fails.
-      _rs = ReservedSpace(byte_size);
+      _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
     }
     MetaspaceShared::set_shared_rs(&_rs);
   } else {
-    _rs = ReservedSpace(byte_size);
+    bool large_pages = should_commit_large_pages_when_reserving(bytes);
+
+    _rs = ReservedSpace(bytes, Metaspace::reserve_alignment(), large_pages);
   }
 
-  MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
+  if (_rs.is_reserved()) {
+    assert(_rs.base() != NULL, "Catch if we get a NULL address");
+    assert(_rs.size() != 0, "Catch if we get a 0 size");
+    assert_is_ptr_aligned(_rs.base(), Metaspace::reserve_alignment());
+    assert_is_size_aligned(_rs.size(), Metaspace::reserve_alignment());
+
+    MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
+  }
 }
 
 void VirtualSpaceNode::purge(ChunkManager* chunk_manager) {
@@ -410,8 +444,6 @@ uint VirtualSpaceNode::container_count_slow() {
 #endif
 
 // List of VirtualSpaces for metadata allocation.
-// It has a  _next link for singly linked list and a MemRegion
-// for total space in the VirtualSpace.
 class VirtualSpaceList : public CHeapObj<mtClass> {
   friend class VirtualSpaceNode;
 
@@ -419,16 +451,13 @@ class VirtualSpaceList : public CHeapObj<mtClass> {
     VirtualSpaceSize = 256 * K
   };
 
-  // Global list of virtual spaces
   // Head of the list
   VirtualSpaceNode* _virtual_space_list;
   // virtual space currently being used for allocations
   VirtualSpaceNode* _current_virtual_space;
 
-  // Can this virtual list allocate >1 spaces?  Also, used to determine
-  // whether to allocate unlimited small chunks in this virtual space
+  // Is this VirtualSpaceList used for the compressed class space
   bool _is_class;
-  bool can_grow() const { return !is_class() || !UseCompressedClassPointers; }
 
   // Sum of reserved and committed memory in the virtual spaces
   size_t _reserved_words;
@@ -453,7 +482,7 @@ class VirtualSpaceList : public CHeapObj<mtClass> {
   // Get another virtual space and add it to the list.  This
   // is typically prompted by a failed attempt to allocate a chunk
   // and is typically followed by the allocation of a chunk.
-  bool grow_vs(size_t vs_word_size);
+  bool create_new_virtual_space(size_t vs_word_size);
 
  public:
   VirtualSpaceList(size_t word_size);
@@ -465,12 +494,12 @@ class VirtualSpaceList : public CHeapObj<mtClass> {
                            size_t grow_chunks_by_words,
                            size_t medium_chunk_bunch);
 
-  bool expand_by(VirtualSpaceNode* node, size_t word_size, bool pre_touch = false);
+  bool expand_node_by(VirtualSpaceNode* node,
+                      size_t min_words,
+                      size_t preferred_words);
 
-  // Get the first chunk for a Metaspace.  Used for
-  // special cases such as the boot class loader, reflection
-  // class loader and anonymous class loader.
-  Metachunk* get_initialization_chunk(size_t word_size, size_t chunk_bunch);
+  bool expand_by(size_t min_words,
+                 size_t preferred_words);
 
   VirtualSpaceNode* current_virtual_space() {
     return _current_virtual_space;
@@ -478,8 +507,7 @@ class VirtualSpaceList : public CHeapObj<mtClass> {
 
   bool is_class() const { return _is_class; }
 
-  // Allocate the first virtualspace.
-  void initialize(size_t word_size);
+  bool initialization_succeeded() { return _virtual_space_list != NULL; }
 
   size_t reserved_words()  { return _reserved_words; }
   size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
@@ -708,6 +736,9 @@ class SpaceManager : public CHeapObj<mtClass> {
   // and allocates from that chunk.
   MetaWord* grow_and_allocate(size_t word_size);
 
+  // Notify memory usage to MemoryService.
+  void track_metaspace_memory_usage();
+
   // debugging support.
 
   void dump(outputStream* const out) const;
@@ -869,6 +900,12 @@ Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
   MetaWord* chunk_limit = top();
   assert(chunk_limit != NULL, "Not safe to call this method");
 
+  // The virtual spaces are always expanded by the
+  // commit granularity to enforce the following condition.
+  // Without this the is_available check will not work correctly.
+  assert(_virtual_space.committed_size() == _virtual_space.actual_committed_size(),
+      "The committed memory doesn't match the expanded memory.");
+
   if (!is_available(chunk_word_size)) {
     if (TraceMetadataChunkAllocation) {
       gclog_or_tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
@@ -888,14 +925,21 @@ Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
 
 
 // Expand the virtual space (commit more of the reserved space)
-bool VirtualSpaceNode::expand_by(size_t words, bool pre_touch) {
-  size_t bytes = words * BytesPerWord;
-  bool result =  virtual_space()->expand_by(bytes, pre_touch);
-  if (TraceMetavirtualspaceAllocation && !result) {
-    gclog_or_tty->print_cr("VirtualSpaceNode::expand_by() failed "
-                           "for byte size " SIZE_FORMAT, bytes);
-    virtual_space()->print_on(gclog_or_tty);
+bool VirtualSpaceNode::expand_by(size_t min_words, size_t preferred_words) {
+  size_t min_bytes = min_words * BytesPerWord;
+  size_t preferred_bytes = preferred_words * BytesPerWord;
+
+  size_t uncommitted = virtual_space()->reserved_size() - virtual_space()->actual_committed_size();
+
+  if (uncommitted < min_bytes) {
+    return false;
   }
+
+  size_t commit = MIN2(preferred_bytes, uncommitted);
+  bool result = virtual_space()->expand_by(commit, false);
+
+  assert(result, "Failed to commit memory");
+
   return result;
 }
 
@@ -914,12 +958,23 @@ bool VirtualSpaceNode::initialize() {
     return false;
   }
 
-  // An allocation out of this Virtualspace that is larger
-  // than an initial commit size can waste that initial committed
-  // space.
-  size_t committed_byte_size = 0;
-  bool result = virtual_space()->initialize(_rs, committed_byte_size);
+  // These are necessary restriction to make sure that the virtual space always
+  // grows in steps of Metaspace::commit_alignment(). If both base and size are
+  // aligned only the middle alignment of the VirtualSpace is used.
+  assert_is_ptr_aligned(_rs.base(), Metaspace::commit_alignment());
+  assert_is_size_aligned(_rs.size(), Metaspace::commit_alignment());
+
+  // ReservedSpaces marked as special will have the entire memory
+  // pre-committed. Setting a committed size will make sure that
+  // committed_size and actual_committed_size agrees.
+  size_t pre_committed_size = _rs.special() ? _rs.size() : 0;
+
+  bool result = virtual_space()->initialize_with_granularity(_rs, pre_committed_size,
+                                            Metaspace::commit_alignment());
   if (result) {
+    assert(virtual_space()->committed_size() == virtual_space()->actual_committed_size(),
+        "Checking that the pre-committed memory was registered by the VirtualSpace");
+
     set_top((MetaWord*)virtual_space()->low());
     set_reserved(MemRegion((HeapWord*)_rs.base(),
                  (HeapWord*)(_rs.base() + _rs.size())));
@@ -976,13 +1031,23 @@ void VirtualSpaceList::dec_reserved_words(size_t v) {
   _reserved_words = _reserved_words - v;
 }
 
+#define assert_committed_below_limit()                             \
+  assert(MetaspaceAux::committed_bytes() <= MaxMetaspaceSize,      \
+      err_msg("Too much committed memory. Committed: " SIZE_FORMAT \
+              " limit (MaxMetaspaceSize): " SIZE_FORMAT,           \
+          MetaspaceAux::committed_bytes(), MaxMetaspaceSize));
+
 void VirtualSpaceList::inc_committed_words(size_t v) {
   assert_lock_strong(SpaceManager::expand_lock());
   _committed_words = _committed_words + v;
+
+  assert_committed_below_limit();
 }
 void VirtualSpaceList::dec_committed_words(size_t v) {
   assert_lock_strong(SpaceManager::expand_lock());
   _committed_words = _committed_words - v;
+
+  assert_committed_below_limit();
 }
 
 void VirtualSpaceList::inc_virtual_space_count() {
@@ -1025,8 +1090,8 @@ void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
     if (vsl->container_count() == 0 && vsl != current_virtual_space()) {
       // Unlink it from the list
       if (prev_vsl == vsl) {
-        // This is the case of the current note being the first note.
-        assert(vsl == virtual_space_list(), "Expected to be the first note");
+        // This is the case of the current node being the first node.
+        assert(vsl == virtual_space_list(), "Expected to be the first node");
         set_virtual_space_list(vsl->next());
       } else {
         prev_vsl->set_next(vsl->next());
@@ -1054,7 +1119,7 @@ void VirtualSpaceList::purge(ChunkManager* chunk_manager) {
 #endif
 }
 
-VirtualSpaceList::VirtualSpaceList(size_t word_size ) :
+VirtualSpaceList::VirtualSpaceList(size_t word_size) :
                                    _is_class(false),
                                    _virtual_space_list(NULL),
                                    _current_virtual_space(NULL),
@@ -1063,9 +1128,7 @@ VirtualSpaceList::VirtualSpaceList(size_t word_size ) :
                                    _virtual_space_count(0) {
   MutexLockerEx cl(SpaceManager::expand_lock(),
                    Mutex::_no_safepoint_check_flag);
-  bool initialization_succeeded = grow_vs(word_size);
-  assert(initialization_succeeded,
-    " VirtualSpaceList initialization should not fail");
+  create_new_virtual_space(word_size);
 }
 
 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
@@ -1079,8 +1142,9 @@ VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
                    Mutex::_no_safepoint_check_flag);
   VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
   bool succeeded = class_entry->initialize();
-  assert(succeeded, " VirtualSpaceList initialization should not fail");
-  link_vs(class_entry);
+  if (succeeded) {
+    link_vs(class_entry);
+  }
 }
 
 size_t VirtualSpaceList::free_bytes() {
@@ -1088,14 +1152,24 @@ size_t VirtualSpaceList::free_bytes() {
 }
 
 // Allocate another meta virtual space and add it to the list.
-bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
+bool VirtualSpaceList::create_new_virtual_space(size_t vs_word_size) {
   assert_lock_strong(SpaceManager::expand_lock());
+
+  if (is_class()) {
+    assert(false, "We currently don't support more than one VirtualSpace for"
+                  " the compressed class space. The initialization of the"
+                  " CCS uses another code path and should not hit this path.");
+    return false;
+  }
+
   if (vs_word_size == 0) {
+    assert(false, "vs_word_size should always be at least _reserve_alignment large.");
     return false;
   }
+
   // Reserve the space
   size_t vs_byte_size = vs_word_size * BytesPerWord;
-  assert(vs_byte_size % os::vm_allocation_granularity() == 0, "Not aligned");
+  assert_is_size_aligned(vs_byte_size, Metaspace::reserve_alignment());
 
   // Allocate the meta virtual space and initialize it.
   VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
@@ -1103,7 +1177,8 @@ bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
     delete new_entry;
     return false;
   } else {
-    assert(new_entry->reserved_words() == vs_word_size, "Must be");
+    assert(new_entry->reserved_words() == vs_word_size,
+        "Reserved memory size differs from requested memory size");
     // ensure lock-free iteration sees fully initialized node
     OrderAccess::storestore();
     link_vs(new_entry);
@@ -1130,20 +1205,67 @@ void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry) {
   }
 }
 
-bool VirtualSpaceList::expand_by(VirtualSpaceNode* node, size_t word_size, bool pre_touch) {
+bool VirtualSpaceList::expand_node_by(VirtualSpaceNode* node,
+                                      size_t min_words,
+                                      size_t preferred_words) {
   size_t before = node->committed_words();
 
-  bool result = node->expand_by(word_size, pre_touch);
+  bool result = node->expand_by(min_words, preferred_words);
 
   size_t after = node->committed_words();
 
   // after and before can be the same if the memory was pre-committed.
-  assert(after >= before, "Must be");
+  assert(after >= before, "Inconsistency");
   inc_committed_words(after - before);
 
   return result;
 }
 
+bool VirtualSpaceList::expand_by(size_t min_words, size_t preferred_words) {
+  assert_is_size_aligned(min_words,       Metaspace::commit_alignment_words());
+  assert_is_size_aligned(preferred_words, Metaspace::commit_alignment_words());
+  assert(min_words <= preferred_words, "Invalid arguments");
+
+  if (!MetaspaceGC::can_expand(min_words, this->is_class())) {
+    return  false;
+  }
+
+  size_t allowed_expansion_words = MetaspaceGC::allowed_expansion();
+  if (allowed_expansion_words < min_words) {
+    return false;
+  }
+
+  size_t max_expansion_words = MIN2(preferred_words, allowed_expansion_words);
+
+  // Commit more memory from the the current virtual space.
+  bool vs_expanded = expand_node_by(current_virtual_space(),
+                                    min_words,
+                                    max_expansion_words);
+  if (vs_expanded) {
+    return true;
+  }
+
+  // Get another virtual space.
+  size_t grow_vs_words = MAX2((size_t)VirtualSpaceSize, preferred_words);
+  grow_vs_words = align_size_up(grow_vs_words, Metaspace::reserve_alignment_words());
+
+  if (create_new_virtual_space(grow_vs_words)) {
+    if (current_virtual_space()->is_pre_committed()) {
+      // The memory was pre-committed, so we are done here.
+      assert(min_words <= current_virtual_space()->committed_words(),
+          "The new VirtualSpace was pre-committed, so it"
+          "should be large enough to fit the alloc request.");
+      return true;
+    }
+
+    return expand_node_by(current_virtual_space(),
+                          min_words,
+                          max_expansion_words);
+  }
+
+  return false;
+}
+
 Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
                                            size_t grow_chunks_by_words,
                                            size_t medium_chunk_bunch) {
@@ -1151,63 +1273,27 @@ Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
   // Allocate a chunk out of the current virtual space.
   Metachunk* next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
 
-  if (next == NULL) {
-    // Not enough room in current virtual space.  Try to commit
-    // more space.
-    size_t expand_vs_by_words = MAX2(medium_chunk_bunch,
-                                     grow_chunks_by_words);
-    size_t page_size_words = os::vm_page_size() / BytesPerWord;
-    size_t aligned_expand_vs_by_words = align_size_up(expand_vs_by_words,
-                                                        page_size_words);
-    bool vs_expanded =
-      expand_by(current_virtual_space(), aligned_expand_vs_by_words);
-    if (!vs_expanded) {
-      // Should the capacity of the metaspaces be expanded for
-      // this allocation?  If it's the virtual space for classes and is
-      // being used for CompressedHeaders, don't allocate a new virtualspace.
-      if (can_grow() && MetaspaceGC::should_expand(this, word_size)) {
-        // Get another virtual space.
-        size_t allocation_aligned_expand_words =
-            align_size_up(aligned_expand_vs_by_words, os::vm_allocation_granularity() / BytesPerWord);
-        size_t grow_vs_words =
-            MAX2((size_t)VirtualSpaceSize, allocation_aligned_expand_words);
-        if (grow_vs(grow_vs_words)) {
-          // Got it.  It's on the list now.  Get a chunk from it.
-          assert(current_virtual_space()->expanded_words() == 0,
-              "New virtual space nodes should not have expanded");
-
-          size_t grow_chunks_by_words_aligned = align_size_up(grow_chunks_by_words,
-                                                              page_size_words);
-          // We probably want to expand by aligned_expand_vs_by_words here.
-          expand_by(current_virtual_space(), grow_chunks_by_words_aligned);
-          next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
-        }
-      } else {
-        // Allocation will fail and induce a GC
-        if (TraceMetadataChunkAllocation && Verbose) {
-          gclog_or_tty->print_cr("VirtualSpaceList::get_new_chunk():"
-            " Fail instead of expand the metaspace");
-        }
-      }
-    } else {
-      // The virtual space expanded, get a new chunk
-      next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
-      assert(next != NULL, "Just expanded, should succeed");
-    }
+  if (next != NULL) {
+    return next;
   }
 
-  assert(next == NULL || (next->next() == NULL && next->prev() == NULL),
-         "New chunk is still on some list");
-  return next;
-}
+  // The expand amount is currently only determined by the requested sizes
+  // and not how much committed memory is left in the current virtual space.
 
-Metachunk* VirtualSpaceList::get_initialization_chunk(size_t chunk_word_size,
-                                                      size_t chunk_bunch) {
-  // Get a chunk from the chunk freelist
-  Metachunk* new_chunk = get_new_chunk(chunk_word_size,
-                                       chunk_word_size,
-                                       chunk_bunch);
-  return new_chunk;
+  size_t min_word_size       = align_size_up(grow_chunks_by_words, Metaspace::commit_alignment_words());
+  size_t preferred_word_size = align_size_up(medium_chunk_bunch,   Metaspace::commit_alignment_words());
+  if (min_word_size >= preferred_word_size) {
+    // Can happen when humongous chunks are allocated.
+    preferred_word_size = min_word_size;
+  }
+
+  bool expanded = expand_by(min_word_size, preferred_word_size);
+  if (expanded) {
+    next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
+    assert(next != NULL, "The allocation was expected to succeed after the expansion");
+  }
+
+   return next;
 }
 
 void VirtualSpaceList::print_on(outputStream* st) const {
@@ -1256,96 +1342,96 @@ bool VirtualSpaceList::contains(const void *ptr) {
 // Calculate the amount to increase the high water mark (HWM).
 // Increase by a minimum amount (MinMetaspaceExpansion) so that
 // another expansion is not requested too soon.  If that is not
-// enough to satisfy the allocation (i.e. big enough for a word_size
-// allocation), increase by MaxMetaspaceExpansion.  If that is still
-// not enough, expand by the size of the allocation (word_size) plus
-// some.
-size_t MetaspaceGC::delta_capacity_until_GC(size_t word_size) {
-  size_t before_inc = MetaspaceGC::capacity_until_GC();
-  size_t min_delta_words = MinMetaspaceExpansion / BytesPerWord;
-  size_t max_delta_words = MaxMetaspaceExpansion / BytesPerWord;
-  size_t page_size_words = os::vm_page_size() / BytesPerWord;
-  size_t size_delta_words = align_size_up(word_size, page_size_words);
-  size_t delta_words = MAX2(size_delta_words, min_delta_words);
-  if (delta_words > min_delta_words) {
+// enough to satisfy the allocation, increase by MaxMetaspaceExpansion.
+// If that is still not enough, expand by the size of the allocation
+// plus some.
+size_t MetaspaceGC::delta_capacity_until_GC(size_t bytes) {
+  size_t min_delta = MinMetaspaceExpansion;
+  size_t max_delta = MaxMetaspaceExpansion;
+  size_t delta = align_size_up(bytes, Metaspace::commit_alignment());
+
+  if (delta <= min_delta) {
+    delta = min_delta;
+  } else if (delta <= max_delta) {
     // Don't want to hit the high water mark on the next
     // allocation so make the delta greater than just enough
     // for this allocation.
-    delta_words = MAX2(delta_words, max_delta_words);
-    if (delta_words > max_delta_words) {
-      // This allocation is large but the next ones are probably not
-      // so increase by the minimum.
-      delta_words = delta_words + min_delta_words;
-    }
+    delta = max_delta;
+  } else {
+    // This allocation is large but the next ones are probably not
+    // so increase by the minimum.
+    delta = delta + min_delta;
   }
-  return delta_words;
+
+  assert_is_size_aligned(delta, Metaspace::commit_alignment());
+
+  return delta;
+}
+
+size_t MetaspaceGC::capacity_until_GC() {
+  size_t value = (size_t)OrderAccess::load_ptr_acquire(&_capacity_until_GC);
+  assert(value >= MetaspaceSize, "Not initialied properly?");
+  return value;
 }
 
-bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
+size_t MetaspaceGC::inc_capacity_until_GC(size_t v) {
+  assert_is_size_aligned(v, Metaspace::commit_alignment());
 
-  // If the user wants a limit, impose one.
-  // The reason for someone using this flag is to limit reserved space.  So
-  // for non-class virtual space, compare against virtual spaces that are reserved.
-  // For class virtual space, we only compare against the committed space, not
-  // reserved space, because this is a larger space prereserved for compressed
-  // class pointers.
-  if (!FLAG_IS_DEFAULT(MaxMetaspaceSize)) {
-    size_t nonclass_allocated = MetaspaceAux::reserved_bytes(Metaspace::NonClassType);
-    size_t class_allocated    = MetaspaceAux::allocated_capacity_bytes(Metaspace::ClassType);
-    size_t real_allocated     = nonclass_allocated + class_allocated;
-    if (real_allocated >= MaxMetaspaceSize) {
+  return (size_t)Atomic::add_ptr(v, &_capacity_until_GC);
+}
+
+size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
+  assert_is_size_aligned(v, Metaspace::commit_alignment());
+
+  return (size_t)Atomic::add_ptr(-(intptr_t)v, &_capacity_until_GC);
+}
+
+bool MetaspaceGC::can_expand(size_t word_size, bool is_class) {
+  // Check if the compressed class space is full.
+  if (is_class && Metaspace::using_class_space()) {
+    size_t class_committed = MetaspaceAux::committed_bytes(Metaspace::ClassType);
+    if (class_committed + word_size * BytesPerWord > CompressedClassSpaceSize) {
       return false;
     }
   }
 
-  // Class virtual space should always be expanded.  Call GC for the other
-  // metadata virtual space.
-  if (Metaspace::using_class_space() &&
-      (vsl == Metaspace::class_space_list())) return true;
+  // Check if the user has imposed a limit on the metaspace memory.
+  size_t committed_bytes = MetaspaceAux::committed_bytes();
+  if (committed_bytes + word_size * BytesPerWord > MaxMetaspaceSize) {
+    return false;
+  }
+
+  return true;
+}
+
+size_t MetaspaceGC::allowed_expansion() {
+  size_t committed_bytes = MetaspaceAux::committed_bytes();
 
-  // If this is part of an allocation after a GC, expand
-  // unconditionally.
-  if (MetaspaceGC::expand_after_GC()) {
-    return true;
+  size_t left_until_max  = MaxMetaspaceSize - committed_bytes;
+
+  // Always grant expansion if we are initiating the JVM,
+  // or if the GC_locker is preventing GCs.
+  if (!is_init_completed() || GC_locker::is_active_and_needs_gc()) {
+    return left_until_max / BytesPerWord;
   }
 
+  size_t capacity_until_gc = capacity_until_GC();
 
-  // 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.
-  size_t committed_capacity_bytes = MetaspaceAux::allocated_capacity_bytes();
-  size_t metaspace_size_bytes = MetaspaceSize;
-  if (committed_capacity_bytes < metaspace_size_bytes ||
-      capacity_until_GC() == 0) {
-    set_capacity_until_GC(metaspace_size_bytes);
-    return true;
-  } else {
-    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
-                        "  allocated_capacity_bytes " SIZE_FORMAT,
-                        word_size,
-                        capacity_until_GC(),
-                        MetaspaceAux::allocated_capacity_bytes());
-      }
-      return false;
-    }
+  if (capacity_until_gc <= committed_bytes) {
+    return 0;
   }
-}
 
+  size_t left_until_GC = capacity_until_gc - committed_bytes;
+  size_t left_to_commit = MIN2(left_until_GC, left_until_max);
 
+  return left_to_commit / BytesPerWord;
+}
 
 void MetaspaceGC::compute_new_size() {
   assert(_shrink_factor <= 100, "invalid shrink factor");
   uint current_shrink_factor = _shrink_factor;
   _shrink_factor = 0;
 
-  // Until a faster way of calculating the "used" quantity is implemented,
-  // use "capacity".
   const size_t used_after_gc = MetaspaceAux::allocated_capacity_bytes();
   const size_t capacity_until_GC = MetaspaceGC::capacity_until_GC();
 
@@ -1377,9 +1463,10 @@ void MetaspaceGC::compute_new_size() {
     // If we have less capacity below the metaspace HWM, then
     // increment the HWM.
     size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
+    expand_bytes = align_size_up(expand_bytes, Metaspace::commit_alignment());
     // Don't expand unless it's significant
     if (expand_bytes >= MinMetaspaceExpansion) {
-      MetaspaceGC::set_capacity_until_GC(capacity_until_GC + expand_bytes);
+      MetaspaceGC::inc_capacity_until_GC(expand_bytes);
     }
     if (PrintGCDetails && Verbose) {
       size_t new_capacity_until_GC = capacity_until_GC;
@@ -1436,6 +1523,9 @@ void MetaspaceGC::compute_new_size() {
       // on the third call, and 100% by the fourth call.  But if we recompute
       // size without shrinking, it goes back to 0%.
       shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
+
+      shrink_bytes = align_size_down(shrink_bytes, Metaspace::commit_alignment());
+
       assert(shrink_bytes <= max_shrink_bytes,
         err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
           shrink_bytes, max_shrink_bytes));
@@ -1467,7 +1557,7 @@ void MetaspaceGC::compute_new_size() {
   // Don't shrink unless it's significant
   if (shrink_bytes >= MinMetaspaceExpansion &&
       ((capacity_until_GC - shrink_bytes) >= MetaspaceSize)) {
-    MetaspaceGC::set_capacity_until_GC(capacity_until_GC - shrink_bytes);
+    MetaspaceGC::dec_capacity_until_GC(shrink_bytes);
   }
 }
 
@@ -1700,7 +1790,6 @@ Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
     assert(free_list != NULL, "Sanity check");
 
     chunk = free_list->head();
-    debug_only(Metachunk* debug_head = chunk;)
 
     if (chunk == NULL) {
       return NULL;
@@ -1709,9 +1798,6 @@ Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
     // Remove the chunk as the head of the list.
     free_list->remove_chunk(chunk);
 
-    // Chunk is being removed from the chunks free list.
-    dec_free_chunks_total(chunk->capacity_word_size());
-
     if (TraceMetadataChunkAllocation && Verbose) {
       gclog_or_tty->print_cr("ChunkManager::free_chunks_get: free_list "
                              PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
@@ -1722,21 +1808,22 @@ Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
       word_size,
       FreeBlockDictionary<Metachunk>::atLeast);
 
-    if (chunk != NULL) {
-      if (TraceMetadataHumongousAllocation) {
-        size_t waste = chunk->word_size() - word_size;
-        gclog_or_tty->print_cr("Free list allocate humongous chunk size "
-                               SIZE_FORMAT " for requested size " SIZE_FORMAT
-                               " waste " SIZE_FORMAT,
-                               chunk->word_size(), word_size, waste);
-      }
-      // Chunk is being removed from the chunks free list.
-      dec_free_chunks_total(chunk->capacity_word_size());
-    } else {
+    if (chunk == NULL) {
       return NULL;
     }
+
+    if (TraceMetadataHumongousAllocation) {
+      size_t waste = chunk->word_size() - word_size;
+      gclog_or_tty->print_cr("Free list allocate humongous chunk size "
+                             SIZE_FORMAT " for requested size " SIZE_FORMAT
+                             " waste " SIZE_FORMAT,
+                             chunk->word_size(), word_size, waste);
+    }
   }
 
+  // Chunk is being removed from the chunks free list.
+  dec_free_chunks_total(chunk->capacity_word_size());
+
   // Remove it from the links to this freelist
   chunk->set_next(NULL);
   chunk->set_prev(NULL);
@@ -1977,6 +2064,15 @@ size_t SpaceManager::calc_chunk_size(size_t word_size) {
   return chunk_word_size;
 }
 
+void SpaceManager::track_metaspace_memory_usage() {
+  if (is_init_completed()) {
+    if (is_class()) {
+      MemoryService::track_compressed_class_memory_usage();
+    }
+    MemoryService::track_metaspace_memory_usage();
+  }
+}
+
 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
   assert(vs_list()->current_virtual_space() != NULL,
          "Should have been set");
@@ -2002,15 +2098,24 @@ MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
   size_t grow_chunks_by_words = calc_chunk_size(word_size);
   Metachunk* next = get_new_chunk(word_size, grow_chunks_by_words);
 
+  if (next != NULL) {
+    Metadebug::deallocate_chunk_a_lot(this, grow_chunks_by_words);
+  }
+
+  MetaWord* mem = NULL;
+
   // If a chunk was available, add it to the in-use chunk list
   // and do an allocation from it.
   if (next != NULL) {
-    Metadebug::deallocate_chunk_a_lot(this, grow_chunks_by_words);
     // Add to this manager's list of chunks in use.
     add_chunk(next, false);
-    return next->allocate(word_size);
+    mem = next->allocate(word_size);
   }
-  return NULL;
+
+  // Track metaspace memory usage statistic.
+  track_metaspace_memory_usage();
+
+  return mem;
 }
 
 void SpaceManager::print_on(outputStream* st) const {
@@ -2366,6 +2471,7 @@ MetaWord* SpaceManager::allocate_work(size_t word_size) {
     inc_used_metrics(word_size);
     return current_chunk()->allocate(word_size); // caller handles null result
   }
+
   if (current_chunk() != NULL) {
     result = current_chunk()->allocate(word_size);
   }
@@ -2373,7 +2479,8 @@ MetaWord* SpaceManager::allocate_work(size_t word_size) {
   if (result == NULL) {
     result = grow_and_allocate(word_size);
   }
-  if (result != 0) {
+
+  if (result != NULL) {
     inc_used_metrics(word_size);
     assert(result != (MetaWord*) chunks_in_use(MediumIndex),
            "Head of the list is being allocated");
@@ -2639,24 +2746,26 @@ void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
 void MetaspaceAux::print_on(outputStream* out) {
   Metaspace::MetadataType nct = Metaspace::NonClassType;
 
-  out->print_cr(" Metaspace total "
-                SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
-                " reserved " SIZE_FORMAT "K",
-                allocated_capacity_bytes()/K, allocated_used_bytes()/K, reserved_bytes()/K);
-
-  out->print_cr("  data space     "
-                SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
-                " reserved " SIZE_FORMAT "K",
-                allocated_capacity_bytes(nct)/K,
-                allocated_used_bytes(nct)/K,
-                reserved_bytes(nct)/K);
+  out->print_cr(" Metaspace       "
+                "used "      SIZE_FORMAT "K, "
+                "capacity "  SIZE_FORMAT "K, "
+                "committed " SIZE_FORMAT "K, "
+                "reserved "  SIZE_FORMAT "K",
+                allocated_used_bytes()/K,
+                allocated_capacity_bytes()/K,
+                committed_bytes()/K,
+                reserved_bytes()/K);
+
   if (Metaspace::using_class_space()) {
     Metaspace::MetadataType ct = Metaspace::ClassType;
     out->print_cr("  class space    "
-                  SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
-                  " reserved " SIZE_FORMAT "K",
-                  allocated_capacity_bytes(ct)/K,
+                  "used "      SIZE_FORMAT "K, "
+                  "capacity "  SIZE_FORMAT "K, "
+                  "committed " SIZE_FORMAT "K, "
+                  "reserved "  SIZE_FORMAT "K",
                   allocated_used_bytes(ct)/K,
+                  allocated_capacity_bytes(ct)/K,
+                  committed_bytes(ct)/K,
                   reserved_bytes(ct)/K);
   }
 }
@@ -2808,6 +2917,9 @@ void MetaspaceAux::verify_metrics() {
 size_t Metaspace::_first_chunk_word_size = 0;
 size_t Metaspace::_first_class_chunk_word_size = 0;
 
+size_t Metaspace::_commit_alignment = 0;
+size_t Metaspace::_reserve_alignment = 0;
+
 Metaspace::Metaspace(Mutex* lock, MetaspaceType type) {
   initialize(lock, type);
 }
@@ -2869,21 +2981,30 @@ void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, a
   assert(UseCompressedClassPointers, "Only use with CompressedKlassPtrs");
   assert(class_metaspace_size() < KlassEncodingMetaspaceMax,
          "Metaspace size is too big");
+  assert_is_ptr_aligned(requested_addr,          _reserve_alignment);
+  assert_is_ptr_aligned(cds_base,                _reserve_alignment);
+  assert_is_size_aligned(class_metaspace_size(), _reserve_alignment);
+
+  // Don't use large pages for the class space.
+  bool large_pages = false;
 
   ReservedSpace metaspace_rs = ReservedSpace(class_metaspace_size(),
-                                             os::vm_allocation_granularity(),
-                                             false, requested_addr, 0);
+                                             _reserve_alignment,
+                                             large_pages,
+                                             requested_addr, 0);
   if (!metaspace_rs.is_reserved()) {
     if (UseSharedSpaces) {
+      size_t increment = align_size_up(1*G, _reserve_alignment);
+
       // Keep trying to allocate the metaspace, increasing the requested_addr
       // by 1GB each time, until we reach an address that will no longer allow
       // use of CDS with compressed klass pointers.
       char *addr = requested_addr;
-      while (!metaspace_rs.is_reserved() && (addr + 1*G > addr) &&
-             can_use_cds_with_metaspace_addr(addr + 1*G, cds_base)) {
-        addr = addr + 1*G;
+      while (!metaspace_rs.is_reserved() && (addr + increment > addr) &&
+             can_use_cds_with_metaspace_addr(addr + increment, cds_base)) {
+        addr = addr + increment;
         metaspace_rs = ReservedSpace(class_metaspace_size(),
-                                     os::vm_allocation_granularity(), false, addr, 0);
+                                     _reserve_alignment, large_pages, addr, 0);
       }
     }
 
@@ -2894,7 +3015,7 @@ void Metaspace::allocate_metaspace_compressed_klass_ptrs(char* requested_addr, a
     // So, UseCompressedClassPointers cannot be turned off at this point.
     if (!metaspace_rs.is_reserved()) {
       metaspace_rs = ReservedSpace(class_metaspace_size(),
-                                   os::vm_allocation_granularity(), false);
+                                   _reserve_alignment, large_pages);
       if (!metaspace_rs.is_reserved()) {
         vm_exit_during_initialization(err_msg("Could not allocate metaspace: %d bytes",
                                               class_metaspace_size()));
@@ -2933,34 +3054,96 @@ void Metaspace::initialize_class_space(ReservedSpace rs) {
   assert(using_class_space(), "Must be using class space");
   _class_space_list = new VirtualSpaceList(rs);
   _chunk_manager_class = new ChunkManager(SpecializedChunk, ClassSmallChunk, ClassMediumChunk);
+
+  if (!_class_space_list->initialization_succeeded()) {
+    vm_exit_during_initialization("Failed to setup compressed class space virtual space list.");
+  }
 }
 
 #endif
 
+// Align down. If the aligning result in 0, return 'alignment'.
+static size_t restricted_align_down(size_t size, size_t alignment) {
+  return MAX2(alignment, align_size_down_(size, alignment));
+}
+
+void Metaspace::ergo_initialize() {
+  if (DumpSharedSpaces) {
+    // Using large pages when dumping the shared archive is currently not implemented.
+    FLAG_SET_ERGO(bool, UseLargePagesInMetaspace, false);
+  }
+
+  size_t page_size = os::vm_page_size();
+  if (UseLargePages && UseLargePagesInMetaspace) {
+    page_size = os::large_page_size();
+  }
+
+  _commit_alignment  = page_size;
+  _reserve_alignment = MAX2(page_size, (size_t)os::vm_allocation_granularity());
+
+  // Do not use FLAG_SET_ERGO to update MaxMetaspaceSize, since this will
+  // override if MaxMetaspaceSize was set on the command line or not.
+  // This information is needed later to conform to the specification of the
+  // java.lang.management.MemoryUsage API.
+  //
+  // Ideally, we would be able to set the default value of MaxMetaspaceSize in
+  // globals.hpp to the aligned value, but this is not possible, since the
+  // alignment depends on other flags being parsed.
+  MaxMetaspaceSize = restricted_align_down(MaxMetaspaceSize, _reserve_alignment);
+
+  if (MetaspaceSize > MaxMetaspaceSize) {
+    MetaspaceSize = MaxMetaspaceSize;
+  }
+
+  MetaspaceSize = restricted_align_down(MetaspaceSize, _commit_alignment);
+
+  assert(MetaspaceSize <= MaxMetaspaceSize, "MetaspaceSize should be limited by MaxMetaspaceSize");
+
+  if (MetaspaceSize < 256*K) {
+    vm_exit_during_initialization("Too small initial Metaspace size");
+  }
+
+  MinMetaspaceExpansion = restricted_align_down(MinMetaspaceExpansion, _commit_alignment);
+  MaxMetaspaceExpansion = restricted_align_down(MaxMetaspaceExpansion, _commit_alignment);
+
+  CompressedClassSpaceSize = restricted_align_down(CompressedClassSpaceSize, _reserve_alignment);
+  set_class_metaspace_size(CompressedClassSpaceSize);
+}
+
 void Metaspace::global_initialize() {
   // Initialize the alignment for shared spaces.
   int max_alignment = os::vm_page_size();
   size_t cds_total = 0;
 
-  set_class_metaspace_size(align_size_up(CompressedClassSpaceSize,
-                                         os::vm_allocation_granularity()));
-
   MetaspaceShared::set_max_alignment(max_alignment);
 
   if (DumpSharedSpaces) {
-    SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment);
+    SharedReadOnlySize  = align_size_up(SharedReadOnlySize,  max_alignment);
     SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
-    SharedMiscDataSize  = align_size_up(SharedMiscDataSize, max_alignment);
-    SharedMiscCodeSize  = align_size_up(SharedMiscCodeSize, max_alignment);
+    SharedMiscDataSize  = align_size_up(SharedMiscDataSize,  max_alignment);
+    SharedMiscCodeSize  = align_size_up(SharedMiscCodeSize,  max_alignment);
 
     // Initialize with the sum of the shared space sizes.  The read-only
     // and read write metaspace chunks will be allocated out of this and the
     // remainder is the misc code and data chunks.
     cds_total = FileMapInfo::shared_spaces_size();
+    cds_total = align_size_up(cds_total, _reserve_alignment);
     _space_list = new VirtualSpaceList(cds_total/wordSize);
     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
 
+    if (!_space_list->initialization_succeeded()) {
+      vm_exit_during_initialization("Unable to dump shared archive.", NULL);
+    }
+
 #ifdef _LP64
+    if (cds_total + class_metaspace_size() > (uint64_t)max_juint) {
+      vm_exit_during_initialization("Unable to dump shared archive.",
+          err_msg("Size of archive (" SIZE_FORMAT ") + compressed class space ("
+                  SIZE_FORMAT ") == total (" SIZE_FORMAT ") is larger than compressed "
+                  "klass limit: " SIZE_FORMAT, cds_total, class_metaspace_size(),
+                  cds_total + class_metaspace_size(), (size_t)max_juint));
+    }
+
     // Set the compressed klass pointer base so that decoding of these pointers works
     // properly when creating the shared archive.
     assert(UseCompressedOops && UseCompressedClassPointers,
@@ -2971,9 +3154,6 @@ void Metaspace::global_initialize() {
                              _space_list->current_virtual_space()->bottom());
     }
 
-    // Set the shift to zero.
-    assert(class_metaspace_size() < (uint64_t)(max_juint) - cds_total,
-           "CDS region is too large");
     Universe::set_narrow_klass_shift(0);
 #endif
 
@@ -2992,12 +3172,12 @@ void Metaspace::global_initialize() {
       // Map in spaces now also
       if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
         FileMapInfo::set_current_info(mapinfo);
+        cds_total = FileMapInfo::shared_spaces_size();
+        cds_address = (address)mapinfo->region_base(0);
       } else {
         assert(!mapinfo->is_open() && !UseSharedSpaces,
                "archive file not closed or shared spaces not disabled.");
       }
-      cds_total = FileMapInfo::shared_spaces_size();
-      cds_address = (address)mapinfo->region_base(0);
     }
 
 #ifdef _LP64
@@ -3005,7 +3185,9 @@ void Metaspace::global_initialize() {
     // above the heap and above the CDS area (if it exists).
     if (using_class_space()) {
       if (UseSharedSpaces) {
-        allocate_metaspace_compressed_klass_ptrs((char *)(cds_address + cds_total), cds_address);
+        char* cds_end = (char*)(cds_address + cds_total);
+        cds_end = (char *)align_ptr_up(cds_end, _reserve_alignment);
+        allocate_metaspace_compressed_klass_ptrs(cds_end, cds_address);
       } else {
         allocate_metaspace_compressed_klass_ptrs((char *)CompressedKlassPointersBase, 0);
       }
@@ -3023,11 +3205,19 @@ void Metaspace::global_initialize() {
     _first_class_chunk_word_size = align_word_size_up(_first_class_chunk_word_size);
     // Arbitrarily set the initial virtual space to a multiple
     // of the boot class loader size.
-    size_t word_size = VIRTUALSPACEMULTIPLIER * first_chunk_word_size();
+    size_t word_size = VIRTUALSPACEMULTIPLIER * _first_chunk_word_size;
+    word_size = align_size_up(word_size, Metaspace::reserve_alignment_words());
+
     // Initialize the list of virtual spaces.
     _space_list = new VirtualSpaceList(word_size);
     _chunk_manager_metadata = new ChunkManager(SpecializedChunk, SmallChunk, MediumChunk);
+
+    if (!_space_list->initialization_succeeded()) {
+      vm_exit_during_initialization("Unable to setup metadata virtual space list.", NULL);
+    }
   }
+
+  MetaspaceGC::initialize();
 }
 
 Metachunk* Metaspace::get_initialization_chunk(MetadataType mdtype,
@@ -3039,7 +3229,7 @@ Metachunk* Metaspace::get_initialization_chunk(MetadataType mdtype,
     return chunk;
   }
 
-  return get_space_list(mdtype)->get_initialization_chunk(chunk_word_size, chunk_bunch);
+  return get_space_list(mdtype)->get_new_chunk(chunk_word_size, chunk_word_size, chunk_bunch);
 }
 
 void Metaspace::initialize(Mutex* lock, MetaspaceType type) {
@@ -3112,19 +3302,18 @@ MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
 }
 
 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_bytes = MetaspaceGC::delta_capacity_until_GC(word_size) * BytesPerWord;
-  MetaspaceGC::inc_capacity_until_GC(delta_bytes);
+  size_t delta_bytes = MetaspaceGC::delta_capacity_until_GC(word_size * BytesPerWord);
+  assert(delta_bytes > 0, "Must be");
+
+  size_t after_inc = MetaspaceGC::inc_capacity_until_GC(delta_bytes);
+  size_t before_inc = after_inc - 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());
+        " to " SIZE_FORMAT, before_inc, after_inc);
   }
 
-  result = allocate(word_size, mdtype);
-
-  return result;
+  return allocate(word_size, mdtype);
 }
 
 // Space allocated in the Metaspace.  This may
@@ -3206,6 +3395,7 @@ void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
   }
 }
 
+
 Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
                               bool read_only, MetaspaceObj::Type type, TRAPS) {
   if (HAS_PENDING_EXCEPTION) {
@@ -3213,20 +3403,16 @@ Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
     return NULL;  // caller does a CHECK_NULL too
   }
 
-  MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType;
-
-  // SSS: Should we align the allocations and make sure the sizes are aligned.
-  MetaWord* result = NULL;
-
   assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
         "ClassLoaderData::the_null_class_loader_data() should have been used.");
+
   // Allocate in metaspaces without taking out a lock, because it deadlocks
   // with the SymbolTable_lock.  Dumping is single threaded for now.  We'll have
   // to revisit this for application class data sharing.
   if (DumpSharedSpaces) {
     assert(type > MetaspaceObj::UnknownType && type < MetaspaceObj::_number_of_types, "sanity");
     Metaspace* space = read_only ? loader_data->ro_metaspace() : loader_data->rw_metaspace();
-    result = space->allocate(word_size, NonClassType);
+    MetaWord* result = space->allocate(word_size, NonClassType);
     if (result == NULL) {
       report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
     } else {
@@ -3235,42 +3421,64 @@ Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
     return Metablock::initialize(result, word_size);
   }
 
-  result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
+  MetadataType mdtype = (type == MetaspaceObj::ClassType) ? ClassType : NonClassType;
+
+  // Try to allocate metadata.
+  MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
 
   if (result == NULL) {
-    // Try to clean out some memory and retry.
-    result =
-      Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
-        loader_data, word_size, mdtype);
+    // Allocation failed.
+    if (is_init_completed()) {
+      // Only start a GC if the bootstrapping has completed.
 
-    // If result is still null, we are out of memory.
-    if (result == NULL) {
-      if (Verbose && TraceMetadataChunkAllocation) {
-        gclog_or_tty->print_cr("Metaspace allocation failed for size "
-          SIZE_FORMAT, word_size);
-        if (loader_data->metaspace_or_null() != NULL) loader_data->dump(gclog_or_tty);
-        MetaspaceAux::dump(gclog_or_tty);
-      }
-      // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
-      const char* space_string = is_class_space_allocation(mdtype) ? "Compressed class space" :
-                                                                     "Metadata space";
-      report_java_out_of_memory(space_string);
-
-      if (JvmtiExport::should_post_resource_exhausted()) {
-        JvmtiExport::post_resource_exhausted(
-            JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
-            space_string);
-      }
-      if (is_class_space_allocation(mdtype)) {
-        THROW_OOP_0(Universe::out_of_memory_error_class_metaspace());
-      } else {
-        THROW_OOP_0(Universe::out_of_memory_error_metaspace());
-      }
+      // Try to clean out some memory and retry.
+      result = Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
+          loader_data, word_size, mdtype);
     }
   }
+
+  if (result == NULL) {
+    report_metadata_oome(loader_data, word_size, mdtype, THREAD);
+    // Will not reach here.
+    return NULL;
+  }
+
   return Metablock::initialize(result, word_size);
 }
 
+void Metaspace::report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetadataType mdtype, TRAPS) {
+  // If result is still null, we are out of memory.
+  if (Verbose && TraceMetadataChunkAllocation) {
+    gclog_or_tty->print_cr("Metaspace allocation failed for size "
+        SIZE_FORMAT, word_size);
+    if (loader_data->metaspace_or_null() != NULL) {
+      loader_data->dump(gclog_or_tty);
+    }
+    MetaspaceAux::dump(gclog_or_tty);
+  }
+
+  // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
+  const char* space_string = is_class_space_allocation(mdtype) ? "Compressed class space" :
+                                                                 "Metadata space";
+  report_java_out_of_memory(space_string);
+
+  if (JvmtiExport::should_post_resource_exhausted()) {
+    JvmtiExport::post_resource_exhausted(
+        JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
+        space_string);
+  }
+
+  if (!is_init_completed()) {
+    vm_exit_during_initialization("OutOfMemoryError", space_string);
+  }
+
+  if (is_class_space_allocation(mdtype)) {
+    THROW_OOP(Universe::out_of_memory_error_class_metaspace());
+  } else {
+    THROW_OOP(Universe::out_of_memory_error_metaspace());
+  }
+}
+
 void Metaspace::record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size) {
   assert(DumpSharedSpaces, "sanity");
 

src/share/vm/memory/metaspace.hpp

@@ -87,9 +87,10 @@ class Metaspace : public CHeapObj<mtClass> {
   friend class MetaspaceAux;
 
  public:
-  enum MetadataType {ClassType = 0,
-                     NonClassType = ClassType + 1,
-                     MetadataTypeCount = ClassType + 2
+  enum MetadataType {
+    ClassType,
+    NonClassType,
+    MetadataTypeCount
   };
   enum MetaspaceType {
     StandardMetaspaceType,
@@ -103,6 +104,9 @@ class Metaspace : public CHeapObj<mtClass> {
  private:
   void initialize(Mutex* lock, MetaspaceType type);
 
+  // Get the first chunk for a Metaspace.  Used for
+  // special cases such as the boot class loader, reflection
+  // class loader and anonymous class loader.
   Metachunk* get_initialization_chunk(MetadataType mdtype,
                                       size_t chunk_word_size,
                                       size_t chunk_bunch);
@@ -123,6 +127,9 @@ class Metaspace : public CHeapObj<mtClass> {
   static size_t _first_chunk_word_size;
   static size_t _first_class_chunk_word_size;
 
+  static size_t _commit_alignment;
+  static size_t _reserve_alignment;
+
   SpaceManager* _vsm;
   SpaceManager* vsm() const { return _vsm; }
 
@@ -191,12 +198,17 @@ class Metaspace : public CHeapObj<mtClass> {
   Metaspace(Mutex* lock, MetaspaceType type);
   ~Metaspace();
 
-  // Initialize globals for Metaspace
+  static void ergo_initialize();
   static void global_initialize();
 
   static size_t first_chunk_word_size() { return _first_chunk_word_size; }
   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
 
+  static size_t reserve_alignment()       { return _reserve_alignment; }
+  static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
+  static size_t commit_alignment()        { return _commit_alignment; }
+  static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }
+
   char*  bottom() const;
   size_t used_words_slow(MetadataType mdtype) const;
   size_t free_words_slow(MetadataType mdtype) const;
@@ -219,6 +231,9 @@ class Metaspace : public CHeapObj<mtClass> {
   static void purge(MetadataType mdtype);
   static void purge();
 
+  static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
+                                   MetadataType mdtype, TRAPS);
+
   void print_on(outputStream* st) const;
   // Debugging support
   void verify();
@@ -352,17 +367,10 @@ class MetaspaceAux : AllStatic {
 
 class MetaspaceGC : AllStatic {
 
-  // The current high-water-mark for inducing a GC.  When
-  // the capacity of all space in the virtual lists reaches this value,
-  // a GC is induced and the value is increased.  This should be changed
-  // to the space actually used for allocations to avoid affects of
-  // fragmentation losses to partially used chunks.  Size is in words.
-  static size_t _capacity_until_GC;
-
-  // After a GC is done any allocation that fails should try to expand
-  // the capacity of the Metaspaces.  This flag is set during attempts
-  // to allocate in the VMGCOperation that does the GC.
-  static bool _expand_after_GC;
+  // The current high-water-mark for inducing a GC.
+  // When committed memory of all metaspaces reaches this value,
+  // a GC is induced and the value is increased. Size is in bytes.
+  static volatile intptr_t _capacity_until_GC;
 
   // For a CMS collection, signal that a concurrent collection should
   // be started.
@@ -370,20 +378,16 @@ class MetaspaceGC : AllStatic {
 
   static uint _shrink_factor;
 
-  static void set_capacity_until_GC(size_t v) { _capacity_until_GC = v; }
-
   static size_t shrink_factor() { return _shrink_factor; }
   void set_shrink_factor(uint v) { _shrink_factor = v; }
 
  public:
 
-  static size_t capacity_until_GC() { return _capacity_until_GC; }
-  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;
-  }
-  static bool expand_after_GC()           { return _expand_after_GC; }
-  static void set_expand_after_GC(bool v) { _expand_after_GC = v; }
+  static void initialize() { _capacity_until_GC = MetaspaceSize; }
+
+  static size_t capacity_until_GC();
+  static size_t inc_capacity_until_GC(size_t v);
+  static size_t dec_capacity_until_GC(size_t v);
 
   static bool should_concurrent_collect() { return _should_concurrent_collect; }
   static void set_should_concurrent_collect(bool v) {
@@ -391,11 +395,14 @@ class MetaspaceGC : AllStatic {
   }
 
   // The amount to increase the high-water-mark (_capacity_until_GC)
-  static size_t delta_capacity_until_GC(size_t word_size);
+  static size_t delta_capacity_until_GC(size_t bytes);
+
+  // Tells if we have can expand metaspace without hitting set limits.
+  static bool can_expand(size_t words, bool is_class);
 
-  // It is expected that this will be called when the current capacity
-  // has been used and a GC should be considered.
-  static bool should_expand(VirtualSpaceList* vsl, size_t word_size);
+  // Returns amount that we can expand without hitting a GC,
+  // measured in words.
+  static size_t allowed_expansion();
 
   // Calculate the new high-water mark at which to induce
   // a GC.

src/share/vm/opto/graphKit.cpp

@@ -3713,7 +3713,8 @@ void GraphKit::g1_write_barrier_post(Node* oop_store,
   Node* no_base = __ top();
   float likely  = PROB_LIKELY(0.999);
   float unlikely  = PROB_UNLIKELY(0.999);
-  Node* zero = __ ConI(0);
+  Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
+  Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
   Node* zeroX = __ ConX(0);
 
   // Get the alias_index for raw card-mark memory
@@ -3769,8 +3770,16 @@ void GraphKit::g1_write_barrier_post(Node* oop_store,
         // load the original value of the card
         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
 
-        __ if_then(card_val, BoolTest::ne, zero); {
-          g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
+        __ if_then(card_val, BoolTest::ne, young_card); {
+          sync_kit(ideal);
+          // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
+          insert_mem_bar(Op_MemBarVolatile, oop_store);
+          __ sync_kit(this);
+
+          Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
+          __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
+            g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
+          } __ end_if();
         } __ end_if();
       } __ end_if();
     } __ end_if();

src/share/vm/runtime/arguments.cpp

@@ -2657,16 +2657,16 @@ jint Arguments::parse_each_vm_init_arg(const JavaVMInitArgs* args,
       FLAG_SET_CMDLINE(bool, BackgroundCompilation, false);
     // -Xmn for compatibility with other JVM vendors
     } else if (match_option(option, "-Xmn", &tail)) {
-      julong long_initial_eden_size = 0;
-      ArgsRange errcode = parse_memory_size(tail, &long_initial_eden_size, 1);
+      julong long_initial_young_size = 0;
+      ArgsRange errcode = parse_memory_size(tail, &long_initial_young_size, 1);
       if (errcode != arg_in_range) {
         jio_fprintf(defaultStream::error_stream(),
-                    "Invalid initial eden size: %s\n", option->optionString);
+                    "Invalid initial young generation size: %s\n", option->optionString);
         describe_range_error(errcode);
         return JNI_EINVAL;
       }
-      FLAG_SET_CMDLINE(uintx, MaxNewSize, (uintx)long_initial_eden_size);
-      FLAG_SET_CMDLINE(uintx, NewSize, (uintx)long_initial_eden_size);
+      FLAG_SET_CMDLINE(uintx, MaxNewSize, (uintx)long_initial_young_size);
+      FLAG_SET_CMDLINE(uintx, NewSize, (uintx)long_initial_young_size);
     // -Xms
     } else if (match_option(option, "-Xms", &tail)) {
       julong long_initial_heap_size = 0;
@@ -3666,6 +3666,9 @@ jint Arguments::apply_ergo() {
   assert(verify_serial_gc_flags(), "SerialGC unset");
 #endif // INCLUDE_ALL_GCS
 
+  // Initialize Metaspace flags and alignments.
+  Metaspace::ergo_initialize();
+
   // Set bytecode rewriting flags
   set_bytecode_flags();
 

src/share/vm/runtime/globals.hpp

@@ -481,21 +481,21 @@ class CommandLineFlags {
 #define RUNTIME_FLAGS(develop, develop_pd, product, product_pd, diagnostic, experimental, notproduct, manageable, product_rw, lp64_product) \
                                                                             \
   lp64_product(bool, UseCompressedOops, false,                              \
-            "Use 32-bit object references in 64-bit VM  "                   \
-            "lp64_product means flag is always constant in 32 bit VM")      \
+          "Use 32-bit object references in 64-bit VM. "                     \
+          "lp64_product means flag is always constant in 32 bit VM")        \
                                                                             \
   lp64_product(bool, UseCompressedClassPointers, false,                     \
-            "Use 32-bit class pointers in 64-bit VM  "                      \
-            "lp64_product means flag is always constant in 32 bit VM")      \
+          "Use 32-bit class pointers in 64-bit VM. "                        \
+          "lp64_product means flag is always constant in 32 bit VM")        \
                                                                             \
   notproduct(bool, CheckCompressedOops, true,                               \
-            "generate checks in encoding/decoding code in debug VM")        \
+          "Generate checks in encoding/decoding code in debug VM")          \
                                                                             \
   product_pd(uintx, HeapBaseMinAddress,                                     \
-            "OS specific low limit for heap base address")                  \
+          "OS specific low limit for heap base address")                    \
                                                                             \
   diagnostic(bool, PrintCompressedOopsMode, false,                          \
-            "Print compressed oops base address and encoding mode")         \
+          "Print compressed oops base address and encoding mode")           \
                                                                             \
   lp64_product(intx, ObjectAlignmentInBytes, 8,                             \
           "Default object alignment in bytes, 8 is minimum")                \
@@ -517,7 +517,7 @@ class CommandLineFlags {
           "Use lwsync instruction if true, else use slower sync")           \
                                                                             \
   develop(bool, CleanChunkPoolAsync, falseInEmbedded,                       \
-          "Whether to clean the chunk pool asynchronously")                 \
+          "Clean the chunk pool asynchronously")                            \
                                                                             \
   /* Temporary: See 6948537 */                                              \
   experimental(bool, UseMemSetInBOT, true,                                  \
@@ -527,10 +527,12 @@ class CommandLineFlags {
           "Enable normal processing of flags relating to field diagnostics")\
                                                                             \
   experimental(bool, UnlockExperimentalVMOptions, false,                    \
-          "Enable normal processing of flags relating to experimental features")\
+          "Enable normal processing of flags relating to experimental "     \
+          "features")                                                       \
                                                                             \
   product(bool, JavaMonitorsInStackTrace, true,                             \
-          "Print info. about Java monitor locks when the stacks are dumped")\
+          "Print information about Java monitor locks when the stacks are"  \
+          "dumped")                                                         \
                                                                             \
   product_pd(bool, UseLargePages,                                           \
           "Use large page memory")                                          \
@@ -541,8 +543,12 @@ class CommandLineFlags {
   develop(bool, LargePagesIndividualAllocationInjectError, false,           \
           "Fail large pages individual allocation")                         \
                                                                             \
+  product(bool, UseLargePagesInMetaspace, false,                            \
+          "Use large page memory in metaspace. "                            \
+          "Only used if UseLargePages is enabled.")                         \
+                                                                            \
   develop(bool, TracePageSizes, false,                                      \
-          "Trace page size selection and usage.")                           \
+          "Trace page size selection and usage")                            \
                                                                             \
   product(bool, UseNUMA, false,                                             \
           "Use NUMA if available")                                          \
@@ -557,12 +563,12 @@ class CommandLineFlags {
           "Force NUMA optimizations on single-node/UMA systems")            \
                                                                             \
   product(uintx, NUMAChunkResizeWeight, 20,                                 \
-          "Percentage (0-100) used to weigh the current sample when "      \
+          "Percentage (0-100) used to weigh the current sample when "       \
           "computing exponentially decaying average for "                   \
           "AdaptiveNUMAChunkSizing")                                        \
                                                                             \
   product(uintx, NUMASpaceResizeRate, 1*G,                                  \
-          "Do not reallocate more that this amount per collection")         \
+          "Do not reallocate more than this amount per collection")         \
                                                                             \
   product(bool, UseAdaptiveNUMAChunkSizing, true,                           \
           "Enable adaptive chunk sizing for NUMA")                          \
@@ -579,17 +585,17 @@ class CommandLineFlags {
   product(intx, UseSSE, 99,                                                 \
           "Highest supported SSE instructions set on x86/x64")              \
                                                                             \
-  product(bool, UseAES, false,                                               \
+  product(bool, UseAES, false,                                              \
           "Control whether AES instructions can be used on x86/x64")        \
                                                                             \
   product(uintx, LargePageSizeInBytes, 0,                                   \
-          "Large page size (0 to let VM choose the page size")              \
+          "Large page size (0 to let VM choose the page size)")             \
                                                                             \
   product(uintx, LargePageHeapSizeThreshold, 128*M,                         \
-          "Use large pages if max heap is at least this big")               \
+          "Use large pages if maximum heap is at least this big")           \
                                                                             \
   product(bool, ForceTimeHighResolution, false,                             \
-          "Using high time resolution(For Win32 only)")                     \
+          "Using high time resolution (for Win32 only)")                    \
                                                                             \
   develop(bool, TraceItables, false,                                        \
           "Trace initialization and use of itables")                        \
@@ -605,10 +611,10 @@ class CommandLineFlags {
                                                                             \
   develop(bool, TraceLongCompiles, false,                                   \
           "Print out every time compilation is longer than "                \
-          "a given threashold")                                             \
+          "a given threshold")                                              \
                                                                             \
   develop(bool, SafepointALot, false,                                       \
-          "Generates a lot of safepoints. Works with "                      \
+          "Generate a lot of safepoints. This works with "                  \
           "GuaranteedSafepointInterval")                                    \
                                                                             \
   product_pd(bool, BackgroundCompilation,                                   \
@@ -616,13 +622,13 @@ class CommandLineFlags {
           "compilation")                                                    \
                                                                             \
   product(bool, PrintVMQWaitTime, false,                                    \
-          "Prints out the waiting time in VM operation queue")              \
+          "Print out the waiting time in VM operation queue")               \
                                                                             \
   develop(bool, NoYieldsInMicrolock, false,                                 \
           "Disable yields in microlock")                                    \
                                                                             \
   develop(bool, TraceOopMapGeneration, false,                               \
-          "Shows oopmap generation")                                        \
+          "Show OopMapGeneration")                                          \
                                                                             \
   product(bool, MethodFlushing, true,                                       \
           "Reclamation of zombie and not-entrant methods")                  \
@@ -631,10 +637,11 @@ class CommandLineFlags {
           "Verify stack of each thread when it is entering a runtime call") \
                                                                             \
   diagnostic(bool, ForceUnreachable, false,                                 \
-          "Make all non code cache addresses to be unreachable with forcing use of 64bit literal fixups") \
+          "Make all non code cache addresses to be unreachable by "         \
+          "forcing use of 64bit literal fixups")                            \
                                                                             \
   notproduct(bool, StressDerivedPointers, false,                            \
-          "Force scavenge when a derived pointers is detected on stack "    \
+          "Force scavenge when a derived pointer is detected on stack "     \
           "after rtm call")                                                 \
                                                                             \
   develop(bool, TraceDerivedPointers, false,                                \
@@ -653,86 +660,86 @@ class CommandLineFlags {
           "Use Inline Caches for virtual calls ")                           \
                                                                             \
   develop(bool, InlineArrayCopy, true,                                      \
-          "inline arraycopy native that is known to be part of "            \
+          "Inline arraycopy native that is known to be part of "            \
           "base library DLL")                                               \
                                                                             \
   develop(bool, InlineObjectHash, true,                                     \
-          "inline Object::hashCode() native that is known to be part "      \
+          "Inline Object::hashCode() native that is known to be part "      \
           "of base library DLL")                                            \
                                                                             \
   develop(bool, InlineNatives, true,                                        \
-          "inline natives that are known to be part of base library DLL")   \
+          "Inline natives that are known to be part of base library DLL")   \
                                                                             \
   develop(bool, InlineMathNatives, true,                                    \
-          "inline SinD, CosD, etc.")                                        \
+          "Inline SinD, CosD, etc.")                                        \
                                                                             \
   develop(bool, InlineClassNatives, true,                                   \
-          "inline Class.isInstance, etc")                                   \
+          "Inline Class.isInstance, etc")                                   \
                                                                             \
   develop(bool, InlineThreadNatives, true,                                  \
-          "inline Thread.currentThread, etc")                               \
+          "Inline Thread.currentThread, etc")                               \
                                                                             \
   develop(bool, InlineUnsafeOps, true,                                      \
-          "inline memory ops (native methods) from sun.misc.Unsafe")        \
+          "Inline memory ops (native methods) from sun.misc.Unsafe")        \
                                                                             \
   product(bool, CriticalJNINatives, true,                                   \
-          "check for critical JNI entry points")                            \
+          "Check for critical JNI entry points")                            \
                                                                             \
   notproduct(bool, StressCriticalJNINatives, false,                         \
-            "Exercise register saving code in critical natives")            \
+          "Exercise register saving code in critical natives")              \
                                                                             \
   product(bool, UseSSE42Intrinsics, false,                                  \
           "SSE4.2 versions of intrinsics")                                  \
                                                                             \
   product(bool, UseAESIntrinsics, false,                                    \
-          "use intrinsics for AES versions of crypto")                      \
+          "Use intrinsics for AES versions of crypto")                      \
                                                                             \
   product(bool, UseCRC32Intrinsics, false,                                  \
           "use intrinsics for java.util.zip.CRC32")                         \
                                                                             \
   develop(bool, TraceCallFixup, false,                                      \
-          "traces all call fixups")                                         \
+          "Trace all call fixups")                                          \
                                                                             \
   develop(bool, DeoptimizeALot, false,                                      \
-          "deoptimize at every exit from the runtime system")               \
+          "Deoptimize at every exit from the runtime system")               \
                                                                             \
   notproduct(ccstrlist, DeoptimizeOnlyAt, "",                               \
-          "a comma separated list of bcis to deoptimize at")                \
+          "A comma separated list of bcis to deoptimize at")                \
                                                                             \
   product(bool, DeoptimizeRandom, false,                                    \
-          "deoptimize random frames on random exit from the runtime system")\
+          "Deoptimize random frames on random exit from the runtime system")\
                                                                             \
   notproduct(bool, ZombieALot, false,                                       \
-          "creates zombies (non-entrant) at exit from the runt. system")    \
+          "Create zombies (non-entrant) at exit from the runtime system")   \
                                                                             \
   product(bool, UnlinkSymbolsALot, false,                                   \
-          "unlink unreferenced symbols from the symbol table at safepoints")\
+          "Unlink unreferenced symbols from the symbol table at safepoints")\
                                                                             \
   notproduct(bool, WalkStackALot, false,                                    \
-          "trace stack (no print) at every exit from the runtime system")   \
+          "Trace stack (no print) at every exit from the runtime system")   \
                                                                             \
   product(bool, Debugging, false,                                           \
-          "set when executing debug methods in debug.ccp "                  \
+          "Set when executing debug methods in debug.cpp "                  \
           "(to prevent triggering assertions)")                             \
                                                                             \
   notproduct(bool, StrictSafepointChecks, trueInDebug,                      \
           "Enable strict checks that safepoints cannot happen for threads " \
-          "that used No_Safepoint_Verifier")                                \
+          "that use No_Safepoint_Verifier")                                 \
                                                                             \
   notproduct(bool, VerifyLastFrame, false,                                  \
           "Verify oops on last frame on entry to VM")                       \
                                                                             \
   develop(bool, TraceHandleAllocation, false,                               \
-          "Prints out warnings when suspicious many handles are allocated") \
+          "Print out warnings when suspiciously many handles are allocated")\
                                                                             \
   product(bool, UseCompilerSafepoints, true,                                \
           "Stop at safepoints in compiled code")                            \
                                                                             \
   product(bool, FailOverToOldVerifier, true,                                \
-          "fail over to old verifier when split verifier fails")            \
+          "Fail over to old verifier when split verifier fails")            \
                                                                             \
   develop(bool, ShowSafepointMsgs, false,                                   \
-          "Show msg. about safepoint synch.")                               \
+          "Show message about safepoint synchronization")                   \
                                                                             \
   product(bool, SafepointTimeout, false,                                    \
           "Time out and warn or fail after SafepointTimeoutDelay "          \
@@ -756,19 +763,19 @@ class CommandLineFlags {
           "Trace external suspend wait failures")                           \
                                                                             \
   product(bool, MaxFDLimit, true,                                           \
-          "Bump the number of file descriptors to max in solaris.")         \
+          "Bump the number of file descriptors to maximum in Solaris")      \
                                                                             \
   diagnostic(bool, LogEvents, true,                                         \
-             "Enable the various ring buffer event logs")                   \
+          "Enable the various ring buffer event logs")                      \
                                                                             \
   diagnostic(uintx, LogEventsBufferEntries, 10,                             \
-             "Enable the various ring buffer event logs")                   \
+          "Number of ring buffer event logs")                               \
                                                                             \
   product(bool, BytecodeVerificationRemote, true,                           \
-          "Enables the Java bytecode verifier for remote classes")          \
+          "Enable the Java bytecode verifier for remote classes")           \
                                                                             \
   product(bool, BytecodeVerificationLocal, false,                           \
-          "Enables the Java bytecode verifier for local classes")           \
+          "Enable the Java bytecode verifier for local classes")            \
                                                                             \
   develop(bool, ForceFloatExceptions, trueInDebug,                          \
           "Force exceptions on FP stack under/overflow")                    \
@@ -780,7 +787,7 @@ class CommandLineFlags {
           "Trace java language assertions")                                 \
                                                                             \
   notproduct(bool, CheckAssertionStatusDirectives, false,                   \
-          "temporary - see javaClasses.cpp")                                \
+          "Temporary - see javaClasses.cpp")                                \
                                                                             \
   notproduct(bool, PrintMallocFree, false,                                  \
           "Trace calls to C heap malloc/free allocation")                   \
@@ -799,16 +806,16 @@ class CommandLineFlags {
           "entering the VM")                                                \
                                                                             \
   notproduct(bool, CheckOopishValues, false,                                \
-          "Warn if value contains oop ( requires ZapDeadLocals)")           \
+          "Warn if value contains oop (requires ZapDeadLocals)")            \
                                                                             \
   develop(bool, UseMallocOnly, false,                                       \
-          "use only malloc/free for allocation (no resource area/arena)")   \
+          "Use only malloc/free for allocation (no resource area/arena)")   \
                                                                             \
   develop(bool, PrintMalloc, false,                                         \
-          "print all malloc/free calls")                                    \
+          "Print all malloc/free calls")                                    \
                                                                             \
   develop(bool, PrintMallocStatistics, false,                               \
-          "print malloc/free statistics")                                   \
+          "Print malloc/free statistics")                                   \
                                                                             \
   develop(bool, ZapResourceArea, trueInDebug,                               \
           "Zap freed resource/arena space with 0xABABABAB")                 \
@@ -820,7 +827,7 @@ class CommandLineFlags {
           "Zap freed JNI handle space with 0xFEFEFEFE")                     \
                                                                             \
   notproduct(bool, ZapStackSegments, trueInDebug,                           \
-             "Zap allocated/freed Stack segments with 0xFADFADED")          \
+          "Zap allocated/freed stack segments with 0xFADFADED")             \
                                                                             \
   develop(bool, ZapUnusedHeapArea, trueInDebug,                             \
           "Zap unused heap space with 0xBAADBABE")                          \
@@ -835,7 +842,7 @@ class CommandLineFlags {
           "Zap filler objects with 0xDEAFBABE")                             \
                                                                             \
   develop(bool, PrintVMMessages, true,                                      \
-          "Print vm messages on console")                                   \
+          "Print VM messages on console")                                   \
                                                                             \
   product(bool, PrintGCApplicationConcurrentTime, false,                    \
           "Print the time the application has been running")                \
@@ -844,21 +851,21 @@ class CommandLineFlags {
           "Print the time the application has been stopped")                \
                                                                             \
   diagnostic(bool, VerboseVerification, false,                              \
-             "Display detailed verification details")                       \
+          "Display detailed verification details")                          \
                                                                             \
   notproduct(uintx, ErrorHandlerTest, 0,                                    \
-          "If > 0, provokes an error after VM initialization; the value"    \
-          "determines which error to provoke.  See test_error_handler()"    \
+          "If > 0, provokes an error after VM initialization; the value "   \
+          "determines which error to provoke. See test_error_handler() "    \
           "in debug.cpp.")                                                  \
                                                                             \
   develop(bool, Verbose, false,                                             \
-          "Prints additional debugging information from other modes")       \
+          "Print additional debugging information from other modes")        \
                                                                             \
   develop(bool, PrintMiscellaneous, false,                                  \
-          "Prints uncategorized debugging information (requires +Verbose)") \
+          "Print uncategorized debugging information (requires +Verbose)")  \
                                                                             \
   develop(bool, WizardMode, false,                                          \
-          "Prints much more debugging information")                         \
+          "Print much more debugging information")                          \
                                                                             \
   product(bool, ShowMessageBoxOnError, false,                               \
           "Keep process alive on VM fatal error")                           \
@@ -870,7 +877,7 @@ class CommandLineFlags {
           "Let VM fatal error propagate to the OS (ie. WER on Windows)")    \
                                                                             \
   product(bool, SuppressFatalErrorMessage, false,                           \
-          "Do NO Fatal Error report [Avoid deadlock]")                      \
+          "Report NO fatal error message (avoid deadlock)")                 \
                                                                             \
   product(ccstrlist, OnError, "",                                           \
           "Run user-defined commands on fatal error; see VMError.cpp "      \
@@ -880,17 +887,17 @@ class CommandLineFlags {
           "Run user-defined commands on first java.lang.OutOfMemoryError")  \
                                                                             \
   manageable(bool, HeapDumpBeforeFullGC, false,                             \
-          "Dump heap to file before any major stop-world GC")               \
+          "Dump heap to file before any major stop-the-world GC")           \
                                                                             \
   manageable(bool, HeapDumpAfterFullGC, false,                              \
-          "Dump heap to file after any major stop-world GC")                \
+          "Dump heap to file after any major stop-the-world GC")            \
                                                                             \
   manageable(bool, HeapDumpOnOutOfMemoryError, false,                       \
           "Dump heap to file when java.lang.OutOfMemoryError is thrown")    \
                                                                             \
   manageable(ccstr, HeapDumpPath, NULL,                                     \
-          "When HeapDumpOnOutOfMemoryError is on, the path (filename or"    \
-          "directory) of the dump file (defaults to java_pid<pid>.hprof"    \
+          "When HeapDumpOnOutOfMemoryError is on, the path (filename or "   \
+          "directory) of the dump file (defaults to java_pid<pid>.hprof "   \
           "in the working directory)")                                      \
                                                                             \
   develop(uintx, SegmentedHeapDumpThreshold, 2*G,                           \
@@ -904,10 +911,10 @@ class CommandLineFlags {
           "Execute breakpoint upon encountering VM warning")                \
                                                                             \
   develop(bool, TraceVMOperation, false,                                    \
-          "Trace vm operations")                                            \
+          "Trace VM operations")                                            \
                                                                             \
   develop(bool, UseFakeTimers, false,                                       \
-          "Tells whether the VM should use system time or a fake timer")    \
+          "Tell whether the VM should use system time or a fake timer")     \
                                                                             \
   product(ccstr, NativeMemoryTracking, "off",                               \
           "Native memory tracking options")                                 \
@@ -917,7 +924,7 @@ class CommandLineFlags {
                                                                             \
   diagnostic(bool, AutoShutdownNMT, true,                                   \
           "Automatically shutdown native memory tracking under stress "     \
-          "situation. When set to false, native memory tracking tries to "  \
+          "situations. When set to false, native memory tracking tries to " \
           "stay alive at the expense of JVM performance")                   \
                                                                             \
   diagnostic(bool, LogCompilation, false,                                   \
@@ -927,12 +934,12 @@ class CommandLineFlags {
           "Print compilations")                                             \
                                                                             \
   diagnostic(bool, TraceNMethodInstalls, false,                             \
-             "Trace nmethod intallation")                                   \
+          "Trace nmethod installation")                                     \
                                                                             \
   diagnostic(intx, ScavengeRootsInCode, 2,                                  \
-             "0: do not allow scavengable oops in the code cache; "         \
-             "1: allow scavenging from the code cache; "                    \
-             "2: emit as many constants as the compiler can see")           \
+          "0: do not allow scavengable oops in the code cache; "            \
+          "1: allow scavenging from the code cache; "                       \
+          "2: emit as many constants as the compiler can see")              \
                                                                             \
   product(bool, AlwaysRestoreFPU, false,                                    \
           "Restore the FPU control word after every JNI call (expensive)")  \
@@ -953,7 +960,7 @@ class CommandLineFlags {
           "Print assembly code (using external disassembler.so)")           \
                                                                             \
   diagnostic(ccstr, PrintAssemblyOptions, NULL,                             \
-          "Options string passed to disassembler.so")                       \
+          "Print options string passed to disassembler.so")                 \
                                                                             \
   diagnostic(bool, PrintNMethods, false,                                    \
           "Print assembly code for nmethods when generated")                \
@@ -974,20 +981,21 @@ class CommandLineFlags {
           "Print exception handler tables for all nmethods when generated") \
                                                                             \
   develop(bool, StressCompiledExceptionHandlers, false,                     \
-         "Exercise compiled exception handlers")                            \
+          "Exercise compiled exception handlers")                           \
                                                                             \
   develop(bool, InterceptOSException, false,                                \
-          "Starts debugger when an implicit OS (e.g., NULL) "               \
+          "Start debugger when an implicit OS (e.g. NULL) "                 \
           "exception happens")                                              \
                                                                             \
   product(bool, PrintCodeCache, false,                                      \
           "Print the code cache memory usage when exiting")                 \
                                                                             \
   develop(bool, PrintCodeCache2, false,                                     \
-          "Print detailed usage info on the code cache when exiting")       \
+          "Print detailed usage information on the code cache when exiting")\
                                                                             \
   product(bool, PrintCodeCacheOnCompilation, false,                         \
-          "Print the code cache memory usage each time a method is compiled") \
+          "Print the code cache memory usage each time a method is "        \
+          "compiled")                                                       \
                                                                             \
   diagnostic(bool, PrintStubCode, false,                                    \
           "Print generated stub code")                                      \
@@ -999,40 +1007,40 @@ class CommandLineFlags {
           "Omit backtraces for some 'hot' exceptions in optimized code")    \
                                                                             \
   product(bool, ProfilerPrintByteCodeStatistics, false,                     \
-          "Prints byte code statictics when dumping profiler output")       \
+          "Print bytecode statistics when dumping profiler output")         \
                                                                             \
   product(bool, ProfilerRecordPC, false,                                    \
-          "Collects tick for each 16 byte interval of compiled code")       \
+          "Collect ticks for each 16 byte interval of compiled code")       \
                                                                             \
   product(bool, ProfileVM, false,                                           \
-          "Profiles ticks that fall within VM (either in the VM Thread "    \
+          "Profile ticks that fall within VM (either in the VM Thread "     \
           "or VM code called through stubs)")                               \
                                                                             \
   product(bool, ProfileIntervals, false,                                    \
-          "Prints profiles for each interval (see ProfileIntervalsTicks)")  \
+          "Print profiles for each interval (see ProfileIntervalsTicks)")   \
                                                                             \
   notproduct(bool, ProfilerCheckIntervals, false,                           \
-          "Collect and print info on spacing of profiler ticks")            \
+          "Collect and print information on spacing of profiler ticks")     \
                                                                             \
   develop(bool, PrintJVMWarnings, false,                                    \
-          "Prints warnings for unimplemented JVM functions")                \
+          "Print warnings for unimplemented JVM functions")                 \
                                                                             \
   product(bool, PrintWarnings, true,                                        \
-          "Prints JVM warnings to output stream")                           \
+          "Print JVM warnings to output stream")                            \
                                                                             \
   notproduct(uintx, WarnOnStalledSpinLock, 0,                               \
-          "Prints warnings for stalled SpinLocks")                          \
+          "Print warnings for stalled SpinLocks")                           \
                                                                             \
   product(bool, RegisterFinalizersAtInit, true,                             \
           "Register finalizable objects at end of Object.<init> or "        \
           "after allocation")                                               \
                                                                             \
   develop(bool, RegisterReferences, true,                                   \
-          "Tells whether the VM should register soft/weak/final/phantom "   \
+          "Tell whether the VM should register soft/weak/final/phantom "    \
           "references")                                                     \
                                                                             \
   develop(bool, IgnoreRewrites, false,                                      \
-          "Supress rewrites of bytecodes in the oopmap generator. "         \
+          "Suppress rewrites of bytecodes in the oopmap generator. "        \
           "This is unsafe!")                                                \
                                                                             \
   develop(bool, PrintCodeCacheExtension, false,                             \
@@ -1042,8 +1050,7 @@ class CommandLineFlags {
           "Enable the security JVM functions")                              \
                                                                             \
   develop(bool, ProtectionDomainVerification, true,                         \
-          "Verifies protection domain before resolution in system "         \
-          "dictionary")                                                     \
+          "Verify protection domain before resolution in system dictionary")\
                                                                             \
   product(bool, ClassUnloading, true,                                       \
           "Do unloading of classes")                                        \
@@ -1056,14 +1063,14 @@ class CommandLineFlags {
           "Write memory usage profiling to log file")                       \
                                                                             \
   notproduct(bool, PrintSystemDictionaryAtExit, false,                      \
-          "Prints the system dictionary at exit")                           \
+          "Print the system dictionary at exit")                            \
                                                                             \
   experimental(intx, PredictedLoadedClassCount, 0,                          \
-          "Experimental: Tune loaded class cache starting size.")           \
+          "Experimental: Tune loaded class cache starting size")            \
                                                                             \
   diagnostic(bool, UnsyncloadClass, false,                                  \
           "Unstable: VM calls loadClass unsynchronized. Custom "            \
-          "class loader  must call VM synchronized for findClass "          \
+          "class loader must call VM synchronized for findClass "           \
           "and defineClass.")                                               \
                                                                             \
   product(bool, AlwaysLockClassLoader, false,                               \
@@ -1079,22 +1086,22 @@ class CommandLineFlags {
           "Call loadClassInternal() rather than loadClass()")               \
                                                                             \
   product_pd(bool, DontYieldALot,                                           \
-          "Throw away obvious excess yield calls (for SOLARIS only)")       \
+          "Throw away obvious excess yield calls (for Solaris only)")       \
                                                                             \
   product_pd(bool, ConvertSleepToYield,                                     \
-          "Converts sleep(0) to thread yield "                              \
-          "(may be off for SOLARIS to improve GUI)")                        \
+          "Convert sleep(0) to thread yield "                               \
+          "(may be off for Solaris to improve GUI)")                        \
                                                                             \
   product(bool, ConvertYieldToSleep, false,                                 \
-          "Converts yield to a sleep of MinSleepInterval to simulate Win32 "\
-          "behavior (SOLARIS only)")                                        \
+          "Convert yield to a sleep of MinSleepInterval to simulate Win32 " \
+          "behavior (Solaris only)")                                        \
                                                                             \
   product(bool, UseBoundThreads, true,                                      \
-          "Bind user level threads to kernel threads (for SOLARIS only)")   \
+          "Bind user level threads to kernel threads (for Solaris only)")   \
                                                                             \
   develop(bool, UseDetachedThreads, true,                                   \
           "Use detached threads that are recycled upon termination "        \
-          "(for SOLARIS only)")                                             \
+          "(for Solaris only)")                                             \
                                                                             \
   product(bool, UseLWPSynchronization, true,                                \
           "Use LWP-based instead of libthread-based synchronization "       \
@@ -1104,41 +1111,43 @@ class CommandLineFlags {
           "(Unstable) Various monitor synchronization tunables")            \
                                                                             \
   product(intx, EmitSync, 0,                                                \
-          "(Unsafe,Unstable) "                                              \
-          " Controls emission of inline sync fast-path code")               \
+          "(Unsafe, Unstable) "                                             \
+          "Control emission of inline sync fast-path code")                 \
                                                                             \
   product(intx, MonitorBound, 0, "Bound Monitor population")                \
                                                                             \
   product(bool, MonitorInUseLists, false, "Track Monitors for Deflation")   \
                                                                             \
-  product(intx, SyncFlags, 0, "(Unsafe,Unstable) Experimental Sync flags" ) \
+  product(intx, SyncFlags, 0, "(Unsafe, Unstable) Experimental Sync flags") \
                                                                             \
-  product(intx, SyncVerbose, 0, "(Unstable)" )                              \
+  product(intx, SyncVerbose, 0, "(Unstable)")                               \
                                                                             \
-  product(intx, ClearFPUAtPark, 0, "(Unsafe,Unstable)" )                    \
+  product(intx, ClearFPUAtPark, 0, "(Unsafe, Unstable)")                    \
                                                                             \
   product(intx, hashCode, 5,                                                \
-         "(Unstable) select hashCode generation algorithm" )                \
+          "(Unstable) select hashCode generation algorithm")                \
                                                                             \
   product(intx, WorkAroundNPTLTimedWaitHang, 1,                             \
-         "(Unstable, Linux-specific)"                                       \
-         " avoid NPTL-FUTEX hang pthread_cond_timedwait" )                  \
+          "(Unstable, Linux-specific) "                                     \
+          "avoid NPTL-FUTEX hang pthread_cond_timedwait")                   \
                                                                             \
   product(bool, FilterSpuriousWakeups, true,                                \
           "Prevent spurious or premature wakeups from object.wait "         \
           "(Solaris only)")                                                 \
                                                                             \
-  product(intx, NativeMonitorTimeout, -1, "(Unstable)" )                    \
-  product(intx, NativeMonitorFlags, 0, "(Unstable)" )                       \
-  product(intx, NativeMonitorSpinLimit, 20, "(Unstable)" )                  \
+  product(intx, NativeMonitorTimeout, -1, "(Unstable)")                     \
+                                                                            \
+  product(intx, NativeMonitorFlags, 0, "(Unstable)")                        \
+                                                                            \
+  product(intx, NativeMonitorSpinLimit, 20, "(Unstable)")                   \
                                                                             \
   develop(bool, UsePthreads, false,                                         \
           "Use pthread-based instead of libthread-based synchronization "   \
           "(SPARC only)")                                                   \
                                                                             \
   product(bool, AdjustConcurrency, false,                                   \
-          "call thr_setconcurrency at thread create time to avoid "         \
-          "LWP starvation on MP systems (For Solaris Only)")                \
+          "Call thr_setconcurrency at thread creation time to avoid "       \
+          "LWP starvation on MP systems (for Solaris Only)")                \
                                                                             \
   product(bool, ReduceSignalUsage, false,                                   \
           "Reduce the use of OS signals in Java and/or the VM")             \
@@ -1147,13 +1156,14 @@ class CommandLineFlags {
           "Share vtable stubs (smaller code but worse branch prediction")   \
                                                                             \
   develop(bool, LoadLineNumberTables, true,                                 \
-          "Tells whether the class file parser loads line number tables")   \
+          "Tell whether the class file parser loads line number tables")    \
                                                                             \
   develop(bool, LoadLocalVariableTables, true,                              \
-          "Tells whether the class file parser loads local variable tables")\
+          "Tell whether the class file parser loads local variable tables") \
                                                                             \
   develop(bool, LoadLocalVariableTypeTables, true,                          \
-          "Tells whether the class file parser loads local variable type tables")\
+          "Tell whether the class file parser loads local variable type"    \
+          "tables")                                                         \
                                                                             \
   product(bool, AllowUserSignalHandlers, false,                             \
           "Do not complain if the application installs signal handlers "    \
@@ -1184,10 +1194,12 @@ class CommandLineFlags {
                                                                             \
   product(bool, EagerXrunInit, false,                                       \
           "Eagerly initialize -Xrun libraries; allows startup profiling, "  \
-          " but not all -Xrun libraries may support the state of the VM at this time") \
+          "but not all -Xrun libraries may support the state of the VM "    \
+          "at this time")                                                   \
                                                                             \
   product(bool, PreserveAllAnnotations, false,                              \
-          "Preserve RuntimeInvisibleAnnotations as well as RuntimeVisibleAnnotations") \
+          "Preserve RuntimeInvisibleAnnotations as well "                   \
+          "as RuntimeVisibleAnnotations")                                   \
                                                                             \
   develop(uintx, PreallocatedOutOfMemoryErrorCount, 4,                      \
           "Number of OutOfMemoryErrors preallocated with backtrace")        \
@@ -1262,7 +1274,7 @@ class CommandLineFlags {
           "Trace level for JVMTI RedefineClasses")                          \
                                                                             \
   develop(bool, StressMethodComparator, false,                              \
-          "run the MethodComparator on all loaded methods")                 \
+          "Run the MethodComparator on all loaded methods")                 \
                                                                             \
   /* change to false by default sometime after Mustang */                   \
   product(bool, VerifyMergedCPBytecodes, true,                              \
@@ -1296,7 +1308,7 @@ class CommandLineFlags {
           "Trace dependencies")                                             \
                                                                             \
   develop(bool, VerifyDependencies, trueInDebug,                            \
-         "Exercise and verify the compilation dependency mechanism")        \
+          "Exercise and verify the compilation dependency mechanism")       \
                                                                             \
   develop(bool, TraceNewOopMapGeneration, false,                            \
           "Trace OopMapGeneration")                                         \
@@ -1314,7 +1326,7 @@ class CommandLineFlags {
           "Trace monitor matching failures during OopMapGeneration")        \
                                                                             \
   develop(bool, TraceOopMapRewrites, false,                                 \
-          "Trace rewritting of method oops during oop map generation")      \
+          "Trace rewriting of method oops during oop map generation")       \
                                                                             \
   develop(bool, TraceSafepoint, false,                                      \
           "Trace safepoint operations")                                     \
@@ -1332,10 +1344,10 @@ class CommandLineFlags {
           "Trace setup time")                                               \
                                                                             \
   develop(bool, TraceProtectionDomainVerification, false,                   \
-          "Trace protection domain verifcation")                            \
+          "Trace protection domain verification")                           \
                                                                             \
   develop(bool, TraceClearedExceptions, false,                              \
-          "Prints when an exception is forcibly cleared")                   \
+          "Print when an exception is forcibly cleared")                    \
                                                                             \
   product(bool, TraceClassResolution, false,                                \
           "Trace all constant pool resolutions (for debugging)")            \
@@ -1349,7 +1361,7 @@ class CommandLineFlags {
   /* gc */                                                                  \
                                                                             \
   product(bool, UseSerialGC, false,                                         \
-          "Use the serial garbage collector")                               \
+          "Use the Serial garbage collector")                               \
                                                                             \
   product(bool, UseG1GC, false,                                             \
           "Use the Garbage-First garbage collector")                        \
@@ -1368,16 +1380,16 @@ class CommandLineFlags {
           "The collection count for the first maximum compaction")          \
                                                                             \
   product(bool, UseMaximumCompactionOnSystemGC, true,                       \
-          "In the Parallel Old garbage collector maximum compaction for "   \
-          "a system GC")                                                    \
+          "Use maximum compaction in the Parallel Old garbage collector "   \
+          "for a system GC")                                                \
                                                                             \
   product(uintx, ParallelOldDeadWoodLimiterMean, 50,                        \
-          "The mean used by the par compact dead wood"                      \
-          "limiter (a number between 0-100).")                              \
+          "The mean used by the parallel compact dead wood "                \
+          "limiter (a number between 0-100)")                               \
                                                                             \
   product(uintx, ParallelOldDeadWoodLimiterStdDev, 80,                      \
-          "The standard deviation used by the par compact dead wood"        \
-          "limiter (a number between 0-100).")                              \
+          "The standard deviation used by the parallel compact dead wood "  \
+          "limiter (a number between 0-100)")                               \
                                                                             \
   product(uintx, ParallelGCThreads, 0,                                      \
           "Number of parallel threads parallel gc will use")                \
@@ -1387,7 +1399,7 @@ class CommandLineFlags {
           "parallel gc will use")                                           \
                                                                             \
   diagnostic(bool, ForceDynamicNumberOfGCThreads, false,                    \
-          "Force dynamic selection of the number of"                        \
+          "Force dynamic selection of the number of "                       \
           "parallel threads parallel gc will use to aid debugging")         \
                                                                             \
   product(uintx, HeapSizePerGCThread, ScaleForWordSize(64*M),               \
@@ -1398,7 +1410,7 @@ class CommandLineFlags {
           "Trace the dynamic GC thread usage")                              \
                                                                             \
   develop(bool, ParallelOldGCSplitALot, false,                              \
-          "Provoke splitting (copying data from a young gen space to"       \
+          "Provoke splitting (copying data from a young gen space to "      \
           "multiple destination spaces)")                                   \
                                                                             \
   develop(uintx, ParallelOldGCSplitInterval, 3,                             \
@@ -1408,19 +1420,19 @@ class CommandLineFlags {
           "Number of threads concurrent gc will use")                       \
                                                                             \
   product(uintx, YoungPLABSize, 4096,                                       \
-          "Size of young gen promotion labs (in HeapWords)")                \
+          "Size of young gen promotion LAB's (in HeapWords)")               \
                                                                             \
   product(uintx, OldPLABSize, 1024,                                         \
-          "Size of old gen promotion labs (in HeapWords)")                  \
+          "Size of old gen promotion LAB's (in HeapWords)")                 \
                                                                             \
   product(uintx, GCTaskTimeStampEntries, 200,                               \
           "Number of time stamp entries per gc worker thread")              \
                                                                             \
   product(bool, AlwaysTenure, false,                                        \
-          "Always tenure objects in eden. (ParallelGC only)")               \
+          "Always tenure objects in eden (ParallelGC only)")                \
                                                                             \
   product(bool, NeverTenure, false,                                         \
-          "Never tenure objects in eden, May tenure on overflow "           \
+          "Never tenure objects in eden, may tenure on overflow "           \
           "(ParallelGC only)")                                              \
                                                                             \
   product(bool, ScavengeBeforeFullGC, true,                                 \
@@ -1428,14 +1440,14 @@ class CommandLineFlags {
           "used with UseParallelGC")                                        \
                                                                             \
   develop(bool, ScavengeWithObjectsInToSpace, false,                        \
-          "Allow scavenges to occur when to_space contains objects.")       \
+          "Allow scavenges to occur when to-space contains objects")        \
                                                                             \
   product(bool, UseConcMarkSweepGC, false,                                  \
           "Use Concurrent Mark-Sweep GC in the old generation")             \
                                                                             \
   product(bool, ExplicitGCInvokesConcurrent, false,                         \
-          "A System.gc() request invokes a concurrent collection;"          \
-          " (effective only when UseConcMarkSweepGC)")                      \
+          "A System.gc() request invokes a concurrent collection; "         \
+          "(effective only when UseConcMarkSweepGC)")                       \
                                                                             \
   product(bool, ExplicitGCInvokesConcurrentAndUnloadsClasses, false,        \
           "A System.gc() request invokes a concurrent collection and "      \
@@ -1443,19 +1455,19 @@ class CommandLineFlags {
           "(effective only when UseConcMarkSweepGC)")                       \
                                                                             \
   product(bool, GCLockerInvokesConcurrent, false,                           \
-          "The exit of a JNI CS necessitating a scavenge also"              \
-          " kicks off a bkgrd concurrent collection")                       \
+          "The exit of a JNI critical section necessitating a scavenge, "   \
+          "also kicks off a background concurrent collection")              \
                                                                             \
   product(uintx, GCLockerEdenExpansionPercent, 5,                           \
-          "How much the GC can expand the eden by while the GC locker  "    \
+          "How much the GC can expand the eden by while the GC locker "     \
           "is active (as a percentage)")                                    \
                                                                             \
   diagnostic(intx, GCLockerRetryAllocationCount, 2,                         \
-          "Number of times to retry allocations when"                       \
-          " blocked by the GC locker")                                      \
+          "Number of times to retry allocations when "                      \
+          "blocked by the GC locker")                                       \
                                                                             \
   develop(bool, UseCMSAdaptiveFreeLists, true,                              \
-          "Use Adaptive Free Lists in the CMS generation")                  \
+          "Use adaptive free lists in the CMS generation")                  \
                                                                             \
   develop(bool, UseAsyncConcMarkSweepGC, true,                              \
           "Use Asynchronous Concurrent Mark-Sweep GC in the old generation")\
@@ -1470,44 +1482,46 @@ class CommandLineFlags {
           "Use passing of collection from background to foreground")        \
                                                                             \
   product(bool, UseParNewGC, false,                                         \
-          "Use parallel threads in the new generation.")                    \
+          "Use parallel threads in the new generation")                     \
                                                                             \
   product(bool, ParallelGCVerbose, false,                                   \
-          "Verbose output for parallel GC.")                                \
+          "Verbose output for parallel gc")                                 \
                                                                             \
   product(uintx, ParallelGCBufferWastePct, 10,                              \
-          "Wasted fraction of parallel allocation buffer.")                 \
+          "Wasted fraction of parallel allocation buffer")                  \
                                                                             \
   diagnostic(bool, ParallelGCRetainPLAB, false,                             \
-             "Retain parallel allocation buffers across scavenges; "        \
-             " -- disabled because this currently conflicts with "          \
-             " parallel card scanning under certain conditions ")           \
+          "Retain parallel allocation buffers across scavenges; "           \
+          "it is disabled because this currently conflicts with "           \
+          "parallel card scanning under certain conditions.")               \
                                                                             \
   product(uintx, TargetPLABWastePct, 10,                                    \
           "Target wasted space in last buffer as percent of overall "       \
           "allocation")                                                     \
                                                                             \
   product(uintx, PLABWeight, 75,                                            \
-          "Percentage (0-100) used to weight the current sample when"       \
-          "computing exponentially decaying average for ResizePLAB.")       \
+          "Percentage (0-100) used to weigh the current sample when "       \
+          "computing exponentially decaying average for ResizePLAB")        \
                                                                             \
   product(bool, ResizePLAB, true,                                           \
-          "Dynamically resize (survivor space) promotion labs")             \
+          "Dynamically resize (survivor space) promotion LAB's")            \
                                                                             \
   product(bool, PrintPLAB, false,                                           \
-          "Print (survivor space) promotion labs sizing decisions")         \
+          "Print (survivor space) promotion LAB's sizing decisions")        \
                                                                             \
   product(intx, ParGCArrayScanChunk, 50,                                    \
-          "Scan a subset and push remainder, if array is bigger than this") \
+          "Scan a subset of object array and push remainder, if array is "  \
+          "bigger than this")                                               \
                                                                             \
   product(bool, ParGCUseLocalOverflow, false,                               \
           "Instead of a global overflow list, use local overflow stacks")   \
                                                                             \
   product(bool, ParGCTrimOverflow, true,                                    \
-          "Eagerly trim the local overflow lists (when ParGCUseLocalOverflow") \
+          "Eagerly trim the local overflow lists "                          \
+          "(when ParGCUseLocalOverflow)")                                   \
                                                                             \
   notproduct(bool, ParGCWorkQueueOverflowALot, false,                       \
-          "Whether we should simulate work queue overflow in ParNew")       \
+          "Simulate work queue overflow in ParNew")                         \
                                                                             \
   notproduct(uintx, ParGCWorkQueueOverflowInterval, 1000,                   \
           "An `interval' counter that determines how frequently "           \
@@ -1525,43 +1539,46 @@ class CommandLineFlags {
           "during card table scanning")                                     \
                                                                             \
   product(uintx, CMSParPromoteBlocksToClaim, 16,                            \
-          "Number of blocks to attempt to claim when refilling CMS LAB for "\
-          "parallel GC.")                                                   \
+          "Number of blocks to attempt to claim when refilling CMS LAB's "  \
+          "for parallel GC")                                                \
                                                                             \
   product(uintx, OldPLABWeight, 50,                                         \
-          "Percentage (0-100) used to weight the current sample when"       \
-          "computing exponentially decaying average for resizing CMSParPromoteBlocksToClaim.") \
+          "Percentage (0-100) used to weight the current sample when "      \
+          "computing exponentially decaying average for resizing "          \
+          "CMSParPromoteBlocksToClaim")                                     \
                                                                             \
   product(bool, ResizeOldPLAB, true,                                        \
-          "Dynamically resize (old gen) promotion labs")                    \
+          "Dynamically resize (old gen) promotion LAB's")                   \
                                                                             \
   product(bool, PrintOldPLAB, false,                                        \
-          "Print (old gen) promotion labs sizing decisions")                \
+          "Print (old gen) promotion LAB's sizing decisions")               \
                                                                             \
   product(uintx, CMSOldPLABMin, 16,                                         \
-          "Min size of CMS gen promotion lab caches per worker per blksize")\
+          "Minimum size of CMS gen promotion LAB caches per worker "        \
+          "per block size")                                                 \
                                                                             \
   product(uintx, CMSOldPLABMax, 1024,                                       \
-          "Max size of CMS gen promotion lab caches per worker per blksize")\
+          "Maximum size of CMS gen promotion LAB caches per worker "        \
+          "per block size")                                                 \
                                                                             \
   product(uintx, CMSOldPLABNumRefills, 4,                                   \
-          "Nominal number of refills of CMS gen promotion lab cache"        \
-          " per worker per block size")                                     \
+          "Nominal number of refills of CMS gen promotion LAB cache "       \
+          "per worker per block size")                                      \
                                                                             \
   product(bool, CMSOldPLABResizeQuicker, false,                             \
-          "Whether to react on-the-fly during a scavenge to a sudden"       \
-          " change in block demand rate")                                   \
+          "React on-the-fly during a scavenge to a sudden "                 \
+          "change in block demand rate")                                    \
                                                                             \
   product(uintx, CMSOldPLABToleranceFactor, 4,                              \
-          "The tolerance of the phase-change detector for on-the-fly"       \
-          " PLAB resizing during a scavenge")                               \
+          "The tolerance of the phase-change detector for on-the-fly "      \
+          "PLAB resizing during a scavenge")                                \
                                                                             \
   product(uintx, CMSOldPLABReactivityFactor, 2,                             \
-          "The gain in the feedback loop for on-the-fly PLAB resizing"      \
-          " during a scavenge")                                             \
+          "The gain in the feedback loop for on-the-fly PLAB resizing "     \
+          "during a scavenge")                                              \
                                                                             \
   product(bool, AlwaysPreTouch, false,                                      \
-          "It forces all freshly committed pages to be pre-touched.")       \
+          "Force all freshly committed pages to be pre-touched")            \
                                                                             \
   product_pd(uintx, CMSYoungGenPerWorker,                                   \
           "The maximum size of young gen chosen by default per GC worker "  \
@@ -1571,64 +1588,67 @@ class CommandLineFlags {
           "Whether CMS GC should operate in \"incremental\" mode")          \
                                                                             \
   product(uintx, CMSIncrementalDutyCycle, 10,                               \
-          "CMS incremental mode duty cycle (a percentage, 0-100).  If"      \
-          "CMSIncrementalPacing is enabled, then this is just the initial"  \
-          "value")                                                          \
+          "Percentage (0-100) of CMS incremental mode duty cycle. If "      \
+          "CMSIncrementalPacing is enabled, then this is just the initial " \
+          "value.")                                                         \
                                                                             \
   product(bool, CMSIncrementalPacing, true,                                 \
           "Whether the CMS incremental mode duty cycle should be "          \
           "automatically adjusted")                                         \
                                                                             \
   product(uintx, CMSIncrementalDutyCycleMin, 0,                             \
-          "Lower bound on the duty cycle when CMSIncrementalPacing is "     \
-          "enabled (a percentage, 0-100)")                                  \
+          "Minimum percentage (0-100) of the CMS incremental duty cycle "   \
+          "used when CMSIncrementalPacing is enabled")                      \
                                                                             \
   product(uintx, CMSIncrementalSafetyFactor, 10,                            \
           "Percentage (0-100) used to add conservatism when computing the " \
           "duty cycle")                                                     \
                                                                             \
   product(uintx, CMSIncrementalOffset, 0,                                   \
-          "Percentage (0-100) by which the CMS incremental mode duty cycle" \
-          " is shifted to the right within the period between young GCs")   \
+          "Percentage (0-100) by which the CMS incremental mode duty cycle "\
+          "is shifted to the right within the period between young GCs")    \
                                                                             \
   product(uintx, CMSExpAvgFactor, 50,                                       \
-          "Percentage (0-100) used to weight the current sample when"       \
-          "computing exponential averages for CMS statistics.")             \
+          "Percentage (0-100) used to weigh the current sample when "       \
+          "computing exponential averages for CMS statistics")              \
                                                                             \
   product(uintx, CMS_FLSWeight, 75,                                         \
-          "Percentage (0-100) used to weight the current sample when"       \
-          "computing exponentially decating averages for CMS FLS statistics.") \
+          "Percentage (0-100) used to weigh the current sample when "       \
+          "computing exponentially decaying averages for CMS FLS "          \
+          "statistics")                                                     \
                                                                             \
   product(uintx, CMS_FLSPadding, 1,                                         \
-          "The multiple of deviation from mean to use for buffering"        \
-          "against volatility in free list demand.")                        \
+          "The multiple of deviation from mean to use for buffering "       \
+          "against volatility in free list demand")                         \
                                                                             \
   product(uintx, FLSCoalescePolicy, 2,                                      \
-          "CMS: Aggression level for coalescing, increasing from 0 to 4")   \
+          "CMS: aggressiveness level for coalescing, increasing "           \
+          "from 0 to 4")                                                    \
                                                                             \
   product(bool, FLSAlwaysCoalesceLarge, false,                              \
-          "CMS: Larger free blocks are always available for coalescing")    \
+          "CMS: larger free blocks are always available for coalescing")    \
                                                                             \
   product(double, FLSLargestBlockCoalesceProximity, 0.99,                   \
-          "CMS: the smaller the percentage the greater the coalition force")\
+          "CMS: the smaller the percentage the greater the coalescing "     \
+          "force")                                                          \
                                                                             \
   product(double, CMSSmallCoalSurplusPercent, 1.05,                         \
-          "CMS: the factor by which to inflate estimated demand of small"   \
-          " block sizes to prevent coalescing with an adjoining block")     \
+          "CMS: the factor by which to inflate estimated demand of small "  \
+          "block sizes to prevent coalescing with an adjoining block")      \
                                                                             \
   product(double, CMSLargeCoalSurplusPercent, 0.95,                         \
-          "CMS: the factor by which to inflate estimated demand of large"   \
-          " block sizes to prevent coalescing with an adjoining block")     \
+          "CMS: the factor by which to inflate estimated demand of large "  \
+          "block sizes to prevent coalescing with an adjoining block")      \
                                                                             \
   product(double, CMSSmallSplitSurplusPercent, 1.10,                        \
-          "CMS: the factor by which to inflate estimated demand of small"   \
-          " block sizes to prevent splitting to supply demand for smaller"  \
-          " blocks")                                                        \
+          "CMS: the factor by which to inflate estimated demand of small "  \
+          "block sizes to prevent splitting to supply demand for smaller "  \
+          "blocks")                                                         \
                                                                             \
   product(double, CMSLargeSplitSurplusPercent, 1.00,                        \
-          "CMS: the factor by which to inflate estimated demand of large"   \
-          " block sizes to prevent splitting to supply demand for smaller"  \
-          " blocks")                                                        \
+          "CMS: the factor by which to inflate estimated demand of large "  \
+          "block sizes to prevent splitting to supply demand for smaller "  \
+          "blocks")                                                         \
                                                                             \
   product(bool, CMSExtrapolateSweep, false,                                 \
           "CMS: cushion for block demand during sweep")                     \
@@ -1640,11 +1660,11 @@ class CommandLineFlags {
                                                                             \
   product(uintx, CMS_SweepPadding, 1,                                       \
           "The multiple of deviation from mean to use for buffering "       \
-          "against volatility in inter-sweep duration.")                    \
+          "against volatility in inter-sweep duration")                     \
                                                                             \
   product(uintx, CMS_SweepTimerThresholdMillis, 10,                         \
           "Skip block flux-rate sampling for an epoch unless inter-sweep "  \
-          "duration exceeds this threhold in milliseconds")                 \
+          "duration exceeds this threshold in milliseconds")                \
                                                                             \
   develop(bool, CMSTraceIncrementalMode, false,                             \
           "Trace CMS incremental mode")                                     \
@@ -1659,14 +1679,15 @@ class CommandLineFlags {
           "Whether class unloading enabled when using CMS GC")              \
                                                                             \
   product(uintx, CMSClassUnloadingMaxInterval, 0,                           \
-          "When CMS class unloading is enabled, the maximum CMS cycle count"\
-          " for which classes may not be unloaded")                         \
+          "When CMS class unloading is enabled, the maximum CMS cycle "     \
+          "count for which classes may not be unloaded")                    \
                                                                             \
   product(bool, CMSCompactWhenClearAllSoftRefs, true,                       \
-          "Compact when asked to collect CMS gen with clear_all_soft_refs") \
+          "Compact when asked to collect CMS gen with "                     \
+          "clear_all_soft_refs()")                                          \
                                                                             \
   product(bool, UseCMSCompactAtFullCollection, true,                        \
-          "Use mark sweep compact at full collections")                     \
+          "Use Mark-Sweep-Compact algorithm at full collections")           \
                                                                             \
   product(uintx, CMSFullGCsBeforeCompaction, 0,                             \
           "Number of CMS full collection done before compaction if > 0")    \
@@ -1688,38 +1709,37 @@ class CommandLineFlags {
           "Warn in case of excessive CMS looping")                          \
                                                                             \
   develop(bool, CMSOverflowEarlyRestoration, false,                         \
-          "Whether preserved marks should be restored early")               \
+          "Restore preserved marks early")                                  \
                                                                             \
   product(uintx, MarkStackSize, NOT_LP64(32*K) LP64_ONLY(4*M),              \
           "Size of marking stack")                                          \
                                                                             \
   product(uintx, MarkStackSizeMax, NOT_LP64(4*M) LP64_ONLY(512*M),          \
-          "Max size of marking stack")                                      \
+          "Maximum size of marking stack")                                  \
                                                                             \
   notproduct(bool, CMSMarkStackOverflowALot, false,                         \
-          "Whether we should simulate frequent marking stack / work queue"  \
-          " overflow")                                                      \
+          "Simulate frequent marking stack / work queue overflow")          \
                                                                             \
   notproduct(uintx, CMSMarkStackOverflowInterval, 1000,                     \
-          "An `interval' counter that determines how frequently"            \
-          " we simulate overflow; a smaller number increases frequency")    \
+          "An \"interval\" counter that determines how frequently "         \
+          "to simulate overflow; a smaller number increases frequency")     \
                                                                             \
   product(uintx, CMSMaxAbortablePrecleanLoops, 0,                           \
-          "(Temporary, subject to experimentation)"                         \
+          "(Temporary, subject to experimentation) "                        \
           "Maximum number of abortable preclean iterations, if > 0")        \
                                                                             \
   product(intx, CMSMaxAbortablePrecleanTime, 5000,                          \
-          "(Temporary, subject to experimentation)"                         \
-          "Maximum time in abortable preclean in ms")                       \
+          "(Temporary, subject to experimentation) "                        \
+          "Maximum time in abortable preclean (in milliseconds)")           \
                                                                             \
   product(uintx, CMSAbortablePrecleanMinWorkPerIteration, 100,              \
-          "(Temporary, subject to experimentation)"                         \
+          "(Temporary, subject to experimentation) "                        \
           "Nominal minimum work per abortable preclean iteration")          \
                                                                             \
   manageable(intx, CMSAbortablePrecleanWaitMillis, 100,                     \
-          "(Temporary, subject to experimentation)"                         \
-          " Time that we sleep between iterations when not given"           \
-          " enough work per iteration")                                     \
+          "(Temporary, subject to experimentation) "                        \
+          "Time that we sleep between iterations when not given "           \
+          "enough work per iteration")                                      \
                                                                             \
   product(uintx, CMSRescanMultiple, 32,                                     \
           "Size (in cards) of CMS parallel rescan task")                    \
@@ -1737,23 +1757,24 @@ class CommandLineFlags {
           "Whether parallel remark enabled (only if ParNewGC)")             \
                                                                             \
   product(bool, CMSParallelSurvivorRemarkEnabled, true,                     \
-          "Whether parallel remark of survivor space"                       \
-          " enabled (effective only if CMSParallelRemarkEnabled)")          \
+          "Whether parallel remark of survivor space "                      \
+          "enabled (effective only if CMSParallelRemarkEnabled)")           \
                                                                             \
   product(bool, CMSPLABRecordAlways, true,                                  \
-          "Whether to always record survivor space PLAB bdries"             \
-          " (effective only if CMSParallelSurvivorRemarkEnabled)")          \
+          "Always record survivor space PLAB boundaries (effective only "   \
+          "if CMSParallelSurvivorRemarkEnabled)")                           \
                                                                             \
   product(bool, CMSEdenChunksRecordAlways, true,                            \
-          "Whether to always record eden chunks used for "                  \
-          "the parallel initial mark or remark of eden" )                   \
+          "Always record eden chunks used for the parallel initial mark "   \
+          "or remark of eden")                                              \
                                                                             \
   product(bool, CMSPrintEdenSurvivorChunks, false,                          \
           "Print the eden and the survivor chunks used for the parallel "   \
           "initial mark or remark of the eden/survivor spaces")             \
                                                                             \
   product(bool, CMSConcurrentMTEnabled, true,                               \
-          "Whether multi-threaded concurrent work enabled (if ParNewGC)")   \
+          "Whether multi-threaded concurrent work enabled "                 \
+          "(effective only if ParNewGC)")                                   \
                                                                             \
   product(bool, CMSPrecleaningEnabled, true,                                \
           "Whether concurrent precleaning enabled")                         \
@@ -1762,12 +1783,12 @@ class CommandLineFlags {
           "Maximum number of precleaning iteration passes")                 \
                                                                             \
   product(uintx, CMSPrecleanNumerator, 2,                                   \
-          "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence"  \
-          " ratio")                                                         \
+          "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence " \
+          "ratio")                                                          \
                                                                             \
   product(uintx, CMSPrecleanDenominator, 3,                                 \
-          "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence"  \
-          " ratio")                                                         \
+          "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence " \
+          "ratio")                                                          \
                                                                             \
   product(bool, CMSPrecleanRefLists1, true,                                 \
           "Preclean ref lists during (initial) preclean phase")             \
@@ -1782,7 +1803,7 @@ class CommandLineFlags {
           "Preclean survivors during abortable preclean phase")             \
                                                                             \
   product(uintx, CMSPrecleanThreshold, 1000,                                \
-          "Don't re-iterate if #dirty cards less than this")                \
+          "Do not iterate again if number of dirty cards is less than this")\
                                                                             \
   product(bool, CMSCleanOnEnter, true,                                      \
           "Clean-on-enter optimization for reducing number of dirty cards") \
@@ -1791,14 +1812,16 @@ class CommandLineFlags {
           "Choose variant (1,2) of verification following remark")          \
                                                                             \
   product(uintx, CMSScheduleRemarkEdenSizeThreshold, 2*M,                   \
-          "If Eden used is below this value, don't try to schedule remark") \
+          "If Eden size is below this, do not try to schedule remark")      \
                                                                             \
   product(uintx, CMSScheduleRemarkEdenPenetration, 50,                      \
-          "The Eden occupancy % at which to try and schedule remark pause") \
+          "The Eden occupancy percentage (0-100) at which "                 \
+          "to try and schedule remark pause")                               \
                                                                             \
   product(uintx, CMSScheduleRemarkSamplingRatio, 5,                         \
-          "Start sampling Eden top at least before yg occupancy reaches"    \
-          " 1/<ratio> of the size at which we plan to schedule remark")     \
+          "Start sampling eden top at least before young gen "              \
+          "occupancy reaches 1/<ratio> of the size at which "               \
+          "we plan to schedule remark")                                     \
                                                                             \
   product(uintx, CMSSamplingGrain, 16*K,                                    \
           "The minimum distance between eden samples for CMS (see above)")  \
@@ -1820,27 +1843,27 @@ class CommandLineFlags {
           "should start a collection cycle")                                \
                                                                             \
   product(bool, CMSYield, true,                                             \
-          "Yield between steps of concurrent mark & sweep")                 \
+          "Yield between steps of CMS")                                     \
                                                                             \
   product(uintx, CMSBitMapYieldQuantum, 10*M,                               \
-          "Bitmap operations should process at most this many bits"         \
+          "Bitmap operations should process at most this many bits "        \
           "between yields")                                                 \
                                                                             \
   product(bool, CMSDumpAtPromotionFailure, false,                           \
           "Dump useful information about the state of the CMS old "         \
-          " generation upon a promotion failure.")                          \
+          "generation upon a promotion failure")                            \
                                                                             \
   product(bool, CMSPrintChunksInDump, false,                                \
           "In a dump enabled by CMSDumpAtPromotionFailure, include "        \
-          " more detailed information about the free chunks.")              \
+          "more detailed information about the free chunks")                \
                                                                             \
   product(bool, CMSPrintObjectsInDump, false,                               \
           "In a dump enabled by CMSDumpAtPromotionFailure, include "        \
-          " more detailed information about the allocated objects.")        \
+          "more detailed information about the allocated objects")          \
                                                                             \
   diagnostic(bool, FLSVerifyAllHeapReferences, false,                       \
-          "Verify that all refs across the FLS boundary "                   \
-          " are to valid objects")                                          \
+          "Verify that all references across the FLS boundary "             \
+          "are to valid objects")                                           \
                                                                             \
   diagnostic(bool, FLSVerifyLists, false,                                   \
           "Do lots of (expensive) FreeListSpace verification")              \
@@ -1852,17 +1875,18 @@ class CommandLineFlags {
           "Do lots of (expensive) FLS dictionary verification")             \
                                                                             \
   develop(bool, VerifyBlockOffsetArray, false,                              \
-          "Do (expensive!) block offset array verification")                \
+          "Do (expensive) block offset array verification")                 \
                                                                             \
   diagnostic(bool, BlockOffsetArrayUseUnallocatedBlock, false,              \
-          "Maintain _unallocated_block in BlockOffsetArray"                 \
-          " (currently applicable only to CMS collector)")                  \
+          "Maintain _unallocated_block in BlockOffsetArray "                \
+          "(currently applicable only to CMS collector)")                   \
                                                                             \
   develop(bool, TraceCMSState, false,                                       \
           "Trace the state of the CMS collection")                          \
                                                                             \
   product(intx, RefDiscoveryPolicy, 0,                                      \
-          "Whether reference-based(0) or referent-based(1)")                \
+          "Select type of reference discovery policy: "                     \
+          "reference-based(0) or referent-based(1)")                        \
                                                                             \
   product(bool, ParallelRefProcEnabled, false,                              \
           "Enable parallel reference processing whenever possible")         \
@@ -1890,7 +1914,7 @@ class CommandLineFlags {
           "denotes 'do constant GC cycles'.")                               \
                                                                             \
   product(bool, UseCMSInitiatingOccupancyOnly, false,                       \
-          "Only use occupancy as a crierion for starting a CMS collection") \
+          "Only use occupancy as a criterion for starting a CMS collection")\
                                                                             \
   product(uintx, CMSIsTooFullPercentage, 98,                                \
           "An absolute ceiling above which CMS will always consider the "   \
@@ -1902,7 +1926,7 @@ class CommandLineFlags {
                                                                             \
   notproduct(bool, CMSVerifyReturnedBytes, false,                           \
           "Check that all the garbage collected was returned to the "       \
-          "free lists.")                                                    \
+          "free lists")                                                     \
                                                                             \
   notproduct(bool, ScavengeALot, false,                                     \
           "Force scavenge at every Nth exit from the runtime system "       \
@@ -1917,16 +1941,16 @@ class CommandLineFlags {
                                                                             \
   product(bool, PrintPromotionFailure, false,                               \
           "Print additional diagnostic information following "              \
-          " promotion failure")                                             \
+          "promotion failure")                                              \
                                                                             \
   notproduct(bool, PromotionFailureALot, false,                             \
           "Use promotion failure handling on every youngest generation "    \
           "collection")                                                     \
                                                                             \
   develop(uintx, PromotionFailureALotCount, 1000,                           \
-          "Number of promotion failures occurring at ParGCAllocBuffer"      \
+          "Number of promotion failures occurring at ParGCAllocBuffer "     \
           "refill attempts (ParNew) or promotion attempts "                 \
-          "(other young collectors) ")                                      \
+          "(other young collectors)")                                       \
                                                                             \
   develop(uintx, PromotionFailureALotInterval, 5,                           \
           "Total collections between promotion failures alot")              \
@@ -1945,7 +1969,7 @@ class CommandLineFlags {
           "Ratio of hard spins to calls to yield")                          \
                                                                             \
   develop(uintx, ObjArrayMarkingStride, 512,                                \
-          "Number of ObjArray elements to push onto the marking stack"      \
+          "Number of object array elements to push onto the marking stack " \
           "before pushing a continuation entry")                            \
                                                                             \
   develop(bool, MetadataAllocationFailALot, false,                          \
@@ -1953,7 +1977,7 @@ class CommandLineFlags {
           "MetadataAllocationFailALotInterval")                             \
                                                                             \
   develop(uintx, MetadataAllocationFailALotInterval, 1000,                  \
-          "metadata allocation failure alot interval")                      \
+          "Metadata allocation failure a lot interval")                     \
                                                                             \
   develop(bool, MetaDataDeallocateALot, false,                              \
           "Deallocation bunches of metadata at intervals controlled by "    \
@@ -1972,7 +1996,7 @@ class CommandLineFlags {
           "Trace virtual space metadata allocations")                       \
                                                                             \
   notproduct(bool, ExecuteInternalVMTests, false,                           \
-          "Enable execution of internal VM tests.")                         \
+          "Enable execution of internal VM tests")                          \
                                                                             \
   notproduct(bool, VerboseInternalVMTests, false,                           \
           "Turn on logging for internal VM tests.")                         \
@@ -1980,7 +2004,7 @@ class CommandLineFlags {
   product_pd(bool, UseTLAB, "Use thread-local object allocation")           \
                                                                             \
   product_pd(bool, ResizeTLAB,                                              \
-          "Dynamically resize tlab size for threads")                       \
+          "Dynamically resize TLAB size for threads")                       \
                                                                             \
   product(bool, ZeroTLAB, false,                                            \
           "Zero out the newly created TLAB")                                \
@@ -1992,7 +2016,8 @@ class CommandLineFlags {
           "Print various TLAB related information")                         \
                                                                             \
   product(bool, TLABStats, true,                                            \
-          "Print various TLAB related information")                         \
+          "Provide more detailed and expensive TLAB statistics "            \
+          "(with PrintTLAB)")                                               \
                                                                             \
   EMBEDDED_ONLY(product(bool, LowMemoryProtection, true,                    \
           "Enable LowMemoryProtection"))                                    \
@@ -2026,14 +2051,14 @@ class CommandLineFlags {
           "Fraction (1/n) of real memory used for initial heap size")       \
                                                                             \
   develop(uintx, MaxVirtMemFraction, 2,                                     \
-          "Maximum fraction (1/n) of virtual memory used for ergonomically" \
+          "Maximum fraction (1/n) of virtual memory used for ergonomically "\
           "determining maximum heap size")                                  \
                                                                             \
   product(bool, UseAutoGCSelectPolicy, false,                               \
           "Use automatic collection selection policy")                      \
                                                                             \
   product(uintx, AutoGCSelectPauseMillis, 5000,                             \
-          "Automatic GC selection pause threshhold in ms")                  \
+          "Automatic GC selection pause threshold in milliseconds")         \
                                                                             \
   product(bool, UseAdaptiveSizePolicy, true,                                \
           "Use adaptive generation sizing policies")                        \
@@ -2048,7 +2073,7 @@ class CommandLineFlags {
           "Use adaptive young-old sizing policies at major collections")    \
                                                                             \
   product(bool, UseAdaptiveSizePolicyWithSystemGC, false,                   \
-          "Use statistics from System.GC for adaptive size policy")         \
+          "Include statistics from System.gc() for adaptive size policy")   \
                                                                             \
   product(bool, UseAdaptiveGCBoundary, false,                               \
           "Allow young-old boundary to move")                               \
@@ -2060,16 +2085,16 @@ class CommandLineFlags {
           "Resize the virtual spaces of the young or old generations")      \
                                                                             \
   product(uintx, AdaptiveSizeThroughPutPolicy, 0,                           \
-          "Policy for changeing generation size for throughput goals")      \
+          "Policy for changing generation size for throughput goals")       \
                                                                             \
   product(uintx, AdaptiveSizePausePolicy, 0,                                \
           "Policy for changing generation size for pause goals")            \
                                                                             \
   develop(bool, PSAdjustTenuredGenForMinorPause, false,                     \
-          "Adjust tenured generation to achive a minor pause goal")         \
+          "Adjust tenured generation to achieve a minor pause goal")        \
                                                                             \
   develop(bool, PSAdjustYoungGenForMajorPause, false,                       \
-          "Adjust young generation to achive a major pause goal")           \
+          "Adjust young generation to achieve a major pause goal")          \
                                                                             \
   product(uintx, AdaptiveSizePolicyInitializingSteps, 20,                   \
           "Number of steps where heuristics is used before data is used")   \
@@ -2124,14 +2149,15 @@ class CommandLineFlags {
           "Decay factor to TenuredGenerationSizeIncrement")                 \
                                                                             \
   product(uintx, MaxGCPauseMillis, max_uintx,                               \
-          "Adaptive size policy maximum GC pause time goal in msec, "       \
-          "or (G1 Only) the max. GC time per MMU time slice")               \
+          "Adaptive size policy maximum GC pause time goal in millisecond, "\
+          "or (G1 Only) the maximum GC time per MMU time slice")            \
                                                                             \
   product(uintx, GCPauseIntervalMillis, 0,                                  \
           "Time slice for MMU specification")                               \
                                                                             \
   product(uintx, MaxGCMinorPauseMillis, max_uintx,                          \
-          "Adaptive size policy maximum GC minor pause time goal in msec")  \
+          "Adaptive size policy maximum GC minor pause time goal "          \
+          "in millisecond")                                                 \
                                                                             \
   product(uintx, GCTimeRatio, 99,                                           \
           "Adaptive size policy application time to GC time ratio")         \
@@ -2159,8 +2185,8 @@ class CommandLineFlags {
           "before an OutOfMemory error is thrown")                          \
                                                                             \
   product(uintx, GCTimeLimit, 98,                                           \
-          "Limit of proportion of time spent in GC before an OutOfMemory"   \
-          "error is thrown (used with GCHeapFreeLimit)")                    \
+          "Limit of the proportion of time spent in GC before "             \
+          "an OutOfMemoryError is thrown (used with GCHeapFreeLimit)")      \
                                                                             \
   product(uintx, GCHeapFreeLimit, 2,                                        \
           "Minimum percentage of free space after a full GC before an "     \
@@ -2182,7 +2208,7 @@ class CommandLineFlags {
           "How many fields ahead to prefetch in oop scan (<= 0 means off)") \
                                                                             \
   diagnostic(bool, VerifySilently, false,                                   \
-          "Don't print print the verification progress")                    \
+          "Do not print the verification progress")                         \
                                                                             \
   diagnostic(bool, VerifyDuringStartup, false,                              \
           "Verify memory system before executing any Java code "            \
@@ -2205,7 +2231,7 @@ class CommandLineFlags {
                                                                             \
   diagnostic(bool, DeferInitialCardMark, false,                             \
           "When +ReduceInitialCardMarks, explicitly defer any that "        \
-           "may arise from new_pre_store_barrier")                          \
+          "may arise from new_pre_store_barrier")                           \
                                                                             \
   diagnostic(bool, VerifyRememberedSets, false,                             \
           "Verify GC remembered sets")                                      \
@@ -2214,10 +2240,10 @@ class CommandLineFlags {
           "Verify GC object start array if verify before/after")            \
                                                                             \
   product(bool, DisableExplicitGC, false,                                   \
-          "Tells whether calling System.gc() does a full GC")               \
+          "Ignore calls to System.gc()")                                    \
                                                                             \
   notproduct(bool, CheckMemoryInitialization, false,                        \
-          "Checks memory initialization")                                   \
+          "Check memory initialization")                                    \
                                                                             \
   product(bool, CollectGen0First, false,                                    \
           "Collect youngest generation before each full GC")                \
@@ -2238,44 +2264,45 @@ class CommandLineFlags {
           "Stride through processors when distributing processes")          \
                                                                             \
   product(uintx, CMSCoordinatorYieldSleepCount, 10,                         \
-          "number of times the coordinator GC thread will sleep while "     \
+          "Number of times the coordinator GC thread will sleep while "     \
           "yielding before giving up and resuming GC")                      \
                                                                             \
   product(uintx, CMSYieldSleepCount, 0,                                     \
-          "number of times a GC thread (minus the coordinator) "            \
+          "Number of times a GC thread (minus the coordinator) "            \
           "will sleep while yielding before giving up and resuming GC")     \
                                                                             \
   /* gc tracing */                                                          \
   manageable(bool, PrintGC, false,                                          \
-          "Print message at garbage collect")                               \
+          "Print message at garbage collection")                            \
                                                                             \
   manageable(bool, PrintGCDetails, false,                                   \
-          "Print more details at garbage collect")                          \
+          "Print more details at garbage collection")                       \
                                                                             \
   manageable(bool, PrintGCDateStamps, false,                                \
-          "Print date stamps at garbage collect")                           \
+          "Print date stamps at garbage collection")                        \
                                                                             \
   manageable(bool, PrintGCTimeStamps, false,                                \
-          "Print timestamps at garbage collect")                            \
+          "Print timestamps at garbage collection")                         \
                                                                             \
   product(bool, PrintGCTaskTimeStamps, false,                               \
           "Print timestamps for individual gc worker thread tasks")         \
                                                                             \
   develop(intx, ConcGCYieldTimeout, 0,                                      \
-          "If non-zero, assert that GC threads yield within this # of ms.") \
+          "If non-zero, assert that GC threads yield within this "          \
+          "number of milliseconds")                                         \
                                                                             \
   notproduct(bool, TraceMarkSweep, false,                                   \
           "Trace mark sweep")                                               \
                                                                             \
   product(bool, PrintReferenceGC, false,                                    \
           "Print times spent handling reference objects during GC "         \
-          " (enabled only when PrintGCDetails)")                            \
+          "(enabled only when PrintGCDetails)")                             \
                                                                             \
   develop(bool, TraceReferenceGC, false,                                    \
           "Trace handling of soft/weak/final/phantom references")           \
                                                                             \
   develop(bool, TraceFinalizerRegistration, false,                          \
-         "Trace registration of final references")                          \
+          "Trace registration of final references")                         \
                                                                             \
   notproduct(bool, TraceScavenge, false,                                    \
           "Trace scavenge")                                                 \
@@ -2312,7 +2339,7 @@ class CommandLineFlags {
           "Print heap layout before and after each GC")                     \
                                                                             \
   product_rw(bool, PrintHeapAtGCExtended, false,                            \
-          "Prints extended information about the layout of the heap "       \
+          "Print extended information about the layout of the heap "        \
           "when -XX:+PrintHeapAtGC is set")                                 \
                                                                             \
   product(bool, PrintHeapAtSIGBREAK, true,                                  \
@@ -2349,45 +2376,45 @@ class CommandLineFlags {
           "Trace actions of the GC task threads")                           \
                                                                             \
   product(bool, PrintParallelOldGCPhaseTimes, false,                        \
-          "Print the time taken by each parallel old gc phase."             \
-          "PrintGCDetails must also be enabled.")                           \
+          "Print the time taken by each phase in ParallelOldGC "            \
+          "(PrintGCDetails must also be enabled)")                          \
                                                                             \
   develop(bool, TraceParallelOldGCMarkingPhase, false,                      \
-          "Trace parallel old gc marking phase")                            \
+          "Trace marking phase in ParallelOldGC")                           \
                                                                             \
   develop(bool, TraceParallelOldGCSummaryPhase, false,                      \
-          "Trace parallel old gc summary phase")                            \
+          "Trace summary phase in ParallelOldGC")                           \
                                                                             \
   develop(bool, TraceParallelOldGCCompactionPhase, false,                   \
-          "Trace parallel old gc compaction phase")                         \
+          "Trace compaction phase in ParallelOldGC")                        \
                                                                             \
   develop(bool, TraceParallelOldGCDensePrefix, false,                       \
-          "Trace parallel old gc dense prefix computation")                 \
+          "Trace dense prefix computation for ParallelOldGC")               \
                                                                             \
   develop(bool, IgnoreLibthreadGPFault, false,                              \
           "Suppress workaround for libthread GP fault")                     \
                                                                             \
   product(bool, PrintJNIGCStalls, false,                                    \
-          "Print diagnostic message when GC is stalled"                     \
+          "Print diagnostic message when GC is stalled "                    \
           "by JNI critical section")                                        \
                                                                             \
   experimental(double, ObjectCountCutOffPercent, 0.5,                       \
           "The percentage of the used heap that the instances of a class "  \
-          "must occupy for the class to generate a trace event.")           \
+          "must occupy for the class to generate a trace event")            \
                                                                             \
   /* GC log rotation setting */                                             \
                                                                             \
   product(bool, UseGCLogFileRotation, false,                                \
-          "Prevent large gclog file for long running app. "                 \
-          "Requires -Xloggc:<filename>")                                    \
+          "Rotate gclog files (for long running applications). It requires "\
+          "-Xloggc:<filename>")                                             \
                                                                             \
   product(uintx, NumberOfGCLogFiles, 0,                                     \
-          "Number of gclog files in rotation, "                             \
-          "Default: 0, no rotation")                                        \
+          "Number of gclog files in rotation "                              \
+          "(default: 0, no rotation)")                                      \
                                                                             \
   product(uintx, GCLogFileSize, 0,                                          \
-          "GC log file size, Default: 0 bytes, no rotation "                \
-          "Only valid with UseGCLogFileRotation")                           \
+          "GC log file size (default: 0 bytes, no rotation). "              \
+          "It requires UseGCLogFileRotation")                               \
                                                                             \
   /* JVMTI heap profiling */                                                \
                                                                             \
@@ -2464,40 +2491,40 @@ class CommandLineFlags {
           "Generate range checks for array accesses")                       \
                                                                             \
   develop_pd(bool, ImplicitNullChecks,                                      \
-          "generate code for implicit null checks")                         \
+          "Generate code for implicit null checks")                         \
                                                                             \
   product(bool, PrintSafepointStatistics, false,                            \
-          "print statistics about safepoint synchronization")               \
+          "Print statistics about safepoint synchronization")               \
                                                                             \
   product(intx, PrintSafepointStatisticsCount, 300,                         \
-          "total number of safepoint statistics collected "                 \
+          "Total number of safepoint statistics collected "                 \
           "before printing them out")                                       \
                                                                             \
   product(intx, PrintSafepointStatisticsTimeout,  -1,                       \
-          "print safepoint statistics only when safepoint takes"            \
-          " more than PrintSafepointSatisticsTimeout in millis")            \
+          "Print safepoint statistics only when safepoint takes "           \
+          "more than PrintSafepointSatisticsTimeout in millis")             \
                                                                             \
   product(bool, TraceSafepointCleanupTime, false,                           \
-          "print the break down of clean up tasks performed during"         \
-          " safepoint")                                                     \
+          "Print the break down of clean up tasks performed during "        \
+          "safepoint")                                                      \
                                                                             \
   product(bool, Inline, true,                                               \
-          "enable inlining")                                                \
+          "Enable inlining")                                                \
                                                                             \
   product(bool, ClipInlining, true,                                         \
-          "clip inlining if aggregate method exceeds DesiredMethodLimit")   \
+          "Clip inlining if aggregate method exceeds DesiredMethodLimit")   \
                                                                             \
   develop(bool, UseCHA, true,                                               \
-          "enable CHA")                                                     \
+          "Enable CHA")                                                     \
                                                                             \
   product(bool, UseTypeProfile, true,                                       \
           "Check interpreter profile for historically monomorphic calls")   \
                                                                             \
   notproduct(bool, TimeCompiler, false,                                     \
-          "time the compiler")                                              \
+          "Time the compiler")                                              \
                                                                             \
   diagnostic(bool, PrintInlining, false,                                    \
-          "prints inlining optimizations")                                  \
+          "Print inlining optimizations")                                   \
                                                                             \
   product(bool, UsePopCountInstruction, false,                              \
           "Use population count instruction")                               \
@@ -2509,57 +2536,59 @@ class CommandLineFlags {
           "Print when methods are replaced do to recompilation")            \
                                                                             \
   develop(bool, PrintMethodFlushing, false,                                 \
-          "print the nmethods being flushed")                               \
+          "Print the nmethods being flushed")                               \
                                                                             \
   develop(bool, UseRelocIndex, false,                                       \
-         "use an index to speed random access to relocations")              \
+          "Use an index to speed random access to relocations")             \
                                                                             \
   develop(bool, StressCodeBuffers, false,                                   \
-         "Exercise code buffer expansion and other rare state changes")     \
+          "Exercise code buffer expansion and other rare state changes")    \
                                                                             \
   diagnostic(bool, DebugNonSafepoints, trueInDebug,                         \
-         "Generate extra debugging info for non-safepoints in nmethods")    \
+          "Generate extra debugging information for non-safepoints in "     \
+          "nmethods")                                                       \
                                                                             \
   product(bool, PrintVMOptions, false,                                      \
-         "Print flags that appeared on the command line")                   \
+          "Print flags that appeared on the command line")                  \
                                                                             \
   product(bool, IgnoreUnrecognizedVMOptions, false,                         \
-         "Ignore unrecognized VM options")                                  \
+          "Ignore unrecognized VM options")                                 \
                                                                             \
   product(bool, PrintCommandLineFlags, false,                               \
-         "Print flags specified on command line or set by ergonomics")      \
+          "Print flags specified on command line or set by ergonomics")     \
                                                                             \
   product(bool, PrintFlagsInitial, false,                                   \
-         "Print all VM flags before argument processing and exit VM")       \
+          "Print all VM flags before argument processing and exit VM")      \
                                                                             \
   product(bool, PrintFlagsFinal, false,                                     \
-         "Print all VM flags after argument and ergonomic processing")      \
+          "Print all VM flags after argument and ergonomic processing")     \
                                                                             \
   notproduct(bool, PrintFlagsWithComments, false,                           \
-         "Print all VM flags with default values and descriptions and exit")\
+          "Print all VM flags with default values and descriptions and "    \
+          "exit")                                                           \
                                                                             \
   diagnostic(bool, SerializeVMOutput, true,                                 \
-         "Use a mutex to serialize output to tty and LogFile")              \
+          "Use a mutex to serialize output to tty and LogFile")             \
                                                                             \
   diagnostic(bool, DisplayVMOutput, true,                                   \
-         "Display all VM output on the tty, independently of LogVMOutput")  \
+          "Display all VM output on the tty, independently of LogVMOutput") \
                                                                             \
   diagnostic(bool, LogVMOutput, false,                                      \
-         "Save VM output to LogFile")                                       \
+          "Save VM output to LogFile")                                      \
                                                                             \
   diagnostic(ccstr, LogFile, NULL,                                          \
-         "If LogVMOutput or LogCompilation is on, save VM output to "       \
-         "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)") \
+          "If LogVMOutput or LogCompilation is on, save VM output to "      \
+          "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
                                                                             \
   product(ccstr, ErrorFile, NULL,                                           \
-         "If an error occurs, save the error data to this file "            \
-         "[default: ./hs_err_pid%p.log] (%p replaced with pid)")            \
+          "If an error occurs, save the error data to this file "           \
+          "[default: ./hs_err_pid%p.log] (%p replaced with pid)")           \
                                                                             \
   product(bool, DisplayVMOutputToStderr, false,                             \
-         "If DisplayVMOutput is true, display all VM output to stderr")     \
+          "If DisplayVMOutput is true, display all VM output to stderr")    \
                                                                             \
   product(bool, DisplayVMOutputToStdout, false,                             \
-         "If DisplayVMOutput is true, display all VM output to stdout")     \
+          "If DisplayVMOutput is true, display all VM output to stdout")    \
                                                                             \
   product(bool, UseHeavyMonitors, false,                                    \
           "use heavyweight instead of lightweight Java monitors")           \
@@ -2583,7 +2612,7 @@ class CommandLineFlags {
                                                                             \
   notproduct(ccstr, AbortVMOnExceptionMessage, NULL,                        \
           "Call fatal if the exception pointed by AbortVMOnException "      \
-          "has this message.")                                              \
+          "has this message")                                               \
                                                                             \
   develop(bool, DebugVtables, false,                                        \
           "add debugging code to vtable dispatch")                          \
@@ -2650,29 +2679,29 @@ class CommandLineFlags {
                                                                             \
   /* statistics */                                                          \
   develop(bool, CountCompiledCalls, false,                                  \
-          "counts method invocations")                                      \
+          "Count method invocations")                                       \
                                                                             \
   notproduct(bool, CountRuntimeCalls, false,                                \
-          "counts VM runtime calls")                                        \
+          "Count VM runtime calls")                                         \
                                                                             \
   develop(bool, CountJNICalls, false,                                       \
-          "counts jni method invocations")                                  \
+          "Count jni method invocations")                                   \
                                                                             \
   notproduct(bool, CountJVMCalls, false,                                    \
-          "counts jvm method invocations")                                  \
+          "Count jvm method invocations")                                   \
                                                                             \
   notproduct(bool, CountRemovableExceptions, false,                         \
-          "count exceptions that could be replaced by branches due to "     \
+          "Count exceptions that could be replaced by branches due to "     \
           "inlining")                                                       \
                                                                             \
   notproduct(bool, ICMissHistogram, false,                                  \
-          "produce histogram of IC misses")                                 \
+          "Produce histogram of IC misses")                                 \
                                                                             \
   notproduct(bool, PrintClassStatistics, false,                             \
-          "prints class statistics at end of run")                          \
+          "Print class statistics at end of run")                           \
                                                                             \
   notproduct(bool, PrintMethodStatistics, false,                            \
-          "prints method statistics at end of run")                         \
+          "Print method statistics at end of run")                          \
                                                                             \
   /* interpreter */                                                         \
   develop(bool, ClearInterpreterLocals, false,                              \
@@ -2686,7 +2715,7 @@ class CommandLineFlags {
           "Rewrite frequently used bytecode pairs into a single bytecode")  \
                                                                             \
   diagnostic(bool, PrintInterpreter, false,                                 \
-          "Prints the generated interpreter code")                          \
+          "Print the generated interpreter code")                           \
                                                                             \
   product(bool, UseInterpreter, true,                                       \
           "Use interpreter for non-compiled methods")                       \
@@ -2704,8 +2733,8 @@ class CommandLineFlags {
           "Use fast method entry code for accessor methods")                \
                                                                             \
   product_pd(bool, UseOnStackReplacement,                                   \
-           "Use on stack replacement, calls runtime if invoc. counter "     \
-           "overflows in loop")                                             \
+          "Use on stack replacement, calls runtime if invoc. counter "      \
+          "overflows in loop")                                              \
                                                                             \
   notproduct(bool, TraceOnStackReplacement, false,                          \
           "Trace on stack replacement")                                     \
@@ -2753,10 +2782,10 @@ class CommandLineFlags {
           "Trace frequency based inlining")                                 \
                                                                             \
   develop_pd(bool, InlineIntrinsics,                                        \
-           "Inline intrinsics that can be statically resolved")             \
+          "Inline intrinsics that can be statically resolved")              \
                                                                             \
   product_pd(bool, ProfileInterpreter,                                      \
-           "Profile at the bytecode level during interpretation")           \
+          "Profile at the bytecode level during interpretation")            \
                                                                             \
   develop_pd(bool, ProfileTraps,                                            \
           "Profile deoptimization traps at the bytecode level")             \
@@ -2766,7 +2795,7 @@ class CommandLineFlags {
           "CompileThreshold) before using the method's profile")            \
                                                                             \
   develop(bool, PrintMethodData, false,                                     \
-           "Print the results of +ProfileInterpreter at end of run")        \
+          "Print the results of +ProfileInterpreter at end of run")         \
                                                                             \
   develop(bool, VerifyDataPointer, trueInDebug,                             \
           "Verify the method data pointer during interpreter profiling")    \
@@ -2781,7 +2810,7 @@ class CommandLineFlags {
                                                                             \
   /* compilation */                                                         \
   product(bool, UseCompiler, true,                                          \
-          "use compilation")                                                \
+          "Use Just-In-Time compilation")                                   \
                                                                             \
   develop(bool, TraceCompilationPolicy, false,                              \
           "Trace compilation policy")                                       \
@@ -2790,20 +2819,21 @@ class CommandLineFlags {
           "Time the compilation policy")                                    \
                                                                             \
   product(bool, UseCounterDecay, true,                                      \
-           "adjust recompilation counters")                                 \
+          "Adjust recompilation counters")                                  \
                                                                             \
   develop(intx, CounterHalfLifeTime,    30,                                 \
-          "half-life time of invocation counters (in secs)")                \
+          "Half-life time of invocation counters (in seconds)")             \
                                                                             \
   develop(intx, CounterDecayMinIntervalLength,   500,                       \
-          "Min. ms. between invocation of CounterDecay")                    \
+          "The minimum interval (in milliseconds) between invocation of "   \
+          "CounterDecay")                                                   \
                                                                             \
   product(bool, AlwaysCompileLoopMethods, false,                            \
-          "when using recompilation, never interpret methods "              \
+          "When using recompilation, never interpret methods "              \
           "containing loops")                                               \
                                                                             \
   product(bool, DontCompileHugeMethods, true,                               \
-          "don't compile methods > HugeMethodLimit")                        \
+          "Do not compile methods > HugeMethodLimit")                       \
                                                                             \
   /* Bytecode escape analysis estimation. */                                \
   product(bool, EstimateArgEscape, true,                                    \
@@ -2813,10 +2843,10 @@ class CommandLineFlags {
           "How much tracing to do of bytecode escape analysis estimates")   \
                                                                             \
   product(intx, MaxBCEAEstimateLevel, 5,                                    \
-          "Maximum number of nested calls that are analyzed by BC EA.")     \
+          "Maximum number of nested calls that are analyzed by BC EA")      \
                                                                             \
   product(intx, MaxBCEAEstimateSize, 150,                                   \
-          "Maximum bytecode size of a method to be analyzed by BC EA.")     \
+          "Maximum bytecode size of a method to be analyzed by BC EA")      \
                                                                             \
   product(intx,  AllocatePrefetchStyle, 1,                                  \
           "0 = no prefetch, "                                               \
@@ -2831,7 +2861,8 @@ class CommandLineFlags {
           "Number of lines to prefetch ahead of array allocation pointer")  \
                                                                             \
   product(intx,  AllocateInstancePrefetchLines, 1,                          \
-          "Number of lines to prefetch ahead of instance allocation pointer") \
+          "Number of lines to prefetch ahead of instance allocation "       \
+          "pointer")                                                        \
                                                                             \
   product(intx,  AllocatePrefetchStepSize, 16,                              \
           "Step size in bytes of sequential prefetch instructions")         \
@@ -2851,8 +2882,8 @@ class CommandLineFlags {
           "(0 means off)")                                                  \
                                                                             \
   product(intx, MaxJavaStackTraceDepth, 1024,                               \
-          "Max. no. of lines in the stack trace for Java exceptions "       \
-          "(0 means all)")                                                  \
+          "The maximum number of lines in the stack trace for Java "        \
+          "exceptions (0 means all)")                                       \
                                                                             \
   NOT_EMBEDDED(diagnostic(intx, GuaranteedSafepointInterval, 1000,          \
           "Guarantee a safepoint (at least) every so many milliseconds "    \
@@ -2876,10 +2907,10 @@ class CommandLineFlags {
           "result in more aggressive sweeping")                             \
                                                                             \
   notproduct(bool, LogSweeper, false,                                       \
-            "Keep a ring buffer of sweeper activity")                       \
+          "Keep a ring buffer of sweeper activity")                         \
                                                                             \
   notproduct(intx, SweeperLogEntries, 1024,                                 \
-            "Number of records in the ring buffer of sweeper activity")     \
+          "Number of records in the ring buffer of sweeper activity")       \
                                                                             \
   notproduct(intx, MemProfilingInterval, 500,                               \
           "Time between each invocation of the MemProfiler")                \
@@ -2922,34 +2953,35 @@ class CommandLineFlags {
           "less than this")                                                 \
                                                                             \
   product(intx, MaxInlineSize, 35,                                          \
-          "maximum bytecode size of a method to be inlined")                \
+          "The maximum bytecode size of a method to be inlined")            \
                                                                             \
   product_pd(intx, FreqInlineSize,                                          \
-          "maximum bytecode size of a frequent method to be inlined")       \
+          "The maximum bytecode size of a frequent method to be inlined")   \
                                                                             \
   product(intx, MaxTrivialSize, 6,                                          \
-          "maximum bytecode size of a trivial method to be inlined")        \
+          "The maximum bytecode size of a trivial method to be inlined")    \
                                                                             \
   product(intx, MinInliningThreshold, 250,                                  \
-          "min. invocation count a method needs to have to be inlined")     \
+          "The minimum invocation count a method needs to have to be "      \
+          "inlined")                                                        \
                                                                             \
   develop(intx, MethodHistogramCutoff, 100,                                 \
-          "cutoff value for method invoc. histogram (+CountCalls)")         \
+          "The cutoff value for method invocation histogram (+CountCalls)") \
                                                                             \
   develop(intx, ProfilerNumberOfInterpretedMethods, 25,                     \
-          "# of interpreted methods to show in profile")                    \
+          "Number of interpreted methods to show in profile")               \
                                                                             \
   develop(intx, ProfilerNumberOfCompiledMethods, 25,                        \
-          "# of compiled methods to show in profile")                       \
+          "Number of compiled methods to show in profile")                  \
                                                                             \
   develop(intx, ProfilerNumberOfStubMethods, 25,                            \
-          "# of stub methods to show in profile")                           \
+          "Number of stub methods to show in profile")                      \
                                                                             \
   develop(intx, ProfilerNumberOfRuntimeStubNodes, 25,                       \
-          "# of runtime stub nodes to show in profile")                     \
+          "Number of runtime stub nodes to show in profile")                \
                                                                             \
   product(intx, ProfileIntervalsTicks, 100,                                 \
-          "# of ticks between printing of interval profile "                \
+          "Number of ticks between printing of interval profile "           \
           "(+ProfileIntervals)")                                            \
                                                                             \
   notproduct(intx, ScavengeALotInterval,     1,                             \
@@ -2970,7 +3002,7 @@ class CommandLineFlags {
                                                                             \
   develop(intx, MinSleepInterval,     1,                                    \
           "Minimum sleep() interval (milliseconds) when "                   \
-          "ConvertSleepToYield is off (used for SOLARIS)")                  \
+          "ConvertSleepToYield is off (used for Solaris)")                  \
                                                                             \
   develop(intx, ProfilerPCTickThreshold,    15,                             \
           "Number of ticks in a PC buckets to be a hotspot")                \
@@ -2985,22 +3017,22 @@ class CommandLineFlags {
           "Mark nmethods non-entrant at registration")                      \
                                                                             \
   diagnostic(intx, MallocVerifyInterval,     0,                             \
-          "if non-zero, verify C heap after every N calls to "              \
+          "If non-zero, verify C heap after every N calls to "              \
           "malloc/realloc/free")                                            \
                                                                             \
   diagnostic(intx, MallocVerifyStart,     0,                                \
-          "if non-zero, start verifying C heap after Nth call to "          \
+          "If non-zero, start verifying C heap after Nth call to "          \
           "malloc/realloc/free")                                            \
                                                                             \
   diagnostic(uintx, MallocMaxTestWords,     0,                              \
-          "if non-zero, max # of Words that malloc/realloc can allocate "   \
-          "(for testing only)")                                             \
+          "If non-zero, maximum number of words that malloc/realloc can "   \
+          "allocate (for testing only)")                                    \
                                                                             \
   product(intx, TypeProfileWidth,     2,                                    \
-          "number of receiver types to record in call/cast profile")        \
+          "Number of receiver types to record in call/cast profile")        \
                                                                             \
   develop(intx, BciProfileWidth,      2,                                    \
-          "number of return bci's to record in ret profile")                \
+          "Number of return bci's to record in ret profile")                \
                                                                             \
   product(intx, PerMethodRecompilationCutoff, 400,                          \
           "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
@@ -3067,7 +3099,7 @@ class CommandLineFlags {
           "Percentage of Eden that can be wasted")                          \
                                                                             \
   product(uintx, TLABRefillWasteFraction,    64,                            \
-          "Max TLAB waste at a refill (internal fragmentation)")            \
+          "Maximum TLAB waste at a refill (internal fragmentation)")        \
                                                                             \
   product(uintx, TLABWasteIncrement,    4,                                  \
           "Increment allowed waste at slow allocation")                     \
@@ -3076,7 +3108,7 @@ class CommandLineFlags {
           "Ratio of eden/survivor space size")                              \
                                                                             \
   product(uintx, NewRatio, 2,                                               \
-          "Ratio of new/old generation sizes")                              \
+          "Ratio of old/new generation sizes")                              \
                                                                             \
   product_pd(uintx, NewSizeThreadIncrease,                                  \
           "Additional size added to desired new generation size per "       \
@@ -3093,28 +3125,30 @@ class CommandLineFlags {
           "class pointers are used")                                        \
                                                                             \
   product(uintx, MinHeapFreeRatio,    40,                                   \
-          "Min percentage of heap free after GC to avoid expansion")        \
+          "The minimum percentage of heap free after GC to avoid expansion")\
                                                                             \
   product(uintx, MaxHeapFreeRatio,    70,                                   \
-          "Max percentage of heap free after GC to avoid shrinking")        \
+          "The maximum percentage of heap free after GC to avoid shrinking")\
                                                                             \
   product(intx, SoftRefLRUPolicyMSPerMB, 1000,                              \
           "Number of milliseconds per MB of free space in the heap")        \
                                                                             \
   product(uintx, MinHeapDeltaBytes, ScaleForWordSize(128*K),                \
-          "Min change in heap space due to GC (in bytes)")                  \
+          "The minimum change in heap space due to GC (in bytes)")          \
                                                                             \
   product(uintx, MinMetaspaceExpansion, ScaleForWordSize(256*K),            \
-          "Min expansion of Metaspace (in bytes)")                          \
+          "The minimum expansion of Metaspace (in bytes)")                  \
                                                                             \
   product(uintx, MinMetaspaceFreeRatio,    40,                              \
-          "Min percentage of Metaspace free after GC to avoid expansion")   \
+          "The minimum percentage of Metaspace free after GC to avoid "     \
+          "expansion")                                                      \
                                                                             \
   product(uintx, MaxMetaspaceFreeRatio,    70,                              \
-          "Max percentage of Metaspace free after GC to avoid shrinking")   \
+          "The maximum percentage of Metaspace free after GC to avoid "     \
+          "shrinking")                                                      \
                                                                             \
   product(uintx, MaxMetaspaceExpansion, ScaleForWordSize(4*M),              \
-          "Max expansion of Metaspace without full GC (in bytes)")          \
+          "The maximum expansion of Metaspace without full GC (in bytes)")  \
                                                                             \
   product(uintx, QueuedAllocationWarningCount, 0,                           \
           "Number of times an allocation that queues behind a GC "          \
@@ -3136,13 +3170,14 @@ class CommandLineFlags {
           "Desired percentage of survivor space used after scavenge")       \
                                                                             \
   product(uintx, MarkSweepDeadRatio,     5,                                 \
-          "Percentage (0-100) of the old gen allowed as dead wood."         \
-          "Serial mark sweep treats this as both the min and max value."    \
-          "CMS uses this value only if it falls back to mark sweep."        \
-          "Par compact uses a variable scale based on the density of the"   \
-          "generation and treats this as the max value when the heap is"    \
-          "either completely full or completely empty.  Par compact also"   \
-          "has a smaller default value; see arguments.cpp.")                \
+          "Percentage (0-100) of the old gen allowed as dead wood. "        \
+          "Serial mark sweep treats this as both the minimum and maximum "  \
+          "value. "                                                         \
+          "CMS uses this value only if it falls back to mark sweep. "       \
+          "Par compact uses a variable scale based on the density of the "  \
+          "generation and treats this as the maximum value when the heap "  \
+          "is either completely full or completely empty.  Par compact "    \
+          "also has a smaller default value; see arguments.cpp.")           \
                                                                             \
   product(uintx, MarkSweepAlwaysCompactCount,     4,                        \
           "How often should we fully compact the heap (ignoring the dead "  \
@@ -3161,27 +3196,27 @@ class CommandLineFlags {
           "Census for CMS' FreeListSpace")                                  \
                                                                             \
   develop(uintx, GCExpandToAllocateDelayMillis, 0,                          \
-          "Delay in ms between expansion and allocation")                   \
+          "Delay between expansion and allocation (in milliseconds)")       \
                                                                             \
   develop(uintx, GCWorkerDelayMillis, 0,                                    \
-          "Delay in ms in scheduling GC workers")                           \
+          "Delay in scheduling GC workers (in milliseconds)")               \
                                                                             \
   product(intx, DeferThrSuspendLoopCount,     4000,                         \
           "(Unstable) Number of times to iterate in safepoint loop "        \
-          " before blocking VM threads ")                                   \
+          "before blocking VM threads ")                                    \
                                                                             \
   product(intx, DeferPollingPageLoopCount,     -1,                          \
           "(Unsafe,Unstable) Number of iterations in safepoint loop "       \
           "before changing safepoint polling page to RO ")                  \
                                                                             \
-  product(intx, SafepointSpinBeforeYield, 2000,  "(Unstable)")              \
+  product(intx, SafepointSpinBeforeYield, 2000, "(Unstable)")               \
                                                                             \
   product(bool, PSChunkLargeArrays, true,                                   \
-          "true: process large arrays in chunks")                           \
+          "Process large arrays in chunks")                                 \
                                                                             \
   product(uintx, GCDrainStackTargetSize, 64,                                \
-          "how many entries we'll try to leave on the stack during "        \
-          "parallel GC")                                                    \
+          "Number of entries we will try to leave on the stack "            \
+          "during parallel gc")                                             \
                                                                             \
   /* stack parameters */                                                    \
   product_pd(intx, StackYellowPages,                                        \
@@ -3191,8 +3226,8 @@ class CommandLineFlags {
           "Number of red zone (unrecoverable overflows) pages")             \
                                                                             \
   product_pd(intx, StackShadowPages,                                        \
-          "Number of shadow zone (for overflow checking) pages"             \
-          " this should exceed the depth of the VM and native call stack")  \
+          "Number of shadow zone (for overflow checking) pages "            \
+          "this should exceed the depth of the VM and native call stack")   \
                                                                             \
   product_pd(intx, ThreadStackSize,                                         \
           "Thread Stack Size (in Kbytes)")                                  \
@@ -3232,16 +3267,16 @@ class CommandLineFlags {
           "Reserved code cache size (in bytes) - maximum code cache size")  \
                                                                             \
   product(uintx, CodeCacheMinimumFreeSpace, 500*K,                          \
-          "When less than X space left, we stop compiling.")                \
+          "When less than X space left, we stop compiling")                 \
                                                                             \
   product_pd(uintx, CodeCacheExpansionSize,                                 \
           "Code cache expansion size (in bytes)")                           \
                                                                             \
   develop_pd(uintx, CodeCacheMinBlockLength,                                \
-          "Minimum number of segments in a code cache block.")              \
+          "Minimum number of segments in a code cache block")               \
                                                                             \
   notproduct(bool, ExitOnFullCodeCache, false,                              \
-          "Exit the VM if we fill the code cache.")                         \
+          "Exit the VM if we fill the code cache")                          \
                                                                             \
   product(bool, UseCodeCacheFlushing, true,                                 \
           "Attempt to clean the code cache before shutting off compiler")   \
@@ -3252,31 +3287,31 @@ class CommandLineFlags {
           "switch")                                                         \
                                                                             \
   develop(intx, StopInterpreterAt, 0,                                       \
-          "Stops interpreter execution at specified bytecode number")       \
+          "Stop interpreter execution at specified bytecode number")        \
                                                                             \
   develop(intx, TraceBytecodesAt, 0,                                        \
-          "Traces bytecodes starting with specified bytecode number")       \
+          "Trace bytecodes starting with specified bytecode number")        \
                                                                             \
   /* compiler interface */                                                  \
   develop(intx, CIStart, 0,                                                 \
-          "the id of the first compilation to permit")                      \
+          "The id of the first compilation to permit")                      \
                                                                             \
   develop(intx, CIStop,    -1,                                              \
-          "the id of the last compilation to permit")                       \
+          "The id of the last compilation to permit")                       \
                                                                             \
   develop(intx, CIStartOSR,     0,                                          \
-          "the id of the first osr compilation to permit "                  \
+          "The id of the first osr compilation to permit "                  \
           "(CICountOSR must be on)")                                        \
                                                                             \
   develop(intx, CIStopOSR,    -1,                                           \
-          "the id of the last osr compilation to permit "                   \
+          "The id of the last osr compilation to permit "                   \
           "(CICountOSR must be on)")                                        \
                                                                             \
   develop(intx, CIBreakAtOSR,    -1,                                        \
-          "id of osr compilation to break at")                              \
+          "The id of osr compilation to break at")                          \
                                                                             \
   develop(intx, CIBreakAt,    -1,                                           \
-          "id of compilation to break at")                                  \
+          "The id of compilation to break at")                              \
                                                                             \
   product(ccstrlist, CompileOnly, "",                                       \
           "List of methods (pkg/class.name) to restrict compilation to")    \
@@ -3295,11 +3330,11 @@ class CommandLineFlags {
           "[default: ./replay_pid%p.log] (%p replaced with pid)")           \
                                                                             \
   develop(intx, ReplaySuppressInitializers, 2,                              \
-          "Controls handling of class initialization during replay"         \
-          "0 - don't do anything special"                                   \
-          "1 - treat all class initializers as empty"                       \
-          "2 - treat class initializers for application classes as empty"   \
-          "3 - allow all class initializers to run during bootstrap but"    \
+          "Control handling of class initialization during replay: "        \
+          "0 - don't do anything special; "                                 \
+          "1 - treat all class initializers as empty; "                     \
+          "2 - treat class initializers for application classes as empty; " \
+          "3 - allow all class initializers to run during bootstrap but "   \
           "    pretend they are empty after starting replay")               \
                                                                             \
   develop(bool, ReplayIgnoreInitErrors, false,                              \
@@ -3328,14 +3363,15 @@ class CommandLineFlags {
           "0 : Normal.                                                     "\
           "    VM chooses priorities that are appropriate for normal       "\
           "    applications. On Solaris NORM_PRIORITY and above are mapped "\
-          "    to normal native priority. Java priorities below NORM_PRIORITY"\
-          "    map to lower native priority values. On Windows applications"\
-          "    are allowed to use higher native priorities. However, with  "\
-          "    ThreadPriorityPolicy=0, VM will not use the highest possible"\
-          "    native priority, THREAD_PRIORITY_TIME_CRITICAL, as it may   "\
-          "    interfere with system threads. On Linux thread priorities   "\
-          "    are ignored because the OS does not support static priority "\
-          "    in SCHED_OTHER scheduling class which is the only choice for"\
+          "    to normal native priority. Java priorities below "           \
+          "    NORM_PRIORITY map to lower native priority values. On       "\
+          "    Windows applications are allowed to use higher native       "\
+          "    priorities. However, with ThreadPriorityPolicy=0, VM will   "\
+          "    not use the highest possible native priority,               "\
+          "    THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with     "\
+          "    system threads. On Linux thread priorities are ignored      "\
+          "    because the OS does not support static priority in          "\
+          "    SCHED_OTHER scheduling class which is the only choice for   "\
           "    non-root, non-realtime applications.                        "\
           "1 : Aggressive.                                                 "\
           "    Java thread priorities map over to the entire range of      "\
@@ -3366,16 +3402,35 @@ class CommandLineFlags {
   product(bool, VMThreadHintNoPreempt, false,                               \
           "(Solaris only) Give VM thread an extra quanta")                  \
                                                                             \
-  product(intx, JavaPriority1_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority2_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority3_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority4_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority5_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority6_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority7_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority8_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority9_To_OSPriority, -1, "Map Java priorities to OS priorities") \
-  product(intx, JavaPriority10_To_OSPriority,-1, "Map Java priorities to OS priorities") \
+  product(intx, JavaPriority1_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority2_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority3_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority4_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority5_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority6_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority7_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority8_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority9_To_OSPriority, -1,                            \
+          "Map Java priorities to OS priorities")                           \
+                                                                            \
+  product(intx, JavaPriority10_To_OSPriority,-1,                            \
+          "Map Java priorities to OS priorities")                           \
                                                                             \
   experimental(bool, UseCriticalJavaThreadPriority, false,                  \
           "Java thread priority 10 maps to critical scheduling priority")   \
@@ -3406,37 +3461,38 @@ class CommandLineFlags {
           "Used with +TraceLongCompiles")                                   \
                                                                             \
   product(intx, StarvationMonitorInterval,    200,                          \
-          "Pause between each check in ms")                                 \
+          "Pause between each check (in milliseconds)")                     \
                                                                             \
   /* recompilation */                                                       \
   product_pd(intx, CompileThreshold,                                        \
           "number of interpreted method invocations before (re-)compiling") \
                                                                             \
   product_pd(intx, BackEdgeThreshold,                                       \
-          "Interpreter Back edge threshold at which an OSR compilation is invoked")\
+          "Interpreter Back edge threshold at which an OSR compilation is " \
+          "invoked")                                                        \
                                                                             \
   product(intx, Tier0InvokeNotifyFreqLog, 7,                                \
-          "Interpreter (tier 0) invocation notification frequency.")        \
+          "Interpreter (tier 0) invocation notification frequency")         \
                                                                             \
   product(intx, Tier2InvokeNotifyFreqLog, 11,                               \
-          "C1 without MDO (tier 2) invocation notification frequency.")     \
+          "C1 without MDO (tier 2) invocation notification frequency")      \
                                                                             \
   product(intx, Tier3InvokeNotifyFreqLog, 10,                               \
           "C1 with MDO profiling (tier 3) invocation notification "         \
-          "frequency.")                                                     \
+          "frequency")                                                      \
                                                                             \
   product(intx, Tier23InlineeNotifyFreqLog, 20,                             \
           "Inlinee invocation (tiers 2 and 3) notification frequency")      \
                                                                             \
   product(intx, Tier0BackedgeNotifyFreqLog, 10,                             \
-          "Interpreter (tier 0) invocation notification frequency.")        \
+          "Interpreter (tier 0) invocation notification frequency")         \
                                                                             \
   product(intx, Tier2BackedgeNotifyFreqLog, 14,                             \
-          "C1 without MDO (tier 2) invocation notification frequency.")     \
+          "C1 without MDO (tier 2) invocation notification frequency")      \
                                                                             \
   product(intx, Tier3BackedgeNotifyFreqLog, 13,                             \
           "C1 with MDO profiling (tier 3) invocation notification "         \
-          "frequency.")                                                     \
+          "frequency")                                                      \
                                                                             \
   product(intx, Tier2CompileThreshold, 0,                                   \
           "threshold at which tier 2 compilation is invoked")               \
@@ -3453,7 +3509,7 @@ class CommandLineFlags {
                                                                             \
   product(intx, Tier3CompileThreshold, 2000,                                \
           "Threshold at which tier 3 compilation is invoked (invocation "   \
-          "minimum must be satisfied.")                                     \
+          "minimum must be satisfied")                                      \
                                                                             \
   product(intx, Tier3BackEdgeThreshold,  60000,                             \
           "Back edge threshold at which tier 3 OSR compilation is invoked") \
@@ -3467,7 +3523,7 @@ class CommandLineFlags {
                                                                             \
   product(intx, Tier4CompileThreshold, 15000,                               \
           "Threshold at which tier 4 compilation is invoked (invocation "   \
-          "minimum must be satisfied.")                                     \
+          "minimum must be satisfied")                                      \
                                                                             \
   product(intx, Tier4BackEdgeThreshold, 40000,                              \
           "Back edge threshold at which tier 4 OSR compilation is invoked") \
@@ -3496,12 +3552,12 @@ class CommandLineFlags {
           "Stop at given compilation level")                                \
                                                                             \
   product(intx, Tier0ProfilingStartPercentage, 200,                         \
-          "Start profiling in interpreter if the counters exceed tier 3"    \
+          "Start profiling in interpreter if the counters exceed tier 3 "   \
           "thresholds by the specified percentage")                         \
                                                                             \
   product(uintx, IncreaseFirstTierCompileThresholdAt, 50,                   \
-          "Increase the compile threshold for C1 compilation if the code"   \
-          "cache is filled by the specified percentage.")                   \
+          "Increase the compile threshold for C1 compilation if the code "  \
+          "cache is filled by the specified percentage")                    \
                                                                             \
   product(intx, TieredRateUpdateMinTime, 1,                                 \
           "Minimum rate sampling interval (in milliseconds)")               \
@@ -3516,24 +3572,26 @@ class CommandLineFlags {
           "Print tiered events notifications")                              \
                                                                             \
   product_pd(intx, OnStackReplacePercentage,                                \
-          "NON_TIERED number of method invocations/branches (expressed as %"\
-          "of CompileThreshold) before (re-)compiling OSR code")            \
+          "NON_TIERED number of method invocations/branches (expressed as " \
+          "% of CompileThreshold) before (re-)compiling OSR code")          \
                                                                             \
   product(intx, InterpreterProfilePercentage, 33,                           \
-          "NON_TIERED number of method invocations/branches (expressed as %"\
-          "of CompileThreshold) before profiling in the interpreter")       \
+          "NON_TIERED number of method invocations/branches (expressed as " \
+          "% of CompileThreshold) before profiling in the interpreter")     \
                                                                             \
   develop(intx, MaxRecompilationSearchLength,    10,                        \
-          "max. # frames to inspect searching for recompilee")              \
+          "The maximum number of frames to inspect when searching for "     \
+          "recompilee")                                                     \
                                                                             \
   develop(intx, MaxInterpretedSearchLength,     3,                          \
-          "max. # interp. frames to skip when searching for recompilee")    \
+          "The maximum number of interpreted frames to skip when searching "\
+          "for recompilee")                                                 \
                                                                             \
   develop(intx, DesiredMethodLimit,  8000,                                  \
-          "desired max. method size (in bytecodes) after inlining")         \
+          "The desired maximum method size (in bytecodes) after inlining")  \
                                                                             \
   develop(intx, HugeMethodLimit,  8000,                                     \
-          "don't compile methods larger than this if "                      \
+          "Don't compile methods larger than this if "                      \
           "+DontCompileHugeMethods")                                        \
                                                                             \
   /* New JDK 1.4 reflection implementation */                               \
@@ -3555,7 +3613,7 @@ class CommandLineFlags {
           "in InvocationTargetException. See 6531596")                      \
                                                                             \
   develop(bool, VerifyLambdaBytecodes, false,                               \
-          "Force verification of jdk 8 lambda metafactory bytecodes.")      \
+          "Force verification of jdk 8 lambda metafactory bytecodes")       \
                                                                             \
   develop(intx, FastSuperclassLimit, 8,                                     \
           "Depth of hardwired instanceof accelerator array")                \
@@ -3579,18 +3637,19 @@ class CommandLineFlags {
   /* flags for performance data collection */                               \
                                                                             \
   product(bool, UsePerfData, falseInEmbedded,                               \
-          "Flag to disable jvmstat instrumentation for performance testing" \
-          "and problem isolation purposes.")                                \
+          "Flag to disable jvmstat instrumentation for performance testing "\
+          "and problem isolation purposes")                                 \
                                                                             \
   product(bool, PerfDataSaveToFile, false,                                  \
           "Save PerfData memory to hsperfdata_<pid> file on exit")          \
                                                                             \
   product(ccstr, PerfDataSaveFile, NULL,                                    \
-          "Save PerfData memory to the specified absolute pathname,"        \
-           "%p in the file name if present will be replaced by pid")        \
+          "Save PerfData memory to the specified absolute pathname. "       \
+          "The string %p in the file name (if present) "                    \
+          "will be replaced by pid")                                        \
                                                                             \
-  product(intx, PerfDataSamplingInterval, 50 /*ms*/,                        \
-          "Data sampling interval in milliseconds")                         \
+  product(intx, PerfDataSamplingInterval, 50,                               \
+          "Data sampling interval (in milliseconds)")                       \
                                                                             \
   develop(bool, PerfTraceDataCreation, false,                               \
           "Trace creation of Performance Data Entries")                     \
@@ -3615,7 +3674,7 @@ class CommandLineFlags {
           "Bypass Win32 file system criteria checks (Windows Only)")        \
                                                                             \
   product(intx, UnguardOnExecutionViolation, 0,                             \
-          "Unguard page and retry on no-execute fault (Win32 only)"         \
+          "Unguard page and retry on no-execute fault (Win32 only) "        \
           "0=off, 1=conservative, 2=aggressive")                            \
                                                                             \
   /* Serviceability Support */                                              \
@@ -3624,7 +3683,7 @@ class CommandLineFlags {
           "Create JMX Management Server")                                   \
                                                                             \
   product(bool, DisableAttachMechanism, false,                              \
-         "Disable mechanism that allows tools to attach to this VM")        \
+          "Disable mechanism that allows tools to attach to this VM")       \
                                                                             \
   product(bool, StartAttachListener, false,                                 \
           "Always start Attach Listener at VM startup")                     \
@@ -3647,9 +3706,9 @@ class CommandLineFlags {
           "Require shared spaces for metadata")                             \
                                                                             \
   product(bool, DumpSharedSpaces, false,                                    \
-           "Special mode: JVM reads a class list, loads classes, builds "   \
-            "shared spaces, and dumps the shared spaces to a file to be "   \
-            "used in future JVM runs.")                                     \
+          "Special mode: JVM reads a class list, loads classes, builds "    \
+          "shared spaces, and dumps the shared spaces to a file to be "     \
+          "used in future JVM runs")                                        \
                                                                             \
   product(bool, PrintSharedSpaces, false,                                   \
           "Print usage of shared spaces")                                   \
@@ -3722,7 +3781,7 @@ class CommandLineFlags {
           "Relax the access control checks in the verifier")                \
                                                                             \
   diagnostic(bool, PrintDTraceDOF, false,                                   \
-             "Print the DTrace DOF passed to the system for JSDT probes")   \
+          "Print the DTrace DOF passed to the system for JSDT probes")      \
                                                                             \
   product(uintx, StringTableSize, defaultStringTableSize,                   \
           "Number of buckets in the interned String table")                 \
@@ -3738,8 +3797,8 @@ class CommandLineFlags {
                                                                             \
   product(bool, UseVMInterruptibleIO, false,                                \
           "(Unstable, Solaris-specific) Thread interrupt before or with "   \
-          "EINTR for I/O operations results in OS_INTRPT. The default value"\
-          " of this flag is true for JDK 6 and earlier")                    \
+          "EINTR for I/O operations results in OS_INTRPT. The default "     \
+          "value of this flag is true for JDK 6 and earlier")               \
                                                                             \
   diagnostic(bool, WhiteBoxAPI, false,                                      \
           "Enable internal testing APIs")                                   \
@@ -3760,6 +3819,7 @@ class CommandLineFlags {
                                                                             \
   product(bool, EnableTracing, false,                                       \
           "Enable event-based tracing")                                     \
+                                                                            \
   product(bool, UseLockedTracing, false,                                    \
           "Use locked-tracing when doing event-based tracing")
 

src/share/vm/runtime/virtualspace.cpp

@@ -368,8 +368,15 @@ VirtualSpace::VirtualSpace() {
 
 
 bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) {
+  const size_t max_commit_granularity = os::page_size_for_region(rs.size(), rs.size(), 1);
+  return initialize_with_granularity(rs, committed_size, max_commit_granularity);
+}
+
+bool VirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t committed_size, size_t max_commit_granularity) {
   if(!rs.is_reserved()) return false;  // allocation failed.
   assert(_low_boundary == NULL, "VirtualSpace already initialized");
+  assert(max_commit_granularity > 0, "Granularity must be non-zero.");
+
   _low_boundary  = rs.base();
   _high_boundary = low_boundary() + rs.size();
 
@@ -390,7 +397,7 @@ bool VirtualSpace::initialize(ReservedSpace rs, size_t committed_size) {
   // No attempt is made to force large page alignment at the very top and
   // bottom of the space if they are not aligned so already.
   _lower_alignment  = os::vm_page_size();
-  _middle_alignment = os::page_size_for_region(rs.size(), rs.size(), 1);
+  _middle_alignment = max_commit_granularity;
   _upper_alignment  = os::vm_page_size();
 
   // End of each region
@@ -966,17 +973,52 @@ void TestReservedSpace_test() {
 
 
 class TestVirtualSpace : AllStatic {
+  enum TestLargePages {
+    Default,
+    Disable,
+    Reserve,
+    Commit
+  };
+
+  static ReservedSpace reserve_memory(size_t reserve_size_aligned, TestLargePages mode) {
+    switch(mode) {
+    default:
+    case Default:
+    case Reserve:
+      return ReservedSpace(reserve_size_aligned);
+    case Disable:
+    case Commit:
+      return ReservedSpace(reserve_size_aligned,
+                           os::vm_allocation_granularity(),
+                           /* large */ false, /* exec */ false);
+    }
+  }
+
+  static bool initialize_virtual_space(VirtualSpace& vs, ReservedSpace rs, TestLargePages mode) {
+    switch(mode) {
+    default:
+    case Default:
+    case Reserve:
+      return vs.initialize(rs, 0);
+    case Disable:
+      return vs.initialize_with_granularity(rs, 0, os::vm_page_size());
+    case Commit:
+      return vs.initialize_with_granularity(rs, 0, os::page_size_for_region(rs.size(), rs.size(), 1));
+    }
+  }
+
  public:
-  static void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size) {
+  static void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size,
+                                                        TestLargePages mode = Default) {
     size_t granularity = os::vm_allocation_granularity();
     size_t reserve_size_aligned = align_size_up(reserve_size, granularity);
 
-    ReservedSpace reserved(reserve_size_aligned);
+    ReservedSpace reserved = reserve_memory(reserve_size_aligned, mode);
 
     assert(reserved.is_reserved(), "Must be");
 
     VirtualSpace vs;
-    bool initialized = vs.initialize(reserved, 0);
+    bool initialized = initialize_virtual_space(vs, reserved, mode);
     assert(initialized, "Failed to initialize VirtualSpace");
 
     vs.expand_by(commit_size, false);
@@ -986,7 +1028,10 @@ class TestVirtualSpace : AllStatic {
     } else {
       assert_ge(vs.actual_committed_size(), commit_size);
       // Approximate the commit granularity.
-      size_t commit_granularity = UseLargePages ? os::large_page_size() : os::vm_page_size();
+      // Make sure that we don't commit using large pages
+      // if large pages has been disabled for this VirtualSpace.
+      size_t commit_granularity = (mode == Disable || !UseLargePages) ?
+                                   os::vm_page_size() : os::large_page_size();
       assert_lt(vs.actual_committed_size(), commit_size + commit_granularity);
     }
 
@@ -1042,9 +1087,40 @@ class TestVirtualSpace : AllStatic {
     test_virtual_space_actual_committed_space(10 * M, 10 * M);
   }
 
+  static void test_virtual_space_disable_large_pages() {
+    if (!UseLargePages) {
+      return;
+    }
+    // These test cases verify that if we force VirtualSpace to disable large pages
+    test_virtual_space_actual_committed_space(10 * M, 0, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 4 * K, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 8 * K, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 1 * M, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 2 * M, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 5 * M, Disable);
+    test_virtual_space_actual_committed_space(10 * M, 10 * M, Disable);
+
+    test_virtual_space_actual_committed_space(10 * M, 0, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 4 * K, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 8 * K, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 1 * M, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 2 * M, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 5 * M, Reserve);
+    test_virtual_space_actual_committed_space(10 * M, 10 * M, Reserve);
+
+    test_virtual_space_actual_committed_space(10 * M, 0, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 4 * K, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 8 * K, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 1 * M, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 2 * M, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 5 * M, Commit);
+    test_virtual_space_actual_committed_space(10 * M, 10 * M, Commit);
+  }
+
   static void test_virtual_space() {
     test_virtual_space_actual_committed_space();
     test_virtual_space_actual_committed_space_one_large_page();
+    test_virtual_space_disable_large_pages();
   }
 };
 

src/share/vm/runtime/virtualspace.hpp

@@ -178,6 +178,7 @@ class VirtualSpace VALUE_OBJ_CLASS_SPEC {
  public:
   // Initialization
   VirtualSpace();
+  bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
   bool initialize(ReservedSpace rs, size_t committed_byte_size);
 
   // Destruction

src/share/vm/runtime/vmStructs.cpp

@@ -716,11 +716,17 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   nonstatic_field(PlaceholderEntry,            _loader_data,                                  ClassLoaderData*)                      \
                                                                                                                                      \
   /**************************/                                                                                                       \
-  /* ProctectionDomainEntry */                                                                                                       \
+  /* ProtectionDomainEntry  */                                                                                                       \
   /**************************/                                                                                                       \
                                                                                                                                      \
   nonstatic_field(ProtectionDomainEntry,       _next,                                         ProtectionDomainEntry*)                \
-  nonstatic_field(ProtectionDomainEntry,       _protection_domain,                            oop)                                   \
+  nonstatic_field(ProtectionDomainEntry,       _pd_cache,                                     ProtectionDomainCacheEntry*)           \
+                                                                                                                                     \
+  /*******************************/                                                                                                  \
+  /* ProtectionDomainCacheEntry  */                                                                                                  \
+  /*******************************/                                                                                                  \
+                                                                                                                                     \
+  nonstatic_field(ProtectionDomainCacheEntry,  _literal,                                      oop)                                   \
                                                                                                                                      \
   /*************************/                                                                                                        \
   /* LoaderConstraintEntry */                                                                                                        \
@@ -1563,6 +1569,7 @@ typedef BinaryTreeDictionary<Metablock, FreeList> MetablockTreeDictionary;
   declare_toplevel_type(SystemDictionary)                                 \
   declare_toplevel_type(vmSymbols)                                        \
   declare_toplevel_type(ProtectionDomainEntry)                            \
+  declare_toplevel_type(ProtectionDomainCacheEntry)                       \
                                                                           \
   declare_toplevel_type(GenericGrowableArray)                             \
   declare_toplevel_type(GrowableArray<int>)                               \

src/share/vm/services/memoryService.hpp

@@ -148,6 +148,12 @@ public:
   static void track_code_cache_memory_usage() {
     track_memory_pool_usage(_code_heap_pool);
   }
+  static void track_metaspace_memory_usage() {
+    track_memory_pool_usage(_metaspace_pool);
+  }
+  static void track_compressed_class_memory_usage() {
+    track_memory_pool_usage(_compressed_class_pool);
+  }
   static void track_memory_pool_usage(MemoryPool* pool);
 
   static void gc_begin(bool fullGC, bool recordGCBeginTime,

src/share/vm/utilities/globalDefinitions.hpp

@@ -326,12 +326,15 @@ typedef jlong  s8;
 
 const int max_method_code_size = 64*K - 1;  // JVM spec, 2nd ed. section 4.8.1 (p.134)
 
+// Default ProtectionDomainCacheSize values
+
+const int defaultProtectionDomainCacheSize = NOT_LP64(137) LP64_ONLY(2017);
 
 //----------------------------------------------------------------------------------------------------
 // Default and minimum StringTableSize values
 
 const int defaultStringTableSize = NOT_LP64(1009) LP64_ONLY(60013);
-const int minimumStringTableSize=1009;
+const int minimumStringTableSize = 1009;
 
 const int defaultSymbolTableSize = 20011;
 const int minimumSymbolTableSize = 1009;

test/runtime/memory/LargePages/TestLargePagesFlags.java

+/*
+ * 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 TestLargePagesFlags
+ * @summary Tests how large pages are choosen depending on the given large pages flag combinations.
+ * @library /testlibrary
+ * @run main TestLargePagesFlags
+ */
+
+import com.oracle.java.testlibrary.OutputAnalyzer;
+import com.oracle.java.testlibrary.Platform;
+import com.oracle.java.testlibrary.ProcessTools;
+import java.util.ArrayList;
+
+public class TestLargePagesFlags {
+
+  public static void main(String [] args) throws Exception {
+    if (!Platform.isLinux()) {
+      System.out.println("Skipping. TestLargePagesFlags has only been implemented for Linux.");
+      return;
+    }
+
+    testUseTransparentHugePages();
+    testUseHugeTLBFS();
+    testUseSHM();
+    testCombinations();
+  }
+
+  public static void testUseTransparentHugePages() throws Exception {
+    if (!canUse(UseTransparentHugePages(true))) {
+      System.out.println("Skipping testUseTransparentHugePages");
+      return;
+    }
+
+    // -XX:-UseLargePages overrides all other flags.
+    new FlagTester()
+      .use(UseLargePages(false),
+           UseTransparentHugePages(true))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Explicitly turn on UseTransparentHugePages.
+    new FlagTester()
+      .use(UseTransparentHugePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseTransparentHugePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Setting a specific large pages flag will turn
+    // off heuristics to choose large pages type.
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseTransparentHugePages(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Don't turn on UseTransparentHugePages
+    // unless the user explicitly asks for them.
+    new FlagTester()
+      .use(UseLargePages(true))
+      .expect(
+           UseTransparentHugePages(false));
+  }
+
+  public static void testUseHugeTLBFS() throws Exception {
+    if (!canUse(UseHugeTLBFS(true))) {
+      System.out.println("Skipping testUseHugeTLBFS");
+      return;
+    }
+
+    // -XX:-UseLargePages overrides all other flags.
+    new FlagTester()
+      .use(UseLargePages(false),
+           UseHugeTLBFS(true))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Explicitly turn on UseHugeTLBFS.
+    new FlagTester()
+      .use(UseHugeTLBFS(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    // Setting a specific large pages flag will turn
+    // off heuristics to choose large pages type.
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Using UseLargePages will default to UseHugeTLBFS large pages.
+    new FlagTester()
+      .use(UseLargePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+  }
+
+  public static void testUseSHM() throws Exception {
+    if (!canUse(UseSHM(true))) {
+      System.out.println("Skipping testUseSHM");
+      return;
+    }
+
+    // -XX:-UseLargePages overrides all other flags.
+    new FlagTester()
+      .use(UseLargePages(false),
+           UseSHM(true))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Explicitly turn on UseSHM.
+    new FlagTester()
+      .use(UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(true)) ;
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(true)) ;
+
+    // Setting a specific large pages flag will turn
+    // off heuristics to choose large pages type.
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseSHM(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    // Setting UseLargePages can allow the system to choose
+    // UseHugeTLBFS instead of UseSHM, but never UseTransparentHugePages.
+    new FlagTester()
+      .use(UseLargePages(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false));
+  }
+
+  public static void testCombinations() throws Exception {
+    if (!canUse(UseSHM(true)) || !canUse(UseHugeTLBFS(true))) {
+      System.out.println("Skipping testUseHugeTLBFSAndUseSHMCombination");
+      return;
+    }
+
+    // UseHugeTLBFS takes precedence over SHM.
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(true));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(false))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(true),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false))
+      .expect(
+           UseLargePages(false),
+           UseTransparentHugePages(false),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+
+    if (!canUse(UseTransparentHugePages(true))) {
+      return;
+    }
+
+    // UseTransparentHugePages takes precedence.
+
+    new FlagTester()
+      .use(UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+
+    new FlagTester()
+      .use(UseTransparentHugePages(true),
+           UseHugeTLBFS(true),
+           UseSHM(true))
+      .expect(
+           UseLargePages(true),
+           UseTransparentHugePages(true),
+           UseHugeTLBFS(false),
+           UseSHM(false));
+  }
+
+  private static class FlagTester {
+    private Flag [] useFlags;
+
+    public FlagTester use(Flag... useFlags) {
+      this.useFlags = useFlags;
+      return this;
+    }
+
+    public void expect(Flag... expectedFlags) throws Exception {
+      if (useFlags == null) {
+        throw new IllegalStateException("Must run use() before expect()");
+      }
+
+      OutputAnalyzer output = executeNewJVM(useFlags);
+
+      for (Flag flag : expectedFlags) {
+        System.out.println("Looking for: " + flag.flagString());
+        String strValue = output.firstMatch(".* " + flag.name() +  " .* :?= (\\S+).*", 1);
+
+        if (strValue == null) {
+          throw new RuntimeException("Flag " + flag.name() + " couldn't be found");
+        }
+
+        if (!flag.value().equals(strValue)) {
+          throw new RuntimeException("Wrong value for: " + flag.name()
+                                     + " expected: " + flag.value()
+                                     + " got: " + strValue);
+        }
+      }
+
+      output.shouldHaveExitValue(0);
+    }
+  }
+
+  private static OutputAnalyzer executeNewJVM(Flag... flags) throws Exception {
+    ArrayList<String> args = new ArrayList<>();
+    for (Flag flag : flags) {
+      args.add(flag.flagString());
+    }
+    args.add("-XX:+PrintFlagsFinal");
+    args.add("-version");
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(args.toArray(new String[args.size()]));
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    return output;
+  }
+
+  private static boolean canUse(Flag flag) {
+    try {
+      new FlagTester().use(flag).expect(flag);
+    } catch (Exception e) {
+      return false;
+    }
+
+    return true;
+  }
+
+  private static Flag UseLargePages(boolean value) {
+    return new BooleanFlag("UseLargePages", value);
+  }
+
+  private static Flag UseTransparentHugePages(boolean value) {
+    return new BooleanFlag("UseTransparentHugePages", value);
+  }
+
+  private static Flag UseHugeTLBFS(boolean value) {
+    return new BooleanFlag("UseHugeTLBFS", value);
+  }
+
+  private static Flag UseSHM(boolean value) {
+    return new BooleanFlag("UseSHM", value);
+  }
+
+  private static class BooleanFlag implements Flag {
+    private String name;
+    private boolean value;
+
+    BooleanFlag(String name, boolean value) {
+      this.name = name;
+      this.value = value;
+    }
+
+    public String flagString() {
+      return "-XX:" + (value ? "+" : "-") + name;
+    }
+
+    public String name() {
+      return name;
+    }
+
+    public String value() {
+      return Boolean.toString(value);
+    }
+  }
+
+  private static interface Flag {
+    public String flagString();
+    public String name();
+    public String value();
+  }
+}