Merge

hotspot/src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp

@@ -128,9 +128,7 @@ void ConcurrentG1Refine::worker_threads_do(ThreadClosure * tc) {
 }
 
 uint ConcurrentG1Refine::thread_num() {
-  uint n_threads = (G1ConcRefinementThreads > 0) ? G1ConcRefinementThreads
-                                                : ParallelGCThreads;
-  return MAX2<uint>(n_threads, 1);
+  return G1ConcRefinementThreads;
 }
 
 void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {

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

@@ -262,12 +262,12 @@
           "Percentage (0-100) of the heap size to use as default "          \
           " maximum young gen size.")                                       \
                                                                             \
-  experimental(uintx, G1MixedGCLiveThresholdPercent, 65,                    \
+  experimental(uintx, G1MixedGCLiveThresholdPercent, 85,                    \
           "Threshold for regions to be considered for inclusion in the "    \
           "collection set of mixed GCs. "                                   \
           "Regions with live bytes exceeding this will not be collected.")  \
                                                                             \
-  product(uintx, G1HeapWastePercent, 10,                                    \
+  product(uintx, G1HeapWastePercent, 5,                                     \
           "Amount of space, expressed as a percentage of the heap size, "   \
           "that G1 is willing not to collect to avoid expensive GCs.")      \
                                                                             \

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

@@ -817,7 +817,11 @@ MetaWord* CollectorPolicy::satisfy_failed_metadata_allocation(
   assert(!Heap_lock->owned_by_self(), "Should not be holding the Heap_lock");
 
   do {
-    MetaWord* result = NULL;
+    MetaWord* result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
+    if (result != NULL) {
+      return result;
+    }
+
     if (GC_locker::is_active_and_needs_gc()) {
       // If the GC_locker is active, just expand and allocate.
       // If that does not succeed, wait if this thread is not

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

@@ -1415,10 +1415,31 @@ size_t MetaspaceGC::capacity_until_GC() {
   return value;
 }
 
-size_t MetaspaceGC::inc_capacity_until_GC(size_t v) {
+bool MetaspaceGC::inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC, size_t* old_cap_until_GC) {
   assert_is_size_aligned(v, Metaspace::commit_alignment());
 
-  return (size_t)Atomic::add_ptr(v, &_capacity_until_GC);
+  size_t capacity_until_GC = (size_t) _capacity_until_GC;
+  size_t new_value = capacity_until_GC + v;
+
+  if (new_value < capacity_until_GC) {
+    // The addition wrapped around, set new_value to aligned max value.
+    new_value = align_size_down(max_uintx, Metaspace::commit_alignment());
+  }
+
+  intptr_t expected = (intptr_t) capacity_until_GC;
+  intptr_t actual = Atomic::cmpxchg_ptr((intptr_t) new_value, &_capacity_until_GC, expected);
+
+  if (expected != actual) {
+    return false;
+  }
+
+  if (new_cap_until_GC != NULL) {
+    *new_cap_until_GC = new_value;
+  }
+  if (old_cap_until_GC != NULL) {
+    *old_cap_until_GC = capacity_until_GC;
+  }
+  return true;
 }
 
 size_t MetaspaceGC::dec_capacity_until_GC(size_t v) {
@@ -1518,7 +1539,10 @@ void MetaspaceGC::compute_new_size() {
     expand_bytes = align_size_up(expand_bytes, Metaspace::commit_alignment());
     // Don't expand unless it's significant
     if (expand_bytes >= MinMetaspaceExpansion) {
-      size_t new_capacity_until_GC = MetaspaceGC::inc_capacity_until_GC(expand_bytes);
+      size_t new_capacity_until_GC = 0;
+      bool succeeded = MetaspaceGC::inc_capacity_until_GC(expand_bytes, &new_capacity_until_GC);
+      assert(succeeded, "Should always succesfully increment HWM when at safepoint");
+
       Metaspace::tracer()->report_gc_threshold(capacity_until_GC,
                                                new_capacity_until_GC,
                                                MetaspaceGCThresholdUpdater::ComputeNewSize);
@@ -3321,19 +3345,29 @@ MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype)
   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 = 0;
+  size_t after = 0;
+  MetaWord* res;
+  bool incremented;
 
-  // capacity_until_GC might be updated concurrently, must calculate previous value.
-  size_t before_inc = after_inc - delta_bytes;
+  // Each thread increments the HWM at most once. Even if the thread fails to increment
+  // the HWM, an allocation is still attempted. This is because another thread must then
+  // have incremented the HWM and therefore the allocation might still succeed.
+  do {
+    incremented = MetaspaceGC::inc_capacity_until_GC(delta_bytes, &after, &before);
+    res = allocate(word_size, mdtype);
+  } while (!incremented && res == NULL);
 
-  tracer()->report_gc_threshold(before_inc, after_inc,
-                                MetaspaceGCThresholdUpdater::ExpandAndAllocate);
-  if (PrintGCDetails && Verbose) {
-    gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
-        " to " SIZE_FORMAT, before_inc, after_inc);
+  if (incremented) {
+    tracer()->report_gc_threshold(before, after,
+                                  MetaspaceGCThresholdUpdater::ExpandAndAllocate);
+    if (PrintGCDetails && Verbose) {
+      gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
+          " to " SIZE_FORMAT, before, after);
+    }
   }
 
-  return allocate(word_size, mdtype);
+  return res;
 }
 
 // Space allocated in the Metaspace.  This may

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

@@ -87,6 +87,7 @@ class Metaspace : public CHeapObj<mtClass> {
   friend class VM_CollectForMetadataAllocation;
   friend class MetaspaceGC;
   friend class MetaspaceAux;
+  friend class CollectorPolicy;
 
  public:
   enum MetadataType {
@@ -144,6 +145,8 @@ class Metaspace : public CHeapObj<mtClass> {
   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
   MetaWord* allocate(size_t word_size, MetadataType mdtype);
 
+  MetaWord* expand_and_allocate(size_t size, MetadataType mdtype);
+
   // Virtual Space lists for both classes and other metadata
   static VirtualSpaceList* _space_list;
   static VirtualSpaceList* _class_space_list;
@@ -234,9 +237,6 @@ class Metaspace : public CHeapObj<mtClass> {
                             bool read_only, MetaspaceObj::Type type, TRAPS);
   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
 
-  MetaWord* expand_and_allocate(size_t size,
-                                MetadataType mdtype);
-
   static bool contains(const void* ptr);
 
   void dump(outputStream* const out) const;
@@ -407,7 +407,9 @@ class MetaspaceGC : AllStatic {
   static void post_initialize();
 
   static size_t capacity_until_GC();
-  static size_t inc_capacity_until_GC(size_t v);
+  static bool inc_capacity_until_GC(size_t v,
+                                    size_t* new_cap_until_GC = NULL,
+                                    size_t* old_cap_until_GC = NULL);
   static size_t dec_capacity_until_GC(size_t v);
 
   static bool should_concurrent_collect() { return _should_concurrent_collect; }

hotspot/src/share/vm/prims/whitebox.cpp

@@ -820,6 +820,33 @@ WB_ENTRY(void, WB_FreeMetaspace(JNIEnv* env, jobject wb, jobject class_loader, j
   MetadataFactory::free_array(cld, (Array<u1>*)(uintptr_t)addr);
 WB_END
 
+WB_ENTRY(jlong, WB_IncMetaspaceCapacityUntilGC(JNIEnv* env, jobject wb, jlong inc))
+  if (inc < 0) {
+    THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
+        err_msg("WB_IncMetaspaceCapacityUntilGC: inc is negative: " JLONG_FORMAT, inc));
+  }
+
+  jlong max_size_t = (jlong) ((size_t) -1);
+  if (inc > max_size_t) {
+    THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(),
+        err_msg("WB_IncMetaspaceCapacityUntilGC: inc does not fit in size_t: " JLONG_FORMAT, inc));
+  }
+
+  size_t new_cap_until_GC = 0;
+  size_t aligned_inc = align_size_down((size_t) inc, Metaspace::commit_alignment());
+  bool success = MetaspaceGC::inc_capacity_until_GC(aligned_inc, &new_cap_until_GC);
+  if (!success) {
+    THROW_MSG_0(vmSymbols::java_lang_IllegalStateException(),
+                "WB_IncMetaspaceCapacityUntilGC: could not increase capacity until GC "
+                "due to contention with another thread");
+  }
+  return (jlong) new_cap_until_GC;
+WB_END
+
+WB_ENTRY(jlong, WB_MetaspaceCapacityUntilGC(JNIEnv* env, jobject wb))
+  return (jlong) MetaspaceGC::capacity_until_GC();
+WB_END
+
 //Some convenience methods to deal with objects from java
 int WhiteBox::offset_for_field(const char* field_name, oop object,
     Symbol* signature_symbol) {
@@ -991,6 +1018,8 @@ static JNINativeMethod methods[] = {
      CC"(Ljava/lang/ClassLoader;J)J",                 (void*)&WB_AllocateMetaspace },
   {CC"freeMetaspace",
      CC"(Ljava/lang/ClassLoader;JJ)V",                (void*)&WB_FreeMetaspace },
+  {CC"incMetaspaceCapacityUntilGC", CC"(J)J",         (void*)&WB_IncMetaspaceCapacityUntilGC },
+  {CC"metaspaceCapacityUntilGC", CC"()J",             (void*)&WB_MetaspaceCapacityUntilGC },
   {CC"getCPUFeatures",     CC"()Ljava/lang/String;",  (void*)&WB_GetCPUFeatures     },
   {CC"getNMethod",         CC"(Ljava/lang/reflect/Executable;Z)[Ljava/lang/Object;",
                                                       (void*)&WB_GetNMethod         },

hotspot/src/share/vm/runtime/arguments.cpp

@@ -1690,13 +1690,18 @@ void Arguments::set_g1_gc_flags() {
 #ifdef COMPILER1
   FastTLABRefill = false;
 #endif
-  FLAG_SET_DEFAULT(ParallelGCThreads,
-                     Abstract_VM_Version::parallel_worker_threads());
+  FLAG_SET_DEFAULT(ParallelGCThreads, Abstract_VM_Version::parallel_worker_threads());
   if (ParallelGCThreads == 0) {
-    FLAG_SET_DEFAULT(ParallelGCThreads,
-                     Abstract_VM_Version::parallel_worker_threads());
+    assert(!FLAG_IS_DEFAULT(ParallelGCThreads), "The default value for ParallelGCThreads should not be 0.");
+    vm_exit_during_initialization("The flag -XX:+UseG1GC can not be combined with -XX:ParallelGCThreads=0", NULL);
   }
 
+#if INCLUDE_ALL_GCS
+  if (G1ConcRefinementThreads == 0) {
+    FLAG_SET_DEFAULT(G1ConcRefinementThreads, ParallelGCThreads);
+  }
+#endif
+
   // MarkStackSize will be set (if it hasn't been set by the user)
   // when concurrent marking is initialized.
   // Its value will be based upon the number of parallel marking threads.

hotspot/src/share/vm/utilities/bitMap.cpp

@@ -342,9 +342,9 @@ bool BitMap::set_union_with_result(BitMap other) {
   bm_word_t* other_map = other.map();
   idx_t size = size_in_words();
   for (idx_t index = 0; index < size; index++) {
-    idx_t temp = map(index) | other_map[index];
-    changed = changed || (temp != map(index));
-    map()[index] = temp;
+    idx_t temp = dest_map[index] | other_map[index];
+    changed = changed || (temp != dest_map[index]);
+    dest_map[index] = temp;
   }
   return changed;
 }
@@ -407,10 +407,10 @@ bool BitMap::is_full() const {
   bm_word_t* word = map();
   idx_t rest = size();
   for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
-    if (*word != (bm_word_t) AllBits) return false;
+    if (*word != ~(bm_word_t)0) return false;
     word++;
   }
-  return rest == 0 || (*word | ~right_n_bits((int)rest)) == (bm_word_t) AllBits;
+  return rest == 0 || (*word | ~right_n_bits((int)rest)) == ~(bm_word_t)0;
 }
 
 
@@ -418,10 +418,10 @@ bool BitMap::is_empty() const {
   bm_word_t* word = map();
   idx_t rest = size();
   for (; rest >= (idx_t) BitsPerWord; rest -= BitsPerWord) {
-    if (*word != (bm_word_t) NoBits) return false;
+    if (*word != 0) return false;
     word++;
   }
-  return rest == 0 || (*word & right_n_bits((int)rest)) == (bm_word_t) NoBits;
+  return rest == 0 || (*word & right_n_bits((int)rest)) == 0;
 }
 
 void BitMap::clear_large() {
@@ -441,7 +441,7 @@ bool BitMap::iterate(BitMapClosure* blk, idx_t leftOffset, idx_t rightOffset) {
        offset < rightOffset && index < endIndex;
        offset = (++index) << LogBitsPerWord) {
     idx_t rest = map(index) >> (offset & (BitsPerWord - 1));
-    for (; offset < rightOffset && rest != (bm_word_t)NoBits; offset++) {
+    for (; offset < rightOffset && rest != 0; offset++) {
       if (rest & 1) {
         if (!blk->do_bit(offset)) return false;
         //  resample at each closure application
@@ -468,7 +468,7 @@ void BitMap::init_pop_count_table() {
                                        (intptr_t)  NULL_WORD);
     if (res != NULL_WORD) {
       guarantee( _pop_count_table == (void*) res, "invariant" );
-      FREE_C_HEAP_ARRAY(bm_word_t, table, mtInternal);
+      FREE_C_HEAP_ARRAY(idx_t, table, mtInternal);
     }
   }
 }

hotspot/src/share/vm/utilities/bitMap.hpp

@@ -80,7 +80,7 @@ class BitMap VALUE_OBJ_CLASS_SPEC {
 
   // Set a word to a specified value or to all ones; clear a word.
   void set_word  (idx_t word, bm_word_t val) { _map[word] = val; }
-  void set_word  (idx_t word)            { set_word(word, ~(uintptr_t)0); }
+  void set_word  (idx_t word)            { set_word(word, ~(bm_word_t)0); }
   void clear_word(idx_t word)            { _map[word] = 0; }
 
   // Utilities for ranges of bits.  Ranges are half-open [beg, end).

hotspot/src/share/vm/utilities/bitMap.inline.hpp

@@ -130,7 +130,7 @@ inline void BitMap::par_set_range(idx_t beg, idx_t end, RangeSizeHint hint) {
 
 inline void BitMap::set_range_of_words(idx_t beg, idx_t end) {
   bm_word_t* map = _map;
-  for (idx_t i = beg; i < end; ++i) map[i] = ~(uintptr_t)0;
+  for (idx_t i = beg; i < end; ++i) map[i] = ~(bm_word_t)0;
 }
 
 
@@ -172,8 +172,8 @@ BitMap::get_next_one_offset_inline(idx_t l_offset, idx_t r_offset) const {
 
   // check bits including and to the _left_ of offset's position
   idx_t pos = bit_in_word(res_offset);
-  idx_t res = map(index) >> pos;
-  if (res != (uintptr_t)NoBits) {
+  bm_word_t res = map(index) >> pos;
+  if (res != 0) {
     // find the position of the 1-bit
     for (; !(res & 1); res_offset++) {
       res = res >> 1;
@@ -207,7 +207,7 @@ BitMap::get_next_one_offset_inline(idx_t l_offset, idx_t r_offset) const {
   // skip over all word length 0-bit runs
   for (index++; index < r_index; index++) {
     res = map(index);
-    if (res != (uintptr_t)NoBits) {
+    if (res != 0) {
       // found a 1, return the offset
       for (res_offset = bit_index(index); !(res & 1); res_offset++) {
         res = res >> 1;
@@ -235,9 +235,9 @@ BitMap::get_next_zero_offset_inline(idx_t l_offset, idx_t r_offset) const {
 
   // check bits including and to the _left_ of offset's position
   idx_t pos = res_offset & (BitsPerWord - 1);
-  idx_t res = (map(index) >> pos) | left_n_bits((int)pos);
+  bm_word_t res = (map(index) >> pos) | left_n_bits((int)pos);
 
-  if (res != (uintptr_t)AllBits) {
+  if (res != ~(bm_word_t)0) {
     // find the position of the 0-bit
     for (; res & 1; res_offset++) {
       res = res >> 1;
@@ -248,7 +248,7 @@ BitMap::get_next_zero_offset_inline(idx_t l_offset, idx_t r_offset) const {
   // skip over all word length 1-bit runs
   for (index++; index < r_index; index++) {
     res = map(index);
-    if (res != (uintptr_t)AllBits) {
+    if (res != ~(bm_word_t)0) {
       // found a 0, return the offset
       for (res_offset = index << LogBitsPerWord; res & 1;
            res_offset++) {
@@ -277,8 +277,8 @@ BitMap::get_next_one_offset_inline_aligned_right(idx_t l_offset,
   idx_t res_offset = l_offset;
 
   // check bits including and to the _left_ of offset's position
-  idx_t res = map(index) >> bit_in_word(res_offset);
-  if (res != (uintptr_t)NoBits) {
+  bm_word_t res = map(index) >> bit_in_word(res_offset);
+  if (res != 0) {
     // find the position of the 1-bit
     for (; !(res & 1); res_offset++) {
       res = res >> 1;
@@ -290,7 +290,7 @@ BitMap::get_next_one_offset_inline_aligned_right(idx_t l_offset,
   // skip over all word length 0-bit runs
   for (index++; index < r_index; index++) {
     res = map(index);
-    if (res != (uintptr_t)NoBits) {
+    if (res != 0) {
       // found a 1, return the offset
       for (res_offset = bit_index(index); !(res & 1); res_offset++) {
         res = res >> 1;
@@ -321,11 +321,11 @@ BitMap::inverted_bit_mask_for_range(idx_t beg, idx_t end) const {
 }
 
 inline void BitMap::set_large_range_of_words(idx_t beg, idx_t end) {
-  memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(uintptr_t));
+  memset(_map + beg, ~(unsigned char)0, (end - beg) * sizeof(bm_word_t));
 }
 
 inline void BitMap::clear_large_range_of_words(idx_t beg, idx_t end) {
-  memset(_map + beg, 0, (end - beg) * sizeof(uintptr_t));
+  memset(_map + beg, 0, (end - beg) * sizeof(bm_word_t));
 }
 
 inline BitMap::idx_t BitMap::word_index_round_up(idx_t bit) const {

hotspot/test/TEST.groups

@@ -134,6 +134,13 @@ needs_compact3 = \
   gc/metaspace/TestMetaspaceMemoryPool.java \
   gc/arguments/TestDynMinHeapFreeRatio.java \
   gc/arguments/TestDynMaxHeapFreeRatio.java \
+  gc/g1/TestShrinkAuxiliaryData00.java \
+  gc/g1/TestShrinkAuxiliaryData05.java \
+  gc/g1/TestShrinkAuxiliaryData10.java \
+  gc/g1/TestShrinkAuxiliaryData15.java \
+  gc/g1/TestShrinkAuxiliaryData20.java \
+  gc/g1/TestShrinkAuxiliaryData25.java \
+  gc/g1/TestShrinkAuxiliaryData30.java \
   runtime/InternalApi/ThreadCpuTimesDeadlock.java \
   serviceability/threads/TestFalseDeadLock.java \
 
@@ -221,6 +228,7 @@ needs_g1gc = \
   gc/arguments/TestG1HeapSizeFlags.java \
   gc/arguments/TestMaxHeapSizeTools.java \
   gc/arguments/TestMaxNewSize.java \
+  gc/arguments/TestParallelGCThreads.java \
   gc/arguments/TestUseCompressedOopsErgo.java \
   gc/class_unloading/TestG1ClassUnloadingHWM.java \
   gc/g1/ \
@@ -248,6 +256,7 @@ needs_parallelgc = \
   gc/arguments/TestAlignmentToUseLargePages.java \
   gc/arguments/TestMaxNewSize.java \
   gc/arguments/TestMinInitialErgonomics.java \
+  gc/arguments/TestParallelGCThreads.java \
   gc/arguments/TestUseCompressedOopsErgo.java \
   gc/metaspace/TestMetaspacePerfCounters.java \
   gc/parallelScavenge/ \
@@ -262,6 +271,7 @@ needs_cmsgc = \
   gc/arguments/TestAlignmentToUseLargePages.java \
   gc/arguments/TestCMSHeapSizeFlags.java \
   gc/arguments/TestMaxNewSize.java \
+  gc/arguments/TestParallelGCThreads.java \
   gc/arguments/TestUseCompressedOopsErgo.java \
   gc/class_unloading/TestCMSClassUnloadingEnabledHWM.java \
   gc/concurrentMarkSweep/ \

hotspot/test/gc/arguments/TestG1ConcRefinementThreads.java

@@ -0,0 +1,97 @@
+/*
+* Copyright (c) 2014, 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 TestG1ConcRefinementThreads
+ * @key gc
+ * @bug 8047976
+ * @summary Tests argument processing for G1ConcRefinementThreads
+ * @library /testlibrary
+ */
+
+import com.oracle.java.testlibrary.*;
+import java.util.*;
+import java.util.regex.*;
+
+public class TestG1ConcRefinementThreads {
+
+  static final int AUTO_SELECT_THREADS_COUNT = 0;
+  static final int PASSED_THREADS_COUNT = 11;
+
+  public static void main(String args[]) throws Exception {
+    // default case
+    runG1ConcRefinementThreadsTest(
+        new String[]{}, // automatically selected
+        AUTO_SELECT_THREADS_COUNT /* use default setting */);
+
+    // zero setting case
+    runG1ConcRefinementThreadsTest(
+        new String[]{"-XX:G1ConcRefinementThreads=0"}, // automatically selected
+        AUTO_SELECT_THREADS_COUNT /* set to zero */);
+
+    // non-zero sestting case
+    runG1ConcRefinementThreadsTest(
+        new String[]{"-XX:G1ConcRefinementThreads="+Integer.toString(PASSED_THREADS_COUNT)},
+        PASSED_THREADS_COUNT);
+  }
+
+  private static void runG1ConcRefinementThreadsTest(String[] passedOpts,
+          int expectedValue) throws Exception {
+    List<String> vmOpts = new ArrayList<>();
+    if (passedOpts.length > 0) {
+      Collections.addAll(vmOpts, passedOpts);
+    }
+    Collections.addAll(vmOpts, "-XX:+UseG1GC", "-XX:+PrintFlagsFinal", "-version");
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(vmOpts.toArray(new String[vmOpts.size()]));
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    output.shouldHaveExitValue(0);
+    String stdout = output.getStdout();
+    checkG1ConcRefinementThreadsConsistency(stdout, expectedValue);
+  }
+
+  private static void checkG1ConcRefinementThreadsConsistency(String output, int expectedValue) {
+    int actualValue = getIntValue("G1ConcRefinementThreads", output);
+
+    if (expectedValue == 0) {
+      // If expectedValue is automatically selected, set it same as ParallelGCThreads.
+      expectedValue = getIntValue("ParallelGCThreads", output);
+    }
+
+    if (expectedValue != actualValue) {
+      throw new RuntimeException(
+            "Actual G1ConcRefinementThreads(" + Integer.toString(actualValue)
+            + ") is not equal to expected value(" + Integer.toString(expectedValue) + ")");
+    }
+  }
+
+  public static int getIntValue(String flag, String where) {
+    Matcher m = Pattern.compile(flag + "\\s+:?=\\s+\\d+").matcher(where);
+    if (!m.find()) {
+      throw new RuntimeException("Could not find value for flag " + flag + " in output string");
+    }
+    String match = m.group();
+    return Integer.parseInt(match.substring(match.lastIndexOf(" ") + 1, match.length()));
+  }
+}

hotspot/test/gc/arguments/TestParallelGCThreads.java

@@ -0,0 +1,64 @@
+/*
+* Copyright (c) 2014, 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 TestParallelGCThreads
+ * @key gc
+ * @bug 8059527
+ * @summary Tests argument processing for ParallelGCThreads
+ * @library /testlibrary
+ * @run driver TestParallelGCThreads
+ */
+
+import com.oracle.java.testlibrary.*;
+
+public class TestParallelGCThreads {
+
+  public static void main(String args[]) throws Exception {
+
+    // For each parallel collector (G1, Parallel, ParNew/CMS)
+    for (String gc : new String[] {"G1", "Parallel", "ConcMarkSweep"}) {
+
+      // Make sure the VM does not allow ParallelGCThreads set to 0
+      String[] flags = new String[] {"-XX:+Use" + gc + "GC", "-XX:ParallelGCThreads=0", "-XX:+PrintFlagsFinal", "-version"};
+      ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
+      OutputAnalyzer output = new OutputAnalyzer(pb.start());
+      output.shouldHaveExitValue(1);
+
+      // Do some basic testing to ensure the flag updates the count
+      for (long i = 1; i <= 3; i++) {
+        flags = new String[] {"-XX:+Use" + gc + "GC", "-XX:ParallelGCThreads=" + i, "-XX:+PrintFlagsFinal", "-version"};
+        long count = getParallelGCThreadCount(flags);
+        Asserts.assertEQ(count, i, "Specifying ParallelGCThreads=" + i + " for " + gc + "GC does not set the thread count properly!");
+      }
+    }
+  }
+
+  public static long getParallelGCThreadCount(String flags[]) throws Exception {
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(flags);
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+    output.shouldHaveExitValue(0);
+    String stdout = output.getStdout();
+    return FlagsValue.getFlagLongValue("ParallelGCThreads", stdout);
+  }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData.java

@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2014, 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.
+ */
+
+import static com.oracle.java.testlibrary.Asserts.assertLessThanOrEqual;
+import com.oracle.java.testlibrary.OutputAnalyzer;
+import com.oracle.java.testlibrary.Platform;
+import com.oracle.java.testlibrary.ProcessTools;
+import com.oracle.java.testlibrary.Utils;
+import java.io.IOException;
+import java.lang.management.ManagementFactory;
+import java.lang.management.MemoryUsage;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+import sun.misc.Unsafe;
+
+public class TestShrinkAuxiliaryData {
+
+    private final static String[] initialOpts = new String[]{
+        "-XX:MinHeapFreeRatio=10",
+        "-XX:MaxHeapFreeRatio=11",
+        "-XX:+UseG1GC",
+        "-XX:G1HeapRegionSize=1m",
+        "-XX:+PrintGCDetails"
+    };
+
+    private final int RSetCacheSize;
+
+    protected TestShrinkAuxiliaryData(int RSetCacheSize) {
+        this.RSetCacheSize = RSetCacheSize;
+    }
+
+    protected void test() throws Exception {
+        ArrayList<String> vmOpts = new ArrayList();
+        Collections.addAll(vmOpts, initialOpts);
+
+        int maxCacheSize = Math.max(0, Math.min(31, getMaxCacheSize()));
+        if (maxCacheSize < RSetCacheSize) {
+            System.out.format("Skiping test for %d cache size due max cache size %d",
+                    RSetCacheSize, maxCacheSize
+            );
+            return;
+        }
+
+        printTestInfo(maxCacheSize);
+
+        vmOpts.add("-XX:G1ConcRSLogCacheSize=" + RSetCacheSize);
+
+        vmOpts.addAll(Arrays.asList(Utils.getFilteredTestJavaOpts(
+                ShrinkAuxiliaryDataTest.prohibitedVmOptions)));
+
+        // for 32 bits ObjectAlignmentInBytes is not a option
+        if (Platform.is32bit()) {
+            ArrayList<String> vmOptsWithoutAlign = new ArrayList(vmOpts);
+            vmOptsWithoutAlign.add(ShrinkAuxiliaryDataTest.class.getName());
+            performTest(vmOptsWithoutAlign);
+            return;
+        }
+
+        for (int alignment = 3; alignment <= 8; alignment++) {
+            ArrayList<String> vmOptsWithAlign = new ArrayList(vmOpts);
+            vmOptsWithAlign.add("-XX:ObjectAlignmentInBytes="
+                    + (int) Math.pow(2, alignment));
+            vmOptsWithAlign.add(ShrinkAuxiliaryDataTest.class.getName());
+
+            performTest(vmOptsWithAlign);
+        }
+    }
+
+    private void performTest(List<String> opts) throws Exception {
+        ProcessBuilder pb
+                       = ProcessTools.createJavaProcessBuilder(
+                opts.toArray(new String[opts.size()])
+        );
+
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        output.shouldHaveExitValue(0);
+    }
+
+    private void printTestInfo(int maxCacheSize) {
+
+        DecimalFormat grouped = new DecimalFormat("000,000");
+        DecimalFormatSymbols formatSymbols = grouped.getDecimalFormatSymbols();
+        formatSymbols.setGroupingSeparator(' ');
+        grouped.setDecimalFormatSymbols(formatSymbols);
+
+        System.out.format("Test will use %s bytes of memory of %s available%n"
+                + "Available memory is %s with %d bytes pointer size - can save %s pointers%n"
+                + "Max cache size: 2^%d = %s elements%n",
+                grouped.format(ShrinkAuxiliaryDataTest.getMemoryUsedByTest()),
+                grouped.format(Runtime.getRuntime().freeMemory()),
+                grouped.format(Runtime.getRuntime().freeMemory()
+                        - ShrinkAuxiliaryDataTest.getMemoryUsedByTest()),
+                Unsafe.ADDRESS_SIZE,
+                grouped.format((Runtime.getRuntime().freeMemory()
+                        - ShrinkAuxiliaryDataTest.getMemoryUsedByTest())
+                        / Unsafe.ADDRESS_SIZE),
+                maxCacheSize,
+                grouped.format((int) Math.pow(2, maxCacheSize))
+        );
+    }
+
+    /**
+     * Detects maximum possible size of G1ConcRSLogCacheSize available for
+     * current process based on maximum available process memory size
+     *
+     * @return power of two
+     */
+    private static int getMaxCacheSize() {
+        long availableMemory = Runtime.getRuntime().freeMemory()
+                - ShrinkAuxiliaryDataTest.getMemoryUsedByTest() - 1l;
+        if (availableMemory <= 0) {
+            return 0;
+        }
+        long availablePointersCount = availableMemory / Unsafe.ADDRESS_SIZE;
+        return (63 - (int) Long.numberOfLeadingZeros(availablePointersCount));
+    }
+
+    static class ShrinkAuxiliaryDataTest {
+
+        public static void main(String[] args) throws IOException {
+            int iterateCount = DEFAULT_ITERATION_COUNT;
+
+            if (args.length > 0) {
+                try {
+                    iterateCount = Integer.parseInt(args[0]);
+                } catch (NumberFormatException e) {
+                    //num_iterate remains default
+                }
+            }
+
+            new ShrinkAuxiliaryDataTest().test(iterateCount);
+        }
+
+        class GarbageObject {
+
+            private final List<byte[]> payload = new ArrayList();
+            private final List<GarbageObject> ref = new LinkedList();
+
+            public GarbageObject(int size) {
+                payload.add(new byte[size]);
+            }
+
+            public void addRef(GarbageObject g) {
+                ref.add(g);
+            }
+
+            public void mutate() {
+                if (!payload.isEmpty() && payload.get(0).length > 0) {
+                    payload.get(0)[0] = (byte) (Math.random() * Byte.MAX_VALUE);
+                }
+            }
+        }
+
+        private final List<GarbageObject> garbage = new ArrayList();
+
+        public void test(int num_iterate) throws IOException {
+
+            allocate();
+            link();
+            mutate();
+            deallocate();
+
+            MemoryUsage muBeforeHeap
+                        = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+            MemoryUsage muBeforeNonHeap
+                        = ManagementFactory.getMemoryMXBean().getNonHeapMemoryUsage();
+
+            for (int i = 0; i < num_iterate; i++) {
+                allocate();
+                link();
+                mutate();
+                deallocate();
+            }
+
+            System.gc();
+            MemoryUsage muAfterHeap
+                        = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+            MemoryUsage muAfterNonHeap
+                        = ManagementFactory.getMemoryMXBean().getNonHeapMemoryUsage();
+
+            assertLessThanOrEqual(muAfterHeap.getCommitted(), muBeforeHeap.getCommitted(),
+                    String.format("heap decommit failed - after > before: %d > %d",
+                            muAfterHeap.getCommitted(), muBeforeHeap.getCommitted()
+                    )
+            );
+
+            if (muAfterHeap.getCommitted() < muBeforeHeap.getCommitted()) {
+                assertLessThanOrEqual(muAfterNonHeap.getCommitted(), muBeforeNonHeap.getCommitted(),
+                        String.format("non-heap decommit failed - after > before: %d > %d",
+                                muAfterNonHeap.getCommitted(), muBeforeNonHeap.getCommitted()
+                        )
+                );
+            }
+        }
+
+        private void allocate() {
+            for (int r = 0; r < REGIONS_TO_ALLOCATE; r++) {
+                for (int i = 0; i < NUM_OBJECTS_PER_REGION; i++) {
+                    GarbageObject g = new GarbageObject(REGION_SIZE
+                            / NUM_OBJECTS_PER_REGION);
+                    garbage.add(g);
+                }
+            }
+        }
+
+        /**
+         * Iterate through all allocated objects, and link to objects in another
+         * regions
+         */
+        private void link() {
+            for (int ig = 0; ig < garbage.size(); ig++) {
+                int regionNumber = ig / NUM_OBJECTS_PER_REGION;
+
+                for (int i = 0; i < NUM_LINKS; i++) {
+                    int regionToLink;
+                    do {
+                        regionToLink = (int) (Math.random()
+                                * REGIONS_TO_ALLOCATE);
+                    } while (regionToLink == regionNumber);
+
+                    // get random garbage object from random region
+                    garbage.get(ig).addRef(garbage.get(regionToLink
+                            * NUM_OBJECTS_PER_REGION + (int) (Math.random()
+                            * NUM_OBJECTS_PER_REGION)));
+                }
+            }
+        }
+
+        private void mutate() {
+            for (int ig = 0; ig < garbage.size(); ig++) {
+                garbage.get(ig).mutate();
+            }
+        }
+
+        private void deallocate() {
+            garbage.clear();
+            System.gc();
+        }
+
+        static long getMemoryUsedByTest() {
+            return REGIONS_TO_ALLOCATE * REGION_SIZE;
+        }
+
+        private static final int REGION_SIZE = 1024 * 1024;
+        private static final int DEFAULT_ITERATION_COUNT = 1;   // iterate main scenario
+        private static final int REGIONS_TO_ALLOCATE = 5;
+        private static final int NUM_OBJECTS_PER_REGION = 10;
+        private static final int NUM_LINKS = 20; // how many links create for each object
+
+        private static final String[] prohibitedVmOptions = {
+            // remove this when @requires option will be on duty
+            "-XX:\\+UseParallelGC",
+            "-XX:\\+UseSerialGC",
+            "-XX:\\+UseConcMarkSweepGC",
+            "-XX:\\+UseParallelOldGC",
+            "-XX:\\+UseParNewGC",
+            "-Xconcgc",
+            "-Xincgc"
+        };
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData00.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData00
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData00
+ * @run driver/timeout=720 TestShrinkAuxiliaryData00
+ */
+public class TestShrinkAuxiliaryData00 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(0).test();
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData05.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData05
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData05
+ * @run driver/timeout=720 TestShrinkAuxiliaryData05
+ */
+public class TestShrinkAuxiliaryData05 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(5).test();
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData10.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData10
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData10
+ * @run driver/timeout=720 TestShrinkAuxiliaryData10
+ */
+public class TestShrinkAuxiliaryData10 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(10).test();
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData15.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData15
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData15
+ * @run driver/timeout=720 TestShrinkAuxiliaryData15
+ */
+public class TestShrinkAuxiliaryData15 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(15).test();
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData20.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData20
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData20
+ * @run driver/timeout=720 TestShrinkAuxiliaryData20
+ */
+public class TestShrinkAuxiliaryData20 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(20).test();
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData25.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData25
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData25
+ * @run driver/timeout=720 TestShrinkAuxiliaryData25
+ */
+public class TestShrinkAuxiliaryData25 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(25).test();
+    }
+}

hotspot/test/gc/g1/TestShrinkAuxiliaryData30.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2014, 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 TestShrinkAuxiliaryData30
+ * @bug 8038423
+ * @summary Checks that decommitment occurs for JVM with different
+ * G1ConcRSLogCacheSize and ObjectAlignmentInBytes options values
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestShrinkAuxiliaryData TestShrinkAuxiliaryData30
+ * @run driver/timeout=720 TestShrinkAuxiliaryData30
+ */
+public class TestShrinkAuxiliaryData30 {
+
+    public static void main(String[] args) throws Exception {
+        new TestShrinkAuxiliaryData(30).test();
+    }
+}

hotspot/test/gc/metaspace/TestCapacityUntilGCWrapAround.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2014, 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
+ * @key gc
+ * @bug 8049831
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestCapacityUntilGCWrapAround
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ *                              sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI TestCapacityUntilGCWrapAround
+ */
+
+import sun.hotspot.WhiteBox;
+
+import com.oracle.java.testlibrary.Asserts;
+import com.oracle.java.testlibrary.Platform;
+
+public class TestCapacityUntilGCWrapAround {
+    private static long MB = 1024 * 1024;
+    private static long GB = 1024 * MB;
+    private static long MAX_UINT = 4 * GB - 1; // On 32-bit platforms
+
+    public static void main(String[] args) {
+        if (Platform.is32bit()) {
+            WhiteBox wb = WhiteBox.getWhiteBox();
+
+            long before = wb.metaspaceCapacityUntilGC();
+            // Now force possible overflow of capacity_until_GC.
+            long after = wb.incMetaspaceCapacityUntilGC(MAX_UINT);
+
+            Asserts.assertGTE(after, before,
+                              "Increasing with MAX_UINT should not cause wrap around: " + after + " < " + before);
+            Asserts.assertLTE(after, MAX_UINT,
+                              "Increasing with MAX_UINT should not cause value larger than MAX_UINT:" + after);
+        }
+    }
+}

hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java

@@ -152,6 +152,8 @@ public class WhiteBox {
   public native void readReservedMemory();
   public native long allocateMetaspace(ClassLoader classLoader, long size);
   public native void freeMetaspace(ClassLoader classLoader, long addr, long size);
+  public native long incMetaspaceCapacityUntilGC(long increment);
+  public native long metaspaceCapacityUntilGC();
 
   // force Young GC
   public native void youngGC();