Merge

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp

@@ -193,7 +193,8 @@ ConcurrentMarkSweepGeneration::ConcurrentMarkSweepGeneration(
      FreeBlockDictionary<FreeChunk>::DictionaryChoice dictionaryChoice) :
   CardGeneration(rs, initial_byte_size, level, ct),
   _dilatation_factor(((double)MinChunkSize)/((double)(CollectedHeap::min_fill_size()))),
-  _debug_collection_type(Concurrent_collection_type)
+  _debug_collection_type(Concurrent_collection_type),
+  _did_compact(false)
 {
   HeapWord* bottom = (HeapWord*) _virtual_space.low();
   HeapWord* end    = (HeapWord*) _virtual_space.high();
@@ -917,18 +918,15 @@ void ConcurrentMarkSweepGeneration::compute_new_size() {
     return;
   }
 
-  // Compute some numbers about the state of the heap.
-  const size_t used_after_gc = used();
-  const size_t capacity_after_gc = capacity();
+  // The heap has been compacted but not reset yet.
+  // Any metric such as free() or used() will be incorrect.
 
   CardGeneration::compute_new_size();
 
   // Reset again after a possible resizing
-  cmsSpace()->reset_after_compaction();
-
-  assert(used() == used_after_gc && used_after_gc <= capacity(),
-         err_msg("used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT
-         " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity()));
+  if (did_compact()) {
+    cmsSpace()->reset_after_compaction();
+  }
 }
 
 void ConcurrentMarkSweepGeneration::compute_new_size_free_list() {
@@ -1578,6 +1576,8 @@ bool CMSCollector::shouldConcurrentCollect() {
   return false;
 }
 
+void CMSCollector::set_did_compact(bool v) { _cmsGen->set_did_compact(v); }
+
 // Clear _expansion_cause fields of constituent generations
 void CMSCollector::clear_expansion_cause() {
   _cmsGen->clear_expansion_cause();
@@ -1675,7 +1675,6 @@ void CMSCollector::collect(bool   full,
   }
   acquire_control_and_collect(full, clear_all_soft_refs);
   _full_gcs_since_conc_gc++;
-
 }
 
 void CMSCollector::request_full_gc(unsigned int full_gc_count) {
@@ -1857,6 +1856,7 @@ NOT_PRODUCT(
     }
   }
 
+  set_did_compact(should_compact);
   if (should_compact) {
     // If the collection is being acquired from the background
     // collector, there may be references on the discovered
@@ -2718,6 +2718,7 @@ void CMSCollector::gc_epilogue(bool full) {
     Chunk::clean_chunk_pool();
   }
 
+  set_did_compact(false);
   _between_prologue_and_epilogue = false;  // ready for next cycle
 }
 

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp

@@ -604,6 +604,8 @@ class CMSCollector: public CHeapObj<mtGC> {
   ConcurrentMarkSweepPolicy* _collector_policy;
   ConcurrentMarkSweepPolicy* collector_policy() { return _collector_policy; }
 
+  void set_did_compact(bool v);
+
   // XXX Move these to CMSStats ??? FIX ME !!!
   elapsedTimer _inter_sweep_timer;   // time between sweeps
   elapsedTimer _intra_sweep_timer;   // time _in_ sweeps
@@ -1081,6 +1083,10 @@ class ConcurrentMarkSweepGeneration: public CardGeneration {
 
   CollectionTypes _debug_collection_type;
 
+  // True if a compactiing collection was done.
+  bool _did_compact;
+  bool did_compact() { return _did_compact; }
+
   // Fraction of current occupancy at which to start a CMS collection which
   // will collect this generation (at least).
   double _initiating_occupancy;
@@ -1121,6 +1127,8 @@ class ConcurrentMarkSweepGeneration: public CardGeneration {
   // Adaptive size policy
   CMSAdaptiveSizePolicy* size_policy();
 
+  void set_did_compact(bool v) { _did_compact = v; }
+
   bool refs_discovery_is_atomic() const { return false; }
   bool refs_discovery_is_mt()     const {
     // Note: CMS does MT-discovery during the parallel-remark

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

@@ -1843,33 +1843,32 @@ void G1CollectedHeap::shrink_helper(size_t shrink_bytes) {
     ReservedSpace::page_align_size_down(shrink_bytes);
   aligned_shrink_bytes = align_size_down(aligned_shrink_bytes,
                                          HeapRegion::GrainBytes);
-  uint num_regions_deleted = 0;
-  MemRegion mr = _hrs.shrink_by(aligned_shrink_bytes, &num_regions_deleted);
+  uint num_regions_to_remove = (uint)(shrink_bytes / HeapRegion::GrainBytes);
+
+  uint num_regions_removed = _hrs.shrink_by(num_regions_to_remove);
   HeapWord* old_end = (HeapWord*) _g1_storage.high();
-  assert(mr.end() == old_end, "post-condition");
+  size_t shrunk_bytes = num_regions_removed * HeapRegion::GrainBytes;
 
   ergo_verbose3(ErgoHeapSizing,
                 "shrink the heap",
                 ergo_format_byte("requested shrinking amount")
                 ergo_format_byte("aligned shrinking amount")
                 ergo_format_byte("attempted shrinking amount"),
-                shrink_bytes, aligned_shrink_bytes, mr.byte_size());
-  if (mr.byte_size() > 0) {
+                shrink_bytes, aligned_shrink_bytes, shrunk_bytes);
+  if (num_regions_removed > 0) {
+    _g1_storage.shrink_by(shrunk_bytes);
+    HeapWord* new_end = (HeapWord*) _g1_storage.high();
+
     if (_hr_printer.is_active()) {
-      HeapWord* curr = mr.end();
-      while (curr > mr.start()) {
+      HeapWord* curr = old_end;
+      while (curr > new_end) {
         HeapWord* curr_end = curr;
         curr -= HeapRegion::GrainWords;
         _hr_printer.uncommit(curr, curr_end);
       }
-      assert(curr == mr.start(), "post-condition");
     }
 
-    _g1_storage.shrink_by(mr.byte_size());
-    HeapWord* new_end = (HeapWord*) _g1_storage.high();
-    assert(mr.start() == new_end, "post-condition");
-
-    _expansion_regions += num_regions_deleted;
+    _expansion_regions += num_regions_removed;
     update_committed_space(old_end, new_end);
     HeapRegionRemSet::shrink_heap(n_regions());
     g1_policy()->record_new_heap_size(n_regions());

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

@@ -309,7 +309,8 @@ G1CollectorPolicy::G1CollectorPolicy() :
 
 void G1CollectorPolicy::initialize_flags() {
   set_min_alignment(HeapRegion::GrainBytes);
-  set_max_alignment(GenRemSet::max_alignment_constraint(rem_set_name()));
+  size_t card_table_alignment = GenRemSet::max_alignment_constraint(rem_set_name());
+  set_max_alignment(MAX2(card_table_alignment, min_alignment()));
   if (SurvivorRatio < 1) {
     vm_exit_during_initialization("Invalid survivor ratio specified");
   }

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

@@ -124,11 +124,11 @@ MemRegion HeapRegionSeq::expand_by(HeapWord* old_end,
       }
       assert(_regions[index] == NULL, "invariant");
       _regions[index] = new_hr;
-      increment_length(&_allocated_length);
+      increment_allocated_length();
     }
     // Have to increment the length first, otherwise we will get an
     // assert failure at(index) below.
-    increment_length(&_length);
+    increment_length();
     HeapRegion* hr = at(index);
     list->add_as_tail(hr);
 
@@ -201,45 +201,29 @@ void HeapRegionSeq::iterate_from(HeapRegion* hr, HeapRegionClosure* blk) const {
   }
 }
 
-MemRegion HeapRegionSeq::shrink_by(size_t shrink_bytes,
-                                   uint* num_regions_deleted) {
+uint HeapRegionSeq::shrink_by(uint num_regions_to_remove) {
   // Reset this in case it's currently pointing into the regions that
   // we just removed.
   _next_search_index = 0;
 
-  assert(shrink_bytes % os::vm_page_size() == 0, "unaligned");
-  assert(shrink_bytes % HeapRegion::GrainBytes == 0, "unaligned");
   assert(length() > 0, "the region sequence should not be empty");
   assert(length() <= _allocated_length, "invariant");
   assert(_allocated_length > 0, "we should have at least one region committed");
+  assert(num_regions_to_remove < length(), "We should never remove all regions");
 
-  // around the loop, i will be the next region to be removed
-  uint i = length() - 1;
-  assert(i > 0, "we should never remove all regions");
-  // [last_start, end) is the MemRegion that covers the regions we will remove.
-  HeapWord* end = at(i)->end();
-  HeapWord* last_start = end;
-  *num_regions_deleted = 0;
-  while (shrink_bytes > 0) {
-    HeapRegion* cur = at(i);
-    // We should leave the humongous regions where they are.
-    if (cur->isHumongous()) break;
-    // We should stop shrinking if we come across a non-empty region.
-    if (!cur->is_empty()) break;
+  uint i = 0;
+  for (; i < num_regions_to_remove; i++) {
+    HeapRegion* cur = at(length() - 1);
 
-    i -= 1;
-    *num_regions_deleted += 1;
-    shrink_bytes -= cur->capacity();
-    last_start = cur->bottom();
-    decrement_length(&_length);
-    // We will reclaim the HeapRegion. _allocated_length should be
-    // covering this index. So, even though we removed the region from
-    // the active set by decreasing _length, we still have it
-    // available in the future if we need to re-use it.
-    assert(i > 0, "we should never remove all regions");
-    assert(length() > 0, "we should never remove all regions");
+    if (!cur->is_empty()) {
+      // We have to give up if the region can not be moved
+      break;
   }
-  return MemRegion(last_start, end);
+    assert(!cur->isHumongous(), "Humongous regions should not be empty");
+
+    decrement_length();
+  }
+  return i;
 }
 
 #ifndef PRODUCT

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

@@ -92,14 +92,19 @@ class HeapRegionSeq: public CHeapObj<mtGC> {
   // address is valid.
   inline uintx addr_to_index_biased(HeapWord* addr) const;
 
-  void increment_length(uint* length) {
-    assert(*length < _max_length, "pre-condition");
-    *length += 1;
+  void increment_allocated_length() {
+    assert(_allocated_length < _max_length, "pre-condition");
+    _allocated_length++;
   }
 
-  void decrement_length(uint* length) {
-    assert(*length > 0, "pre-condition");
-    *length -= 1;
+  void increment_length() {
+    assert(_length < _max_length, "pre-condition");
+    _length++;
+  }
+
+  void decrement_length() {
+    assert(_length > 0, "pre-condition");
+    _length--;
   }
 
  public:
@@ -153,11 +158,9 @@ class HeapRegionSeq: public CHeapObj<mtGC> {
   void iterate_from(HeapRegion* hr, HeapRegionClosure* blk) const;
 
   // Tag as uncommitted as many regions that are completely free as
-  // possible, up to shrink_bytes, from the suffix of the committed
-  // sequence. Return a MemRegion that corresponds to the address
-  // range of the uncommitted regions. Assume shrink_bytes is page and
-  // heap region aligned.
-  MemRegion shrink_by(size_t shrink_bytes, uint* num_regions_deleted);
+  // possible, up to num_regions_to_remove, from the suffix of the committed
+  // sequence. Return the actual number of removed regions.
+  uint shrink_by(uint num_regions_to_remove);
 
   // Do some sanity checking.
   void verify_optional() PRODUCT_RETURN;

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

@@ -48,6 +48,17 @@
 // CollectorPolicy methods.
 
 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()));
+
+  if (MaxHeapSize < InitialHeapSize) {
+    vm_exit_during_initialization("Incompatible initial and maximum heap sizes specified");
+  }
+
   if (MetaspaceSize > MaxMetaspaceSize) {
     MaxMetaspaceSize = MetaspaceSize;
   }
@@ -71,21 +82,9 @@ void CollectorPolicy::initialize_flags() {
 }
 
 void CollectorPolicy::initialize_size_info() {
-  // User inputs from -mx and ms are aligned
-  set_initial_heap_byte_size(InitialHeapSize);
-  if (initial_heap_byte_size() == 0) {
-    set_initial_heap_byte_size(NewSize + OldSize);
-  }
-  set_initial_heap_byte_size(align_size_up(_initial_heap_byte_size,
-                                           min_alignment()));
-
-  set_min_heap_byte_size(Arguments::min_heap_size());
-  if (min_heap_byte_size() == 0) {
-    set_min_heap_byte_size(NewSize + OldSize);
-  }
-  set_min_heap_byte_size(align_size_up(_min_heap_byte_size,
-                                       min_alignment()));
-
+  // 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()));
 
   // Check heap parameter properties
@@ -201,9 +200,6 @@ 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());
-  assert(max_alignment() >= min_alignment() &&
-         max_alignment() % min_alignment() == 0,
-         "invalid alignment constraints");
 
   CollectorPolicy::initialize_flags();
 
@@ -233,9 +229,6 @@ void TwoGenerationCollectorPolicy::initialize_flags() {
   GenCollectorPolicy::initialize_flags();
 
   OldSize = align_size_down(OldSize, min_alignment());
-  if (NewSize + OldSize > MaxHeapSize) {
-    MaxHeapSize = NewSize + OldSize;
-  }
 
   if (FLAG_IS_CMDLINE(OldSize) && FLAG_IS_DEFAULT(NewSize)) {
     // NewRatio will be used later to set the young generation size so we use
@@ -250,6 +243,27 @@ void TwoGenerationCollectorPolicy::initialize_flags() {
   }
   MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
 
+  // adjust max heap size if necessary
+  if (NewSize + OldSize > MaxHeapSize) {
+    if (FLAG_IS_CMDLINE(MaxHeapSize)) {
+      // somebody set a maximum heap size with the intention that we should not
+      // exceed it. Adjust New/OldSize as necessary.
+      uintx calculated_size = NewSize + OldSize;
+      double shrink_factor = (double) MaxHeapSize / calculated_size;
+      // align
+      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().
+      OldSize = MaxHeapSize - NewSize;
+    } else {
+      MaxHeapSize = NewSize + OldSize;
+    }
+  }
+  // need to do this again
+  MaxHeapSize = align_size_up(MaxHeapSize, max_alignment());
+
   always_do_update_barrier = UseConcMarkSweepGC;
 
   // Check validity of heap flags

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

@@ -93,6 +93,15 @@ WB_ENTRY(jboolean, WB_IsClassAlive(JNIEnv* env, jobject target, jstring name))
   return closure.found();
 WB_END
 
+WB_ENTRY(void, WB_PrintHeapSizes(JNIEnv* env, jobject o)) {
+  CollectorPolicy * p = Universe::heap()->collector_policy();
+  gclog_or_tty->print_cr("Minimum heap "SIZE_FORMAT" Initial heap "
+    SIZE_FORMAT" Maximum heap "SIZE_FORMAT" Min alignment "SIZE_FORMAT" Max alignment "SIZE_FORMAT,
+    p->min_heap_byte_size(), p->initial_heap_byte_size(), p->max_heap_byte_size(),
+    p->min_alignment(), p->max_alignment());
+}
+WB_END
+
 #if INCLUDE_ALL_GCS
 WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj))
   G1CollectedHeap* g1 = G1CollectedHeap::heap();
@@ -386,6 +395,7 @@ static JNINativeMethod methods[] = {
       CC"(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;",
       (void*) &WB_ParseCommandLine
   },
+  {CC"printHeapSizes",     CC"()V",                   (void*)&WB_PrintHeapSizes    },
 #if INCLUDE_ALL_GCS
   {CC"g1InConcurrentMark", CC"()Z",                   (void*)&WB_G1InConcurrentMark},
   {CC"g1IsHumongous",      CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous     },

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

@@ -747,16 +747,16 @@ void Arguments::add_string(char*** bldarray, int* count, const char* arg) {
     return;
   }
 
-  int index = *count;
+  int new_count = *count + 1;
 
   // expand the array and add arg to the last element
-  (*count)++;
   if (*bldarray == NULL) {
-    *bldarray = NEW_C_HEAP_ARRAY(char*, *count, mtInternal);
+    *bldarray = NEW_C_HEAP_ARRAY(char*, new_count, mtInternal);
   } else {
-    *bldarray = REALLOC_C_HEAP_ARRAY(char*, *bldarray, *count, mtInternal);
+    *bldarray = REALLOC_C_HEAP_ARRAY(char*, *bldarray, new_count, mtInternal);
   }
-  (*bldarray)[index] = strdup(arg);
+  (*bldarray)[*count] = strdup(arg);
+  *count = new_count;
 }
 
 void Arguments::build_jvm_args(const char* arg) {
@@ -1617,30 +1617,38 @@ void Arguments::set_heap_size() {
     FLAG_SET_ERGO(uintx, MaxHeapSize, (uintx)reasonable_max);
   }
 
-  // If the initial_heap_size has not been set with InitialHeapSize
-  // or -Xms, then set it as fraction of the size of physical memory,
-  // respecting the maximum and minimum sizes of the heap.
-  if (FLAG_IS_DEFAULT(InitialHeapSize)) {
+  // If the minimum or initial heap_size have not been set or requested to be set
+  // ergonomically, set them accordingly.
+  if (InitialHeapSize == 0 || min_heap_size() == 0) {
     julong reasonable_minimum = (julong)(OldSize + NewSize);
 
     reasonable_minimum = MIN2(reasonable_minimum, (julong)MaxHeapSize);
 
     reasonable_minimum = limit_by_allocatable_memory(reasonable_minimum);
 
-    julong reasonable_initial = phys_mem / InitialRAMFraction;
+    if (InitialHeapSize == 0) {
+      julong reasonable_initial = phys_mem / InitialRAMFraction;
 
-    reasonable_initial = MAX2(reasonable_initial, reasonable_minimum);
-    reasonable_initial = MIN2(reasonable_initial, (julong)MaxHeapSize);
+      reasonable_initial = MAX3(reasonable_initial, reasonable_minimum, (julong)min_heap_size());
+      reasonable_initial = MIN2(reasonable_initial, (julong)MaxHeapSize);
 
-    reasonable_initial = limit_by_allocatable_memory(reasonable_initial);
+      reasonable_initial = limit_by_allocatable_memory(reasonable_initial);
 
-    if (PrintGCDetails && Verbose) {
-      // Cannot use gclog_or_tty yet.
-      tty->print_cr("  Initial heap size " SIZE_FORMAT, (uintx)reasonable_initial);
-      tty->print_cr("  Minimum heap size " SIZE_FORMAT, (uintx)reasonable_minimum);
+      if (PrintGCDetails && Verbose) {
+        // Cannot use gclog_or_tty yet.
+        tty->print_cr("  Initial heap size " SIZE_FORMAT, (uintx)reasonable_initial);
+      }
+      FLAG_SET_ERGO(uintx, InitialHeapSize, (uintx)reasonable_initial);
+    }
+    // If the minimum heap size has not been set (via -Xms),
+    // synchronize with InitialHeapSize to avoid errors with the default value.
+    if (min_heap_size() == 0) {
+      set_min_heap_size(MIN2((uintx)reasonable_minimum, InitialHeapSize));
+      if (PrintGCDetails && Verbose) {
+        // Cannot use gclog_or_tty yet.
+        tty->print_cr("  Minimum heap size " SIZE_FORMAT, min_heap_size());
+      }
     }
-    FLAG_SET_ERGO(uintx, InitialHeapSize, (uintx)reasonable_initial);
-    set_min_heap_size((uintx)reasonable_minimum);
   }
 }
 
@@ -2426,7 +2434,8 @@ jint Arguments::parse_each_vm_init_arg(const JavaVMInitArgs* args,
     // -Xms
     } else if (match_option(option, "-Xms", &tail)) {
       julong long_initial_heap_size = 0;
-      ArgsRange errcode = parse_memory_size(tail, &long_initial_heap_size, 1);
+      // an initial heap size of 0 means automatically determine
+      ArgsRange errcode = parse_memory_size(tail, &long_initial_heap_size, 0);
       if (errcode != arg_in_range) {
         jio_fprintf(defaultStream::error_stream(),
                     "Invalid initial heap size: %s\n", option->optionString);
@@ -2437,7 +2446,7 @@ jint Arguments::parse_each_vm_init_arg(const JavaVMInitArgs* args,
       // Currently the minimum size and the initial heap sizes are the same.
       set_min_heap_size(InitialHeapSize);
     // -Xmx
-    } else if (match_option(option, "-Xmx", &tail)) {
+    } else if (match_option(option, "-Xmx", &tail) || match_option(option, "-XX:MaxHeapSize=", &tail)) {
       julong long_max_heap_size = 0;
       ArgsRange errcode = parse_memory_size(tail, &long_max_heap_size, 1);
       if (errcode != arg_in_range) {

hotspot/src/share/vm/runtime/globals.hpp

@@ -2968,7 +2968,7 @@ class CommandLineFlags {
                                                                             \
   /* gc parameters */                                                       \
   product(uintx, InitialHeapSize, 0,                                        \
-          "Initial heap size (in bytes); zero means OldSize + NewSize")     \
+          "Initial heap size (in bytes); zero means use ergonomics")        \
                                                                             \
   product(uintx, MaxHeapSize, ScaleForWordSize(96*M),                       \
           "Maximum heap size (in bytes)")                                   \

hotspot/test/gc/concurrentMarkSweep/CheckAllocateAndSystemGC.java

@@ -0,0 +1,66 @@
+/*
+ * 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 CheckAllocateAndSystemGC
+ * @summary CMS: assert(used() == used_after_gc && used_after_gc <= capacity()) failed: used: 0 used_after_gc: 292080 capacity: 1431699456
+ * @bug 8013032
+ * @key gc
+ * @key regression
+ * @library /testlibrary
+ * @run main/othervm CheckAllocateAndSystemGC
+ * @author jon.masamitsu@oracle.com
+ */
+
+import com.oracle.java.testlibrary.*;
+
+public class CheckAllocateAndSystemGC {
+  public static void main(String args[]) throws Exception {
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-showversion",
+      "-XX:+UseConcMarkSweepGC",
+      "-Xmn4m",
+      "-XX:MaxTenuringThreshold=1",
+      "-XX:-UseCMSCompactAtFullCollection",
+      "CheckAllocateAndSystemGC$AllocateAndSystemGC"
+      );
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    output.shouldNotContain("error");
+
+    output.shouldHaveExitValue(0);
+  }
+  static class AllocateAndSystemGC {
+    public static void main(String [] args) {
+      Integer x[] = new Integer [1000];
+      // Allocate enough objects to cause a minor collection.
+      // These allocations suffice for a 4m young geneneration.
+      for (int i = 0; i < 100; i++) {
+        Integer y[] = new Integer[10000];
+      }
+      System.gc();
+    }
+  }
+}

hotspot/test/gc/concurrentMarkSweep/SystemGCOnForegroundCollector.java

@@ -0,0 +1,67 @@
+/*
+ * 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 SystemGCOnForegroundCollector
+ * @summary CMS: Call reset_after_compaction() only if a compaction has been done
+ * @bug 8013184
+ * @key gc
+ * @key regression
+ * @library /testlibrary
+ * @run main/othervm SystemGCOnForegroundCollector
+ * @author jon.masamitsu@oracle.com
+ */
+
+import com.oracle.java.testlibrary.*;
+
+public class SystemGCOnForegroundCollector {
+  public static void main(String args[]) throws Exception {
+
+    ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+      "-showversion",
+      "-XX:+UseConcMarkSweepGC",
+      "-XX:MaxTenuringThreshold=1",
+      "-XX:-UseCMSCompactAtFullCollection",
+      ThreePlusMSSystemGC.class.getName()
+      );
+
+    OutputAnalyzer output = new OutputAnalyzer(pb.start());
+
+    output.shouldNotContain("error");
+
+    output.shouldHaveExitValue(0);
+  }
+
+  static class ThreePlusMSSystemGC {
+    public static void main(String [] args) {
+      // From running this test 3 System.gc() were always
+      // enough to see the failure but the cause of the failure
+      // depends on how objects are allocated in the CMS generation
+      // which is non-deterministic.  Use 30 iterations for a more
+      // reliable test.
+      for (int i = 0; i < 30; i++) {
+        System.gc();
+      }
+    }
+  }
+}

hotspot/test/gc/g1/TestRegionAlignment.java

@@ -0,0 +1,36 @@
+/*
+ * 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 TestRegionAlignment.java
+ * @bug 8013791
+ * @summary Make sure that G1 ergonomics pick a heap size that is aligned with the region size
+ * @run main/othervm -XX:+UseG1GC -XX:G1HeapRegionSize=32m -XX:MaxRAM=555m TestRegionAlignment
+ *
+ * When G1 ergonomically picks a maximum heap size it must be aligned to the region size.
+ * This test tries to get the VM to pick a small and unaligned heap size (by using MaxRAM=555) and a
+ * large region size (by using -XX:G1HeapRegionSize=32m). This will fail without the fix for 8013791.
+ */
+public class TestRegionAlignment {
+    public static void main(String[] args) { }
+}

hotspot/test/gc/g1/TestShrinkToOneRegion.java

@@ -0,0 +1,37 @@
+/*
+ * 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 TestShrinkToOneRegion.java
+ * @bug 8013872
+ * @summary Shrinking the heap down to one region used to hit an assert
+ * @run main/othervm -XX:+UseG1GC -XX:G1HeapRegionSize=32m -Xmx256m TestShrinkToOneRegion
+ *
+ * Doing a System.gc() without having allocated many objects will shrink the heap.
+ * With a large region size we will shrink the heap to one region.
+ */
+public class TestShrinkToOneRegion {
+    public static void main(String[] args) {
+        System.gc();
+    }
+}

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

@@ -61,6 +61,9 @@ public class WhiteBox {
     registerNatives();
   }
 
+  // Arguments
+  public native void printHeapSizes();
+
   // Memory
   public native long getObjectAddress(Object o);
   public native int  getHeapOopSize();