--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1Arguments.cpp	Tue Nov 07 11:58:52 2017 +0100
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.
+ * 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1Arguments.hpp"
+#include "gc/g1/heapRegion.hpp"
+#include "runtime/globals.hpp"
+#include "runtime/globals_extension.hpp"
+#include "runtime/vm_version.hpp"
+
+size_t G1Arguments::conservative_max_heap_alignment() {
+  return HeapRegion::max_region_size();
+}
+
+void G1Arguments::initialize_flags() {
+  GCArguments::initialize_flags();
+  assert(UseG1GC, "Error");
+#if defined(COMPILER1) || INCLUDE_JVMCI
+  FastTLABRefill = false;
+#endif
+  FLAG_SET_DEFAULT(ParallelGCThreads, Abstract_VM_Version::parallel_worker_threads());
+  if (ParallelGCThreads == 0) {
+    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 (FLAG_IS_DEFAULT(G1ConcRefinementThreads)) {
+    FLAG_SET_ERGO(uint, 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.
+  // But we do set the maximum mark stack size here.
+  if (FLAG_IS_DEFAULT(MarkStackSizeMax)) {
+    FLAG_SET_DEFAULT(MarkStackSizeMax, 128 * TASKQUEUE_SIZE);
+  }
+
+  if (FLAG_IS_DEFAULT(GCTimeRatio) || GCTimeRatio == 0) {
+    // In G1, we want the default GC overhead goal to be higher than
+    // it is for PS, or the heap might be expanded too aggressively.
+    // We set it here to ~8%.
+    FLAG_SET_DEFAULT(GCTimeRatio, 12);
+  }
+
+  // Below, we might need to calculate the pause time interval based on
+  // the pause target. When we do so we are going to give G1 maximum
+  // flexibility and allow it to do pauses when it needs to. So, we'll
+  // arrange that the pause interval to be pause time target + 1 to
+  // ensure that a) the pause time target is maximized with respect to
+  // the pause interval and b) we maintain the invariant that pause
+  // time target < pause interval. If the user does not want this
+  // maximum flexibility, they will have to set the pause interval
+  // explicitly.
+
+  if (FLAG_IS_DEFAULT(MaxGCPauseMillis)) {
+    // The default pause time target in G1 is 200ms
+    FLAG_SET_DEFAULT(MaxGCPauseMillis, 200);
+  }
+
+  // Then, if the interval parameter was not set, set it according to
+  // the pause time target (this will also deal with the case when the
+  // pause time target is the default value).
+  if (FLAG_IS_DEFAULT(GCPauseIntervalMillis)) {
+    FLAG_SET_DEFAULT(GCPauseIntervalMillis, MaxGCPauseMillis + 1);
+  }
+
+  log_trace(gc)("MarkStackSize: %uk  MarkStackSizeMax: %uk", (unsigned int) (MarkStackSize / K), (uint) (MarkStackSizeMax / K));
+}