--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/native/gc/g1/test_g1Predictions.cpp	Mon Aug 22 16:43:56 2016 +0300
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2016, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1Predictions.hpp"
+#include "unittest.hpp"
+
+static const double epsilon = 1e-6;
+
+// Some basic formula tests with confidence = 0.0
+TEST_VM(G1Predictions, basic_predictions) {
+  G1Predictions predictor(0.0);
+  TruncatedSeq s;
+
+  double p0 = predictor.get_new_prediction(&s);
+  ASSERT_LT(p0, epsilon) << "Initial prediction of empty sequence must be 0.0";
+
+  s.add(5.0);
+  double p1 = predictor.get_new_prediction(&s);
+  ASSERT_NEAR(p1, 5.0, epsilon);
+
+  for (int i = 0; i < 40; i++) {
+    s.add(5.0);
+  }
+  double p2 = predictor.get_new_prediction(&s);
+  ASSERT_NEAR(p2, 5.0, epsilon);
+}
+
+// The following tests checks that the initial predictions are based on
+// the average of the sequence and not on the stddev (which is 0).
+TEST_VM(G1Predictions, average_not_stdev_predictions) {
+  G1Predictions predictor(0.5);
+  TruncatedSeq s;
+
+  s.add(1.0);
+  double p1 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p1, s.davg()) << "First prediction must be greater than average";
+
+  s.add(1.0);
+  double p2 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p1, p2) << "First prediction must be greater than second";
+
+  s.add(1.0);
+  double p3 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p2, p3) << "Second prediction must be greater than third";
+
+  s.add(1.0);
+  s.add(1.0); // Five elements are now in the sequence.
+  double p4 = predictor.get_new_prediction(&s);
+  ASSERT_LT(p4, p3) << "Fourth prediction must be smaller than third";
+  ASSERT_NEAR(p4, 1.0, epsilon);
+}
+
+// The following tests checks that initially prediction based on
+// the average is used, that gets overridden by the stddev prediction at
+// the end.
+TEST_VM(G1Predictions, average_stdev_predictions) {
+  G1Predictions predictor(0.5);
+  TruncatedSeq s;
+
+  s.add(0.5);
+  double p1 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p1, s.davg()) << "First prediction must be greater than average";
+
+  s.add(0.2);
+  double p2 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p1, p2) << "First prediction must be greater than second";
+
+  s.add(0.5);
+  double p3 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p2, p3) << "Second prediction must be greater than third";
+
+  s.add(0.2);
+  s.add(2.0);
+  double p4 = predictor.get_new_prediction(&s);
+  ASSERT_GT(p4, p3) << "Fourth prediction must be greater than third";
+}