--- a/hotspot/src/share/vm/prims/jvmtiEnv.cpp	Mon Jun 06 12:51:53 2016 -0700
+++ b/hotspot/src/share/vm/prims/jvmtiEnv.cpp	Tue Jun 07 00:06:17 2016 +0000
@@ -319,15 +319,7 @@
 JvmtiEnv::GetObjectSize(jobject object, jlong* size_ptr) {
   oop mirror = JNIHandles::resolve_external_guard(object);
   NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
-
-  if (mirror->klass() == SystemDictionary::Class_klass() &&
-      !java_lang_Class::is_primitive(mirror)) {
-    Klass* k = java_lang_Class::as_Klass(mirror);
-    assert(k != NULL, "class for non-primitive mirror must exist");
-    *size_ptr = (jlong)k->size() * wordSize;
-  } else {
-    *size_ptr = (jlong)mirror->size() * wordSize;
-    }
+  *size_ptr = (jlong)mirror->size() * wordSize;
   return JVMTI_ERROR_NONE;
 } /* end GetObjectSize */
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/serviceability/jvmti/GetObjectSizeClass.java	Tue Jun 07 00:06:17 2016 +0000
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ */
+import java.io.PrintWriter;
+import jdk.test.lib.*;
+
+/*
+ * @test
+ * @bug 8075030
+ * @summary JvmtiEnv::GetObjectSize reports incorrect java.lang.Class instance size
+ * @library /testlibrary
+ * @modules java.base/jdk.internal.misc
+ *          java.compiler
+ *          java.instrument
+ *          java.management
+ *          jdk.jvmstat/sun.jvmstat.monitor
+ * @build ClassFileInstaller jdk.test.lib.* GetObjectSizeClassAgent
+ * @run main ClassFileInstaller GetObjectSizeClassAgent
+ * @run main GetObjectSizeClass
+ */
+public class GetObjectSizeClass {
+    public static void main(String[] args) throws Exception  {
+        PrintWriter pw = new PrintWriter("MANIFEST.MF");
+        pw.println("Premain-Class: GetObjectSizeClassAgent");
+        pw.close();
+
+        ProcessBuilder pb = new ProcessBuilder();
+        pb.command(new String[] { JDKToolFinder.getJDKTool("jar"), "cmf", "MANIFEST.MF", "agent.jar", "GetObjectSizeClassAgent.class"});
+        pb.start().waitFor();
+
+        ProcessBuilder pt = ProcessTools.createJavaProcessBuilder(true, "-javaagent:agent.jar",  "GetObjectSizeClassAgent");
+        OutputAnalyzer output = new OutputAnalyzer(pt.start());
+
+        output.stdoutShouldContain("GetObjectSizeClass passed");
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/serviceability/jvmti/GetObjectSizeClassAgent.java	Tue Jun 07 00:06:17 2016 +0000
@@ -0,0 +1,51 @@
+/*
+ * 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.
+ */
+import java.lang.instrument.*;
+
+public class GetObjectSizeClassAgent {
+
+    static Instrumentation instrumentation;
+
+    public static void premain(String agentArgs, Instrumentation instrumentation) {
+        GetObjectSizeClassAgent.instrumentation = instrumentation;
+    }
+
+    public static void main(String[] args) throws Exception {
+        long sizeA = instrumentation.getObjectSize(A.class);
+        long sizeB = instrumentation.getObjectSize(B.class);
+
+        if (sizeA != sizeB) {
+            throw new RuntimeException("java.lang.Class sizes disagree: " + sizeA + " vs. " + sizeB);
+        }
+
+        System.out.println("GetObjectSizeClass passed");
+    }
+
+    static class A {
+    }
+
+    static class B {
+        void m() {}
+    }
+
+}