--- old/src/jdk.jfr/share/classes/jdk/jfr/internal/ASMToolkit.java	2020-07-19 21:31:04.125291400 +0900
+++ new/src/jdk.jfr/share/classes/jdk/jfr/internal/ASMToolkit.java	2020-07-19 21:31:03.955544600 +0900
@@ -155,6 +155,7 @@
             PrintWriter w = new PrintWriter(baos);
             w.println("Bytecode:");
             cr.accept(new TraceClassVisitor(w), 0);
+            Logger.log(LogTag.JFR_SYSTEM_BYTECODE, LogLevel.TRACE, baos.toString());
         };
     }
 
--- /dev/null	2020-07-19 21:20:25.577740400 +0900
+++ new/test/jdk/jdk/jfr/jvm/TestEventWriterLog.java	2020-07-19 21:31:05.847842600 +0900
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2020, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 TestEventWriterLog
+ * @summary Test that log message of JFR when handle bytecodes
+ * @key jfr
+ * @requires vm.hasJFR
+ * @library /test/lib /test/jdk
+ * @run main/othervm TestEventWriterLog
+ */
+
+import jdk.test.lib.process.ProcessTools;
+import jdk.test.lib.process.OutputAnalyzer;
+
+public class TestEventWriterLog {
+    public static void main(String[] args) throws Exception {
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-Xlog:jfr+system+bytecode=trace", "-XX:StartFlightRecording", "-version");
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        output.shouldContain("extends jdk/jfr/internal/handlers/EventHandler");
+    }
+}
\ No newline at end of file