--- old/src/share/vm/logging/logFileOutput.cpp	2017-07-13 09:55:31.453827836 +0900
+++ new/src/share/vm/logging/logFileOutput.cpp	2017-07-13 09:55:31.359825857 +0900
@@ -36,7 +36,7 @@
 const char* LogFileOutput::FileOpenMode = "a";
 const char* LogFileOutput::PidFilenamePlaceholder = "%p";
 const char* LogFileOutput::TimestampFilenamePlaceholder = "%t";
-const char* LogFileOutput::TimestampFormat = "%Y-%m-%d_%H-%M-%S";
+const char* const LogFileOutput::TimestampFormat = "%Y-%m-%d_%H-%M-%S";
 const char* LogFileOutput::FileSizeOptionKey = "filesize";
 const char* LogFileOutput::FileCountOptionKey = "filecount";
 char        LogFileOutput::_pid_str[PidBufferSize];