Short answer, PA-RISC is not supported. I don't know who does the ports to that platform. HP?
Since part of Java Flight Recorder is closed source, I'm guessing a port of that feature will not be available from the Java licensees.
To use JFR, you need at least JDK 7u4, preferably 7u40.
These are the platforms available:
Solaris SPARC 64-bit
Mac OS X x64