how to set up guaranteed io with XFS?

Question

According to wikipedia XFS is capable to guarantee the rate of IO. How can I setup this under Linux (more specifically Centos 5.5)? Or does that only apply for IRIX?

Answer 1

Quoting Dave Chinner:

   Linux doesn't support GRIO. It's an Irix only thing, and that
    required special hardware support for bandwidth reservation, special
    frame schedulers in the IO path, etc.