I would say the forum is really not the right place to help on an issue like this. High CPU is such a dynamic issue that we really would need to jump on the CLI and follow the breadcrumbs. It could be a loop. flood of control packets that hit the cpu, etc. It is very tough to say. Troubleshooting generally involves some hidden or dm commands that we only advise using under support supervision. Please open a case (see my signature) and we can help you troubleshoot.
Ben Beck, RCNA, Principal Technical Support Engineer support.ruckuswireless.com/contact-us