The FX scheduler provides a scheduling policy for processes that require user or application control of scheduling priorities. The priorities of processes that run under FX are fixed. These priorities are not dynamically adjusted by the system. The FX class has the same priority range as the TS, IA, and FSS classes.
For restrictions on using the FX and FSS schedulers on the same system, see Chapter 9, Fair Share Scheduler, in System Administration Guide: Resource Management and Network Services.