Real-Time Scheduling (CLASS_RT)

The CLASS_RT scheduling class is available only within the SCHED_CLASS scheduler. It implements the same policy as the real-time class of UNIX SVR4.0. Refer to the man page of UNIX SVR4.0 for a complete description.

The real-time scheduling policy is essentially a round-robin policy, with per-thread time quanta. The priority of a thread may vary between K_RT_PRIOMAX (159, highest priority) and K_RT_PRIOMIN (100, lowest priority).

The order of priorities is inverted compared to the CLASS_FIFO priorities. CLASS_RT uses only a sub-range of the SCHED_CLASS priorities. This sub-range corresponds to the range [96, 155] of CLASS_FIFO and CLASS_RR.

The CLASS_RT manages scheduling using configurable priority default time quanta.