System Interface Guide

Dispatcher Parameter Table

The in-core table for real-time establishes the properties for RT scheduling. The rt_dptbl(4) structure consists of an array of parameters, struct rt_dpent_t, one for each of the n priority levels. The properties of a given priority level are specified by the ith parameter structure in the array, rt_dptbl[i].

A parameter structure consists of the following members (also described in the /usr/include/sys/rt.h header file).


The global scheduling priority associated with this priority level. The rt_globpri values cannot be changed with dispadmin(1M).


The length of the time quantum allocated to processes at this level in ticks (see "Timestamp Functions"). The time quantum value is only a default or starting value for processes at a particular level. The time quantum of a realtime process can be changed by using the priocntl(1) command or the priocntl(2) system call.