Programming Interfaces 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. Each of the n priority levels has one parameter. 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, which are 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. For more information, see Timestamp Interfaces. The time quantum value is only a default or starting value for processes at a particular level. The time quantum of a real-time process can be changed by using the priocntl(1) command or the priocntl(2) system call.