One process in the System may be designated the Super High Priority Process (SHPP) in order to receive special handling in the process scheduling mechanism. The SHPP has top priority to all system resources, allowing it to run without interference from other processes. This is implemented for BISYNC communications.
The following rules apply to the SHPP:
SHPP is reactivated when its CPU processing time quantum is used up.
Frame faults for the SHPP are processed as soon as the necessary disk is available.
Disk interrupts, which signal completion of a disk read for the SHPP, cause the SHPP to be activated immediately.
Interrupts from devices with addresses in the range 0x10—0x13, which are for the SHPP, cause the SHPP to be activated immediately.
Voluntary RQMs (process is suspended by terminating its timeslice) by the SHPP allow two other processes to run before the SHPP is activated again.