Communicator e3000 MPE/iX Release 7.0 Express 1 (Software Release C.70.01) (30216-90328)

Chapter 5 85
Technical Articles
BIGPIN Feature: Support Up To 12000 Concurrent Processes.
This article contains:
• A very brief overview of internal changes to MPE/iX (and the relevant potential
external impact).
• Discussion of the BIGPIN feature
• Description of new/enhanced "Program File Event" logging feature, which logs potential
issues on a customer system.
• Description of the new MAXPIN Scaling algorithm.
• Discussion of 5-digit PIN numbers (and changes to :SHOWQ and :SHOWPROC
commands).
OVERVIEW OF INTERNAL OS CHANGES
The MPE/iX concurrent process limit has historically been limited by one of Process
Management data structures called the Process Control Block (PCB). The PCB data
structure predates MPE/iX as the key process management data structure on older
MPE/V-based operating systems. The PCB was ported to MPE/iX and has existed as a
Compatibility Mode data structure. The PCB is very heavily referenced by various
components of the Compatibility Mode Operating System.
Over the years, there have been many changes to the PCB data structure that have
expanded its capacity. Starting with MPE/iX Release 7.0, the PCB has been rearchitected
as Native Mode data structure.
The PCB changes have been designed for maximal backward compatibility. As a result,
existing CM or NM code which accesses the PCB should function correctly, (without
modification) provided there are less than 8190 processes on the system.
BIGPIN Concept
MPE/iX Release 7.0 introduced the concept of "BIGPIN." The term BIGPIN refers to a
system's ability to support greater than 8190 concurrent processes. In MPE/iX Release 7.0
the CORE OS is BIGPIN capable; but the BIGPIN feature (which is Configurable) could
not be enabled.
In MPE/iX Release 7.0 Express 1 customers can enable the BIGPIN feature in sysgen. The
"system" command, which is available in the "misc" area of sysgen, has been modified to
enable/disable the BIGPIN feature. .
To enable BIGPIN do the following:
sysgen
[snip ...]
sysgen> misc
[snip ...]
misc> system bigpin=on
misc> show system
SYSTEM command parameter VALUE