The Question is:
We run several similar multi-process systems based on shared memory,
utilizing the lock and virtual mailbox system services to coordinate within
each system. Each system has it's own region of shared memory and is
independent of the other. However, they
seem to compete for system resources, in that when more than one is
running at once, either one or the other chews
up the lion's share of cpu cycles; they alternate as to which one gets the
Can you point me to some good articles or books on the proper use of system
services for avoiding resource conflicts in multi-process
systems on VMS?
The Answer is :
Please see the articles "Debugging synchronization problems? (SMP)"
in topic (1661) and "Shared memory and Alpha memory barriers (MB)?"
in topic (2681) here in Ask The Wizard, as a start.
The OpenVMS Programming Concepts manual is among the best resources,
with chapters on symmetric multiprocessing (SMP), memory management,
and data and resource synchronization.
One obvious course of action would be to see where the application(s)
are spending the CPU time, through the use of profiling tools, the
OpenVMS Debugger's scripting capabilies, lock monitor tools such as
SDA and DECamds or (often the best approach) using selectively-enabled
application-integrated logging capabilities. There are any number of
potential areas where applications could be spending processing time