z/VSE: Are you running z/VSE on a multiprocessor ?
Ingolf24 120000DRN3 Visits (3650)
This is a topic for customers running z/VSE on mult
that is the usage of system versus application code. If you have e.g. a higher I/O load (system code),
less CPUs may be fully exploitet. You should only activate as many CPUs as your workload can exploit
to reduce the multiprocessor overhead.
You may monitor the non-parallel share and CPU utilization with the Attention
Routine (AR) command QUERY TD - described in z/VSE System Control Statements.
You may also be interested in a little tool called z/VSE CPU Monitoring Tool. It is based on
QUERY TD and measures the CPU utilization over a longer time period.
The download is here http
CPU balancing is especially valuable for low utilized systems or if you have just a small number of
partitions active. It may also reduce the CICS TS MRO overhead in multiprocessor enviroments.
You may activate CPU balancing e.g. via the AR command SYSDEF TD,INT=9, where 9 is the
inspection interval in seconds. I would leave the threshold default as a start, you may tune it later.
CPU balancing will only activate the CPUs, that are required for a workload (depends on CPU utilization).
That is it reduces the multiprocessor overhead.
You can find more information on CPU balancing in the z/VSE Planning book.
Our books are on http
For performance related documention see http