NMPSUBZ parameter

Number of zIIP eligible subtasks

Summary

Default value

0

Parameter type

System

Where set

On User 0's parameter line

Related products

All

Introduced

Model 204 V7.4

Description

Model 204 can run a portion of workload on IBM System z Integrated Information Processor (zIIP) engines. The only unit of work that z/OS schedules to run on a zIIP is the enclave Service Request Block (SRB). An enclave is a collection of resources, such as address spaces, TCBs, and SRBs, that are controlled by Workload Manager (WLM) as an entity. Therefore, an enclave SRB is a part of an enclave.

Model 204 creates an enclave SRB with the same dispatching priorities as the Main Task. Model 204 uses an enclave SRB, in this case zIIP, in the same way as an MP subtask. The term zIIP subtask is the equivalent of enclave SRB.

NMPSUBZ specifies the number of zIIP subtasks attached during initialization (enclave SRBs).

The NMPSUBZ parameter initiates a zIIP infrastructure. If NMPSUBZ is not zero, then a zIIP related infrastructure is created.

As many as NMPSUBZ defined special subtasks named zIIP task are attached. The zIIP tasks are real tasks as opposed to zIIP subtasks that are enclave SRBs. The zIIP tasks are used only for exception handling and enclave SRB creation and deletion. Each active zIIP task creates an enclave SRB at initialization.

Note: MP subtasks and zIIP subtasks may be used together. Therefore, AMPSUBS, NMPSUBS, AMPSUBZ and NMPSUBZ may all be greater than zero.

For more information on zIIP processing, refer to the Rocket Model 204 System Manager's Guide.