ZQMAX parameter
Summary
- Default value
- 65535
- Parameter type
- System
- Where set
- On User 0's parameter line or reset by system manager.
- Related products
- All
- Introduced
- Model 204 V7.4
Description
Applies to z/OS only
On a z/OS system, Model 204 zIIP support enables you to offload Model 204 work from regular processors to zIIP processors.
ZQMAX limits the number of work units that may be placed for execution by the zIIP task.
The default and maximum value for ZQMAX is 65535.
- If ZQMAX is set to a non-zero value: When a work unit is pushed onto the zIIP queue and the current zIIP queue length exceeds the value of ZQMAX, then that work unit is placed on the MP stack instead. Effectively, this limits the amount of work that is done on the zIIP and prevents zIIP overload.
- If ZQMAX is set to zero: No users will be added to the zIIP queue. However, if SCHDOPT-X'80' is on and a zIIP task is active (AMPSUBZ>0), then server swapping will occur on the zIIP task without the overhead of pushing zIIP work units onto the zIIP queue.
For more information about zIIP processing, refer to the Rocket Model 204 System Manager's Guide.