SUP_HIPERDISPATCH

Description:

This check verifies whether the check's expected HiperDispatch state matches the actual HiperDispatch state of the system. The following terms are used to describe the Hiperdispatch State (where terms appearing on the same line are used interchangeably):

YES and enabled
NO and disabled

The check's expected HiperDispatch state is determined by the parameters specified or defaulted for this check. See the parameters section for further details.

Note that the system will register this check only on machines that support HiperDispatch. IBM® System z10® is the first machine that supports HiperDispatch.

Reason for check:

HiperDispatch provides a performance improvement by optimizing the use of system cache. The performance gain HiperDispatch provides typically increases with a newer hardware generation and can improve with newer releases of z/OS®.

Before enabling HiperDispatch for the first time, review the "Planning Considerations for HiperDispatch Mode" White Paper located on IBM Techdocs at http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101229.

When a machine of a newer hardware generation is installed, for any z/OS partition(s) that are running with HiperDispatch disabled, the system programmer should reevaluate whether those z/OS partition(s) should be migrated to run with HiperDispatch enabled in the new environment.

On any z/OS release running on IBM System z10 hardware, HiperDispatch disabled is the default. On IBM System z10 systems, customers are encouraged to try running with HiperDispatch enabled.

Beginning with z/OS V1R13 on zEnterprise® 196 hardware, HiperDispatch enabled is the default. With zEnterprise 196 hardware, z/OS partitions with share greater than two physical processors will typically experience improved processor efficiency with HiperDispatch enabled. z/OS partitions with share less than 2 physical processors typically do not receive a detectable performance improvement with HiperDispatch enabled, but IBM recommends running those partitions with HiperDispatch enabled when the performance improvement is greater than or equal to HiperDispatch disabled. Initially all z/OS partitions on non-IBM System z10 machines that run HiperDispatch disabled will result in this Health Check raising an exception. The system programmer can supply the machine type to this Health Check to indicate that a partition is intentionally running with HiperDispatch disabled on a particular machine type.

IBM suggests that all partitions that experience improved or equivalent processor efficiency with HiperDispatch enabled continue running with HiperDispatch enabled.

z/OS releases the check applies to:

z/OS V1R13 with apar OA36150 on a zEnterprise 196.

Type of check (local or remote):

Local

User override of IBM values:

The following sample shows the defaults for customizable values for this check. Use this sample to make permanent check customizations in an HZSPRMxx parmlib member used at IBM Health Checker for z/OS startup. If you just want a one-time only update to the check defaults, omit the first line (ADDREPLACE POLICY) and use the UPDATE statement on a MODIFY hzsproc command. Note that using non-POLICY UPDATEs in HZSPRMxx can lead to unexpected results and is therefore not recommended. End of change

ADDREPLACE POLICY[(policyname)] [STATEMENT(name)]
UPDATE
CHECK(IBMSUP, SUP_HIPERDISPATCH)
ACTIVE
SEVERITY(MED)
INTERVAL(24:00)
DATE('date_of_the_change')
PARM('HIPERDISPATCH(YES),MachTypes(aaaa,bbbb,...)')
REASON('Your reason for making the update.');

Debug support:

Verbose support:

Parameters accepted: Yes:

If the HIPERDISPATCH keyword has a value of 'YES', theCHECK expects HiperDispatch to be enabled on the machine. The default is 'YES'.
If the HIPERDISPATCH keyword has a value of 'NO' and the machine is an IBM System z10, the check expects that HiperDispatch is disabled on the machine.
If the HiperDispatch keyword has a value of 'NO' and the machine is not an IBM System z10, the check's expected HiperDispatch state depends on the MachTypes parameter.
MachTypes is optional parameter that contains a list of up to 10 machine types (for example, the zEnterprise 196 machine type is 2817). When specified, the MachTypes parameter is always syntactically validated, but it has no effect on theCHECK's expected HiperDispatch state when the system is a IBM System z10 or the HIPERDISPATCH(YES) parameter was specified or defaulted. The MachTypes parameter can only affect the check's expected HiperDispatch state on a non-IBM System z10 machine with the HiperDispatch(NO) parameter specified. In this case, the check's expected HiperDispatch state is determined as follows
- When the current machine type is not in the MachTypes list or the MachTypes parameter is not specified, the check expects HiperDispatch to be enabled.
- When the current machine type is in the MachTypes list, the check expects HiperDispatch to be disabled.

Reference:

IEAOPTxx (OPT parameters) inz/OS MVS Initialization and Tuning Reference
in z/OS MVS System Commands
White Paper titled "Planning Considerations for HiperDispatch Mode" located on IBM Techdocs: http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP101229

Messages:

This check issues the following exception messages:

IEAVEH071E

See the IEAVEH messages in z/OS MVS System Messages, Vol 6 (GOS-IEA).

SECLABEL recommended for multilevel security users:

SYSLOW - see z/OS Planning for Multilevel Security and the Common Criteria for information on using SECLABELs.