USS_KERNEL_STACKS

Description:

This check monitors the current usage of z/OS® UNIX kernel stacks cell pool cells against a suggested threshold.

Reason for check:

If the number of kernel stack cell pool cells in use reaches the system maximum, additional cells cannot be allocated and system calls that use the kernel address space are disallowed. By monitoring stack cell usage installations might be able to prevent impacts to critical workloads by quiescing noncritical workloads before the supply of stack cells is exhausted.

z/OS releases the check applies to:

z/OS V2R1 and later.

User override of IBM® values:

The following statement shows keywords that you can use to override check values on either a POLICY statement in the HZSPRMxx parmlib member or on a MODIFY command. This statement can be copied and modified to override the check defaults:

UPDATE,
CHECK(IBMUSS,USS_KERNEL_STACKS_THRESHOLD),
INTERVAL(00:02),
SEVERITY(HIGH),
PARM('STACKS(85%)’),
DATE('20131005')

Debug support:

Verbose support:

Parameters accepted:

STACKS(n%) where n is an integer, 0-100, indicating the threshold percent for utilization of kernel stack cell pool cells.
Default: STACKS(85%)

Reference:

See:

z/OS MVS Initialization and Tuning Reference.

Messages:

This check issues the following exception messages:

BPXH071E

See the BPXH messages in z/OS MVS System Messages, Vol 3 (ASB-BPX).

SECLABEL recommended for multilevel security users:

SYSLOW - see z/OS Planning for Multilevel Security and the Common Criteria for information about using security labels.