538

Explanation
The system determined  that a requested ENQ or
RESERVE would have exceeded the limit on the number of concurrent
ENQ/GQSCAN/RESERVE requests for all tasks in the address space.

System action
The system ends the task that issued the ENQ or
RESERVE. The system issues an ABEND dump.

Operator response
Obtain an SVC dump if the system programmer
requests it.

System programmer response
Make sure that no tasks in the job step issue repeated ENQ, ISGENQ
or RESERVE macro instructions for resources that are not required.
Make sure that all GQSCAN requests that return TOKENs are either
run to completion or are terminated by a QUIT=YES option on a subsequent
GQSCAN macro instruction.
Make sure that all ISGQUERY requests with RESUMETOKENs have the
corresponding SCANACTION=RESUME and SCANACTION=QUIT options.

Prior to an abend, messages ISG368E and ISG369I monitor
address spaces that are approaching the request maximum. If a particular
subsystem requires more ENQ than normal, use the ISGADMIN service
to raise that subsystem's maximum for unauthorized and authorized
requesters. As a temporary workaround, you can raise the overall system
maximum by issuing the following commands:SETGRS ENQMAXA for authorized
SETGRS ENQMAXU for unauthorized

If the problem persists, set a SLIP trap for abend X'538' and
rerun the job step. When the trap matches, instruct the operator to
obtain an SVC dump that includes the following: The global resource serialization private area.
The system queue area (SQA), to get the address space control
block (ASCB) for the failing program.

Use the GRS QCBTRACE IPCS report to determine the outstanding
ENQs for the failed address space.  If abend code X'538' is issued
for an authorized caller, an SVC dump might not be possible. If the
problem persists, search problem reporting databases for a fix. If
no fix exists, contact the IBM® Support
Center. Provide the ABEND or SVC dump.
If the problem persists,
search problem reporting databases for a fix for the problem. If no
fix exists, contact the IBM Support
Center. Provide the ABEND or SVC dump.

Source
Global resource serialization