SYS and SUBSYS — Performing started task accounting

The system handles accounting for started tasks much as it does for batch jobs and TSO/E work. Started task accounting includes:

• Accumulating CPU time under started task TCBs and SRBs
• Counting started task I/O operations
• Invoking SMF exits for started tasks
• Creating SMF records for started task activity.

For accounting purposes, the system sees the following as started tasks:

• The master address space
• The system address spaces
• The mounts
• The job entry subsystem
• The tasks initiated with a START command (at the operator console as started tasks).

The SYS default in SMFPRMxx requests that SMF write all possible records for what the system sees as started tasks. If you are using SMF data set recording, you can suppress started task accounting records by suppressing the accounting record types through the SUBSYS option in SMFPRMxx (STC parameter). If you specify any other record types it might cause loss of data other than accounting data for started tasks. For example:

• A JES2 installation runs the Resource Measurement Facility™ (RMF™), which the system sees as a started task, to monitor system activity. To suppress started task accounting records for RMF, the installation specifies record type 70. However, the installation has inadvertently suppressed important data collected by RMF about CPU activity.
• An installation suppresses record types 6 and 26 to eliminate accounting for started tasks. However, this eliminates record types 6 and 26 completely (even for batch jobs), because JES, as a started task, is told to not write these record types.

Because CPU time is accumulated for started tasks, wait time limits and job step time limit abends can occur. To avoid these abends, you can code TIME=1440 on the EXEC statement in the cataloged procedure or set on the system task bit in the program properties table (PPT). For more information on the program properties table, see z/OS MVS Initialization and Tuning Reference.