CPU displayed by modules in SHOW NCL=ALL may exceed the total CPU time for the region as displayed by the MVS D A console command. Is this valid?

Products

• CMDB for z/OS
• NetSpy Network Performance
• NetMaster Network Automation
• SOLVE
• NetMaster Network Management for SNA
• NetMaster Network Management for TCP/IP
• NetMaster File Transfer Management
• SOLVE:Operations Automation
• SOLVE:Access Session Management
• SOLVE:FTS

Issue/Introduction

The SHOW NCL=ALL command displays some NCL procedures with a higher CPU time than the total CPU time for the region as seen in a MVS D A command.

Is there a problem with the SHOW NCL command?

 

 

Resolution

This does not necessarily indicate a problem with the SHOW NCL command.

The MVS D A command only shows TCB (task control block) time, not SRB (service control block) time. 

If the region is running on a zIIP processor, then the majority of the total region CPU time will be logged as SRB time and thus will not be reflected in a MVS D A command.

This in turn can result in some individual NCL procedures in the SHOW NCL=ALL displaying CPU times higher than the total CPU time for the region shown in the MVS D A command.