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?

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Article ID: 35755

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

Issue/Introduction

Question:

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?

 

Answer: 

 

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.

 
Example of the MVS D A command:
 
     15.28.49 START SYSCMD d a,SOLVE 
   15.28.49 N86510 COMMAND PASSED TO OPERATING SYSTEM 
   15.28.49 IEE115I 15.28.49 2016.004 ACTIVITY 034 
   15.28.49 JOBS M/S TS USERS SYSAS INITS ACTIVE/MAX VTAM OAS 
   15.28.49 00020 00106 00085 00054 00376 00085/00450 00088 
   15.28.49 SOLVE SOLVE NETMASTR NSW SO A=0294 PER=NO SMC=000 
   15.28.49 PGN=N/A DMN=N/A AFF=NONE 
   15.28.49 CT=887.703S ET=00196.41 <-----------
   15.28.49 WUID=STC17197 USERID=SOLVE 
   15.28.49 WKL=SYSTEM SCL=SYSSTC P=1 
   15.28.49 RGP=N/A SRVR=NO QSC=NO 
   15.28.49 ADDR SPACE ASTE=0F67E500 
   15.28.49 DSPNAME=00000VHS ASTE=0ECD2480 
 
Example of an individual NCL procedure from the same NetMaster region as displayed by the SH NCL=ALL command:
 
   N11936 000469 $RMMF00H $RMMF00H 001 1 SEC-AOMP SOLVBSYS SOLVAOMP 4 1 86880.42
   N11918 ...... PROCESSING &AOMREAD LINE 00358 
   N11946 ...... CPUTIME: 4416.985503 <------------
 
As can be seen, the CPU seconds value of 4416.985503 seen in the SHOW NCL=ALL display for a single NCL procedure far exceeds the total CPU time value of 887.703 seconds for the entire region shown in the MVS D A display.
 
In the example above, the region was running on a zIIP processor, so none of the SRB CPU time the region had used is reflected in the MVS D A command. You can check to see if your region is running on a zIIP processor by issuing the STATUS command from the region, then look for this message in the output:
 
N11427 EXECUTION MODE (REQ ACTUAL): BEST ZIIP
 
In this case the requested execution mode is BEST, and the actual execution mode is zIIP. This setting is controlled by the XM region JCL parameter:
 
 XM={ TASK | ZIIP | BEST }

Specifies whether to move some processing performed by the main task of the region from the central processor (CP) to a zIIP.

  • TASK or T specifies that main task processing occurs on the CP.
  • ZIIP or Z specifies that main task processing occurs on a zIIP. If a zIIP is not available, an error message is generated and processing continues on the CP.
  • BEST or B specifies that main task processing occurs on a zIIP if it is available; otherwise, processing occurs on the CP.

Default: TASK or T

Environment

Release: SLOPFC00200-12.1-NetMaster-File Transfer Management
Component: