Richard, You used 1.6GB of virtual storage.
How much paging did the address do? There's no free lunch, and page faults will increase the TCB time for an address. Ron -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Way, Richard Sent: Monday, July 24, 2017 1:19 PM To: [email protected] Subject: [IBM-MAIN] REGION=0M leads to CPU through the roof In the course of trying to duplicate a customer problem, I have run across unexpected behavior that I wonder if anyone can help to explain. I have an application program (COBOL 4.2, z/OS 2.2, AMODE 31, RENT) that exhibits the following: When run with our *default* REGION (i.e. no REGION= on the EXEC whatsoever): CPU: 0 HR 00 MIN 31.34 SEC SRB: 0 HR 00 MIN 00.06 SEC VIRT: 1056K SYS: 276K EXT: 32740K SYS: 13116K ATB- REAL: 8K SLOTS: 0K VIRT- ALLOC: 10M SHRD: 0M When run with an explicit REGION=0M: CPU: 0 HR 11 MIN 38.43 SEC SRB: 0 HR 00 MIN 00.07 SEC VIRT: 7856K SYS: 276K EXT: 1622548K SYS: 13116K ATB- REAL: 8K SLOTS: 0K VIRT- ALLOC: 10M SHRD: 0M You'll note the large increase in storage - which is of course not surprising - but more interesting (and unwelcome) to me is that the CPU time required increased by roughly a factor of 22X to do the exact same work. (The ONLY difference between the two runs is the addition of REGION=0M to the EXEC.) Can anyone suggest what I should be thinking about here in terms of possible causes? Is it possible that so much "overhead" is needed to manage the much larger memory space? Could it be something to do with LE tuning? Thanks, Richard Way HPE Security - Data Security HPE Software | Enterprise Security Products +1 408 857 0216 Mobile 1140 Enterprise Way, Mail Stop 3048 Sunnyvale, CA 94089 [HPE logo]<http://www.hpe.com/> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
