There's a conflict here. The CA APAR says " This APAR will have a greater affect on regions running STGPROT=NO." Jim said " Therefore, on workloads (i.e. CICS running with STGPROT=YES).... , this can show up as the z196 spending more time"
Can't be both. Alan Schwartz ITO Global Services Operations and Engineering Xerox Business Services, LLC 1500 Towerview Rd. Eagan, MN. 55121-1346 p. 612.266.3150 m. 651.274.5819 f. 612.266.3196 -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Jim Mulder Sent: Thursday, November 15, 2012 12:57 PM To: [email protected] Subject: Re: CA Common services ENF Monitor reporting high CPU time > We observed, while using STROBE, apparent high CPU use in module CAS9C66. > From CA we found that they had the following on file:: > > APAR #: RO43562 > Product: ENFCIC Release: 14.0 Solution #: 7 Type: > OS: OS Group: GCCOMC ISL SUP 2 > Title: PERFORMANCE ENHANCEMENT ON Z/196 PROCESSORS. > > ****************** VERSION 0 EFFECTIVE: MAR 31 2012 2:09 > ****************** > > ***NOTE*** PE: YES CORRECTED BY: RO45646 > > PROBLEM DESCRIPTION: > After a processor upgrade to z/196, some performance monitors may show > increase cpu usage in various csects in the CAS9Cxx module. > The flagged area is usually in a very tight range and will contain a > SPKA instruction. This APAR will have a greater affect on regions > running STGPROT=NO. > > SYMPTOMS: > Performance monitors show increased activity in CAS9Cxx modules. > > We had just moved to a z196 and STROBE was being used to compare > performance against the previous processor (no longer available for > direct comparison). > > Since the z196 and z114 are from the same design cycle and zEC12 is > similar to a z196 we have asked whether this situation could exist on > a z114 or a zEC12 and they said no. > > Has anyone any idea why this might occur, and anyone has seen it on a > z114 or zEC12. > Is the set up code for a SPKA instruction something that would be very > different on a z196 from any other processor? One of the CPU designers gave me the following explanation: System z processor development has identified an aspect of the z196 processor that performs worse than the equivalent instruction on a z10 processor. When an SPKA instruction is executed in problem state, the new out-of-order design of the z196 processor requires more pipeline stalls to give functionally correct results than in prior generations of processors. Therefore, on workloads (i.e. CICS running with STGPROT=YES) that have an intense amount of SPKAs in problem state, this can show up as the z196 spending more time executing the SPKA instruction. Some vendor performance tools or single instruction benchmarks may uncover this additional time spent on the SPKA instruction. This change in SPKA behavior does not offset the benefits the z196 provides for the CICS environment. This aspect of the longer SPKA execution time can be exacerbated by running on a subcapacity machine. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- 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
