VM66894: Z/VM 7.4 CMS: FIX PACK - FEATURE 04 FIX 02

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• This APAR contains service for z/VM CMS version 7 release 4
  Feature Pack 04 Fix Pack 02.
  
  This APAR contains fixes for the following problems:
  
  1. During initialization of applications on z/CMS, storage
     allocation runs noticeably slowly.
  2. SMAPI's Image_Volume_Space_Query_DM API fails with DMSREX476E
     when DirMaint's EXTENT CONTROL file does not exist.
  3. After APAR VM66828, SMAPI's
     Virtual_Network_Vswitch_Query_Extended API can incorrectly
     loop and result in inaccurate output.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of z/CMS and the z/VM System           *
  *                 Management Application Programming Interface *
  *                 (SMAPI)                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  This APAR contains service for z/VM CMS version 7 release 4
  Feature Pack 04 Fix Pack 02.  As such, it contains fixes for
  the following three problems:
  
  Problem 1
  ---------
  During initialization of applications on z/CMS, storage
  allocation runs noticeably slowly.
  
  During application initialization, it is common to acquire
  memory. Especially for large applications, this process can
  exhibit noticeable performance problems under z/Architecture
  CMS. These problems do not occur with CMS/390.
  
  Problem 2
  ---------
  SMAPI's Image_Volume_Space_Query_DM API fails with DMSREX476E
  when DirMaint's EXTENT CONTROL file cannot be read.
  
  When the DirMaint EXTENT CONTROL file can not be read,
  Image_Volume_Space_Query_DM API, fails with:
  
  DMSREX476E Error 41 running DMSSJGDD EXEC received Bad
             arithmetic conversion
  

Problem conclusion

• Problem 1
  ---------
  z/CMS was preventing use of CP Diagnose X'214', Pending Page
  Release. This caused memory initialization to be performed by
  CMS rather than deferred to CP, which resulted in a loop issuing
  a Set Storage Key instruction for each page of allocated memory.
  While Diagnose x'214' is not supported for memory above 2GB in a
  z/Architecture virtual machine, it is supported for memory below
  2GB and provides a significant performance improvement. z/CMS
  has been changed to enable Pending Page Release and use it for
  memory below 2GB.
  
  Problem 2
  ---------
  DMSSJGDD $EXEC has been updated such that retry logic has been
  added with some delay.  The code links and accesses the
  DIRMAINT 1DF disk until the EXTENT CONTROL file can be
  successfully read or the maximum five tries is exhausted.
  
  Problem 3
  ---------
  The error is in DMSSSVQE and requires a one line change to a
  REXX parse instruction.
  

Temporary fix

• FOR RELEASE ES-CMS-740-BASE :
  PREREQ: VM66869
  CO-REQ: NONE
  IF-REQ: NONE
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UM90567

Modules/Macros

• DMSINL   DMSLVLTB DMSSJGDD DMSSSVQE DMSZFRI  7VMCMS40
  

Fix information

• Fixed component name

  VM CMS

• Fixed component ID

  568411201

Applicable component levels

• R740 PSY UM90567

     UP25/10/29 I 1000 {

Fix is available

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