VM66295: PRG004 AFTER MANUAL LEAP SECOND CHANGE ON THE HMC

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• PRG004 abend after a leap second was changed from -1 to 0 on
  the HMC.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of z/VM using the STP timing mode  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  When a z/VM partition is IPL'd with STP timing mode active,
  and a change in the number of configured leap seconds is made,
  it is possible that CP will recognize this change as a backwards
  shift in time. When this happens, and XRC timestamping of IO is
  enabled, then CP will delay the timestamping routine until the
  clock catches back up. The current method for delaying the
  timestamping routine introduces a loss of control which may
  lead to corruption in the call chain. This corruption can
  lead to a variety of different problems including an abnormal
  end of z/VM's control program.
  

Problem conclusion

• Code has been added to protect and preserve the call chain
  over the loss of control, which happens when CP must delay
  timestamping for a leap second change.
  

Temporary fix

• FOR RELEASE VM/ESA CP/ESA R640 :
  PREREQ: VM66023
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESACP/ESAR710 :
  PREREQ: VM66265
  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:

  UM35549 UM35550

Modules/Macros

• HCPSTI
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• R640 PSY UM35549

     UP19/10/23 P 2001 ¢

• R710 PSY UM35550

     UP19/10/23 P 2001 ¢

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.