VM66678: WARNING-TRACK INTERRUPTION FACILITY

Obtain the fix for this APAR.

APAR status

• Closed as new function.

Error description

• This APAR exploits the warning-track-interruption facility,
  enabling CP to act when a logical CPU will be undispatched.
  Warning-track interruptions tell CP when PR/SM is going to
  undispatch a logical CPU. In response, CP can release any
  shared resources and undispatch the guest so it can be run
  elsewhere.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Multi-LPAR configurations that are           *
  *                 vertically polarized, contain CPUs that have *
  *                 low or medium entitlement and experience     *
  *                 guest suspension, will benefit the most from *
  *                 the support delivered in VM66678.            *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  APAR VM66678 enables exploitation of the
  warning-track-interruption facility, implemented by the IBM
  zEC12. The facility introduces interruptions that warn a control
  program (CP) when PR/SM is going to undispatch a logical CPU
  (LCPU) from its physical CPU. When enabled in z/VM CP, these
  warnings allow CP to clean up any guest work and undispatch the
  guest running on the LCPU such that it can be run elsewhere.
  Without exploitation, any work running on an LCPU being
  undispatched ceases to make progress until PR/SM redispatches
  the LCPU.
  
  The symptoms of this situation include long transaction
  response times for guests, excessive use of coping mechanisms by
  guests (diag x'44', diag x'9C'), excessive use of coping
  mechanisms by CP (diag x'9C'), and generally poor performance.
  
  Multi-LPAR configurations that are vertically polarized, contain
  CPUs that have low or medium entitlement and experience guest
  suspension will benefit the most from exploitation, though there
  may be some benefit for other configurations.
  
  With this support applied, CP's exploitation of warning track
  will be enabled by default. CP will use the warning-track
  interruptions to release any shared software resources,
  undispatch the guest and allow the guest to be run elsewhere. In
  the meantime, other guests will have access to the shared
  resource that would have been held up otherwise. Exploitation
  has shown improvement of the above symptoms in the described
  environment.
  
  The support may be enabled/disabled via the new SRM WARNINGTRACK
  statement and the new SET SRM WARNINGTRACK command. The settings
  can be queried through QUERY SRM WARNINGTRACK/ALL.
  
  New and changed trace codes are added by this APAR, along with
  new monitor records. Changes to Perfkit are delivered in APAR
  VM66709. The Perfkit support uses new monitor data to calculate
  the suspend time for guests, taking into account the known time
  spent undispatched due to PR/SM's scheduling of logical CPUs.
  

Problem conclusion

Temporary fix

• FOR RELEASE VM/ESA CP/ESA R730 :
  PREREQ: VM66423 VM66679 VM66434 VM66675 VM66689 VM66673
  CO-REQ: NONE
  IF-REQ: NONE
  

Comments

• This APAR delivers new function support to exploit the
  warning-track-interruption facility in CP. This support improves
  guest response time and overall performance of workloads that
  are run on vertical low or vertical-medium processors.
  
  The support for this facility includes updates to external
  interruption handling, dispatching, along with new externals.
  The externals include a new WARNINGTRACK operand on the SRM
  configuration file statement, and on the SET SRM and QUERY SRM
  commands, new warning track output for QUERY SRM ALL or QUERY
  SRM WARNINGTRACK, new and changed trace codes, new monitor
  records, and an update to the way Perfkit calculates suspend
  time.
  
  The following changes have been made to the z/VM publications:
  
  ***START PUBLICATION CHANGE*************************************
  * PUBLICATION TITLE: z/VM: CP Planning and Administration      *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: SC24-6271-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: CP Planning and
  Administration
  UPDATE: describes the new WARNINGTRACK operand on the SRM
  configuration file statement.
  
  CHAPTER 6: The System Configuration File
  SECTION: SRM Statement
  UPDATE: adds the WARNINGTRACK operand and description to the SRM
  configuration statement and a new usage note to further explain
  the new operand.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM CP Commands and Utilities Reference  *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: SC24-6268-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM CP Commands and Utilities
  Reference
  UPDATE: describes the new WARNINGTRACK operand on the QUERY and
  SET SRM commands.
  
  CHAPTER 2: CP Commands
  SECTION: QUERY SRM
  UPDATE: adds the WARNINGTRACK operand and description to the
  QUERY SRM command and shows the new response. The QUERY SRM ALL
  response is also updated to add the new warning-track
  information to the response.
  
  CHAPTER 2: CP Commands
  SECTION: SET SRM
  UPDATE: add the WARNINGTRACK operand and description to the
  SET SRM command and shows the new response. New message
  variation to HCP1050E is added to the message list for
  unsuccessful enablement of warning track.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM: CP Messages and Codes               *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: GC24-6270-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: CP Messages and Codes
  UPDATE: lists the new messages added by the warning-track
  support.
  
  CHAPTER 3: System Messages
  SECTION: CP Messages
  UPDATE: lists a new HCP1050E variation added for the SET SRM
  WARNINGTRACK ON command and a new HCP1051E variation added for
  the SRM WARNINGTRACK configuration file statement.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM: Diagnosis Guide                     *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: GC24-6280-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: Diagnosis Guide
  UPDATE: describes the updates to trace codes introduced by the
  warning-track support.
  
  CHAPTER: Appendix C
  SECTION: Trace Table Codes
  TABLE 15: Trace codes for 32-byte entries
  UPDATE: shows the updated content of trace entry 3600.
  
  CHAPTER: Appendix C
  SECTION: Trace Table Codes
  TABLE 15: Trace codes for 64-byte entries (Format 2)
  UPDATE: shows the new 3601 and 3602 trace entries.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM: Performance                         *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: SC24-6301-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: Performance
  UPDATE: lists the monitor record changes delivered by this APAR.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM: Migration Guide                     *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: GC24-6294-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: Migration Guide
  UPDATE: lists changes made by the warning-track support.
  
  CHAPTER 1: Introduction
  SECTION: New Function Variables
  UPDATE: shows the new function variable for warning-track
  support.
  
  CHAPTER 2: System Changes
  SECTION: Support and Exploitation of Hardware and Architectures
  UPDATE: describes the warning-track exploitation, the new SRM
  WARNINGTRACK system configuration option, the new QUERY/SET
  SRM WARNINGTRACK options, and the new message variations
  on HCP1050E and HCP1051E.
  
  CHAPTER 3: Changes to External Interfaces
  SECTION: CP Changes
  SUBSECTION: System Configuration Statements
  TABLE 7: Changes to System Configuration Statements
  UPDATE: lists the new WARNINGTRACK operand on the SRM
  configuration statement and new message variation to HCP1051E.
  
  CHAPTER 3: Changes to External Interfaces
  SECTION: CP Changes
  SUBSECTION: CP Commands
  TABLE 9: Changes to CP Commands
  UPDATE: lists the new WARNINGTRACK operand on the QUERY and SET
  SRM commands along with the new message variation to HCP1050E
  for SET SRM WARNINGTRACK.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM: General Information                 *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: GC24-6286-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: General Information
  SUBSECTION: Hardware currency and exploitation
  UPDATE: lists changes made by the warning-track support.
  
  CHAPTER 2: What is new or changed in z/VM 7.3
  SECTION: Product enhancements and other changes
  TABLE 1:Links to enhancement categories, availability, and
  descriptions
  UPDATE: the "Hardware currency and exploitation" category
  lists the new warning-track support.
  
  CHAPTER 2: What is new or changed in z/VM 7.3
  SECTION: Hardware currency and exploitation
  UPDATE: describes the warning-track support.
  
  
  *--------------------------------------------------------------*
  * PUBLICATION TITLE: z/VM: VM Dump Tool                        *
  *           RELEASE: z/VM 7.3                                  *
  *      ORDER NUMBER: GC24-6335-73                              *
  *--------------------------------------------------------------*
  
  SECTION: Summary of Changes for z/VM: VM Dump Tool
  UPDATE: lists the ability to format the new trace entries
  introduced by warning-track support. More information about the
  trace entries can be found in "z/VM Diagnosis Guide".
  
  ***END PUBLICATION CHANGE***************************************
  

APAR Information

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

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

  UM90375

Modules/Macros

• CPLOAD   HCPABN   HCPAFF   HCPALL   HCPAPI   HCPAPJ   HCPBVM
  HCPCFM   HCPCKMST HCPCPA   HCPCPU   HCPCSA   HCPDMP   HCPDSB
  HCPDSP   HCPDSX   HCPEQUAT HCPEXT   HCPHIP   HCPIIO   HCPISR
  HCPLCK   HCPLGN   HCPLMC   HCPMCI   HCPMCW   HCPMDLAT HCPMES
  HCPMESB  HCPMNE   HCPMNU   HCPMNY   HCPMOM   HCPMPC   HCPMPG
  HCPMPS   HCPMTO   HCPMTS   HCPMXL   HCPMXRBK HCPPFXPG HCPPLSBK
  HCPQDO   HCPRCC   HCPRCCBK HCPRFI   HCPRLG   HCPRLU   HCPRUN
  HCPSCJ   HCPSEW   HCPSGP   HCPSNP   HCPSNR   HCPSRM   HCPSRN
  HCPSSI   HCPSTK   HCPSTL   HCPSTM   HCPSTP   HCPSXL   HCPSXLBK
  HCPSYN   HCPSYS   HCPSYSCM HCPSZD   HCPSZE   HCPSZK   HCPSZL
  HCPTHQ   HCPTTA   HCPTTABK HCPUSO   HCPUSP   HCPVMDBK HCPWAI
  HCPWRP   HCPZPQ   HCPZSD   HCP1050E HCP1051E HCQTR730 HCWAI8
  HCWA12   MRMTRSYS MRSCLSRM MRSYTPRP MRSYTSYG MRUSEACT MRUSELOF
  SRM
  

Fix information

• Fixed component name

  VM CP CP

• Fixed component ID

  568411202

Applicable component levels

• R730 PSY UM90375

     UP23/11/08 P 2401  

Fix is available

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