OW57651: ADDRESS SPACE HANG AFTER BEING LOGICALLY SWAPPED

A fix is available

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APAR status

  • Closed as program error.

Error description

  • It is possible for an address space to hang after being
    logically swapped if a SYSEVENT REQSVDAT or SYSEVENT REQPGDAT is
    issued and the OUCBGOI bit is on but IEAVAR02 has not yet been
    posted to restore the address space.  If the OUCBGOI bit is on
    then the REQSVDAT and REQPGDAT routines in IRAEVREQ will call
    IRARMSWI which is the back end of swap in processing.  If the
    ASCBQECB field has not been posted yet and IRARMSWI runs, this
    will cause the SRB for the post to be overlaid and will leave
    the address space swapped in but with the subtasks status
    stopped.  The SRB is built within the OUXB and IRARMSWI restores
    the OUXB values which ends up overlaying the SRB before the post
    is done.  This can also result in an ABEND0C6 in IEAVEPST and an
    ABEND0C1 in IEAVTRG1 due to the overlaid SRB.
    The reported problem was with the BPXOINIT address space.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: Users of OS/390 R9 (JBB6609) and above.      *
    ****************************************************************
    * PROBLEM DESCRIPTION: It is possible for an address space to  *
    *                      hang after being logically swapped if a *
    *                      SYSEVENT REQSVDAT or SYSEVENT REQPGDAT  *
    *                      is issued and the OUCBGOI bit is on but *
    *                      IEAVAR02 has not yet been posted to     *
    *                      restore the address space.  If the      *
    *                      OUCBGOI bit is on then the REQSVDAT and *
    *                      REQPGDAT routines in IRAEVREQ will call *
    *                      IRARMSWI which is the back end of swap  *
    *                      in processing.  If the ASCBQECB field   *
    *                      has not been posted yet and IRARMSWI    *
    *                      runs, this will cause the SRB for the   *
    *                      post to be overlaid and will leave the  *
    *                      address space swapped in but with the   *
    *                      subtasks status stopped.  The SRB is    *
    *                      built within the OUXB and IRARMSWI      *
    *                      restores the OUXB values which ends up  *
    *                      overlaying the SRB before the post is   *
    *                      done.  This can also result in an       *
    *                      ABEND0C6 in IEAVEPST and an ABEND0C1 in *
    *                      IEAVTRG1 due to the overlaid SRB.  The  *
    *                      reported problem was with the BPXOINIT  *
    *                      address space.                          *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    It is possible for an address space to hang after being
    logically swapped if a SYSEVENT REQSVDAT or SYSEVENT REQPGDAT is
    issued and the OUCBGOI bit is on but IEAVAR02 has not yet been
    posted to restore the address space.  If the OUCBGOI bit is on
    then the REQSVDAT and REQPGDAT routines in IRAEVREQ will call
    IRARMSWI which is the back end of swap in processing.  The
    REQSVDAT and REQPGDAT SYSEVENTs are issued during SMF interval
    processing, which in this case was started as part of the swap
    in (IRARMCSI) process.
    If the OUCBCSMF bit is on (set by delayed scheduling routine
    IRARMF80), this indicates SMF needs to be notified when this
    address space is swapped in, and IRARMCSI calls an SMF routine
    that schedules a deferred interval SRB for the address space
    that is being swapped in.
    If the ASCBQECB field has not been posted yet and IRARMSWI runs,
    this will cause the SRM SRB for the post to be overlaid and
    will leave the address space swapped in but with the subtasks
    status stopped.
    The SRM SRB is built within the OUXB and IRARMSWI restores the
    OUXB values which ends up overlaying the SRM SRB before the post
    is done.  This can also result in an ABEND0C6 in IEAVEPST and an
    ABEND0C1 in IEAVTRG1 due to the overlaid SRM SRB. The reported
    problem was with the BPXOINIT address space.
    

Problem conclusion

  • Routine INVOKE_SMF, which notifies SMF when the address space is
    being swapped in, has been moved from IRARMCSI  to IRARME18
    (QSCEFL) and IRARME19 (RSTORCMP), which is later in swap in
    processing. This prevents the SMF SRB from running prior to the
    SRM swap in SRB.
    
    IRARMF80 was changed to delay the schedule only if the address
    space is out (OUCBOUT = on).
    
    The REQSVDAT and REQPGDAT SYSEVENTs no-longer call IRARMSWI when
    OUCBGOI is on.  Now at the time when SMF issues the SYSEVENTs,
    the IRARMSWI routine will have already been called by IRARME18
    or IRARME19.
    

Temporary fix

Comments

  • **** PE04/02/27 FIX IN ERROR. SEE APAR OA06407  FOR DESCRIPTION
    

APAR Information

  • APAR number

    OW57651

  • Reported component name

    5752 SYS RSRCE

  • Reported component ID

    5752SC1CX

  • Reported release

    703

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2002-12-16

  • Closed date

    2003-04-30

  • Last modified date

    2004-02-27

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

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

    UA02751 UA02752 UA02753 UA02754 UA02755 UA02756

Modules/Macros

  •    IRAEVQSC IRAEVREQ IRARMFIP IRARMSWP
    

Fix information

  • Fixed component name

    5752 SYS RSRCE

  • Fixed component ID

    5752SC1CX

Applicable component levels

  • R609 PSY UA02755

       UP03/05/14 P F305

  • R703 PSY UA02751

       UP03/05/14 P F305

  • R705 PSY UA02752

       UP03/05/14 P F305

  • R706 PSY UA02753

       UP03/05/14 P F305

  • R707 PSY UA02754

       UP03/05/14 P F305

  • R713 PSY UA02756

       UP03/05/14 P F305

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.



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Document information


More support for:

z/OS family

Software version:

703

Operating system(s):

MVS, z/OS

Reference #:

OW57651

Modified date:

2004-02-27

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