LI72583: POSSIBLE CRASH/SEGMENTATION-FAULT USING SMP SORTS AND STMM.

DB2 Version 9.1 Fix Pack 7  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 5   for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 6   for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 6a for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 7a  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 8  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 9  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 10  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11  for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12  for Linux, UNIX and Windows

APAR status

• Closed as program error.

Error description

• When SMP parallelism is enable, and STMM for SORTHEAP is enabled
  if some operation requests mutiple smp-sorts to satisfy its
  sorting requirements, a timing hole may expose an uninitialized
  pointer when reserving memory for these smp-sorts. The result is
  typically a segmentation fault/crash.
  Preventive...if the APAR is not applied, and you have SMP
  parallelism enable and have SORTHEAP managed by STMM (AUTOMATIC)
  and invoke operation which may requires smp-sorts under the
  covers, you may be exposed to this segmentation fault.
  Reactive...Typical symptoms are a trap file containing functions
  like:
      stmmSimulateSortCreate
      stmmCreateVirtualSorts
      stmmStartSortListMonitorIfNecessary
      sqlsCreateSort
  Workaround...Disable SMP parallelism (this may hinder
  performance) or disable STMM for SORTHEAP.
  

Local fix

• Disable SMP parallelism (may hinder performance), or, disable
  STMM for SORTHEAP.
  

Problem summary

• Users Affected : All
  Problem Description :
     Possible crash/segmentation fault using SMP SORTS and STMM.
  

Problem conclusion

• Problem was fixed in V9.1 FP5 (s080512).
  

Temporary fix

• Disable SMP parallelism or disable STMM for SORTHEAP.
  

Comments

APAR Information

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

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

  IZ18582

Modules/Macros

• ENGN_SQD
  

Fix information

• Fixed component name

  DB2 UDE ESE LIN

• Fixed component ID

  5765F4104

Applicable component levels

• R910 PSN

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