IV43799: ARRAYLET STATISTICS GATHERING MAY LEAD TO A CRASH IN PRESENCE OF CLASS UNLOADING

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: MM_IncrementalGenerationalGC::exportStats ()
  libj9gc26.so
   MM_IncrementalGenerationalGC::reportGCIncrementStart () from
  libj9gc26.so
   MM_IncrementalGenerationalGC::partialGarbageCollect () from
  libj9gc26.so
   MM_IncrementalGenerationalGC::runPartialGarbageCollect ()
  libj9gc26.so
   MM_IncrementalGenerationalGC::masterThreadGarbageCollect ()
  libj9gc26.so
   MM_MasterGCThread::masterThreadEntryPoint () from
  .
  

Local fix

• This issue can be worked around using the gencon as the GC
  policy, or using the -Xnoclassgc option. Note however that
  option -Xnoclassgc will cause a memory increase over time as it
  prevents classes from being unloaded.
  

Problem summary

• Balanced GC policy only. Verbose GC reports arraylet statistics
  and may relay on class info, which may be unavaliable at certain
  point of time.
  

Problem conclusion

• This defect will be fixed in:
  7.0.0 SR5
  6.0.1 SR6
  .
   Arraylet statistics gathering are updated to report if they
  contain class info that might be unloaded, preventing the
  exportStats() method from crashing.
  

Temporary fix

Comments

APAR Information

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

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

Fix information

• Fixed component name

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R260 PSY

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