IV67653: JAVA JIT - HANG OR SLOW COMPILES TIMES.

APAR status

• Closed as program error.

Error description

• Error Message: Very slow compiles time (possibly as much as
  hours) where a compiler thread is consuming 100% of one CPU, but
  at the same time the JIT verbose shows that the tread is not
  producing new listing output (i.e. it's still working on
  compiling the same method during the time when the hang is
  observed).
  .
  Stack Trace:
  {_ZN17TR_EscapeAnalysis30checkOverlappingLoopAllocationEP7TR_Nod
  eS1_S1_Ri}
  <103 frames total>
  .
  .
  {_ZN17TR_EscapeAnalysis30checkOverlappingLoopAllocationEP7TR_Nod
  eS1_S1_Ri}
  {_ZN17TR_EscapeAnalysis30checkOverlappingLoopAllocationEP7TR_Nod
  eP9Candidate}
  {_ZN17TR_EscapeAnalysis16checkDefsAndUsesEP7TR_NodeP9Candidate}
  {_ZN17TR_EscapeAnalysis16checkDefsAndUsesEv}
  {_ZN17TR_EscapeAnalysis19performAnalysisOnceEv}
  {_ZN17TR_EscapeAnalysis7performEv}
  {_ZN16TR_OptimizerImpl8optimizeEv}
  {_ZN14TR_Compilation20performOptimizationsEv}
  {_ZN14TR_Compilation7compileEv}
  .
  This problem can occur on all platforms.
  

Local fix

• -Xjit:disableEscapeAnalysis
  This will have a small impact on performance.
  

Problem summary

• The JIT can spend a long time analysing the bytecodes of a
  method when the bytecodes form a patten that makes it such that
  we have to iterate over the code several times.
  

Problem conclusion

• The JIT was modified such that it avoids iterating over code
  several times.
  .
  This APAR will be fixed in the following Java Releases:
     6    SR16 FP3  (6.0.16.3)
     6 R1 SR8 FP3   (6.1.8.3)
     7 R1 SR3         (7.1.3.0)
     7    SR8 FP10  (7.0.8.10)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the Service
  Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

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

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R600 PSY

     UP

• R260 PSY

     UP

• R130 PSY

     UP