IV86617: HIGH-CPU HANG RUNNING JAVA CODE

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: N/A
  .
  An unexpected, high-CPU hang is seen running java code. The hang
  will occur in some specific forms of for loop, which contain an
  unnecessary, idiosyncratic conditional branch inside the loop
  body.
  

Local fix

• The Java option -Xjit:disableIdiomRecognition is known to cause
  the incorrect behaviour to stop
  

Problem summary

• The problem was caused by a Java JIT compiler optimization
  incorrectly transforming the loop in question, resulting in an
  infinite loop in the program.
  

Problem conclusion

• The Java JIT compiler has been corrected to ensure the
  optimization transforms loops correctly in all cases.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR3 FP10  (8.0.3.10)
     7 R1 SR4 FP5   (7.1.4.5)
     7    SR10 FP5  (7.0.10.5)
     6 R1 SR8 FP45  (6.1.8.45)
     6    SR16 FP45 (6.0.16.45)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  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

• R130 PSY

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