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IV92568: JAVA JIT -CRASH WHILE USING AOT AND THE BALANCED GC POLICY AFTER CHANGING -XMX

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APAR status

  • Closed as program error.

Error description

  • Error Message: Crash in JIT compiled code is typical for this
issue, but it could also cause a crash in GC or the VM. It could
also cause general heap corruption.
.
Stack Trace: N/A
.
The problem can only occur in Java 6.1, 7.0, 7.1 or 8.0. It can
only occur when using the balanced GC policy and AOT compiled
code. The problem occurs only after making changes to the -Xmx
value without clearing the shared class cache.

Local fix

  • The problem can be avoided by clearing the shared class cache
(-Xshareclasses:destroyAll). To insure that the problem does not
re-occur in the future be sure to clear the shared class cache
before making any changes to the -Xmx value.

Problem summary

  • The JIT can generate AOT code that is specific to a given heap
size (-Xmx setting). If that AOT code is loaded into a JVM that
is using a different heap size it's possible that the AOT code
will not be compatible with that heap size and cause a crash or
heap corruption.

Problem conclusion

  • The JIT was modified so that it tracks what heap sizes are
compatible with the AOT code it is generating. When that code is
load by other JVM instances it checks that the code is
compatible with the the current heap size and only loads AOT
code that is compatible.
.
This APAR will be fixed in the following Java Releases:
   6 R1 SR8 FP45  (6.1.8.45)
   7 R1 SR4 FP5   (7.1.4.5)
   7    SR10 FP5  (7.0.10.5)
   8    SR4 FP1   (8.0.4.1)
.
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

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Comments


    

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APAR Information




    

  • APAR number
    IV92568
    • 

  • Reported component name
    JIT
    • 

  • Reported component ID
    620700124
    • 

  • Reported release
    260
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt / Xsystem
    • 

  • Submitted date
    2017-01-23
    • 

  • Closed date
    2017-01-25
    • 

  • Last modified date
    2017-01-25
    • 





    

  • 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


    

  • R260  PSY
       UP
    • 

  • R130  PSY
       UP
    • 








      
              
                            

              

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Document Information


            

            


                        

            Modified date:
            

            25 January 2017
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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