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IV18275: LOWER PERFORMANCE DUE TO FAILED COMPILATIONS

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APAR status

  • Closed as program error.

Error description

  • Error Message: N/A
.
Stack Trace: N/A
.
Failed compilations can be tracked with a verbose log:
java -Xjit:verbose,vlog=vlog.txt
Note that a compilation can be retried up to 3 times before JIT
giving up. The important case to consider are:
1) Methods continue as interpreted
2) Methods remain in 'profiling' mode

Local fix

  • Depending on the type of failure the following options could
avoid the problem:
-Xjit:{method}(disableProfiling)
-Xjit:{method}(optLevel=cold)  (or any other suitable
optimization level)

Problem summary

  • In some cases the JIT may fail compilations repeatedly such that
the methods in question remain interpreted or in 'profile
collection' mode. This can affect the performance of the JVM to
a varying degree depending on how often the affected methods are
invoked.

Problem conclusion

  • This defect will be fixed in:
6.0.1 SR2
7.0.0 SR1
.
Two of conditions leading to compilation failures have been
addressed such that methods will not be be stuck in profiling or
interpreted code.

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IV18275
    • 

  • Reported component name
    JIT
    • 

  • Reported component ID
    620700124
    • 

  • Reported release
    260
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2012-03-26
    • 

  • Closed date
    2012-03-26
    • 

  • Last modified date
    2012-06-01
    • 





    

  • 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
    • 








      
              
                            

              

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Document Information


            

            


                        

            Modified date:
            

            01 June 2012
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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