IV77911: JAVA PROGRAM WITH -XJIT:ENABLEGPU OPTION FAILS DUE TO A SEGMENTA TION FAULT

APAR status

• Closed as program error.

Error description

• Error Message: When running a Java program with the
  -Xjit:enableGPU option, the program will suddenly end and print
  the following error message:
  Unhandled exception
  Type=Segmentation error vmState=0x00000000
  .
  Stack Trace: Stack Trace
  (0x0000000000000000 <OSB><unknown>+0x0<CSB>)
  (0x00003FFFA6FDB1E4 <OSB>libj9jit28.so+0x116b1e4<CSB>)
  (0x00003FFFA610EF1C <OSB>libj9jit28.so+0x29ef1c<CSB>)
  (0x00003FFFA61092F4 <OSB>libj9jit28.so+0x2992f4<CSB>)
  (0x00003FFFA616B02C <OSB>libj9jit28.so+0x2fb02c<CSB>)
  J9VMDllMain+0xfdc (0x00003FFFA61696DC
  <OSB>libj9jit28.so+0x2f96dc<CSB>)
  (0x00003FFFA7B1F740 <OSB>libj9vm28.so+0xcf740<CSB>)
  (0x00003FFFA7B7531C <OSB>libj9vm28.so+0x12531c<CSB>)
  (0x00003FFFA7B1F490 <OSB>libj9vm28.so+0xcf490<CSB>)
  (0x00003FFFA7B19D6C <OSB>libj9vm28.so+0xc9d6c<CSB>)
  (0x00003FFFA7983CB4 <OSB>libj9prt28.so+0x53cb4<CSB>)
  (0x00003FFFA7B18540 <OSB>libj9vm28.so+0xc8540<CSB>)
  J9_CreateJavaVM+0xb8 (0x00003FFFA7AFAE38
  <OSB>libj9vm28.so+0xaae38<CSB>)
  JNI_CreateJavaVM+0x900 (0x00003FFFA7C0CBC0
  <OSB>libjvm.so+0x1cbc0<CSB>)
  JNI_CreateJavaVM+0x1cc (0x00003FFFA858A52C
  <OSB>libjvm.so+0x1a52c<CSB>)
  (0x00003FFFA87BC22C <OSB>libjli.so+0xc22c<CSB>)
  (0x00003FFFA87E89C8 <OSB>libpthread.so.0+0x89c8<CSB>)
  clone+0x98 (0x00003FFFA86EE570 <OSB>libc.so.6+0x11e570<CSB>)
  .
  When running the Java program, the LD_LIBRARY_PATH environment
  variable is missing the location of one or more of the following
  three GPU libraries: libnvvm.so, libcudart.so, libcuda.so
  

Local fix

• Set the LD_LIBRARY_PATH to point to working copies of
  libnvvm.so, libcudart.so and libcuda.so libraries.
  For example:
  export
  LD_LIBRARY_PATH=path/to/libnvvm.so:path/to/libcudart.so:path/to/
  libcuda.so:$LD_LIBRARY_PATH, where each "path/to" is filled in
  with the proper location of the library.
  

Problem summary

• The JVM does not check to make sure that the GPU libraries were
  all properly loaded before using them. As a result, Java crashes
  when it attempts to use a library that was not properly loaded.
  

Problem conclusion

• The JVM has been updated to ensure that the GPU libraries were
  properly loaded before using them. If the libraries are not
  found, Java will silently fall back and use the CPU to run the
  program instead of the GPU. If the -Xjit:enableGPU={verbose}
  option is used, the error message "Dynamic linking error" will
  also be printed to screen if a library can not be found.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR2       (8.0.2.0)
  .
  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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