Java 1.6 on HP-UX Itanium: which java executable?

[Jose M. del Rio]

Just installed Java 1.6 on HP-UX Itanium.
I have to configure a third-party Java application to point to the java executable.
In PA-RISC, it's OK.
But in Itanium and I wonder which excutable I should use:

desar1:/opt/java6/bin#file java
java: PA-RISC2.0 executable dynamically linked -not stripped

desar1:/opt/java6/bin/IA64W#file java
java: ELF-64 executable object file - IA64

desar1:/opt/java6/jre/bin#file java
java: PA-RISC2.0 executable dynamically linked -not stripped

desar1:/opt/java6/jre/bin/IA64W#file java
java: ELF-64 executable object file - IA64

Thanks.

[Steven E. Protter]

Shalom,

You may use any of the executables listed above on an Itanium system.

Those marked PA-RISC will use the ARIES emulation libraries to translate system calls. Those marked IA64 will execute in native mode.

Executing in native mode is preferred for performance in most cases. This assumes these java files are actually intended for the same purpose.

You might want to, just for grins try the what command on those guys.

SEP

[Dennis Handly · Accepted solution]

>SEP: You may use any of the executables listed above on an Integrity system.

The correct executable is the driver:
/opt/java6/bin/java

This selects the appropriate JVM based on the architecture and options.

>Those marked PA-RISC will use the ARIES emulation libraries to translate system calls.

This isn't true for the driver since it will immediately exec the correct one.

[Steven E. Protter]

Dennis,

It is a really bad habit of yours to direct comments to me via the forums. That is what email is for. That is how Bill Hassell does it when he notices a mistake in one of my posts.

I consider myself parsed.

Back to the question at hand.

If you are building an executable on an IA-64 system you will want to use the native IA-64 executable object file to avoid use of ARIES.

If you are facing a choice between which executable to run, again on an IA-64 system you are better off running in native mode than not.

If you run this executable on a IA-64 system:
java: PA-RISC2.0 executable dynamically linked -not stripped
If there are any system calls, they will be translated to IA-64 system calls by ARIES.

I don't see the word driver in the initial question and fail to connect the dots as to why that is being dragged into the thread.

FYI, We are currently in the middle of a 30 system migration, rp8420 to superdome, many of our binaries are going to be left in PA-RISC mode and will use the ARIES emulation.

We've been conducting performance tests of binaries native versus ARIES mode.

IF possible, on IA-64 systems, don't use ARIES to run PA-RISC executable.

SEP

[James R. Ferguson]

Hi:

For those interested in a bit more background, see this thread:

http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=1434555

It's there that Dennis talks about the Java "driver" code.

I know I learned something from him :-)

Regards!

...JRF...

[Rajesh K Chaurasia]

As Dennis suggested, correct executable to invoke is /opt/java6/bin/java. This is Java driver built as 32-bit PA-RISC executable. Depending on command line options passed, it will invoke correct JVM for IA64 or PA-RISC.

Java driver always runs using ARIES. To invoke different JVM flavors -

32-bit IA64: /opt/java6/bin/java
64-bit IA64: /opt/java6/bin/java -d64
32-bit PA-RISC: /opt/java6/bin/java -pa20
64-bit PA-RISC: /opt/java6/bin/java -pa20w

P.S. To invoke PA-RISC JVM on IA64, you need to install PA-RISC JDK/JRE using -x allow_incompatible=true option to swinstall.

Regards
-Rajesh

[Jose M. del Rio]

Thanks to everybody.
I launched:
tusc [-d64] /opt/java6/bin/java -version
and noticed the right Itanium 32/64-bit version is chosen.

[Dennis Handly]

>SEP: I don't see the word driver in the initial question and fail to connect the dots as to why that is being dragged into the thread.

Because one of those executables that Jose mentioned IS the java driver.