Openj9: OpenJ9 does not recognize -Xnocompressedrefs (yet)

[pdbain-ibm]

java -version
openjdk version "9-internal"
OpenJDK Runtime Environment (build 9-internal+0-adhoc.openj9.openjdk)
Eclipse OpenJ9 VM (build 2.9, JRE 9 Linux amd64-64 Compressed References 20170929_365721 (JIT enabled, AOT enabled)
OpenJ9 - 0ac16fb
OMR - 3b00c11
OpenJDK - dc8928f based on jdk-9+181)

java -Xnocompressedrefs -cp ~/pdbteam/lib/ HelloWorld
Selected VM [default] by option -Xnocompressedrefs does not exist.

This is causing this failure:
https://ci.eclipse.org/openj9/view/Test/job/Test-Extended-linux_ppc-64_cmprssptrs_le/lastBuild/testngreports/org.openj9.test.vmArguments/VmArgumentTests/testCrNocr/

[JamesKingdon]

Looks like the option was recognized, but there is no non-compressed VM to run.

This also implies a max heap size of ~57G

[ashu-mehra]

In the closed world, we used to test with build that contained both comrpessedrefs and non-compressedrefs VM. But I think with OpenJ9 the build contains only the VM corresponding to the spec specified. Since spec is linux_ppc-64_cmprssptrs_le, only "compressedrefs" VM is present in the build.
I think we need to update the test to match this change.

[DanHeidinga]

With the change from the old "composition" build process to "clone / clone / make", the ability to compose multiple vm packages together was dropped. This ability will need to be resurrected.

[pshipton]

Feel free to remove the test in order to keep the builds green.

[jdekonin]

Tracked via: https://github.com/ibmruntimes/openj9-openjdk-jdk9/issues/20

[akrus]

Is there any ETA for -Xnocompressedrefs? Currently Metronome GC cannot work with heaps higher than 25G.

[pshipton]

Is there any ETA for -Xnocompressedrefs?

Not at the moment. As it stands, to support both compressed and noncompressed it requires a second copy of the VM, compiled with different options, to be included in the JVM build in the lib/default (or jre/lib//default for Java 8) directory.

I haven't tried it, but it should be possible to (easily?) build the noncompressed version instead of the compressed version.

Looking at the files in the extensions projects, https://github.com/ibmruntimes/openj9-openjdk-jdk9 or https://github.com/ibmruntimes/openj9-openjdk-jdk8, remove the "_cmprssptrs" from the following files:

• jdk/make/closed/autoconf/custom-hook.m4
• jdk/make/closed/autoconf/generated-configure.sh

and rename "compressedrefs" in closed/OpenJ9.gmk to "default".

[smlambert]

In that case (of no ETA), the test should be excluded, to keep the extended runs green.

[pshipton]

FYI #643

[Valloric]

(dropping a note per @JamesKingdon's request)

The lack of support for heaps >60 GB is my main blocker for experimentation with OpenJ9 (the app I'd like to try it out with runs ~240 GB heaps).

[dsouzai]

@pdbain-ibm can this be closed given that https://github.com/eclipse/openj9/issues/643 is tracking the work?

[pshipton]

@dsouzai This issue is listed in the release notes https://github.com/eclipse/openj9/blob/master/doc/release-notes/0.17/0.17.md and the older versions. For this reason I suggest we keep it open until #643 completes.