Up until now the openJDK has only been able to operate in interpreter mode. Thanks to the good people at SAP the fruits of their 10 years work on the JDK have resulted in code being pushed upstream that enables JIT compiling. Fedora rawhide have a source RPM but, currently, only builds the “zero” mode (or interpreter mode) for s390x. I simply added s390x to the jit_arches and got a clean build. I have not tested it very thoroughly but it is available for playing. To give you an example of the difference in performance I took the PrimeEx.java example from https://www.cs.utexas.edu/~scottm/cs307/codingSamples.htm and ran it under JDK8 (interpreter) and JDK9 (JIT). The interesting bits of the output are:
664579 elapsed time: 33.600410375 seconds. 664579 elapsed time: 0.785404063 seconds. Versus 664579 elapsed time: 3.267570688 seconds. 664579 elapsed time: 0.092451313 seconds. If you wish to play then an RPM that will install on RHEL 7.3 or ClefOS 7.3.1611 (our CentOS clone) http://download.sinenomine.net/clefos/epel7/ If you do not have RHEL or ClefOS then I have a docker container that you can run using: docker run --rm -it sinenomine/openjdk-s390x:latest bash You will then be presented with a bash prompt. You can then use the java and javac commands. For those interested in the s390x integration into upstream: http://openjdk.java.net/jeps/294 Kudos to the SAP folk for doing this port and for making it available to the community. Neale ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
