Merging jdk/hs with jdk/jdk (original) (raw)

jesper.wilhelmsson at oracle.com jesper.wilhelmsson at oracle.com
Wed Mar 14 21:00:28 UTC 2018

All,

Over the last couple of years we have left behind a graph of integration forests where each component in the JVM had its own line of development. Today all HotSpot development is done in the same repository, jdk/hs [1]. As a result of merging we have seen several positive effects, ranging from less confusion around where and how to do things, and reduced time for fixes to propagate, to significantly better cooperation between the components, and improved quality of the product. We would like to improve further and therefore we suggest to merge jdk/hs into jdk/jdk [2].

As before, we expect this change to build a stronger team spirit between the merged areas, and contribute to less confusion - especially around ramp down phases and similar. We also expect further improvements in quality as changes that cause problems in a different area are found faster and can be dealt with immediately.

In the same way as we did in the past, we suggest to try this out as an experiment for at least two weeks (giving us some time to adapt in case of issues). Monitoring and evaluation of the new structure will take place continuously, with an option to revert back if things do not work out. The experiment would keep going for at least a few months, after which we will evaluate it and depending on the results consider making it the new standard. If so, the jdk/hs forest will eventually be retired. As part of this merge we can also retire the newly setup submit-hs [3] repository and do all testing using the submit repo based on jdk/jdk [4].

Much like what we have done in the past we would leave the jdk/hs forest around until we see if the experiment works out. We would also lock it down so that no accidental pushes are made to it. Once the jdk/hs forest is locked down, any work in flight based on it would have to be rebased on jdk/jdk.

We tried this approach during the last few months of JDK 10 development and it worked out fine there.

Please let us know if you have any feedback or questions!

Thanks, /Jesper

[1] http://hg.openjdk.java.net/jdk/hs <http://hg.openjdk.java.net/jdk/hs> [2] http://hg.openjdk.java.net/jdk/jdk <http://hg.openjdk.java.net/jdk/jdk> [3] http://hg.openjdk.java.net/jdk/submit-hs <http://hg.openjdk.java.net/jdk/submit-hs> [4] http://hg.openjdk.java.net/jdk/submit <http://hg.openjdk.java.net/jdk/submit>

More information about the hotspot-dev mailing list