Merging jdk/hs with jdk/jdk

Christian Tornqvist christian.tornqvist at
Tue Mar 20 21:48:21 UTC 2018

Hi Jesper,

This sounds like a step in the right direction, this should simplify a lot of things, thanks for doing this!


> On Mar 14, 2018, at 5:00 28PM, jesper.wilhelmsson at wrote:
> 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] <>
> [2] <>
> [3] <>
> [4] <>

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