Project proposal: s390x port

[Volker Simonis]

Hi everybody,

my name is Volker Simonis and I'm the project lead of the PowerPC/AIX
porting project. I'm writing from my Google mail account for historic
reasons (I've been an OpenJDK contributor before SAP was) but I think
it is no secret that I'm working for SAP :)

We have a complete (i.e. template interpreter, C1 and C2 JIT) and
certified (Java 4-8) s390x port which is used in production since
years. It is based on the our commercially licensed HotSpot sources
but the s390x port is completely written and owned by SAP.

We haven't thought about contributing it to the OpenJDK until now
because we didn't expect any interest from the community :)

I can not make any commitments now, but if there really is any
interest in such a port (and this email thread indicates that there is
:) we may reconsider our decision.

>From a technical point of view and with the experience we gained with
the PowerPC/AIX Port I think the s390x port could be integrated into
the OpenJDK quite smoothly (there are considerably less shared changes
required compared to the PowerPC/AIX port).

So if this sounds reasonable, I could begin to get the internal
approvals so we can get the project started.

Regards,
Volker

On Fri, May 6, 2016 at 3:24 PM, David Edelsohn <dje.gcc at gmail.com> wrote:
> On Fri, May 6, 2016 at 7:25 AM, dalibor topic <dalibor.topic at oracle.com> wrote:
>> Hi David,
>>
>> thank you for your proposal. As usual, I have a few questions in order to
>> better understand the Project being proposed.
>>
>> On 05.05.2016 14:48, David Edelsohn wrote:
>>>
>>> [Sorry if this is a duplicate. An earlier message is awaiting moderation.]
>>>
>>> I would like to propose the creation of a new project to port OpenJDK
>>> to IBM z/Architecture (s390x).
>>
>>
>> I noticed that you sent the proposal from a gmail address, while a person of
>> the same name seems to work [0] at IBM, who happen to produce s390x
>> architecture machines. Do you happen to be the same person by chance? If so,
>> would you be contributing to this Project on behalf of IBM, or on your own
>> behalf?
>
> Hi, Dalibor
>
> Yes, I am the same person.  I prefer this email address for
> discussions with Open Source projects. I sent the feature request from
> my official IBM email address to confirm that this request originates
> from IBM and that IBM supports this effort.
>
> IBM itself will not contribute the port.  I will not contribute this
> port myself -- neither as an IBM employee nor on my own behalf.
>
>>
>> Could you elaborate a bit on the nature of the development work:
>>
>>  * Who would be in the initial set of the Project's Committers?
>
> The port will be developed by Marcin Kościelnicki.
>
>>  * Would you have Reviewers on the Project?
>
> Yes, there will be IBMers who will assist with reviews of the proposed patches.
>
>>  * Would you be starting from scratch within the new OpenJDK Project, or are
>> you looking at bringing an already existing, internal port in?
>
> This is a new port starting from scratch.
>
>>  * In the latter case, does the code you'd like to contribute to the port
>> have any third party dependencies?
>
> N/A
>
>>  * In the former case, are you aware of the Open Mainframe Project, which
>> seems to intend to produce a JIT for OpenJDK, as well? [1]
>
> This proposal is in conjunction with the Open Mainframe Project TSC for OpenJDK.
>
>>  * Which JDK release would you plan to target initially?
>
> I believe that the goal is inclusion in OpenJDK 9. I welcome your
> advice and guidance about this issue.
>
>>
>>> The proposal is support for s390x z12 on LinuxONE (Linux on IBM z
>>> Systems).  The support would include the C++ interpreter, the template
>>> interpreter, and the C2 compiler.
>>
>>
>> OK. I assume that C1 is not something your port needs, or is it something
>> you'll consider for a later iteration?
>
> C1 is not needed.  We may consider it in the future, depending on
> market and/or customer requirements.
>
>>
>>> I have submitted an enhancement request that has been assigned review
>>> ID JI-9036871.  I am hoping that it will be assigned an official JIRA
>>> issue and allow OpenJDK Bug System access.
>>
>>
>> That issue is now https://bugs.openjdk.java.net/browse/JDK-8156104 . It's
>> also been marked as closed, as there is no need to submit issues to create
>> new Projects. The process is documented at
>> http://openjdk.java.net/projects/#new-project .
>>
>> When a new Project is created, its Project Lead, Committers, Reviewers and
>> Authors get write access to the JDK Bug System within their Project.
>
> Thanks.
>
> IBM has very successfully utilized bounties[2] to enable and optimize
> many Open Source packages on LinuxONE (and POWER).  We plan to
> continue with that methodology for this project with multiple feature
> requests in JIRA corresponding to different components / phases of the
> project to enable OpenJDK.
>
> Thanks for your help with the process to formally create this project.
> Your guidance is greatly appreciated.
>
> Thanks, David
>
> [2] https://www.bountysource.com/teams/ibm/bounties