JEP 175: Integrate PowerPC/AIX Port into JDK 8

[Volker Simonis]

On Sat, Feb 2, 2013 at 1:42 PM, David Holmes <david.holmes at oracle.com>wrote:

> On 2/02/2013 9:03 PM, Volker Simonis wrote:
>
>> On Fri, Feb 1, 2013 at 8:11 PM, Phil Race <philip.race at oracle.com
>> <mailto:philip.race at oracle.com**>> wrote:
>>
>> As previously discussed on porters-dev the current target is not the first
>> JDK 8 release but rather the first non-security update (i.e.
>> something like JDK 8u2)
>>
>>     Given the scale and timing, isn't JDK 9 a more appropriate target ?
>>     The goal of a JDK 8 update 2, *should* be stabilisation, and this
>>     sounds rather the opposite.
>>     It also introduces logistic issues like ramping up infrastructure
>>     which in my experience can't solved all that quickly.
>>
>> Well, the MacOS X port made it into 7u4 and we're of course keen to do
>> it better:)
>>
>
> That's probably not likely. The first update is generally intended to be a
> stabilization update (bug fixes only) as 7u2 was. So 8u4 seems the more
> likely target. Certainly I would like to see this come about well before
> Java 9 though.
>
> That said the simple logistics of repository management means the
> integration may not be able to start for some time. Until there is a forked
> forest where these changes can be integrated without affecting earlier
> updates (unduly) then it can't start. Historically that would not happen
> until after 8u2 has been frozen, but that might not leave enough time till
> 8u4. There may be some changes needed to how the 8u project is setup and
> handled. And I guess the 8u project needs to come into existence first as
> well.
>
>
The plan is to bring our port within our porting repository up to the
current jdk8 tip revision within the next two month or so and keep it there
(i.e. synchronize it weekly).
I think this will allow us to do most of the review work in the jdk8 or
jdk8u-dev repository (whichever my be available at that time) and then
back-port the changes to the appropriate 8uX repository once they are
created (much like this is done now for 7u).


> I think the "risks" are a little under-stated. You have changed shared
> code and that potentially impacts all platforms (unless you have only added
> new functions unused on existing platforms?). There is also the matter of
> the "elephant in the room" - the existing proprietary PPC port that Oracle
> has for Java SE Embedded. Someone (from Oracle of course) will have to see
> how the proposed structure of the new port will impact the existing closed
> port. It might be a non-issue, or  a major issue - most likely somewhere in
> between.
>

I am also hoping that this will not simply be a copy'n'modify port as we
> have seen in the past. The proliferation of platform ifdefs in shared code
> is truly horrendous; as is the duplication across the purportedly
> platform-specific code. This problem wasn't addressed for the Mac port but
> in my opinion (and that is all it is) it needs to be before the community
> accepts any further ports.
>
>
That would be nice but that is not and can not be the focus of this port.
It would also have a much bigger impact on all the currently supported
platforms than doing it in the way how all the other ports have been done
until now.

That said, we would warmly welcome any initiative (maybe a JEP) for
refactoring the class library to make it more portable. JDK9 may probably
be the appropriate target for such a project.


> I'd also like to understand the proposed maintenance model going forward.
> We (in Oracle) already have to accommodate our closed ports when they are
> affected by changes to common code that requires per-platform changes as
> well. Who will be providing the changes needed for aix-ppc? And how will
> that happen?
>
>
The changesets will of course be provided by us (IBM and SAP). How this
will happen is up to the OpenJDK cummunity and Oracle. Mark promised to
propose a formal policy for how this may look like.


> Again I think the big picture issues need to discussed on jdk8-dev (or
> perhaps it is time to start jdk8u-dev?) before getting into changeset
> specifics for hotspot and core-libs.
>
> Thanks,
> David
> -----
>
>
>  What do you mean with "ramping up infrastructure":
>>   - hardware resources (like test/build infrastructure)?
>>   - human resources within Oracle?
>>   - human resources within IBM/SAP?
>>
>> I think we have most of these allocated (except the Oracle part which I
>> can not speak about:)
>>
>>
>>     -phil.
>>
>>
>>     On 2/1/2013 5:57 AM, Volker Simonis wrote:
>>
>>         On Fri, Feb 1, 2013 at 12:15 PM, David Holmes
>>         <david.holmes at oracle.com <mailto:david.holmes at oracle.**com<david.holmes at oracle.com>
>> >>__wrote:
>>
>>
>>             On 1/02/2013 8:11 PM, mark.reinhold at oracle.com
>>             <mailto:mark.reinhold at oracle.**com <mark.reinhold at oracle.com>>
>> wrote:
>>
>>                 Posted: http://openjdk.java.net/jeps/***__*175<http://openjdk.java.net/jeps/*__*175>
>>                 <http://openjdk.java.net/jeps/****175<http://openjdk.java.net/jeps/**175>
>> ><http://openjdk.java.**net/__jeps/175<http://openjdk.java.net/__jeps/175>
>>
>>                 <http://openjdk.java.net/jeps/**175<http://openjdk.java.net/jeps/175>
>> >>
>>
>>             I'm forced to send this to porters-dev but I do not
>>             subscribe to that list
>>             (so it will probably get held up).
>>
>>             Given the way the JEP tasks have been split it would seem
>>             much more
>>             appropriate to me for discussions to occur on hotspot-dev
>>             and core-libs-dev
>>             as this, as the JEP says, is about the integration effort
>>             not the porting
>>             effort.
>>
>>         Yes, I agree. I just wanted to wait until the JEP was published
>>         before
>>         posting it to the appropriate lists
>>
>>
>>             That said this is also relevant to jdk8-dev, also cc'd, as
>>             it affects all
>>             JDK 8 development. I have trouble seeing how such a large
>>             effort can be
>>             assimilated within the timeframes of the Java 8 schedule.
>>
>>
>>         As previously discussed on porters-dev the current target is not
>>         the first
>>         JDK 8 release but rather the first non-security update (i.e.
>>         something like
>>         JDK 8u2)
>>
>>         Regards,
>>         Volker
>>
>>         David
>>
>>                - Mark
>>
>>
>>
>>