JEP 175: Integrate PowerPC/AIX Port into JDK 8

[Steve Poole]

On 4 Feb 2013, at 11:39, David Holmes <david.holmes at oracle.com> wrote:

> On 4/02/2013 8:50 PM, Volker Simonis wrote:
>> On Sat, Feb 2, 2013 at 1:42 PM, David Holmes <david.holmes at oracle.com
>>    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.
> 
> I had thought that when this was proposed the issue of not doing a simple copy'n'modify, and the need for an improved architecture to allow ease of porting was raised. But it seems my recollection was incorrect.
> 
> My apologies for that. It is of course not reasonable to expect this as the port is completed.
> 
> That said I still have grave concerns about the maintainability of the codebase due to the excessive use of platform ifdefs in "shared" code, and the excessive duplication in "platform specific" code. And that each new port makes it that much harder to instigate such changes. I feel with this port we will have reached a point now where it is almost impossible to fix this. It would take significant resources to refactor the code etc, dealing with all the existing platforms, while at the same time trying to evolve the platform to Java 9.

I agree we do need to tackle the refactoring problem - I just wanted to keep it a separate concern and not made a precondition for this JEP - which I think we all agree on?  I am more than happy to help with the refactoring necessary in JDK8 proper over  time.  Given that there will be an ARM64 port following on along later we do need to start soon!


> 
> David
> -----
> 
>> 
>> 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>
>>        <mailto:david.holmes at oracle.__com
>>        <mailto:david.holmes at oracle.com>>>__wrote:
>> 
>> 
>>                     On 1/02/2013 8:11 PM, mark.reinhold at oracle.com
>>        <mailto:mark.reinhold at oracle.com>
>>        <mailto:mark.reinhold at oracle.__com
>>        <mailto: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
>> 
>> 
>> 
>> 
>