[aarch64-port-dev ] RFC: JEP - One AArch64 Port, Not Two

[Magnus Ihse Bursie]

On 2018-08-27 16:00, Bob Vandette wrote:
>
>> On Aug 27, 2018, at 2:30 AM, Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com> wrote:
>>
>> On 2018-08-23 17:13, Bob Vandette wrote:
>>> As a follow-on to the previous thread  "ARM port consolidation” [1],
>>> please review and comment on this newly filed JEP that removes
>>> one of the two AArch64 ports from the JDK.
>>>
>>> JEP:
>>>
>>> https://bugs.openjdk.java.net/browse/JDK-8209093
>> Looks good! (Or as we say in Sweden: Äntligen! :-))
>>
>> One question: I remember there were some guys from Linaro who compared aarch64 vs arm64 in microbenchmarks, and found that while aarch64 had the superior performance most of the time, there were some benchmarks where arm64 was fastest.
>>
>> Has these been analyzed, and the performance on aarch64 brought in line with arm64?
> It looks like this question has been answered.

Yes, thank you.


>
>>> Here’s a prototype of the changes that would be done under this JEP.
>>>
>>> http://cr.openjdk.java.net/~bobv/8209093/webrev.00
>> Generally looks good. I have not looked at too much detail since it's just a prototype, but I noted that you just removed --with-cpu-port, instead of deprecating it. That needs to be fixed for the real deal.
> What’s the process for deprecation of build options?  Do I just change the help text and have the arm64 option select the aarch64 port?

You remove the old code, just as you have done, and then add:

BASIC_DEPRECATED_ARG_WITH(cpu-port)

I'd suggest you add next to "BASIC_DEPRECATED_ARG_WITH(jvm-interpreter)".

This will activate code that makes sure --with-cpu-port does not break, 
but instead prints a warning.

/Magnus

>
> Thanks,
> Bob.
>
>> /Magnus
>>
>>
>>
>>>
>>> [1] http://mail.openjdk.java.net/pipermail/hotspot-dev/2018-June/032756.html
>>>
>>> Bob.
>>>
>>>
>>>
>>>