RFR: 8252114: Windows-AArch64: Enable and test ZGC and ShenandoahGC [v2]

[Stuart Monteith]

On 11/09/2020 04:48, Monica Beckwith wrote:
> On Thu, 10 Sep 2020 17:09:00 GMT, Monica Beckwith <mbeckwit at openjdk.org> wrote:
> 
>>> This looks good to me with Alexsey's changes applied.
>>
>> Ref: https://github.com/openjdk/jdk/pull/97#issuecomment-690077743
>> Hi David,
>> Thanks. I wanted to start a conversation here as it does modify common code (the aarch64-linux combo check) and also
>> wanted to highlight the difference between Shenandoah and ZGC checks. IMHO, Shenandoah checks are cleaner and if people
>> agree, I would like to apply those to ZGC as well. (When that happens, it *will* be outside of the windows-aarch64 port
>> and I will change the info in JBS accordingly) Please let me know what you think.
> 
> Ref: https://github.com/openjdk/jdk/pull/97#issuecomment-690811308
> I empathize with your comment, David. Here's a bit of a background for all -
> When I started the port, both ZGC, and Shenandoah had the "xlinux-aarch64" check whereas the "xx86" check was more
> elaborate for ZGC.  At that time I chose the ZGC route for both the GCs and added separate checks for each OS. This is
> what the windows-aarch64 port has as well. (Since then Shenandoah has moved on to just checking the arch.) I already
> had a JBS entry, and the (partial) patch, I decided to use that for my first GitHub PR. and was hoping to start the
> conversation of the simpler route that Shenandoah took in the comments mentioning that as my preference and modify the
> JBS entry (and the patch) accordingly.
> 
> Now coming back to this - @stooart-mon, do you think it is OK to just check for aarch64 (similar to Shenandoah)?
> @stefank what do you think of simplifying the x86 checks (similar to Shenandoah)? Thanks all.
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jdk/pull/97
> 

Hi Monica,
	I guess the choice is either to enable aarch64, and have the Mac port disable ZGC if necessary, or do what you have 
done here and just enable by by architecture and supported platform. If Anton is happy with the simple check for 
aarch64, then I'm happy.

BR,
	Stuart