RFR: 8310187: Improve Generational ZGC jtreg testing [v2]

[Axel Boldt-Christmas]

On Sat, 17 Jun 2023 13:24:24 GMT, Alan Bateman <alanb at openjdk.org> wrote:

>> Axel Boldt-Christmas has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix wrong ZGenerational flag in VectorRebracket128Test.java
>
> test/jdk/java/lang/Thread/virtual/stress/Skynet.java line 25:
> 
>> 23: 
>> 24: /*
>> 25:  * @test
> 
> Would you mind adding "id=default" to this test? If a test has several `@test` tags, some with an identifier, and some without, then it can be tricky to understand test selection and exclusion.

Done. 

I tried to reduce changes to other ids as much as possible as they may be used for problemlisting etc. The first run would have been `#id0` before and after this patch. However does not seem to be any exclusion filters in the repo for Skynet so added a default id. 

Because this patch adds extra `@test` some `#idX` will change. I've tried to double check that there are no problemlistings that depend on this, and I can find none. 

Ideally all multi `@test` tests should use explicit ids so changing that updating existing tests is less fragile with respect to exclusions. However I know that there are more gotchas here with how problemlisting works. Not sure I remember the exact details but I believe that under certain circumstances the id will be ignored, and if a problemlisting includes it, it will not filter it out. 

For now updating tests will always require going through all relevant problemlisting files and check that the exclusions are still valid.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/14509#discussion_r1233609799