RFR: 8340419: ZGC: Create an UseLargePages adaptation of TestAllocateHeapAt.java

[Axel Boldt-Christmas]

On Wed, 25 Sep 2024 08:02:39 GMT, Stefan Johansson <sjohanss at openjdk.org> wrote:

>> [JDK-8340146](https://bugs.openjdk.org/browse/JDK-8340146) / #21127  disables TestAllocateHeapAt.java when running with persistent hugepages because it makes assumptions on the underlying file systems.
>> 
>> I propose creating a version of this tests which instead first checks if there is an appropriate mount point for a persistent hugepages heap file, and only runs the test if exists.
>
> test/hotspot/jtreg/gc/z/TestAllocateHeapAtWithHugeTLBFS.java line 80:
> 
>> 78:         ProcessTools.executeTestJava(
>> 79:             "-XX:+UseZGC",
>> 80:             "-XX:+ZGenerational",
> 
> Any reason to include `-XX:+ZGenerational` or should we just skip it?

I try to keep this option explicit in tests until it is removed. Avoid assumptions about default values.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21128#discussion_r1774882896