RFR: 8276796: gc/TestSystemGC.java large pages subtest fails with ZGC [v3]

[Aleksey Shipilev]

On Wed, 10 Nov 2021 11:45:12 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> ZGC would not start when it cannot allocate the heap with `-XX:+UseLargePages`. This makes the `UseLargePages` subtest fail on systems with (default) `nr_hugepages = 0`. It was exposed after [JDK-8269077](https://bugs.openjdk.java.net/browse/JDK-8269077) moved that test config from G1-specific to generic one.
>> 
>> While fixing this bug, I decided to massage a test a bit: make it consistently choosing the configuration based on GC availability, doing `UseLargePages` tests only for GCs that fall back to non-large pages if not available, added test IDs. This basically goes the other way JDK-8269077 went: put in the GC-specific configs.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java` (runs all 5 configs)
>>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseSerialGC` (runs 1 config)
>>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseParallelGC` (runs 1 config)
>>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseG1GC` (runs 1 config)
>>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseShenandoahGC` (runs 1 config)
>>  - [x] Linux x86_64 fastdebug, `gc/TestSystemGC.java`, `TEST_VM_OPTS=-XX:+UseZGC` (runs 1 config)
>
> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8276796-zgc-systemgc
>  - Review comments
>  - Fix

GHA tests are green.

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PR: https://git.openjdk.java.net/jdk/pull/6310