RFR: 8300658: memory_and_swap_limit() reporting wrong values on systems with swapaccount=0 [v2]

[Severin Gehwolf]

On Thu, 16 Feb 2023 14:08:19 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

>> Please review this change which brings the hotspot code up to date with how the Java metrics behave. On a system where swap accounting is disabled `VM.info` jcmd - for example - no longer reports an unsupported metric, but the memory limit instead as that is actually what is being in place.
>> 
>> I had to update the `TestMemoryWithCgroupV1.java` test as it skipped the swappiness testing based on the now gone output.
>> 
>> Testing:
>> - [x] Linux container tests on cg1 and cg2 with and without swap accounting.
>> - [x] New regression test fails on unpatched systems with `swapaccount=0` kernel option. Passes after.
>> - [x] GHA (windows tier1 failure is unrelated).
>> 
>> Thoughts?
>
> Severin Gehwolf has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:
> 
>  - Read mem swap as julong as before
>  - Whitespace fix-up after merge
>  - Merge branch 'master' into jdk-8300658-memory-swap-hs-fix
>  - 8300658: memory_and_swap_limit() reporting wrong values on systems with swapaccount=0

Hi @iklam! Could I ask you to look at this container-related change as well, please? Thanks!

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

PR: https://git.openjdk.org/jdk/pull/12262