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

[Johan Sjölen]

On Fri, 27 Jan 2023 17:09:35 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?

Hi,

Thanks for these changes. They look good to me.

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Marked as reviewed by jsjolen (Committer).

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