RFR: JDK-8287011: Improve container information [v3]

[Thomas Stuefe]

On Fri, 3 Jun 2022 14:05:27 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> The change adds some potentially interesting cgroup v1 and v2 metrics to hs_err / hs_info files.
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   handle new cgroupv1 and v2 values in TestMisc

As I wrote in a comment, if it is a problem expanding the OsContainer API and getting a good and useful v1-v2-abstraction, then let's not. 

All I really wanted was 1) have c-groups info in hs-err and Vm.Info and 2) have a clarification wrt different meaning of `memory_and_swap_limit_in_bytes()` for v1 vs v2. I can live without (2), and for 1), I can live with a solution where OsContainer just exposes the memory controller path and in os_linux.cpp we print out the various files we are interested in directly. I can also live with Matthias' patch as it is now, which I think is clean and looks good.

Cheers, Thomas

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PR: https://git.openjdk.java.net/jdk/pull/8991