[jdk8u-dev] RFR: 8245543: Cgroups: Incorrect detection logic on some systems (still reproducible) [v7]

[Jonathan Dowland]

> A backport of 8245543 to jdk8u-dev for cgroups v2 support.
> 
> Not clean: needed minor adjusting for 8u approach to log output.

Jonathan Dowland has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:

 - replace use of Optional.isEmpty
 - 8245543: Cgroups: Incorrect detection logic on some systems (still reproducible)
   
   Backport-of: 2bbf8a2a964a64d88298a3dd184459af506e58ed
 - 8253435: Cgroup: 'stomping of _mount_path' crash if manually mounted cpusets exist
   
   Reviewed-by: sgehwolf
   Backport-of: 0054c15f60cce6470be05d29bfacbdb74cfb7bc9

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Changes: https://git.openjdk.org/jdk8u-dev/pull/159/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=159&range=06
  Stats: 141 lines in 4 files changed: 132 ins; 1 del; 8 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/159.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/159/head:pull/159

PR: https://git.openjdk.org/jdk8u-dev/pull/159