[jdk8u-dev] RFR: 8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10 [v2]

[Jonathan Dowland]

> This is a backport of 8278951 to jdk8u-dev as part of the cgroups v2 backport initiative.
> 
> Dependent PRs are in use.
> 
> It was clean (modulo path shuffles). The use of `log_trace` needed adjusting for jdk8u-dev.

Jonathan Dowland 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 two additional commits since the last revision:

 - replace log_trace with tty->print_cr
 - 8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10
   
   Reviewed-by: sgehwolf
   Backport-of: 35172cdaf38d83cd3ed57a5436bf985dde2d802b

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

Changes:
  - all: https://git.openjdk.org/jdk8u-dev/pull/155/files
  - new: https://git.openjdk.org/jdk8u-dev/pull/155/files/bfc817ed..e6c38804

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=155&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=155&range=00-01

  Stats: 115 lines in 4 files changed: 105 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/155.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/155/head:pull/155

PR: https://git.openjdk.org/jdk8u-dev/pull/155