[jdk8u-dev] RFR: 8239559: Cgroups: Incorrect detection logic on some systems [v4]

[Jonathan Dowland]

> This is a backport of 53ee0c4963007b86db7979312b81f990e6ce271a via the 11u backport 53ee0c4963007b86db7979312b81f990e6ce271a for cgroups v2 support in jdk8u-dev.
> 
> It isn't clean: context differences in CgroupSubsystemFactory.java around the use of post-8u logging in the original patch.
> 
> I also had to Optional.isEmpty which is not present in 8u's Optional.

Jonathan Dowland has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 58 commits:

 - replace post-jdk8u Optional.isEmpty
 - 8239559: Cgroups: Incorrect detection logic on some systems
   
   Adjust heuristic with cgroup mounts according to mountinfo
   
   Backport-of: 53ee0c4963007b86db7979312b81f990e6ce271a
 - 8240189: [TESTBUG] Some cgroup tests are failing after JDK-8231111
   
   Reviewed-by: mdoerr
   Backport-of: c92adf41587767e9c5c8e116cfaeb375d36928aa
 - Don't pass --add-exports to jdk8u java inside docker
   
   These are JDK9+ module specific parameters.
 - 8244500: jtreg test error in test/hotspot/jtreg/containers/docker/TestMemoryAwareness.java
   
   When the kernel doesn't support swap limits, expect host values instead.
   
   Reviewed-by: sgehwolf
   Backport-of: fb5132254d834ba01a4b65ce64143843e83c674e
 - Move test to a more 8u-appropriate location
   
   Container (cgroups, docker) tests in 8u reside in
   hotspot/test/runtime/containers
 - remove duplicate include of osContainer_linux
   
   With the backport of 8189762, the include of osContainer_linux was
   moved to a later #ifdef stanza, relative to the original. This caused
   a context problem with this backport.
 - 8239785: Cgroups: Incorrect detection logic on old systems in hotspot
   
   Return NULL subsystem if no cgroup controllers are mounted.
   
   Reviewed-by: sgehwolf
   Backport-of: add18914fb1294999877b563c734a25b4c17b922
 - 8237479: 8230305 causes slowdebug build failure
   
   Declare methods as pure virtual.
   
   Backport-of: 4ca06995855b5c974321d7b3622d661b8d27ba76
 - 8253714: [cgroups v2] Soft memory limit incorrectly using memory.high
   
   The early implementation of cgroups v2 support was done with
   crun 0.8 and it contained a bug which set memory.high over
   memory.low when --memory-reservation was being used as a CLI
   option.
   
   This bug has been fixed in later crun versions, starting with
   crun 0.11. Use memory.low in OpenJDK as well.
   
   Backport-of: ff6843ca4842498791061f924c545fa9469cc1dc
 - ... and 48 more: https://git.openjdk.org/jdk8u-dev/compare/f0ac3199...45ec61df

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

Changes: https://git.openjdk.org/jdk8u-dev/pull/136/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=136&range=03
  Stats: 13049 lines in 114 files changed: 8449 ins; 3811 del; 789 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/136.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/136/head:pull/136

PR: https://git.openjdk.org/jdk8u-dev/pull/136