[11u] RFR: 8250984: Memory Docker tests fail on some Linux kernels w/o cgroupv1 swap limit capabilities

[Severin Gehwolf]

Hi,

Please review this backport for Oracle 11.0.10 parity. The jdk-jdk
patch needs to be significantly reworked since JDK 15+ has the cgroups
v2 patches. The gist of the change is to only report memory values if
swap accounting is disabled on the system (i.e. no swap memory) for
metrics which would otherwise report values for memory + swap.

Here is the list of changes I've done as compared to the JDK 16 patch:

 * Drop ProblemList.txt hunks. The test was not problem-listed in
   OpenJDK 11u. It's not applicable.
 * Dropped hunk in test/hotspot/jtreg/containers/cgroup/PlainRead.java,
   which also is not applicable (cgroups v2 and later refactorings
   related).
 * Moved changes from CgroupV1Subsystem.java to cgroupv1/Metrics.java
   class. That's where the code lived prior the cgroups v2 addition.
 * Moved code changes from CgroupV1MemorySubSystemController.java to
   MemorySubsystem in SubSystem.java
 * test/hotspot/jtreg/containers/docker/TestMemoryAwareness.java
   adjusted since JDK-8226575 for JDK 11 was different to JDK 15 (no
   new methods)
 * MetricsMemoryTester.java the code is again different in JDK 15+
   because of JDK-8231111. But the changes for this bug only move it
   into a conditional testing whether swap is enabled and only test if
   it is.
 * MetricsTesterCgroupV1 => MetricsTester

Bug: https://bugs.openjdk.java.net/browse/JDK-8250984
webrev: https://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8250984/01/webrev/

Testing: Container tests on a system with swapaccount=0 and on a system
with it enabled on Linux x86_64. Tests mentioned in the bug failed
before, pass after.

Thoughts?

Thanks,
Severin