Backport cgroups v2 to 8u

[Jonathan Dowland]

On Wed, Oct 05, 2022 at 11:40:11AM +0100, Jonathan Dowland wrote:
>Severin has shared the "hit list" of things we think should be
>backported, which is largely in the order they need to happen. Please
>point out if there's anything missing, or out of order.

Ah Severin's list was not ordered. This is approximately the order we
think they need to be done in:

JDK-8230305: Cgroups v2: Container awareness
JDK-8231111: Cgroups v2: Rework Metrics in java.base so as to recognize unified hierarchy
JDK-8237479: 8230305 causes slowdebug build failure
JDK-8253714: [cgroups v2] Soft memory limit incorrectly using memory.high
JDK-8239785: Cgroups: Incorrect detection logic on old systems in hotspot
JDK-8253727: [cgroups v2] Memory and swap limits reported incorrectly
JDK-8239559: Cgroups: Incorrect detection logic on some systems
JDK-8244500: jtreg test error in test/hotspot/jtreg/containers/docker/TestMemoryAwareness.java
JDK-8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10
JDK-8253797: [cgroups v2] Account for the fact that swap accounting is disabled on some systems
JDK-8245543: Cgroups: Incorrect detection logic on some systems (still reproducible)
JDK-8254001: [Metrics] Enhance parsing of cgroup interface files for version detection
JDK-8252359: HotSpot Not Identifying it is Running in a Container
JDK-8253435: Cgroup: 'stomping of _mount_path' crash if manually mounted cpusets exist
JDK-8253939: [TESTBUG] Increase coverage of the cgroups detection code
JDK-8262379: Add regression test for JDK-8257746

These ones I'm not sure about ordering

JDK-8284102: [TESTBUG] Retroactively add regression test for JDK-8272124
JDK-8284756: [11u] Remove unused isUseContainerSupport in CgroupV1Subsystem
JDK-8266391: Replace use of reflection in jdk.internal.platform.Metrics
JDK-8254997: Remove unimplemented OSContainer::read_memory_limit_in_bytes
JDK-8252957: Wrong comment in CgroupV1Subsystem::cpu_quota
JDK-8240189: [TESTBUG] Some cgroup tests are failing after JDK-8231111

And I did this one to ease one of the earlier backports, it was not
strictly necessary but resolved conflicts that would otherwise occur,
and looked like a good idea

JDK-8206456: [TESTBUG] docker jtreg tests fail on systems without cpuset.effective_cpus / cpuset.effective_mems

-- 
👱🏻 Jonathan Dowland <jdowland at redhat.com>
Senior Software Engineer, OpenJDK, Red Hat