On Linux x86_64 and Linux aarch64 we see after JDK-8302744 (starting 30th May) the test containers/cgroup/PlainRead.java failing.
Seems some output/logging has been adjusted with this change.

Example stderr for test failure, do you think it is related ? Before the test was running fine.
stderr
---- snip ---------------
Thu May 30 02:29:44 CEST 2024

 stdout: [[0.000s][trace][os,container] OSContainer::init: Initializing Container Support
[0.001s][debug][os,container] Detected optional pids controller entry in /proc/cgroups
[0.001s][debug][os,container] Detected cgroups v2 unified hierarchy
[0.001s][trace][os,container] Path to /cpu.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max
[0.001s][debug][os,container] Open of file /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max failed, No such file or directory
[0.001s][trace][os,container] Path to /cpu.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max
[0.001s][debug][os,container] Open of file /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max failed, No such file or directory
[0.001s][trace][os,container] CPU Period failed: -2
[0.001s][trace][os,container] OSContainer::active_processor_count: 16
[0.001s][trace][os,container] CgroupSubsystem::active_processor_count (cached): 16
[0.001s][trace][os,container] total physical memory: 33631973376
[0.001s][trace][os,container] Path to /memory.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/memory.max
[0.001s][trace][os,container] Memory Limit is: -1
[0.001s][debug][os,container] container memory limit unlimited: -1, using host value 33631973376
[0.003s][trace][os,container] CgroupSubsystem::active_processor_count (cached): 16
[0.112s][trace][os,container] total physical memory: 33631973376
[0.112s][trace][os,container] Path to /memory.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/memory.max
[0.112s][trace][os,container] Memory Limit is: -1
[0.112s][debug][os,container] container memory limit unlimited: -1, using host value 33631973376
[0.203s][trace][os,container] Path to /cpu.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max
[0.203s][debug][os,container] Open of file /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max failed, No such file or directory
[0.203s][trace][os,container] Path to /cpu.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max
[0.203s][debug][os,container] Open of file /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/cpu.max failed, No such file or directory
[0.203s][trace][os,container] CPU Period failed: -2
[0.203s][trace][os,container] OSContainer::active_processor_count: 16
[0.314s][trace][os,container] total physical memory: 33631973376
[0.314s][trace][os,container] Path to /memory.max is /sys/fs/cgroup/user.slice/user-3670.slice/session-1002.scope/memory.max
[0.314s][trace][os,container] Memory Limit is: -1
[0.314s][debug][os,container] container memory limit unlimited: -1, using host value 33631973376
];
 stderr: [openjdk version "23-internal" 2024-05-30
OpenJDK Runtime Environment (fastdebug build 23-internal-adhoc.jenkinsi.jdk)
OpenJDK 64-Bit Server VM (fastdebug build 23-internal-adhoc.jenkinsi.jdk, mixed mode, sharing)
]
 exitValue = 0

java.lang.RuntimeException: '^.*CPU Quota is: *(\d+|-1|-2|Unlimited).*$' missing from stdout/stderr
at jdk.test.lib.process.OutputAnalyzer.shouldMatch(OutputAnalyzer.java:371)
at PlainRead.match(PlainRead.java:43)
at PlainRead.isContainer(PlainRead.java:57)
at PlainRead.main(PlainRead.java:75)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:1575)

JavaTest Message: Test threw exception: java.lang.RuntimeException: '^.*CPU Quota is: *(\d+|-1|-2|Unlimited).*$' missing from stdout/stderr
JavaTest Message: shutting down test