The following test failed in the JDK20 CI:

vmTestbase/nsk/monitoring/MemoryPoolMBean/isCollectionUsageThresholdExceeded/isexceeded002/TestDescription.java

Here's a snippet from the log file:

#section:main
----------messages:(6/400)----------
command: main nsk.monitoring.MemoryPoolMBean.isCollectionUsageThresholdExceeded.isexceeded001 -testMode=server
reason: User specified action: run main/othervm nsk.monitoring.MemoryPoolMBean.isCollectionUsageThresholdExceeded.isexceeded001 -testMode=server
started: Wed Dec 07 07:25:30 GMT 2022
Mode: othervm [/othervm specified]
finished: Wed Dec 07 07:26:07 GMT 2022
elapsed time (seconds): 37.024
----------configuration:(0/0)----------
----------System.out:(39/2299)----------
MemoryMonitor > Test mode: access to MBean through MBeanServer
MemoryMonitor > MBeanServer: DEFAULT
MemoryMonitor > Memory: heap (This setting is used in lowmem* tests only)
MemoryMonitor > Monitoring: notification (This setting is used in lowmem* tests only)
MemoryMonitor > Threshold: usage (This setting is used in lowmem* tests only)
MemoryMonitor > Timeout: 30 (This setting is used in lowmem* tests only)
0 pool java.lang:name=Metaspace,type=MemoryPool
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
1 pool java.lang:name=ZHeap,type=MemoryPool
  supports collection usage thresholds
  setting threshold 6291457 init = 8388608(8192K) used = 6291456(6144K) committed = 268435456(262144K) max = 717225984(700416K)
  threshold 6291457 is set, (used = 6291456, isExceeded = false)
  used value (6291456) did not cross the threshold value (6291457)
# ERROR: isCollectionUsageThresholdExceeded() returned true, while threshold = 6291457 and used = 6291456
The following stacktrace is for failure analysis.
nsk.share.TestFailure: isCollectionUsageThresholdExceeded() returned true, while threshold = 6291457 and used = 6291456
at nsk.share.Log.logExceptionForFailureAnalysis(Log.java:432)
at nsk.share.Log.complain(Log.java:403)
at nsk.monitoring.MemoryPoolMBean.isCollectionUsageThresholdExceeded.isexceeded001.run(isexceeded001.java:144)
at nsk.monitoring.MemoryPoolMBean.isCollectionUsageThresholdExceeded.isexceeded001.main(isexceeded001.java:37)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
at java.base/java.lang.reflect.Method.invoke(Method.java:578)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:125)
at java.base/java.lang.Thread.run(Thread.java:1599)
2 pool java.lang:name=Compressed Class Space,type=MemoryPool
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
3 pool java.lang:name=CodeCache,type=MemoryPool
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
TEST FAILED


#>
#> SUMMARY: Following errors occured
#> during test execution:
#>
# ERROR: isCollectionUsageThresholdExceeded() returned true, while threshold = 6291457 and used = 6291456
----------System.err:(0/0)----------
----------rerun:(37/8781)*----------