The following test failed in the JDK21 CI:

vmTestbase/nsk/monitoring/MemoryPoolMBean/isCollectionUsageThresholdExceeded/isexceeded005/TestDescription.java

Here's a snippet from the log file:

#section:main
----------messages:(6/444)----------
command: main nsk.monitoring.MemoryPoolMBean.isCollectionUsageThresholdExceeded.isexceeded001 -testMode=proxy -MBeanServer=custom
reason: User specified action: run main/othervm nsk.monitoring.MemoryPoolMBean.isCollectionUsageThresholdExceeded.isexceeded001 -testMode=proxy -MBeanServer=custom
started: Thu Feb 23 14:54:03 UTC 2023
Mode: othervm [/othervm specified]
finished: Thu Feb 23 14:55:04 UTC 2023
elapsed time (seconds): 61.421
----------configuration:(0/0)----------
----------System.out:(55/2978)----------
MemoryMonitor > Test mode: access to MBean through proxy
MemoryMonitor > MBeanServer: CUSTOM
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 CodeHeap 'non-nmethods'
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
1 pool Metaspace
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
2 pool CodeHeap 'profiled nmethods'
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
3 pool PS Old Gen
  supports collection usage thresholds
  setting threshold 1 init = 268435456(262144K) used = 0(0K) committed = 0(0K) max = 716177408(699392K)
  threshold 1 is set, (used = 0, isExceeded = false)
  used value (0) did not cross the threshold value (1)
# ERROR: isCollectionUsageThresholdExceeded() returned true, while threshold = 1 and used = 0
The following stacktrace is for failure analysis.
nsk.share.TestFailure: isCollectionUsageThresholdExceeded() returned true, while threshold = 1 and used = 0
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:103)
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:1623)
4 pool Compressed Class Space
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
5 pool PS Survivor Space
  supports collection usage thresholds
  setting threshold 1 init = 16777216(16384K) used = 0(0K) committed = 16777216(16384K) max = 16777216(16384K)
  threshold 1 is set, (used = 0, isExceeded = false)
  used value (0) did not cross the threshold value (1)
6 pool PS Eden Space
  supports collection usage thresholds
  setting threshold 1 init = 100663296(98304K) used = 0(0K) committed = 100663296(98304K) max = 324009984(316416K)
  threshold 1 is set, (used = 0, isExceeded = false)
  used value (0) did not cross the threshold value (1)
7 pool CodeHeap 'non-profiled nmethods'
  does not support collection usage thresholds
  UnsupportedOperationException is thrown
TEST FAILED


#>
#> SUMMARY: Following errors occured
#> during test execution:
#>
# ERROR: isCollectionUsageThresholdExceeded() returned true, while threshold = 1 and used = 0
----------System.err:(0/0)----------
----------rerun:(41/7238)*----------