The following test failed in the JDK16 CI:

jdk/jfr/event/os/TestThreadContextSwitches.java

Here's a snippet from the log file:

#section:main
----------messages:(5/291)----------
command: main jdk.jfr.event.os.TestThreadContextSwitches
reason: User specified action: run main/othervm jdk.jfr.event.os.TestThreadContextSwitches
Mode: othervm [/othervm specified]
Additional options from @modules: --add-modules jdk.jfr,java.management
elapsed time (seconds): 8.451
----------configuration:(3/54)----------
Boot Layer
  add modules: jdk.jfr java.management

----------System.out:(0/0)----------
----------System.err:(16/1062)----------
java.lang.RuntimeException: No events: expected false, was true
at jdk.test.lib.Asserts.fail(Asserts.java:594)
at jdk.test.lib.Asserts.assertFalse(Asserts.java:461)
at jdk.test.lib.jfr.Events.hasEvents(Events.java:161)
at jdk.jfr.event.os.TestThreadContextSwitches.main(TestThreadContextSwitches.java:50)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)

JavaTest Message: Test threw exception: java.lang.RuntimeException: No events: expected false, was true
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: No events: expected false, was true
----------rerun:(42/4959)*----------