The following test timed out in the JDK16 CI:

vmTestbase/gc/gctests/PhantomReference/phantom001/phantom001.java

Here's a snippet from the log file:

#section:main
----------messages:(6/296)----------
command: main gc.gctests.PhantomReference.phantom001.phantom001 -ms low
reason: User specified action: run main/othervm gc.gctests.PhantomReference.phantom001.phantom001 -ms low 
Mode: othervm [/othervm specified]
Timeout information:
--- Timeout information end.
elapsed time (seconds): 611.916
----------configuration:(0/0)----------
----------System.out:(5366/74960)----------
Stress time: 120 seconds
Stress iterations factor: 1
Stress threads factor: 1
Stress runs factor: 1
Max memory: 1988100096
Sleep time: 500
Iterations: 0
Number of threads: 16
Run GC thread: false
Run mem diag thread: false
Run forever: false
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@6f936f3,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@5ec25245,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@1143b9c0,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@62d66930,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@3165088f,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@7d79249c,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@71781f4a,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@20b677bc,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@398e3255,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@d67bc3c,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@3cd47095,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@2fcceb24,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@67186812,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@57aeae91,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@48613c29,5,MainThreadGroup]
Starting Thread[gc.gctests.PhantomReference.phantom001.phantom001$Test@bc6bca,5,MainThreadGroup]
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
iteration 0
For random generator using seed: -6063212143315736562
To re-run test with same seed value please add "-Djdk.test.lib.random.seed=-6063212143315736562" to command line.
iteration 1
iteration 1

<snip>

iteration 319
iteration 316
iteration 345
iteration 342
iteration 309
iteration 329
Timeout refired 480 times
----------System.err:(0/0)----------
----------rerun:(35/8372)*----------
<snip>

result: Error. Program `/opt/mach5/mesos/work_dir/jib-master/install/jdk-16+31-2134/linux-x64.jdk/jdk-16/bin/java' timed out (timeout set to 480000ms, elapsed time including timeout handling was 492210ms).