The following two tests timed out in the JDK16 CI:

serviceability/sa/TestJmapCoreMetaspace.java
serviceability/sa/TestJmapCore.java

Here's a snippet from the TestJmapCoreMetaspace.java log file:

Run test with ulimit -c: unlimited
[2020-09-29T09:30:27.668129Z] Gathering output for process 21119
[2020-09-29T09:44:40.228878Z] Waiting for completion for process 21119
[2020-09-29T09:44:40.229294Z] Waiting for completion finished for process 21119
Output and diagnostic info for process 21119 was saved into 'pid-21119-output.log'
crashOutputString = [Aborting due to java.lang.OutOfMemoryError: Metaspace
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/debug.cpp:339
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/System/Volumes/Data/mesos/work_dir/slaves/4076d11c-c6ed-4d07-84c1-4ab8d55cd975-S106713/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3a47f114-21ce-479f-82fc-5093d6bb37e2/runs/054d5517-db89-4bf7-bd08-92949929bcd4/workspace/open/src/hotspot/share/utilities/debug.cpp:339)
result: Error. Agent error: java.lang.Exception: Agent 8 timed out with a timeout of 1920 seconds; check console log for any additional details


Here's a snippet from the TestJmapCore.java log file:

Run test with ulimit -c: unlimited
[2020-09-29T09:29:34.105170Z] Gathering output for process 21113
[2020-09-29T09:39:05.635488Z] Waiting for completion for process 21113
[2020-09-29T09:39:05.635667Z] Waiting for completion finished for process 21113
Output and diagnostic info for process 21113 was saved into 'pid-21113-output.log'
crashOutputString = [Aborting due to java.lang.OutOfMemoryError: Java heap space
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/debug.cpp:339
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/System/Volumes/Data/mesos/work_dir/slaves/4076d11c-c6ed-4d07-84c1-4ab8d55cd975-S106713/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/3a47f114-21ce-479f-82fc-5093d6bb37e2/runs/054d5517-db89-4bf7-bd08-92949929bcd4/workspace/open/src/hotspot/share/utilities/debug.cpp:339), pid=21114, tid=8707
# fatal error: OutOfMemory encountered: Java heap space
#
# JRE version: Java(TM) SE Runtime Environment (16.0+18) (fastdebug build 16-ea+18-869)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16-ea+18-869, mixed mode, sharing, tiered, compressed oops, g1 gc, bsd-amd64)
# Core dump will be written. Default location: core.21114
#
# An error report file with more information is saved as:
# /mesos/work_dir/slaves/4076d11c-c6ed-4d07-84c1-4ab8d55cd975-S106665/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/61e03623-cf1d-4c2a-a966-8adeb9a4eb05/runs/07cb6a77-7711-473a-9793-43ddf8fe98d0/testoutput/test-support/jtreg_open_test_hotspot_jtreg_hotspot_tier2_serviceability/scratch/0/hs_err_pid21114.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
]
getCoreFileLocation found stringWithLocation = core.21114
Found core file: core.21114
[2020-09-29T09:39:05.652707Z] Gathering output for process 21127
Attaching to core core.21114 from executable /mesos/work_dir/jib-master/install/jdk-16+18-869/macosx-x64-debug.jdk/jdk-16/fastdebug/bin/java, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 16-ea+18-869
dumpStack: not java Thread.
heap written to heap.hprof

PASSED
----------System.err:(4/36)----------


JavaTest Message: Test complete.

result: Error. Agent error: java.lang.Exception: Agent 7 timed out with a timeout of 960 seconds; check console log for any additional details