jdk17 MiniMix_5m getMySurplusQueuedTaskCount() expected:<1> but was:<-7>

The extended.system target MiniMix_5m reports a failure from one of the tests in the workload followed by the jdk hanging until it is killed.

Does not happen all the time, but often (maybe 50%).

Occurs on both openj9 and hotspot, and on all platforms. Not seen on jdk8, jdk11 or jdk16,

The test is set to run for five minutes - at the end of the test some threads do not terminate. A run on a local Windows machine showed that when the test is at the hanging stage the jdk is not consuming CPU.

The output from the failing subtest is:
```
14:13:08 LT testStarted : testAPI(net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest)
14:13:08 LT testFailure: testAPI(net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest): 25 : getMySurplusQueuedTaskCount() expected:<1> but was:<-7>
```

The test output at point of the failure including the hang:
```
14:08:58 LT 08:08:57.902 - Starting thread. Suite=0 thread=0
14:08:58 LT 08:08:57.905 - Starting thread. Suite=0 thread=1
14:08:58 LT 08:08:57.906 - Starting thread. Suite=0 thread=2
14:08:58 LT 08:08:57.906 - Starting thread. Suite=0 thread=3
14:08:58 LT 08:08:57.907 - Starting thread. Suite=0 thread=4
14:08:58 LT 08:08:57.907 - Starting thread. Suite=0 thread=5
14:08:58 LT 08:08:57.908 - Starting thread. Suite=0 thread=6
14:08:58 LT 08:08:57.908 - Starting thread. Suite=0 thread=7
14:08:58 LT 08:08:57.909 - Starting thread. Suite=0 thread=8
14:08:58 LT 08:08:57.909 - Starting thread. Suite=0 thread=9
14:09:19 LT 08:09:17.882 - Completed 6.7%. Number of tests started=6587
14:09:39 LT 08:09:37.899 - Completed 13.4%. Number of tests started=11342 (+4755)
14:10:00 LT 08:09:57.844 - Completed 20.1%. Number of tests started=16729 (+5387)
14:10:20 LT 08:10:17.810 - Completed 26.8%. Number of tests started=21217 (+4488)
14:10:40 LT 08:10:37.861 - Completed 33.5%. Number of tests started=25330 (+4113)
14:11:01 LT 08:10:57.892 - Completed 40.3%. Number of tests started=27937 (+2607)
14:11:18 LT 08:11:17.835 - Completed 46.9%. Number of tests started=31971 (+4034)
14:11:38 LT 08:11:37.870 - Completed 53.7%. Number of tests started=34567 (+2596)
14:11:59 LT 08:11:57.804 - Completed 60.3%. Number of tests started=39477 (+4910)
14:12:19 LT 08:12:17.849 - Completed 67.1%. Number of tests started=42358 (+2881)
14:12:39 LT 08:12:37.825 - Completed 73.8%. Number of tests started=44796 (+2438)
14:12:59 LT 08:12:57.824 - Completed 80.5%. Number of tests started=46736 (+1940)
14:13:08 LT 08:13:07.577 - First failure detected by thread: load-6. Not creating dumps as no dump generation is requested for this load test
14:13:08 LT 08:13:07.580 - suite.getInventory().getInventoryFileRef(): openjdk.test.load/config/inventories/mix/mix-more.xml
14:13:08 LT 08:13:07.581 - suite.isCreateDump() : false
14:13:08 LT 08:13:07.583 - Test failed
14:13:08 LT Failure num. = 1
14:13:08 LT Test number = 3718
14:13:08 LT Test details = 'JUnit[net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest]'
14:13:08 LT Suite number = 0
14:13:08 LT Thread number = 6
14:13:08 LT >>> Captured test output >>>
14:13:08 LT testStarted : testAPI(net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest)
14:13:08 LT testFailure: testAPI(net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest): 25 : getMySurplusQueuedTaskCount() expected:<1> but was:<-7>
14:13:08 LT junit.framework.AssertionFailedError: 25 : getMySurplusQueuedTaskCount() expected:<1> but was:<-7>
14:13:08 LT at junit.framework.Assert.fail(Assert.java:57)
14:13:08 LT at junit.framework.Assert.failNotEquals(Assert.java:329)
14:13:08 LT at junit.framework.Assert.assertEquals(Assert.java:78)
14:13:08 LT at junit.framework.Assert.assertEquals(Assert.java:234)
14:13:08 LT at junit.framework.TestCase.assertEquals(TestCase.java:401)
14:13:08 LT at net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest.testAPI(ForkJoinTaskTest.java:174)
14:13:08 LT at jdk.internal.reflect.GeneratedMethodAccessor8280.invoke(Unknown Source)
14:13:08 LT at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
14:13:08 LT at java.base/java.lang.reflect.Method.invoke(Method.java:566)
14:13:08 LT at junit.framework.TestCase.runTest(TestCase.java:176)
14:13:08 LT at junit.framework.TestCase.runBare(TestCase.java:141)
14:13:08 LT at junit.framework.TestResult$1.protect(TestResult.java:122)
14:13:08 LT at junit.framework.TestResult.runProtected(TestResult.java:142)
14:13:08 LT at junit.framework.TestResult.run(TestResult.java:125)
14:13:08 LT at junit.framework.TestCase.run(TestCase.java:129)
14:13:08 LT at junit.framework.TestSuite.runTest(TestSuite.java:252)
14:13:08 LT at junit.framework.TestSuite.run(TestSuite.java:247)
14:13:08 LT at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
14:13:08 LT at org.junit.runners.Suite.runChild(Suite.java:128)
14:13:08 LT at org.junit.runners.Suite.runChild(Suite.java:27)
14:13:08 LT at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
14:13:08 LT at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
14:13:08 LT at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
14:13:08 LT at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
14:13:08 LT at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
14:13:08 LT at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
14:13:08 LT at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
14:13:08 LT at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
14:13:08 LT at net.adoptopenjdk.loadTest.adaptors.JUnitAdaptor.executeTest(JUnitAdaptor.java:130)
14:13:08 LT at net.adoptopenjdk.loadTest.LoadTestRunner$2.run(LoadTestRunner.java:182)
14:13:08 LT at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135)
14:13:08 LT at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
14:13:08 LT at java.base/java.lang.Thread.run(Thread.java:853)
14:13:08 LT testFinished: testAPI(net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest)
14:13:08 LT
14:13:08 LT JUnit Test Results for: net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest
14:13:08 LT Ran : 1
14:13:08 LT Passed : 0
14:13:08 LT Failed : 1
14:13:08 LT Ignored: 0
14:13:08 LT Result : FAILED
14:13:08 LT <<<
14:13:08 LT
14:13:19 LT 08:13:17.819 - Completed 87.2%. Number of tests started=48665 (+1929) (with 1 failure(s))
14:13:39 LT 08:13:37.862 - Completed 93.9%. Number of tests started=51824 (+3159) (with 1 failure(s))
14:13:54 STF 08:13:54.017 - Heartbeat: Process LT is still running
14:13:57 LT 08:13:56.207 - Thread completed. Suite=0 thread=9
14:13:58 LT 08:13:57.877 - Completed 100.0%. Number of tests started=53557 (+1733) (with 1 failure(s))
14:13:58 LT 08:13:58.352 - Thread completed. Suite=0 thread=0
14:14:01 LT 08:14:00.764 - Thread completed. Suite=0 thread=1
14:14:12 LT 08:14:10.938 - Thread completed. Suite=0 thread=5
14:14:13 LT 08:14:13.103 - Thread completed. Suite=0 thread=3
14:14:15 LT 08:14:14.819 - Thread completed. Suite=0 thread=2
14:14:18 LT 08:14:17.817 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:14:39 LT 08:14:37.849 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:14:59 LT 08:14:57.882 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:15:19 LT 08:15:17.814 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:15:39 LT 08:15:37.856 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:16:00 LT 08:15:57.888 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:16:20 LT 08:16:17.819 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:16:37 LT 08:16:37.847 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:17:01 LT 08:16:57.878 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:17:18 LT 08:17:17.808 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:17:39 LT 08:17:37.841 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:17:59 LT 08:17:57.872 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:18:20 LT 08:18:17.805 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:18:40 LT 08:18:37.834 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:18:55 STF 08:18:54.109 - Heartbeat: Process LT is still running
14:18:59 LT 08:18:57.865 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:19:19 LT 08:19:17.898 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:19:39 LT 08:19:37.829 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:20:00 LT 08:19:57.860 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:20:20 LT 08:20:17.891 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:20:40 LT 08:20:37.822 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:21:01 LT 08:20:57.850 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:21:18 LT 08:21:17.880 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:21:38 LT 08:21:37.811 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:21:59 LT 08:21:57.840 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:22:19 LT 08:22:17.870 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:22:40 LT 08:22:37.898 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:23:00 LT 08:22:57.827 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:23:20 LT 08:23:17.857 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:23:41 LT 08:23:37.887 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:23:55 STF 08:23:54.187 - Heartbeat: Process LT is still running
14:23:59 LT 08:23:57.818 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:24:19 LT 08:24:17.848 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:24:40 LT 08:24:37.879 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:25:00 LT 08:24:57.808 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:25:20 LT 08:25:17.838 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:25:41 LT 08:25:37.867 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:25:58 LT 08:25:57.800 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:26:19 LT 08:26:17.831 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:26:39 LT 08:26:37.866 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:27:00 LT 08:26:57.897 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:27:20 LT 08:27:17.827 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:27:40 LT 08:27:37.858 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:28:00 LT 08:27:57.886 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:28:18 LT 08:28:17.814 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:28:38 LT 08:28:37.842 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:28:56 STF 08:28:54.275 - Heartbeat: Process LT is still running
14:28:58 LT 08:28:57.871 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:29:16 LT 08:29:14.997 - **POSSIBLE HANG DETECTED**
14:29:16 STF 08:29:15.316 - **FAILED** Process LT has hung
14:29:16 STF 08:29:15.316 - Collecting dumps for: LT
14:29:16 STF 08:29:15.316 - Sending SIG 3 to the java process to generate a javacore
14:29:16 STF 08:29:15.317 - Running command: kill -3 11789
14:29:16 STF 08:29:15.317 - Redirecting stderr to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_3.stderr
14:29:16 STF 08:29:15.317 - Redirecting stdout to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_3.stdout
14:29:16 STF 08:29:15.319 - Pausing for 30 seconds
14:29:49 STF 08:29:45.319 - Sending SIG 3 to the java process to generate a javacore
14:29:49 STF 08:29:45.320 - Running command: kill -3 11789
14:29:49 STF 08:29:45.320 - Redirecting stderr to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_3.stderr
14:29:49 STF 08:29:45.320 - Redirecting stdout to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_3.stdout
14:29:49 STF 08:29:45.321 - Pausing for 30 seconds
14:30:17 STF 08:30:15.322 - Sending SIG 3 to the java process to generate a javacore
14:30:17 STF 08:30:15.322 - Running command: kill -3 11789
14:30:17 STF 08:30:15.322 - Redirecting stderr to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_3.stderr
14:30:17 STF 08:30:15.322 - Redirecting stdout to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_3.stdout
14:30:17 STF 08:30:15.324 - Pausing for 30 seconds
14:30:45 STF 08:30:45.324 - Sending SIGABRT (kill -6) to the java process to generate a core
14:30:45 STF 08:30:45.325 - Running command: kill -6 11789
14:30:45 STF 08:30:45.325 - Redirecting stderr to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_6.stderr
14:30:45 STF 08:30:45.325 - Redirecting stdout to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_6.stdout
14:30:45 STF 08:30:45.327 - Pausing for 30 seconds
14:31:19 STF 08:31:15.327 - Sending SIGXCPU (kill -24) to the java process to generate an OS dump
14:31:19 STF 08:31:15.328 - Running command: kill -24 11789
14:31:19 STF 08:31:15.329 - Redirecting stderr to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_24.stderr
14:31:19 STF 08:31:15.329 - Redirecting stdout to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/1.LT.kill_24.stdout
14:31:19 LT 08:29:17.897 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:31:19 LT 08:29:20.001 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:25.008 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:30.015 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:35.023 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:37.827 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:31:19 LT 08:29:40.031 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:45.038 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:50.039 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:55.046 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:29:57.850 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:31:19 LT 08:30:00.053 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:05.060 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:10.066 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:15.073 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:17.801 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:31:19 LT 08:30:20.104 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:25.112 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:30.119 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:35.126 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:37.830 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:31:19 LT 08:30:40.133 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:45.141 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:50.150 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:55.158 - **POSSIBLE HANG DETECTED**
14:31:19 LT 08:30:57.871 - Completed 100.0%. Number of tests started=53557 (+0) (with 1 failure(s))
14:31:19 LT 08:31:00.174 - **POSSIBLE HANG DETECTED**
14:31:19 LT stderr JVMDUMP039I Processing dump event "user", detail "" at 2021/02/14 08:29:15 - please wait.
14:31:19 LT stderr JVMDUMP032I JVM requested Java dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.082915.11789.0001.txt' in response to an event
14:31:19 LT stderr JVMDUMP010I Java dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.082915.11789.0001.txt
14:31:19 LT stderr JVMDUMP013I Processed dump event "user", detail "".
14:31:19 LT stderr JVMDUMP039I Processing dump event "user", detail "" at 2021/02/14 08:29:45 - please wait.
14:31:19 LT stderr JVMDUMP032I JVM requested Java dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.082945.11789.0002.txt' in response to an event
14:31:19 LT stderr JVMDUMP010I Java dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.082945.11789.0002.txt
14:31:19 LT stderr JVMDUMP013I Processed dump event "user", detail "".
14:31:19 LT stderr JVMDUMP039I Processing dump event "user", detail "" at 2021/02/14 08:30:15 - please wait.
14:31:19 LT stderr JVMDUMP032I JVM requested Java dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.083015.11789.0003.txt' in response to an event
14:31:19 LT stderr JVMDUMP010I Java dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.083015.11789.0003.txt
14:31:19 LT stderr JVMDUMP013I Processed dump event "user", detail "".
14:31:19 LT stderr JVMDUMP039I Processing dump event "abort", detail "" at 2021/02/14 08:30:45 - please wait.
14:31:19 LT stderr JVMDUMP032I JVM requested System dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/core.20210214.083045.11789.0004.dmp' in response to an event
14:31:19 LT stderr JVMDUMP010I System dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/core.20210214.083045.11789.0004.dmp
14:31:19 LT stderr JVMDUMP032I JVM requested Java dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.083045.11789.0005.txt' in response to an event
14:31:19 LT stderr JVMDUMP010I Java dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/javacore.20210214.083045.11789.0005.txt
14:31:19 LT stderr JVMDUMP032I JVM requested Snap dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/Snap.20210214.083045.11789.0006.trc' in response to an event
14:31:19 LT stderr JVMDUMP010I Snap dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/Snap.20210214.083045.11789.0006.trc
14:31:19 LT stderr JVMDUMP032I JVM requested JIT dump using '/home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/jitdump.20210214.083045.11789.0007.dmp' in response to an event
14:31:19 LT stderr JVMDUMP010I JIT dump written to /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/results/jitdump.20210214.083045.11789.0007.dmp
14:31:19 LT stderr JVMDUMP013I Processed dump event "abort", detail "".
14:31:19 STF 08:31:15.331 - Monitoring Report Summary:
14:31:19 STF 08:31:15.332 - o Process LT has hung
14:31:19 STF 08:31:15.332 - Killing processes: LT
14:31:19 STF 08:31:15.333 - o Process LT pid 11789 is not running
14:31:19 **FAILED** at step 1 (Run mixed unit tests). Expected return value=0 Actual=1 at /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/../TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/execute.pl line 96.
14:31:19 STF 08:31:15.560 - **FAILED** execute script failed. Expected return value=0 Actual=1
14:31:19 STF 08:31:15.560 -
14:31:19 STF 08:31:15.560 - ==================== T E A R D O W N ====================
14:31:19 STF 08:31:15.560 - Running teardown: perl /home/jenkins/workspace/Test_openjdk17_j9_extended.system_x86-64_linux/openjdk-tests/TKG/../TKG/output_16133080911379/MiniMix_5m_0/20210214-080848-MixedLoadTest/tearDown.pl
14:31:19 STF 08:31:15.605 - TEARDOWN stage completed
14:31:19 STF 08:31:15.609 -
14:31:19 STF 08:31:15.609 - ===================== R E S U L T S =====================
14:31:19 STF 08:31:15.609 - Stage results:
14:31:19 STF 08:31:15.609 - setUp: pass
14:31:19 STF 08:31:15.609 - execute: *fail*
14:31:19 STF 08:31:15.609 - teardown: pass
14:31:19 STF 08:31:15.609 -
14:31:19 STF 08:31:15.609 - Overall result: **FAILED**
14:31:19
14:31:19 MiniMix_5m_0_FAILED
```
To rerun the test: https://ci.adoptopenjdk.net/job/Grinder/parambuild/?JDK_VERSION=17&JDK_IMPL=openj9&JDK_VENDOR=adoptopenjdk&BUILD_LIST=system&PLATFORM=x86-64_linux&TARGET=MiniMix_5m_0

Start with the extended.system target MiniMix_5m and inspect net.adoptopenjdk.test.concurrent.jsr166y.ForkJoinTaskTest.testAPI at line 174, where getMySurplusQueuedTaskCount() fails. Reproduce the five-minute workload on JDK 17 and compare the failure and thread hang with other JDK versions. Done means the intermittent assertion failure and non-terminating threads are resolved.

Written by the indexing model from the issue text.