The following tests are failing in Tier6:

   4 applications/jcstress/accessAtomic.java
   4 applications/jcstress/acqrel.java
   4 applications/jcstress/atomicity.java
   4 applications/jcstress/coherence.java

The linux-x64-debug failure logs all look like this:

applications/jcstress/coherence.java

org.openjdk.jcstress.tests.coherence.varHandles.byteArray.big.acqrel.CharTest [-Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -XX:MaxRAMPercentage=25, -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/21/35/bundles/linux-x64/jdk-21_linux-x64_bin.tar.gz/jdk-21, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/tmp, -XX:+HeapDumpOnOutOfMemoryError, -XX:+CrashOnOutOfMemoryError, -Xmx768M] had failed with the pre-test error.


applications/jcstress/acqrel.java

org.openjdk.jcstress.tests.acqrel.varHandles.byteBuffer.heap.big.acqrel.IntShortTest [-Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -XX:MaxRAMPercentage=25, -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/21/35/bundles/linux-x64/jdk-21_linux-x64_bin.tar.gz/jdk-21, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/tmp, -XX:+HeapDumpOnOutOfMemoryError, -XX:+CrashOnOutOfMemoryError, -Xmx768M] had failed with the pre-test error.


applications/jcstress/accessAtomic.java

org.openjdk.jcstress.tests.accessAtomic.varHandles.byteBuffer.heap.little.acqrel.IntTest [-Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/scratch, -XX:MaxRAMPercentage=25, -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/21/35/bundles/linux-x64/jdk-21_linux-x64_bin.tar.gz/jdk-21, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/0db9c48f-6638-40d0-9a4b-bd9cc7533eb8-S9900/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/261e7f75-1b2e-4b6b-9b5d-456a51428f67/runs/5cfdfc2d-0d7a-4f85-98c5-62d0d63a5cdd/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part2/tmp, -XX:+HeapDumpOnOutOfMemoryError, -XX:+CrashOnOutOfMemoryError, -Xmx768M] had failed with the pre-test error.


applications/jcstress/atomicity.java

org.openjdk.jcstress.tests.atomicity.varHandles.byteArray.little.CASTest.CompareAndSetInt [-Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/73e57426-9086-438c-bf1c-51bfaf1790ad-S52585/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/651a8f9b-291f-40bb-b55a-c9e84806430d/runs/f59230eb-1eb0-4ae6-a8b5-071009fa085b/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part3/scratch, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/73e57426-9086-438c-bf1c-51bfaf1790ad-S52585/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/651a8f9b-291f-40bb-b55a-c9e84806430d/runs/f59230eb-1eb0-4ae6-a8b5-071009fa085b/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part3/scratch, -XX:MaxRAMPercentage=25, -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/21/35/bundles/linux-x64/jdk-21_linux-x64_bin.tar.gz/jdk-21, -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/73e57426-9086-438c-bf1c-51bfaf1790ad-S52585/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/651a8f9b-291f-40bb-b55a-c9e84806430d/runs/f59230eb-1eb0-4ae6-a8b5-071009fa085b/testoutput/test-support/jtreg_open_test_hotspot_jtreg_jcstress_part3/tmp, -XX:+HeapDumpOnOutOfMemoryError, -XX:+CrashOnOutOfMemoryError, -Xmx768M] had failed with the pre-test error.


All of these pre-test error msgs happen after the logs were limited
with this error mesg:

...
Output overflow:
JT Harness has limited the test output to the text
at the beginning and the end, so that you can see how the
test began, and how it completed.

If you need to see more of the output from the test,
set the system property javatest.maxOutputSize to a higher
value. The current value is 100000
...

so whatever happened was not captured in the log files.

There are a total of 12 change sets tested in jdk-23+10-720-tier6
and none of them jumps out at me as an obvious candidate for
the root cause of these failures.

I'm starting this bug in hotspot/runtime just as a place to land
it since I have no idea what's going in here.