The following tests timed out in the Valhalla CI:

gc/TestJNIWeak/TestJNIWeak.java
gc/stringdedup/TestStringDeduplicationYoungGC.java#Z
gc/stringdedup/TestStringDeduplicationPrintOptions.java#Z
gc/stringdedup/TestStringDeduplicationAgeThreshold.java#Z

Each of the tests timed out, but PASSed while the timeout handler was running.

Here's a log file snippet from TestJNIWeak.java:

#section:main
----------messages:(11/596)----------
command: main -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xcomp gc.TestJNIWeak.TestJNIWeak
reason: User specified action: run main/othervm/native -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xcomp gc.TestJNIWeak.TestJNIWeak
started: Thu Jan 29 02:03:38.855 UTC 2026
Mode: othervm [/othervm specified]
Process id: 3388734
Timeout information:
[02:11:38.925] starting timeout handler action(s)
[02:23:43.872] timeout handler action(s) completed
--- Timeout information end.
finished: Thu Jan 29 02:23:43.955 UTC 2026
elapsed time (seconds): 1205.1
----------configuration:(0/0)----------
----------System.out:(13/307)----------
Check with jweak resolved
running checkSanity
running checkSurvival
running checkClear
running checkShouldNotClear
[02:11:38.917] Timeout signalled after 480 seconds
Check passed
Check with jweak returned
running checkSanity
running checkSurvival
running checkClear
running checkShouldNotClear
Check passed
----------System.err:(6/706)----------
WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::loadLibrary has been called by gc.TestJNIWeak.TestJNIWeak in an unnamed module (file:/opt/mach5/mesos/work_dir/slaves/da1065b5-7b94-4f0d-85e9-a3a252b9a32e-S93109/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/5eba0433-e601-460a-bea0-8e4cd2d43053/runs/e417e6b3-5a29-4a9f-b8ad-d6788aa6efa8/testoutput/test-support/jtreg_open_test_hotspot_jtreg_tier1_gc/classes/1/gc/TestJNIWeak/TestJNIWeak.d/)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

STATUS:Passed.
----------rerun:(50/8887)*----------


Here's a log file snippet from TestStringDeduplicationYoungGC.java#Z:

#section:driver
----------messages:(14/620)----------
command: driver gc.stringdedup.TestStringDeduplicationYoungGC Z
reason: User specified action: run driver gc.stringdedup.TestStringDeduplicationYoungGC Z
started: Thu Jan 29 02:00:29.661 UTC 2026
Mode: agentvm
Agent id: 14
Process id: 3385901
Additional opens to unnamed modules from @modules: java.base/jdk.internal.misc java.base/java.lang
[02:08:29.718] Timeout signalled after 480 seconds
Timeout information:
[02:08:29.736] starting timeout handler action(s)
[02:37:42.895] timeout handler action(s) completed
--- Timeout information end.
finished: Thu Jan 29 02:37:42.901 UTC 2026
elapsed time (seconds): 2233.24
----------configuration:(17/2164)----------

This test generates a huge amount of output to stdout so it's
hard to figure out a good bit to snip and include here.


Here's a log file snippet from TestStringDeduplicationPrintOptions.java#Z:

#section:driver
----------messages:(14/631)----------
command: driver gc.stringdedup.TestStringDeduplicationPrintOptions Z
reason: User specified action: run driver gc.stringdedup.TestStringDeduplicationPrintOptions Z
started: Thu Jan 29 01:57:48.105 UTC 2026
Mode: agentvm
Agent id: 15
Process id: 3386245
Additional opens to unnamed modules from @modules: java.base/jdk.internal.misc java.base/java.lang
[02:05:48.110] Timeout signalled after 480 seconds
Timeout information:
[02:05:48.118] starting timeout handler action(s)
[02:36:10.295] timeout handler action(s) completed
--- Timeout information end.
finished: Thu Jan 29 02:36:10.479 UTC 2026
elapsed time (seconds): 2302.374
----------configuration:(17/2174)----------


Here's a log file snippet from TestStringDeduplicationAgeThreshold.java#Z:

#section:driver
----------messages:(14/631)----------
command: driver gc.stringdedup.TestStringDeduplicationAgeThreshold Z
reason: User specified action: run driver gc.stringdedup.TestStringDeduplicationAgeThreshold Z
started: Thu Jan 29 01:57:44.052 UTC 2026
Mode: agentvm
Agent id: 18
Process id: 3388061
Additional opens to unnamed modules from @modules: java.base/jdk.internal.misc java.base/java.lang
[02:05:45.917] Timeout signalled after 480 seconds
Timeout information:
[02:05:45.929] starting timeout handler action(s)
[02:38:37.785] timeout handler action(s) completed
--- Timeout information end.
finished: Thu Jan 29 02:38:37.786 UTC 2026
elapsed time (seconds): 2453.734
----------configuration:(17/2174)----------

This set of timeout failures is odd and I can't find any other instances
of these tests timing out in the same way.
TestStringDeduplicationAgeThreshold.java#Z did have an "Agent"
timeout error, but that's a different problem.

I don't see anything suspicious in the build-ID in which these
timeouts occurred and the next Tier4 build-ID is GREEN.