StringInternSync2/TestDescription.java FAILED on RISC-V Linux

**Failing Test Info**
Test Name: vmTestbase/gc/gctests/StringInternSync2/TestDescription.java
Test Duration: 51 seconds
Machine it fails on: [test-rise-ubuntu2404-riscv64-21](https://ci.adoptium.net/computer/test-rise-ubuntu2404-riscv64-21), [test-rise-ubuntu2404-riscv64-24](https://ci.adoptium.net/computer/test-rise-ubuntu2404-riscv64-24)
Machines it passes on (if intermittent):

**Jenkins Test Job Info**
Jenkins Test Job Name: Test_openjdk21_hs_extended.openjdk_riscv64_linux_testList_1_rerun
Jenkins Test Job URL: https://ci.adoptium.net/job/Test_openjdk21_hs_extended.openjdk_riscv64_linux_testList_1_rerun/1/
TRSS link for the build (if available): Not available. Deep history found for test target though.

**Deep History Link from TRSS (if available)** https://trss.adoptium.net/deepHistory?testId=6a5b5f2afc7968006d06a93b

** Rerun in Grinder Link (if available) or Steps to Reproduce**

[Grinder rerun link](https://ci.adoptium.net/job/Grinder/parambuild/?SDK_RESOURCE=customized&TARGET=hotspot_custom&TEST_FLAG=&UPSTREAM_TEST_JOB_NAME=Test_openjdk21_hs_extended.openjdk_riscv64_linux&DOCKER_REQUIRED=false&ACTIVE_NODE_TIMEOUT=10&VENDOR_TEST_DIRS=%2Ftest%2Fsystem&EXTRA_DOCKER_ARGS=&TKG_OWNER_BRANCH=adoptium%3Amaster&OPENJ9_SYSTEMTEST_OWNER_BRANCH=eclipse%3Amaster&PLATFORM=riscv64_linux&GENERATE_JOBS=false&KEEP_REPORTDIR=true&PERSONAL_BUILD=false&ADOPTOPENJDK_REPO=https%3A%2F%2Fgithub.com%2Fadoptium%2Faqa-tests.git&RERUN_ITERATIONS=0&LABEL=test-rise-ubuntu2404-riscv64-21&EXTRA_OPTIONS=&CUSTOMIZED_SDK_URL=https%3A%2F%2Fci.adoptium.net%2Fjob%2Fbuild-scripts%2Fjob%2Fjobs%2Fjob%2Frelease%2Fjob%2Fjobs%2Fjob%2Fjdk21u%2Fjob%2Fjdk21u-release-linux-riscv64-temurin%2F34%2F%2Fartifact%2Fworkspace%2Ftarget%2FOpenJDK21U-jdk_riscv64_linux_hotspot_21.0.12.1_1.tar.gz+https%3A%2F%2Fci.adoptium.net%2Fjob%2Fbuild-scripts%2Fjob%2Fjobs%2Fjob%2Frelease%2Fjob%2Fjobs%2Fjob%2Fjdk21u%2Fjob%2Fjdk21u-release-linux-riscv64-temurin%2F34%2F%2Fartifact%2Fworkspace%2Ftarget%2FOpenJDK21U-testimage_riscv64_linux_hotspot_21.0.12.1_1.tar.gz+https%3A%2F%2Fci.adoptium.net%2Fjob%2Fbuild-scripts%2Fjob%2Fjobs%2Fjob%2Frelease%2Fjob%2Fjobs%2Fjob%2Fjdk21u%2Fjob%2Fjdk21u-release-linux-riscv64-temurin%2F34%2F%2Fartifact%2Fworkspace%2Ftarget%2FOpenJDK21U-sbom_riscv64_linux_hotspot_21.0.12.1_1.json&BUILD_IDENTIFIER=&ADOPTOPENJDK_BRANCH=v1.0.14.1-release&LIGHT_WEIGHT_CHECKOUT=false&NON_AQA_TEST_REPOS=&USE_JRE=false&ARTIFACTORY_SERVER=&KEEP_WORKSPACE=false&USER_CREDENTIALS_ID=&JDK_VERSION=21&ITERATIONS=1&VENDOR_TEST_REPOS=https%3A%2F%2Fgithub.com%2Fadoptium%2Ftemurin-build&JDK_REPO=&OPENJ9_BRANCH=master&OPENJ9_SHA=&JCK_GIT_REPO=&VENDOR_TEST_BRANCHES=v2026.08.01&OPENJ9_REPO=https%3A%2F%2Fgithub.com%2Feclipse-openj9%2Fopenj9.git&UPSTREAM_JOB_NAME=&CLOUD_PROVIDER=&PLATFORM_AND_MACHINE=&CUSTOM_TARGET=vmTestbase%2Fgc%2Fgctests%2FStringInternSync2%2FTestDescription.java&VENDOR_TEST_SHAS=&JDK_BRANCH=&TEST_IMAGES_REQUIRED=true&LABEL_ADDITION=&ARTIFACTORY_REPO=&ARTIFACTORY_ROOT_DIR=&UPSTREAM_TEST_JOB_NUMBER=174&DOCKERIMAGE_TAG=&JDK_IMPL=hotspot&TEST_TIME=&SSH_AGENT_CREDENTIAL=&AUTO_DETECT=true&SLACK_CHANNEL=aqavit-bot&DYNAMIC_COMPILE=false&ADOPTOPENJDK_SYSTEMTEST_OWNER_BRANCH=adoptium%3Amaster&APPLICATION_OPTIONS=&CUSTOMIZED_SDK_URL_CREDENTIAL_ID=eclipse_temurin_bot_email_and_token&ARCHIVE_TEST_RESULTS=false&OPENJDK_SHA=&NUM_MACHINES=&RERUN_FAILURE=false&BUILD_LIST=openjdk&USE_TESTENV_PROPERTIES=true&UPSTREAM_JOB_NUMBER=&STF_OWNER_BRANCH=adoptium%3Amaster&TIME_LIMIT=25&JVM_OPTIONS=&PARALLEL=None)

**Java Version output (from console output)**

```
22:05:11 openjdk version "21.0.12.1" 2026-08-18 LTS
22:05:11 OpenJDK Runtime Environment Temurin-21.0.12.1+1 (build 21.0.12.1+1-LTS)
22:05:11 OpenJDK 64-Bit Server VM Temurin-21.0.12.1+1 (build 21.0.12.1+1-LTS, mixed mode, sharing)
```

**Relevant Console Output (showing exceptions/errors/crashes)**

```
02:04:26 Starting Thread[#30,gc.gctests.StringInternSync.StringInternSync$StringGenerator@6e6cdb4d,5,MainThreadGroup]
02:04:26 Exception in
02:04:26 gc.gctests.StringInternSync.StringInternSync$StringGenerator@56779749
02:04:26 nsk.share.TestFailure: The equal interned strings are not the same.
02:04:26 at gc.gctests.StringInternSync.StringInternSync$StringGenerator.run(StringInternSync.java:125)
02:04:26 at nsk.share.runner.ThreadsRunner$ManagedThread.run(ThreadsRunner.java:119)
02:04:26 at java.base/java.lang.Thread.run(Thread.java:1583)
```

**Attach or link to relevant artifacts**

Start with vmTestbase/gc/gctests/StringInternSync2/TestDescription.java and the failure at StringInternSync.java:125. Use the linked Grinder rerun on the RISC-V Linux machines, then compare the failing behavior with the deep history and passing platforms. Done means identifying and fixing the cause so the test passes reliably on the affected machines.

Written by the indexing model from the issue text.