8325074: ZGC fails assert(index == 0 || is_power_of_2(index)) failed: Incorrect load shift: 11

[shipilev]

Clean backport to fix a regression introduced by JDK-8321619 in 21.0.3.

Additional testing:

• Linux x86_64 server fastdebug, all with -XX:+UseZGC -XX:+ZGenerational (some known failures)

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8325074 needs maintainer approval

Issue

• JDK-8325074: ZGC fails assert(index == 0 || is_power_of_2(index)) failed: Incorrect load shift: 11 (Bug - P2 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/268/head:pull/268
$ git checkout pull/268

Update a local copy of the PR:
$ git checkout pull/268
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/268/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 268

View PR using the GUI difftool:
$ git pr show -t 268

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/268.diff

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[bridgekeeper]

👋 Welcome back shade! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

⚠️ @shipilev This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (3c823a0b)

[shipilev]

/approval request Clean backport to fix a regression introduced by JDK-8321619 in 21.0.3. Only affects Generational ZGC (new in 21), all tests pass with some known failures.

[openjdk]

@shipilev
8325074: The approval request has been created successfully.

[openjdk]

@shipilev This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8325074: ZGC fails assert(index == 0 || is_power_of_2(index)) failed: Incorrect load shift: 11

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 8 new commits pushed to the master branch:

• 3b4932b: 8315726: Open source several AWT applet tests
• 92d533e: 8323640: [TESTBUG]testMemoryFailCount in jdk/internal/platform/docker/TestDockerMemoryMetrics.java always fail because OOM killed
• 36569de: 8314629: Generational ZGC: Clearing All SoftReferences log line lacks GCId
• 90c9f70: 8314164: java/net/HttpURLConnection/HttpURLConnectionExpectContinueTest.java fails intermittently in timeout
• 4fcc5c7: 8322790: RISC-V: Tune costs for shuffles with no conversion
• a9792a8: 8324874: AArch64: crypto pmull based CRC32/CRC32C intrinsics clobber V8-V15 registers
• d6f4f5e: 8318737: Fallback linker passes bad JNI handle
• 4d4c47d: 8320890: [AIX] Find a better way to mimic dl handle equality

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[shipilev]

/integrate

[openjdk]

Going to push as commit 9adc281.
Since your change was applied there have been 8 commits pushed to the master branch:

• 3b4932b: 8315726: Open source several AWT applet tests
• 92d533e: 8323640: [TESTBUG]testMemoryFailCount in jdk/internal/platform/docker/TestDockerMemoryMetrics.java always fail because OOM killed
• 36569de: 8314629: Generational ZGC: Clearing All SoftReferences log line lacks GCId
• 90c9f70: 8314164: java/net/HttpURLConnection/HttpURLConnectionExpectContinueTest.java fails intermittently in timeout
• 4fcc5c7: 8322790: RISC-V: Tune costs for shuffles with no conversion
• a9792a8: 8324874: AArch64: crypto pmull based CRC32/CRC32C intrinsics clobber V8-V15 registers
• d6f4f5e: 8318737: Fallback linker passes bad JNI handle
• 4d4c47d: 8320890: [AIX] Find a better way to mimic dl handle equality

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 9adc281.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.