8357968: RISC-V: Interpreter volatile reference stores with G1 are not sequentially consistent

[feilongjiang]

Hi all,

This pull request contains a backport of commit c5a1543e from the openjdk/jdk repository.

The commit being backported was authored by Robbin Ehn on 2 Jun 2025 and was reviewed by Erik Österlund, Fredrik Bredberg, Aleksey Shipilev and Fei Yang.

Thanks!

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8357968 needs maintainer approval

Issue

• JDK-8357968: RISC-V: Interpreter volatile reference stores with G1 are not sequentially consistent (Bug - P4 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/1910/head:pull/1910
$ git checkout pull/1910

Update a local copy of the PR:
$ git checkout pull/1910
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/1910/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 1910

View PR using the GUI difftool:
$ git pr show -t 1910

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/1910.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back fjiang! 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]

@feilongjiang 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:

8357968: RISC-V: Interpreter volatile reference stores with G1 are not sequentially consistent

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 20 new commits pushed to the master branch:

• 8e68eb1: 8340276: Test java/lang/management/ThreadMXBean/Locks.java failed with NullPointerException
• 773a2be: 8349378: Build splashscreen lib with SIZE optimization
• 10929bd: 8358538: Update GHA Windows runner to 2025
• ... and 17 more: https://git.openjdk.org/jdk21u-dev/compare/9a6ef52b82e66dfd5779f66113c28371ff2fd776...master

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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[openjdk]

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

[openjdk]

⚠️ @feilongjiang 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 (535a7329)

[feilongjiang]

/approval request
Same issue exists in jdk21u repo as well. And the bug is reproducible with jcstress RefDekker test with jdk21u.
Backport is clean. This is a RISC-V specific change, should be low risk.
Tier1-3 tested on linux-riscv64 platform. jcstress RefDekker test passes with this backport.

[openjdk]

@feilongjiang
8357968: The approval request has been created successfully.

[robehn]

Thanks!

[feilongjiang]

/integrate

[openjdk]

@feilongjiang
Your change (at version 535a732) is now ready to be sponsored by a Committer.

[RealFYang]

/sponsor

[openjdk]

Going to push as commit f2614cc.
Since your change was applied there have been 20 commits pushed to the master branch:

• 8e68eb1: 8340276: Test java/lang/management/ThreadMXBean/Locks.java failed with NullPointerException
• 773a2be: 8349378: Build splashscreen lib with SIZE optimization
• 10929bd: 8358538: Update GHA Windows runner to 2025
• ... and 17 more: https://git.openjdk.org/jdk21u-dev/compare/9a6ef52b82e66dfd5779f66113c28371ff2fd776...master

Your commit was automatically rebased without conflicts.

[openjdk]

@RealFYang @feilongjiang Pushed as commit f2614cc.

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