8380390: Shenandoah: Missing store barrier when resetting bitmaps

[earthling-amzn]

Resolved a trivial conflict in includes.

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• JDK-8386798 needs maintainer approval
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8380390 needs maintainer approval

Issues

• JDK-8380390: Shenandoah: Missing store barrier when resetting bitmaps (Bug - P4)
• JDK-8386798: Shenandoah: Missing load barrier when making assertions about mark bitmap (Bug - P4)

Reviewers

• Xiaolong Peng (@pengxiaolong - Author)

Reviewing

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$ git fetch https://git.openjdk.org/jdk25u-dev.git pull/611/head:pull/611
$ git checkout pull/611

Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk25u-dev.git pull/611/head

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Using Webrev

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[bridgekeeper]

👋 Welcome back wkemper! 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 change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

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

[mlbridge]

Webrevs

• 01: Full - Incremental (7fd8de88)
• 00: Full (5fdf0c54)

[earthling-amzn]

/approval request I believe this is a low risk change. It introduces a store barrier into the bitmap clearing sequence for Shenandoah to prevent other threads from observing stale mark bits. The issue manifests most readily on PPC machines with high core counts.

[openjdk]

@earthling-amzn
8380390: The approval request has been created successfully.

[earthling-amzn]

/approval cancel

We have a follow up PR coming.

[openjdk]

@earthling-amzn
8380390: The approval request has been cancelled successfully.

[earthling-amzn]

/issue add 8386798

[openjdk]

@earthling-amzn
Adding additional issue to issue list: 8386798: Shenandoah: Missing load barrier when making assertions about mark bitmap.

[pengxiaolong]

LGTM