8300148: Consider using a StoreStore barrier instead of Release barrier on ctor exit

[shipilev]

The backport is not clean because the hunk in macro.cpp does not apply to JDK 21, because it was added later with JDK-8287061.

We have been carrying this patch in our internal releases for 4 months, with some services using it successfully. It is time to bring it to JDK 21u.

Additional testing:

• New benchmark improves
• New IR test passes
• Linux AArch64 server fastdebug, all
• Linux x86_64 server fastdebug, all

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8300148 needs maintainer approval

Issue

• JDK-8300148: Consider using a StoreStore barrier instead of Release barrier on ctor exit (Enhancement - P3 - Rejected)

Reviewers

• Paul Hohensee (@phohensee - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/530/head:pull/530
$ git checkout pull/530

Update a local copy of the PR:
$ git checkout pull/530
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/530/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 530

View PR using the GUI difftool:
$ git pr show -t 530

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/530.diff

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[bridgekeeper]

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[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.

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@shipilev This pull request has been inactive for more than 8 weeks and will be automatically closed if another 8 weeks passes without any activity. To avoid this, simply add a new comment to the pull request. Feel free to ask for assistance if you need help with progressing this pull request towards integration!

[shipilev]

Not now, bot.

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[mlbridge]

Webrevs

• 00: Full (a3ae1ca1)

[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.

[shipilev]

/approval request Significantly improves performance on weakly ordered architectures. Was in mainline for 4 months without bugtail, released in JDK 23. Patch applies with minor conflicts. Testing passes. We have been carrying a variant of this patch (with flag off by default, requiring explicit opt-in) in our internal releases, with some services using it successfully in production. Risk is medium: affects synchronization, there is a diagnostic flag to restore old behavior.

[openjdk]

@shipilev
8300148: The approval request has been created successfully.

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@shipilev This pull request has been inactive for more than 8 weeks and will now be automatically closed. If you would like to continue working on this pull request in the future, feel free to reopen it! This can be done using the /open pull request command.