8318986: Improve GenericWaitBarrier performance

[shipilev]

Clean backport to drastically improve safepoint performance under heavy load, fixing regression between JDK 11 and JDK 17.

Additional testing:

• Ad-hoc performance runs, expected improvements
• MacOS AArch64 server fastdebug, tier{1,2,3}

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8318986 needs maintainer approval

Issue

• JDK-8318986: Improve GenericWaitBarrier performance (Enhancement - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk17u-dev.git pull/2041/head:pull/2041
$ git checkout pull/2041

Update a local copy of the PR:
$ git checkout pull/2041
$ git pull https://git.openjdk.org/jdk17u-dev.git pull/2041/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 2041

View PR using the GUI difftool:
$ git pr show -t 2041

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk17u-dev/pull/2041.diff

Webrev

Link to Webrev Comment

[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.

[bridgekeeper]

@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.

[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:

8318986: Improve GenericWaitBarrier performance

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

[shipilev]

/approval request Clean backport to drastically improve safepoint performance under heavy load, fixing regression between JDK 11 and JDK 17. Applies cleanly. There is no bugtail in mainline since integration in Nov 2023. tier{1,2,3} tests pass. Risk is medium, as it touches the common code path for non-Linux platforms, but it is also frequently exercised, and thus a breakage would manifest often.

[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.

[openjdk]

@shipilev
8318986: The approval request has been created successfully.

[mlbridge]

Webrevs

• 01: Full - Incremental (6a7c9ca7)
• 00: Full (5db67531)

[shipilev]

GHA failures are environmental.

[bridgekeeper]

@shipilev This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 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.

[bridgekeeper]

@shipilev This pull request has been inactive for more than 4 weeks and will be automatically closed if another 4 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. We are planning this for October LTS release.

[shipilev]

Re-ran tier{1,2,3} on MacOS AArch64, looks fine.

/integrate

[openjdk]

Going to push as commit 515bc9a.
Since your change was applied there have been 4 commits pushed to the master branch:

• dcb2c35: 8295111: dpkg appears to have problems resolving symbolically linked native libraries
• 8faeefc: 8289182: NMT: MemTracker::baseline should return void
• e85eecb: 8288568: Reduce runtime of java.security microbenchmarks
• 2d834b3: 8326446: The User and System of jdk.CPULoad on Apple M1 are inaccurate

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 515bc9a.

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