8170817: G1: Returning MinTLABSize from unsafe_max_tlab_alloc causes TLAB flapping

[pengxiaolong]

Hi all,

This pull request contains a backport of commit 4c79e7d5 from the openjdk/jdk repository.

The commit being backported was authored by Ivan Walulya on 12 Oct 2023 and was reviewed by Thomas Schatzl and Albert Mingkun Yang.

Thanks!

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8170817 needs maintainer approval

Issue

• JDK-8170817: G1: Returning MinTLABSize from unsafe_max_tlab_alloc causes TLAB flapping (Enhancement - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/774/head:pull/774
$ git checkout pull/774

Update a local copy of the PR:
$ git checkout pull/774
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/774/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 774

View PR using the GUI difftool:
$ git pr show -t 774

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/774.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back xpeng! 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]

@pengxiaolong 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:

8170817: G1: Returning MinTLABSize from unsafe_max_tlab_alloc causes TLAB flapping

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 48 new commits pushed to the master branch:

• e456f8b: 8319406: x86: Shorter movptr(reg, imm) for 32-bit immediates
• 75287b5: 8330027: Identity hashes of archived objects must be based on a reproducible random seed
• cbd67f9: Merge
• a0b3c6c: 8334441: Mark tests in jdk_security_infra group as manual
• 3ce370a: 8323584: AArch64: Unnecessary ResourceMark in NativeCall::set_destination_mt_safe
• ad5e16f: 8325587: Shenandoah: ShenandoahLock should allow blocking in VM
• 03a7176: 8333099: Missing check for is_LoadVector in StoreNode::Identity
• f9f11d7: 8334867: Add back assertion from JDK-8325494
• 65cf18a: 8328896: Fontmetrics for large Fonts has zero width
• e257ae5: 8051959: Add thread and timestamp options to java.security.debug system property
• ... and 38 more: https://git.openjdk.org/jdk21u-dev/compare/fe999ba7840f9bd306f46178747e743a502d3535...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]

⚠️ @pengxiaolong 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 (284d6a17)

[pengxiaolong]

/approval request Backport JDK-8170817 to jdk21; applies cleanly; risk is low, the fix has been in tip for over 6 months, also ran tier1 and tier2 test.

[openjdk]

@pengxiaolong
8170817: The approval request has been created successfully.

[pengxiaolong]

Thanks for the review and approval.

/integrate

[openjdk]

@pengxiaolong
Your change (at version 284d6a1) is now ready to be sponsored by a Committer.

[phohensee]

/sponsor

[openjdk]

Going to push as commit 6b4fa86.
Since your change was applied there have been 48 commits pushed to the master branch:

• e456f8b: 8319406: x86: Shorter movptr(reg, imm) for 32-bit immediates
• 75287b5: 8330027: Identity hashes of archived objects must be based on a reproducible random seed
• cbd67f9: Merge
• a0b3c6c: 8334441: Mark tests in jdk_security_infra group as manual
• 3ce370a: 8323584: AArch64: Unnecessary ResourceMark in NativeCall::set_destination_mt_safe
• ad5e16f: 8325587: Shenandoah: ShenandoahLock should allow blocking in VM
• 03a7176: 8333099: Missing check for is_LoadVector in StoreNode::Identity
• f9f11d7: 8334867: Add back assertion from JDK-8325494
• 65cf18a: 8328896: Fontmetrics for large Fonts has zero width
• e257ae5: 8051959: Add thread and timestamp options to java.security.debug system property
• ... and 38 more: https://git.openjdk.org/jdk21u-dev/compare/fe999ba7840f9bd306f46178747e743a502d3535...master

Your commit was automatically rebased without conflicts.

[openjdk]

@phohensee @pengxiaolong Pushed as commit 6b4fa86.

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