8329528: G1 does not update TAMS correctly when dropping retained regions during Concurrent Start pause

[tschatzl]

Hi all,

please review this backport for https://bugs.openjdk.org/browse/JDK-8329528; it applies cleanly apart from the hunk now in inline void HeapRegion::note_start_of_marking() - in jdk23 this method moved from there to concurrent marking code, although the change itself is the same.

This issue causes random crashes in G1. There is no workaround.

The change baked in jdk23 for a week or so, with no issues. Risk is little at this point as the patch is small and well understood, and there is a regression test.

Testing: gha, tier1-5

---

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-8329528 needs maintainer approval

Issue

• JDK-8329528: G1 does not update TAMS correctly when dropping retained regions during Concurrent Start pause (Bug - P1 - Approved) ⚠️ Issue is already resolved. Consider making this a "backport pull request" by setting the PR title to Backport <hash> with the hash of the original commit. See Backports.

Reviewers

• Albert Mingkun Yang (@albertnetymk - no project role)
• Chris Hegarty (@ChrisHegarty - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk22u.git pull/145/head:pull/145
$ git checkout pull/145

Update a local copy of the PR:
$ git checkout pull/145
$ git pull https://git.openjdk.org/jdk22u.git pull/145/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 145

View PR using the GUI difftool:
$ git pr show -t 145

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk22u/pull/145.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back tschatzl! 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]

@tschatzl 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:

8329528: G1 does not update TAMS correctly when dropping retained regions during Concurrent Start pause

Reviewed-by: ayang, chegar

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 30 new commits pushed to the master branch:

• 1188d40: 8323782: Race: Thread::interrupt vs. AbstractInterruptibleChannel.begin
• 0c57256: 8327990: [macosx-aarch64] Various tests fail with -XX:+AssertWXAtThreadSync
• 2ae0188: 8330242: RISC-V: Simplify and remove CORRECT_COMPILER_ATOMIC_SUPPORT in atomic_linux_riscv.hpp
• 829d047: Merge
• 8ba20c7: 8327391: Add SipHash attribution file
• e351052: 8325313: Header format error in TestIntrinsicBailOut after JDK-8317299
• 1d7689d: Merge
• ae46fb7: Merge
• bf87bb7: Merge
• 733b837: 8322122: Enhance generation of addresses
• ... and 20 more: https://git.openjdk.org/jdk22u/compare/22230b34d79010c6e639f55248cd6ce6be8c22e5...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.

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

[mlbridge]

Webrevs

• 00: Full (9e02b9fc)

[ChrisHegarty]

LGTM

[openjdk]

⚠️ @tschatzl 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.

[tschatzl]

Thanks @albertnetymk @ChrisHegarty for your reviews. Now applying for push approval.

[mlbridge]

Mailing list message from Chris Hegarty on jdk-updates-dev:

Thanks for backporting this Thomas.

Given the severe nature of this bug and its impact, it renders JDK 22
and JDK 22u1 effectively useless (or even worse dangerous) to many
applications.

I would like to propose a 22.0.1.1 be considered to get this fix into
releases prior to 22u2.

-Chris.

On 17/04/2024 10:59, Chris Hegarty wrote:

[tschatzl]

/integrate

[openjdk]

Going to push as commit ac9ca97.
Since your change was applied there have been 30 commits pushed to the master branch:

• 1188d40: 8323782: Race: Thread::interrupt vs. AbstractInterruptibleChannel.begin
• 0c57256: 8327990: [macosx-aarch64] Various tests fail with -XX:+AssertWXAtThreadSync
• 2ae0188: 8330242: RISC-V: Simplify and remove CORRECT_COMPILER_ATOMIC_SUPPORT in atomic_linux_riscv.hpp
• 829d047: Merge
• 8ba20c7: 8327391: Add SipHash attribution file
• e351052: 8325313: Header format error in TestIntrinsicBailOut after JDK-8317299
• 1d7689d: Merge
• ae46fb7: Merge
• bf87bb7: Merge
• 733b837: 8322122: Enhance generation of addresses
• ... and 20 more: https://git.openjdk.org/jdk22u/compare/22230b34d79010c6e639f55248cd6ce6be8c22e5...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tschatzl Pushed as commit ac9ca97.

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