8318053: GenShen: Control thread may ignore requests to start concurrent GC

[earthling-amzn]

If a request to interrupt an old cycle is accepted, but there is an allocation failure before the requested cycle begins, then the control thread may become stuck in a state where it believes it should ignore further concurrent cycle requests.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed (1 review required, with at least 1 Committer)

Issue

• JDK-8318053: GenShen: Control thread may ignore requests to start concurrent GC (Bug - P4)

Reviewers

• Kelvin Nilsen (@kdnilsen - Committer)
• Y. Srinivas Ramakrishna (@ysramakrishna - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/shenandoah.git pull/339/head:pull/339
$ git checkout pull/339

Update a local copy of the PR:
$ git checkout pull/339
$ git pull https://git.openjdk.org/shenandoah.git pull/339/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 339

View PR using the GUI difftool:
$ git pr show -t 339

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/shenandoah/pull/339.diff

Webrev

Link to Webrev Comment

[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.

[kdnilsen]

Thanks for figuring this out.

[openjdk]

@earthling-amzn 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:

8318053: GenShen: Control thread may ignore requests to start concurrent GC

Reviewed-by: kdnilsen, ysr

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 45 new commits pushed to the master branch:

• 206e5b8: Merge
• fb4098f: 8317730: Change byte_size to return size_t
• c2abf12: 8261894: Remove support for UseSHM
• ad7a8e8: 8315505: CompileTask timestamp printed can overflow
• fcff222: 8317706: Exclude java/awt/Graphics2D/DrawString/RotTransText.java on linux
• ef41aa0: 8317711: Exclude gtest/GTestWrapper.java on AIX
• ad6dce3: 8317705: ProblemList sun/tools/jstat/jstatLineCountsX.sh on linux-ppc64le and aix due to JDK-8248691
• e882718: 8314199: Initial size PBEKeyFactory#validTypes is not up-to-date
• d313915: 8316233: VirtualThreadStart events should not be thread-filtered
• 053f456: 8316447: 8 sun/management/jmxremote tests ignore VM flags
• ... and 35 more: https://git.openjdk.org/shenandoah/compare/f3c9edafa36deb2cf66f1e71ab9a7caeb527d3f8...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.

[ysramakrishna]

Thanks for the extra logging!

Changes look good to me.

Can you add into the ticket the command-line that was used for inducing the errant behavior?

Also can you add into this PR how you tested to confirm that it no longer occurs after the fix?

Thanks!

[mlbridge]

Webrevs

• 00: Full (1f8fdff1)

[earthling-amzn]

I updated the ticket with the command we used to reproduce it. I've seen the issue on the first run and @kdnilsen has seen it usually before the 10th run. If I can get 50 runs without the issue, I'll consider it fixed.

Also, the additional logging showed the _preeption_requested flag was stuck on, when it shouldn't have been.

[earthling-amzn]

/integrate

[openjdk]

Going to push as commit ccbb0d8.
Since your change was applied there have been 45 commits pushed to the master branch:

• 206e5b8: Merge
• fb4098f: 8317730: Change byte_size to return size_t
• c2abf12: 8261894: Remove support for UseSHM
• ad7a8e8: 8315505: CompileTask timestamp printed can overflow
• fcff222: 8317706: Exclude java/awt/Graphics2D/DrawString/RotTransText.java on linux
• ef41aa0: 8317711: Exclude gtest/GTestWrapper.java on AIX
• ad6dce3: 8317705: ProblemList sun/tools/jstat/jstatLineCountsX.sh on linux-ppc64le and aix due to JDK-8248691
• e882718: 8314199: Initial size PBEKeyFactory#validTypes is not up-to-date
• d313915: 8316233: VirtualThreadStart events should not be thread-filtered
• 053f456: 8316447: 8 sun/management/jmxremote tests ignore VM flags
• ... and 35 more: https://git.openjdk.org/shenandoah/compare/f3c9edafa36deb2cf66f1e71ab9a7caeb527d3f8...master

Your commit was automatically rebased without conflicts.

[openjdk]

@earthling-amzn Pushed as commit ccbb0d8.

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