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8256658: Shenandoah: Deadlock between nmethod_entry_barrier and concurrent code root evacuator #1352

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zhengyu123
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@zhengyu123 zhengyu123 commented Nov 20, 2020

Nightly tests revealed a deadlock after JDK-8256415.

The new concurrent code root evacuating/updating task sets up EvacOOM scope on the top level. If OOM occurs and nmethod_entry_barrier holds per-nmethod lock, while concurrent code root evacuating/updating task tries to acquire the exact per-nmethod lock, we deadlock.

The solution is to move EvacOOM scope under per-nmethod lock.

Test:

  • hotspot_gc_shenandoah
  • nightly tests

Progress

  • Change must not contain extraneous whitespace
  • Commit message must refer to an issue
  • Change must be properly reviewed

Testing

Linux aarch64 Linux arm Linux ppc64le Linux s390x Linux x64 Linux x86 Windows x64 macOS x64
Build ✔️ (1/1 passed) ✔️ (1/1 passed) ✔️ (1/1 passed) ✔️ (1/1 passed) ✔️ (6/6 passed) ✔️ (2/2 passed) ✔️ (2/2 passed) ✔️ (2/2 passed)
Test (tier1) ✔️ (9/9 passed) ✔️ (9/9 passed) ✔️ (9/9 passed) ✔️ (9/9 passed)

Issue

  • JDK-8256658: Shenandoah: Deadlock between nmethod_entry_barrier and concurrent code root evacuator

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$ git fetch https://git.openjdk.java.net/jdk pull/1352/head:pull/1352
$ git checkout pull/1352

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@bridgekeeper bridgekeeper bot commented Nov 20, 2020

👋 Welcome back zgu! 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 openjdk bot added the rfr label Nov 20, 2020
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@openjdk openjdk bot commented Nov 20, 2020

@zhengyu123 The following labels will be automatically applied to this pull request:

  • hotspot-gc
  • shenandoah

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

@openjdk openjdk bot added hotspot-gc shenandoah labels Nov 20, 2020
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@mlbridge mlbridge bot commented Nov 20, 2020

Webrevs

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@rkennke rkennke left a comment

Looks good to me! Thanks!

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@openjdk openjdk bot commented Nov 20, 2020

@zhengyu123 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:

8256658: Shenandoah: Deadlock between nmethod_entry_barrier and concurrent code root evacuator

Reviewed-by: rkennke

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 2 new commits pushed to the master branch:

  • ff00c59: 8256569: Add C2 compiler stress flags to CTW
  • e7c7469: 8246378: [Windows] assert on MethodHandle logging code

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

@openjdk openjdk bot added the ready label Nov 20, 2020
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@zhengyu123 zhengyu123 commented Nov 20, 2020

/integrate

@openjdk openjdk bot closed this Nov 20, 2020
@openjdk openjdk bot added integrated and removed ready rfr labels Nov 20, 2020
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@openjdk openjdk bot commented Nov 20, 2020

@zhengyu123 Since your change was applied there have been 8 commits pushed to the master branch:

  • cc0ed40: 8037384: Fix wording in Javadoc of java.io.Serializable
  • 19b2898: 8256751: Incremental rebuild with precompiled header fails when touching a header file
  • 4dd71ae: 8256803: ProblemList runtime/ReservedStack/ReservedStackTestCompiler.java on linux-aarch64
  • 2c3a2be: 8211449: Correction to the spec of implicit negative subpattern in DecimalFormat
  • 11bfdc5: 8235304: JPackage Windows test should be added to set Publisher
  • 2ae3e51: 8229845: Decrease memory consumption of BigInteger.toString()
  • ff00c59: 8256569: Add C2 compiler stress flags to CTW
  • e7c7469: 8246378: [Windows] assert on MethodHandle logging code

Your commit was automatically rebased without conflicts.

Pushed as commit 5ad1e22.

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

openjdk-notifier bot referenced this issue Nov 20, 2020
…rrent code root evacuator

Reviewed-by: rkennke
@zhengyu123 zhengyu123 deleted the JDK-8256658-coderoot-deadlock branch Jul 16, 2021
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