8292969: Bad Thread Utilization in ForkJoinPool

[DougLea]

8292969: This small change in signal propagation rules improves utilization when entry queues are resized,

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Progress

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• Commit message must refer to an issue

Issue

• JDK-8292969: Bad Thread Utilization in ForkJoinPool

Reviewers

• Aleksey Shipilev (@shipilev - Reviewer)
• Alan Bateman (@AlanBateman - Reviewer)

Reviewing

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$ git checkout pull/10198

Update a local copy of the PR:
$ git checkout pull/10198
$ git pull https://git.openjdk.org/jdk pull/10198/head

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[bridgekeeper]

👋 Welcome back dl! 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]

@DougLea The following label will be automatically applied to this pull request:

• core-libs

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

[Martin-Buchholz]

scan's @return needs to be changed to indicate it also now returns a packed int

[DougLea]

Thanks. replaced with:
* @return the next prevSrc value to use, or negative if none found

[openjdk]

⚠️ @DougLea This pull request contains merges that bring in commits not present in the target repository. Since this is not a "merge style" pull request, these changes will be squashed when this pull request in integrated. If this is your intention, then please ignore this message. If you want to preserve the commit structure, you must change the title of this pull request to Merge <project>:<branch> where <project> is the name of another project in the OpenJDK organization (for example Merge jdk:master).

[jaikiran]

Hello Doug, for the bots to trigger the review process, the title of this PR is expected to be <bugid>: <bug summary>, so in this case the title of this PR will have to be edited to 8292969: Bad Thread Utilization in ForkJoinPool

[DougLea]

Thanks. I keep forgetting the required format for these.

[mlbridge]

Webrevs

• 00: Full (f5d3d442)

[shipilev]

Are all of these values (src, prevSrc) less or equal 0x7FFF? Otherwise we are playing with sign bits here.

[DougLea]

Yes, see the discussions around line 391 of internal docs.

[shipilev]

Ah, all right then.

[openjdk]

@DougLea 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:

8292969: Bad Thread Utilization in ForkJoinPool

Reviewed-by: shade, alanb

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 232 new commits pushed to the master branch:

• 36b61c5: 8293872: Make runtime/Thread/ThreadCountLimit.java more robust
• 2be3158: 4797982: Setting negative size of JSplitPane divider leads to unexpected results.
• 050eebf: 8294245: Make Compile::print_inlining_stream stack allocated
• 91a23d7: 8294142: make test should report only on executed tests
• 169a5d4: 8294193: Files.createDirectories throws FileAlreadyExistsException for a symbolic link whose target is an existing directory
• 3675f4c: 8293252: Shenandoah: ThreadMXBean synchronizer tests crash with aggressive heuristics
• 543851d: 8289607: Change hotspot/jtreg tests to not use Thread.suspend/resume
• e2f8251: 8293618: x86: Wrong code generation in class Assembler
• 6ecd081: 8294270: make test passes awkward -status:-status:error,fail to jtreg
• eca9749: 8288325: [windows] Actual and Preferred Size of AWT Non-resizable frame are different
• ... and 222 more: https://git.openjdk.org/jdk/compare/ef20ffe4d222d48f0bdba81a0b864d9fb455e9a6...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.

[AlanBateman]

I've been testing with this change for some time and it has worked well.

[DougLea]

/integrate

[openjdk]

Going to push as commit bc12e95.
Since your change was applied there have been 245 commits pushed to the master branch:

• dd51f7e: 8293996: C2: fix and simplify IdealLoopTree::do_remove_empty_loop
• 14c6ac4: 8293998: [PPC64] JfrGetCallTrace: assert(_pc != nullptr) failed: must have PC
• 02ea338: 8293887: AArch64 build failure with GCC 12 due to maybe-uninitialized warning in libfdlibm k_rem_pio2.c
• 49a7347: 8294408: Problemlist runtime/handshake/HandshakeSuspendExitTest.java
• aa48705: 8289422: Fix and re-enable vector conditional move
• 1ddc92f: 8294404: [BACKOUT] JDK-8294142: make test should report only executed tests
• 1e222bc: 8293462: [macos] app image signature invalid when creating DMG or PKG from post processed signed image
• 43eff2b: 8272687: Replace StringBuffer with StringBuilder in RuleBasedCollator
• b88ee1e: 6251738: Want a top-level summary page that itemizes all spec documents referenced from javadocs (OEM spec)
• aca4276: 8294379: Missing comma after copyright year
• ... and 235 more: https://git.openjdk.org/jdk/compare/ef20ffe4d222d48f0bdba81a0b864d9fb455e9a6...master

Your commit was automatically rebased without conflicts.

[openjdk]

@DougLea Pushed as commit bc12e95.

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