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8264649: runtime/InternalApi/ThreadCpuTimesDeadlock.java crash in fastdebug C2 with -XX:-UseTLAB #3336

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@huishi-hs huishi-hs commented Apr 3, 2021

Please help review this fix. Detailed analysis in https://bugs.openjdk.java.net/browse/JDK-8264649

Tier1/2 release /fastdebug passed


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  • JDK-8264649: runtime/InternalApi/ThreadCpuTimesDeadlock.java crash in fastdebug C2 with -XX:-UseTLAB

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https://git.openjdk.java.net/jdk/pull/3336.diff

…tdebug C2 with -XX:-UseTLAB
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@bridgekeeper bridgekeeper bot commented Apr 3, 2021

👋 Welcome back hshi! 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 Apr 3, 2021
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@openjdk openjdk bot commented Apr 3, 2021

@huishi-hs The following label will be automatically applied to this pull request:

  • hotspot

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.

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@mlbridge mlbridge bot commented Apr 3, 2021

Webrevs

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@huishi-hs huishi-hs commented Apr 3, 2021

/label add hotspot-compiler

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The hotspot-compiler label was successfully added.

/*
* @test
* @bug 8264649
* @summary OSR compiled metthod crash when UseTLAB is off

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@TobiHartmann

TobiHartmann Apr 7, 2021
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Typo metthod.

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@huishi-hs

huishi-hs Apr 7, 2021
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Fixed.

@@ -1481,6 +1481,9 @@ void PhaseIterGVN::subsume_node( Node *old, Node *nn ) {
temp->init_req(0,nn); // Add a use to nn to prevent him from dying

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@TobiHartmann

TobiHartmann Apr 7, 2021
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Just wondering, why do we even need this? Without that code, remove_dead_node(old) would kill nn as well if it becomes dead.

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@huishi-hs

huishi-hs Apr 7, 2021
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Thanks for your review!

Checking code history, this code is quite old. From comments around, it doesn't want nn removed directly in PhaseIterGVN::subsume_node and leaves optimization to next GVN iteration.

In my understanding, it might save callers to insert codes checking if "nn" is removed/dead at every subsume_node/replace_node callsite, simplifies implementation.

8153779 hotspot/src/share/vm/opto/phaseX.cpp (J. Duke 2007-12-01 00:00:00 +0000 1479) // Smash all inputs to 'old', isolating him completely
2a0815a hotspot/src/share/vm/opto/phaseX.cpp (Tobias Hartmann 2014-06-02 08:07:29 +0200 1480) Node *temp = new Node(1);
8153779 hotspot/src/share/vm/opto/phaseX.cpp (J. Duke 2007-12-01 00:00:00 +0000 1481) temp->init_req(0,nn); // Add a use to nn to prevent him from dying
8153779 hotspot/src/share/vm/opto/phaseX.cpp (J. Duke 2007-12-01 00:00:00 +0000 1482) remove_dead_node( old );
8153779 hotspot/src/share/vm/opto/phaseX.cpp (J. Duke 2007-12-01 00:00:00 +0000 1483) temp->del_req(0); // Yank bogus edge

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@vnkozlov

vnkozlov Apr 9, 2021
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Note nn could be new node created during parsing which does not have users yet. that is why we need to keep it

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@TobiHartmann TobiHartmann left a comment

Thanks for the details. Your fix looks reasonable to me.

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@openjdk openjdk bot commented Apr 9, 2021

@huishi-hs 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:

8264649: runtime/InternalApi/ThreadCpuTimesDeadlock.java crash in fastdebug C2 with -XX:-UseTLAB

Reviewed-by: thartmann, kvn

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 99 new commits pushed to the master branch:

  • 76bd313: 8264872: Dependencies: Migrate to PerfData counters
  • 07c8ff4: 8264871: Dependencies: Miscellaneous cleanups in dependencies.cpp
  • 863feab: 8005295: Use mandated information for printing of repeating annotations
  • f26cd2a: 8264997: Remove SystemDictionary::cache_get
  • 9ebc497: 8264765: BreakIterator sees bogus sentence boundary in parenthesized “i.e.” phrase
  • ec31b3a: 8264727: Shenandoah: Remove extraneous whitespace from phase timings report
  • cc54de7: 8264400: (fs) WindowsFileStore equality depends on how the FileStore was constructed
  • 6de0bb2: 8232861: (fc) FileChannel.force fails on WebDAV file systems (macOS)
  • 1ca4abe: 8262881: port JVM/DI tests from JDK-4413752 to JVM/TI
  • 06e6b1f: 8259242: Remove ProtectionDomainSet_lock
  • ... and 89 more: https://git.openjdk.java.net/jdk/compare/66d9961cbd83dbfca20b0af3c20693438d4aff3f...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.

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@vnkozlov vnkozlov left a comment

I agree with change.

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@huishi-hs huishi-hs commented Apr 9, 2021

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@huishi-hs huishi-hs commented Apr 9, 2021

/integrate

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@openjdk openjdk bot commented Apr 9, 2021

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Your change (at version 2f6b68d) is now ready to be sponsored by a Committer.

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@DamonFool DamonFool commented Apr 10, 2021

/sponsor

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@openjdk openjdk bot commented Apr 10, 2021

@DamonFool @huishi-hs Since your change was applied there have been 99 commits pushed to the master branch:

  • 76bd313: 8264872: Dependencies: Migrate to PerfData counters
  • 07c8ff4: 8264871: Dependencies: Miscellaneous cleanups in dependencies.cpp
  • 863feab: 8005295: Use mandated information for printing of repeating annotations
  • f26cd2a: 8264997: Remove SystemDictionary::cache_get
  • 9ebc497: 8264765: BreakIterator sees bogus sentence boundary in parenthesized “i.e.” phrase
  • ec31b3a: 8264727: Shenandoah: Remove extraneous whitespace from phase timings report
  • cc54de7: 8264400: (fs) WindowsFileStore equality depends on how the FileStore was constructed
  • 6de0bb2: 8232861: (fc) FileChannel.force fails on WebDAV file systems (macOS)
  • 1ca4abe: 8262881: port JVM/DI tests from JDK-4413752 to JVM/TI
  • 06e6b1f: 8259242: Remove ProtectionDomainSet_lock
  • ... and 89 more: https://git.openjdk.java.net/jdk/compare/66d9961cbd83dbfca20b0af3c20693438d4aff3f...master

Your commit was automatically rebased without conflicts.

Pushed as commit 42f4d70.

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

@huishi-hs huishi-hs deleted the huishi-hs:8264649 branch Apr 30, 2021
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