8297285: Shenandoah pacing causes assertion failure during VM initialization

[ashu-mehra]

Please review the fix for the assertion failure seen during VM init due to pacing in shenandoah gc.
The fix is to avoid pacing during VM initialization as the main thread is not yet an active java thread.

Signed-off-by: Ashutosh Mehra asmehra@redhat.com

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
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• Commit message must refer to an issue

Issue

• JDK-8297285: Shenandoah pacing causes assertion failure during VM initialization

Reviewers

• Roman Kennke (@rkennke - Reviewer)
• Paul Hohensee (@phohensee - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back ashu-mehra! 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]

@ashu-mehra 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.

[mlbridge]

Webrevs

• 02: Full - Incremental (17a7b3bf)
• 01: Full - Incremental (60f174fc)
• 00: Full (d8d439f0)

[ashu-mehra]

zero build was failing with following compile error:

/usr/bin/ld: /home/runner/work/jdk/jdk/build/linux-x64/hotspot/variant-zero/libjvm/objs/shenandoahPacer.o: in function `JavaThread::is_active_Java_thread() const':
/home/runner/work/jdk/jdk/src/hotspot/share/runtime/javaThread.hpp:514: undefined reference to `JavaThread::is_terminated() const'

Pushed a commit to include the necessary header file.

[ashu-mehra]

Can I please get reviews for this PR.

[rkennke]

Looks good to me! Thank you, Ashu!

[openjdk]

@ashu-mehra 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:

8297285: Shenandoah pacing causes assertion failure during VM initialization

Reviewed-by: rkennke, phh

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 240 new commits pushed to the master branch:

• df07255: 8297984: Turn on warnings as errors for javadoc
• 227364d: 8297953: Fix several C2 IR matching tests for RISC-V
• 1370228: 8297941: Add override modifier in space.hpp
• 319faa5: 8296084: javax/swing/JSpinner/4788637/bug4788637.java fails intermittently on a VM
• b73363f: 8297686: JFR: Improve documentation of EventStream::onMetadata(Consumer)
• 1376f33: 8297911: Memory leak in JfrUpcalls::on_retransform
• 5c0ff26: 8291444: GHA builds/tests won't run manually if disabled from automatic running
• 6d0fbb2: 8297645: Drop the test/jdk/java/net/httpclient/reactivestreams-tck-tests/TckDriver.java test
• 687fd71: 8297549: RISC-V: Add support for Vector API vector load const operation
• d50015a: 8297715: RISC-V: C2: Use single-bit instructions from the Zbs extension
• ... and 230 more: https://git.openjdk.org/jdk/compare/819af69f408261f55af883ba015c1f6179236582...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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@rkennke, @phohensee) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[ashu-mehra]

@rkennke thanks for suggesting and reviewing the fix.

[ashu-mehra]

/integrate

[openjdk]

@ashu-mehra
Your change (at version 60f174f) is now ready to be sponsored by a Committer.

[phohensee]

I'm not familiar with this code, so please bear with me. :) The comment on line 246 says "Thread which is not an active Java thread should also not block.", but the check at line 251 will return (i.e., looks like not block) if the current thread is an active Java thread. Should the check be !current->is_active_Java_thread() instead?

[ashu-mehra]

@phohensee you are right. It should be !current->is_active_Java_thread(), how did I miss that !!
Thanks for catching it in time.

[phohensee]

Looks good now.

[phohensee]

/sponsor

[openjdk]

@phohensee The PR has been updated since the change author (@ashu-mehra) issued the integrate command - the author must perform this command again.

[ashu-mehra]

/integrate

[openjdk]

@ashu-mehra
Your change (at version 17a7b3b) is now ready to be sponsored by a Committer.

[phohensee]

/sponsor

[openjdk]

Going to push as commit 415cfd2.
Since your change was applied there have been 240 commits pushed to the master branch:

• df07255: 8297984: Turn on warnings as errors for javadoc
• 227364d: 8297953: Fix several C2 IR matching tests for RISC-V
• 1370228: 8297941: Add override modifier in space.hpp
• 319faa5: 8296084: javax/swing/JSpinner/4788637/bug4788637.java fails intermittently on a VM
• b73363f: 8297686: JFR: Improve documentation of EventStream::onMetadata(Consumer)
• 1376f33: 8297911: Memory leak in JfrUpcalls::on_retransform
• 5c0ff26: 8291444: GHA builds/tests won't run manually if disabled from automatic running
• 6d0fbb2: 8297645: Drop the test/jdk/java/net/httpclient/reactivestreams-tck-tests/TckDriver.java test
• 687fd71: 8297549: RISC-V: Add support for Vector API vector load const operation
• d50015a: 8297715: RISC-V: C2: Use single-bit instructions from the Zbs extension
• ... and 230 more: https://git.openjdk.org/jdk/compare/819af69f408261f55af883ba015c1f6179236582...master

Your commit was automatically rebased without conflicts.

[openjdk]

@phohensee @ashu-mehra Pushed as commit 415cfd2.

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