8280450: Add task queue printing to STW Full GCs

[tschatzl]

Hi all,

please review this change that adds task queue statistics printing after full gc marking. This helps diagnosing performance issues there.

Testing: compilation, gha, local testing (all new code is guarded by TASKQUEUE_STATS so not compiled in by default)

Thanks,
Thomas

---

Progress

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

Issue

• JDK-8280450: Add task queue printing to STW Full GCs

Reviewers

• Albert Mingkun Yang (@albertnetymk - Reviewer)
• Stefan Johansson (@kstefanj - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/7264/head:pull/7264
$ git checkout pull/7264

Update a local copy of the PR:
$ git checkout pull/7264
$ git pull https://git.openjdk.java.net/jdk pull/7264/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 7264

View PR using the GUI difftool:
$ git pr show -t 7264

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/7264.diff

[bridgekeeper]

👋 Welcome back tschatzl! 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]

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

• hotspot-gc

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[mlbridge]

Webrevs

• 00: Full (5f65c0ab)

[albertnetymk]

I feel TASKQUEUE_STATS and the fact that there are two task queues are too low-level in this context. However, I am not sure hiding them behind a method is definitely better either. Pragmatically, we can keep it this way for now and refine it latter if needed.

[openjdk]

@tschatzl 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:

8280450: Add task queue printing to STW Full GCs

Reviewed-by: ayang, sjohanss

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 14 new commits pushed to the master branch:

• 091aff9: 8278908: [macOS] Unexpected text normalization on pasting from clipboard
• 61794c5: 8280817: Clean up and unify empty VM operations
• c6ed204: 8278263: Remove redundant synchronized from URLStreamHandler.openConnection methods
• 251351f: 8280889: java/lang/instrument/GetObjectSizeIntrinsicsTest.java fails with -XX:-UseCompressedOops
• be9f984: 8280553: resourcehogs/serviceability/sa/TestHeapDumpForLargeArray.java can fail if GC occurs
• 268880b: 8277412: Use String.isBlank to simplify code in sun.net.www.protocol.mailto.Handler
• d366d15: 8280903: javadoc build fails after JDK-4774868
• 9139159: 8280843: macos-Aarch64 SEGV in frame::sender_for_compiled_frame after JDK-8277948
• 0740ac4: 8280555: serviceability/sa/TestObjectMonitorIterate.java is failing due to ObjectMonitor referencing a null Object
• ff34d62: 8280898: ProblemList compiler/regalloc/TestC2IntPressure.java on macosx-aarch64
• ... and 4 more: https://git.openjdk.java.net/jdk/compare/ed826f2927457f73f058732c6d073acf54ee86f7...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.

[tschatzl]

Thanks @kstefanj @albertnetymk for your reviews

/integrate

[openjdk]

Going to push as commit 993a248.
Since your change was applied there have been 16 commits pushed to the master branch:

• dcc666d: 8280139: Report more detailed statistics about task stealing in task queue stats
• bdda43e: 8280705: Parallel: Full gc mark stack draining should prefer to make work available to other threads
• 091aff9: 8278908: [macOS] Unexpected text normalization on pasting from clipboard
• 61794c5: 8280817: Clean up and unify empty VM operations
• c6ed204: 8278263: Remove redundant synchronized from URLStreamHandler.openConnection methods
• 251351f: 8280889: java/lang/instrument/GetObjectSizeIntrinsicsTest.java fails with -XX:-UseCompressedOops
• be9f984: 8280553: resourcehogs/serviceability/sa/TestHeapDumpForLargeArray.java can fail if GC occurs
• 268880b: 8277412: Use String.isBlank to simplify code in sun.net.www.protocol.mailto.Handler
• d366d15: 8280903: javadoc build fails after JDK-4774868
• 9139159: 8280843: macos-Aarch64 SEGV in frame::sender_for_compiled_frame after JDK-8277948
• ... and 6 more: https://git.openjdk.java.net/jdk/compare/ed826f2927457f73f058732c6d073acf54ee86f7...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tschatzl Pushed as commit 993a248.

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