8326446: The User and System of jdk.CPULoad on Apple M1 are inaccurate

[yanglong1010]

Hi all

Could I have a review of this backport.

This pull request contains a backport of commit 8dbd4b391f7deb1a46a5f07f0bc46f23d6715ddb from the openjdk/jdk repository.

This backport is clean.

Testing: I ran test/jdk/jdk/jfr/event/os/TestCPULoad.java and passed.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8326446 needs maintainer approval

Issue

• JDK-8326446: The User and System of jdk.CPULoad on Apple M1 are inaccurate (Bug - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk22u.git pull/161/head:pull/161
$ git checkout pull/161

Update a local copy of the PR:
$ git checkout pull/161
$ git pull https://git.openjdk.org/jdk22u.git pull/161/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 161

View PR using the GUI difftool:
$ git pr show -t 161

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk22u/pull/161.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back lyang! 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]

@yanglong1010 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:

8326446: The User and System of jdk.CPULoad on Apple M1 are inaccurate

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 63 new commits pushed to the master branch:

• e32e05b: 8329840: Fix ZPhysicalMemorySegment::_end type
• a3e51ec: 8329109: Threads::print_on() tries to print CPU time for terminated GC threads
• ae8dae9: 8325587: Shenandoah: ShenandoahLock should allow blocking in VM
• b0cd610: 8332253: Linux arm32 build fails after 8292591
• 4541823: 8329605: hs errfile generic events - move memory protections and nmethod flushes to separate sections
• f539469: 8330464: hserr generic events - add entry for the before_exit calls
• da980f9: 8331031: unify os::dont_yield and os::naked_yield across Posix platforms
• 1e173f9: 8330814: Cleanups for KeepAliveCache tests
• 9836209: 8261433: Better pkcs11 performance for libpkcs11:C_EncryptInit/libpkcs11:C_DecryptInit
• fdb8491: 8331466: Problemlist serviceability/dcmd/gc/RunFinalizationTest.java on generic-all
• ... and 53 more: https://git.openjdk.org/jdk22u/compare/1188d404bc4879fc388209cd32e6c4e46178e200...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.

➡️ 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).

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 02: Full - Incremental (528b2324)
• 01: Full - Incremental (e988afcf)
• 00: Full (87090b2e)

[openjdk]

⚠️ @yanglong1010 This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[yanglong1010]

/approval 8326446 request The JFR's jdk.CPULoad event provides information about how much CPU is occupied by Java process, often used in performance analysis. But the User and System percentages of jdk.CPULoad event on Apple M1 are inaccurate (far below normal). I would like to backport this fix to jdk22u.
Low risk: This patch only affects the User and System percentages of JFR's jdk.CPULoad event.
Testing: I ran test/jdk/jdk/jfr/event/os/TestCPULoad.java and passed.

[openjdk]

@yanglong1010
8326446: The approval request has been created successfully.

[yanglong1010]

/integrate

[openjdk]

@yanglong1010
Your change (at version 528b232) is now ready to be sponsored by a Committer.

[DamonFool]

/sponsor

[openjdk]

Going to push as commit 5a659b7.
Since your change was applied there have been 63 commits pushed to the master branch:

• e32e05b: 8329840: Fix ZPhysicalMemorySegment::_end type
• a3e51ec: 8329109: Threads::print_on() tries to print CPU time for terminated GC threads
• ae8dae9: 8325587: Shenandoah: ShenandoahLock should allow blocking in VM
• b0cd610: 8332253: Linux arm32 build fails after 8292591
• 4541823: 8329605: hs errfile generic events - move memory protections and nmethod flushes to separate sections
• f539469: 8330464: hserr generic events - add entry for the before_exit calls
• da980f9: 8331031: unify os::dont_yield and os::naked_yield across Posix platforms
• 1e173f9: 8330814: Cleanups for KeepAliveCache tests
• 9836209: 8261433: Better pkcs11 performance for libpkcs11:C_EncryptInit/libpkcs11:C_DecryptInit
• fdb8491: 8331466: Problemlist serviceability/dcmd/gc/RunFinalizationTest.java on generic-all
• ... and 53 more: https://git.openjdk.org/jdk22u/compare/1188d404bc4879fc388209cd32e6c4e46178e200...master

Your commit was automatically rebased without conflicts.

[openjdk]

@DamonFool @yanglong1010 Pushed as commit 5a659b7.

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

[yanglong1010]

Thank you all ~