8261600: NMT: Relax memory order for updating MemoryCounter and fix racy updating of peak values

[zhengyu123]

Currently, MemoryCounter is updated with default memory_order_conservative, it is too strong for updating a counter.

Also, updating peak values with regular assignment, which is racy and broken.

• hotspot_nmt on Linux x86_64 and aarch64

---

Progress

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

Issue

• JDK-8261600: NMT: Relax memory order for updating MemoryCounter and fix racy updating of peak values

Reviewers

• David Holmes (@dholmes-ora - Reviewer)
• Aleksey Shipilev (@shipilev - Reviewer)

Download

$ git fetch https://git.openjdk.java.net/jdk pull/2527/head:pull/2527
$ git checkout pull/2527

[bridgekeeper]

👋 Welcome back zgu! 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]

@zhengyu123 The following label will be automatically applied to this pull request:

• hotspot-runtime

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.

[mlbridge]

Webrevs

• 00: Full (f7e4dcb)

[dholmes-ora]

Hi Zhengyu,

This seems okay.

Thanks,
David

[openjdk]

@zhengyu123 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:

8261600: NMT: Relax memory order for updating MemoryCounter and fix racy updating of peak values

Reviewed-by: dholmes, shade

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 100 new commits pushed to the master branch:

• 1a7adc8: 8260416: Remove unused method ReferenceProcessor::is_mt_processing_set_up()
• 3a21e1d: 8260653: Unreachable nodes keep speculative types alive
• b695c7e: 8261925: ProblemList com/sun/jdi/AfterThreadDeathTest.java on Linux
• 97e1657: 8261846: [JVMCI] c2v_iterateFrames can get out of sync with the StackFrameStream
• b8fd614: 8261939: os::strdup_check_oom() should be used in os::same_files() in os_windows.cpp
• 5f30829: 8202750: Reduce the use of get_canonical_path() in CDS
• ea5bf45: 8261621: Delegate Unicode history from JLS to j.l.Character
• d5a4d22: 8261843: incorrect info in docs/building.html
• bf75a3a: 8261851: update ReflectionCallerCacheTest.java test to use ForceGC from test library
• 05301f5: 8257497: Update keytool to create AKID from the SKID of the issuing certificate as specified by RFC 5280
• ... and 90 more: https://git.openjdk.java.net/jdk/compare/a7726390cc00eed9833574ca716f724bd9689952...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.

[shipilev]

This looks fine to me too.

[zhengyu123]

Thanks for reviewing, @dholmes-ora and @shipilev

[zhengyu123]

/integrate

[openjdk]

@zhengyu123 Since your change was applied there have been 100 commits pushed to the master branch:

• 1a7adc8: 8260416: Remove unused method ReferenceProcessor::is_mt_processing_set_up()
• 3a21e1d: 8260653: Unreachable nodes keep speculative types alive
• b695c7e: 8261925: ProblemList com/sun/jdi/AfterThreadDeathTest.java on Linux
• 97e1657: 8261846: [JVMCI] c2v_iterateFrames can get out of sync with the StackFrameStream
• b8fd614: 8261939: os::strdup_check_oom() should be used in os::same_files() in os_windows.cpp
• 5f30829: 8202750: Reduce the use of get_canonical_path() in CDS
• ea5bf45: 8261621: Delegate Unicode history from JLS to j.l.Character
• d5a4d22: 8261843: incorrect info in docs/building.html
• bf75a3a: 8261851: update ReflectionCallerCacheTest.java test to use ForceGC from test library
• 05301f5: 8257497: Update keytool to create AKID from the SKID of the issuing certificate as specified by RFC 5280
• ... and 90 more: https://git.openjdk.java.net/jdk/compare/a7726390cc00eed9833574ca716f724bd9689952...master

Your commit was automatically rebased without conflicts.

Pushed as commit f94a845.

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