8319650: Improve heap dump performance with class metadata caching

[shipilev]

Transplanted from openjdk/jdk21u#388

Unclean backport to improve heap dump performance. The uncleanliness comes from JDK-8306441 that does not exist in JDK 21, and which I don't think we want to backport at the moment. I had to add a few more ResourceMark-s near HeapDumpWriter to manage the cache allocations.

Additional testing:

• MacOS AArch64 server release, heap dump performance improved
• Linux x86_64 server fastdebug, serviceability/ (contains heap dump tests)
• Linux x86_64 server fastdebug, runtime/ErrorHandling (contains heap dump on failure tests)
• Linux x86_64 server fastdebug, gc/epsilon (contains heap dump on failure tests)
• Linux x86_64 server fastdebug, sun/tools/jhsdb (contains heap dump tests)

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• JDK-8319650 needs maintainer approval
• Commit message must refer to an issue

Issue

• JDK-8319650: Improve heap dump performance with class metadata caching (Enhancement - P4 - Approved)

Reviewers

• Paul Hohensee (@phohensee - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/8/head:pull/8
$ git checkout pull/8

Update a local copy of the PR:
$ git checkout pull/8
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/8/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 8

View PR using the GUI difftool:
$ git pr show -t 8

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/8.diff

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[bridgekeeper]

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[openjdk]

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

[mlbridge]

Webrevs

• 04: Full - Incremental (d061d4f9)
• 03: Full - Incremental (6f08fd87)
• 02: Full - Incremental (4e13f967)
• 01: Full - Incremental (da6d93ed)
• 00: Full (d0ba9f6e)

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[shipilev]

Not now, bot.

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[shipilev]

/approval request Unclean backport to improve heap dump performance. Tests pass. Original 21u RFR acked by Paul Hohensee. In mainline since Nov 2023 without a bug tail. The risk is in regressing the frequently used diagnostic subsystem, but that should be considered against the major improvement in performance.

[openjdk]

@shipilev
8319650: The approval request has been updated successfully.

[openjdk]

@shipilev 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:

8319650: Improve heap dump performance with class metadata caching

Reviewed-by: phh

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[shipilev]

/integrate

[openjdk]

Going to push as commit d5f44dc.
Since your change was applied there have been 13 commits pushed to the master branch:

• b9ca253: 8325203: System.exit(0) kills the launched 3rd party application
• 1c4479f: 8325567: jspawnhelper without args fails with segfault
• 35f291b: 8326718: Test java/util/Formatter/Padding.java should timeout on large inputs before fix in JDK-8299677
• 2a56bfb: 8316451: 6 java/lang/instrument/PremainClass tests ignore VM flags
• d5c170a: 8319578: Few java/lang/instrument ignore test.java.opts and accept test.vm.opts only
• e5ee283: 8321163: [test] OutputAnalyzer.getExitValue() unnecessarily logs even when process has already completed
• 3b3ec13: 8314975: JavadocTester should set source path if not specified
• e5c1031: 8293069: Make -XX:+Verbose less verbose
• 8ed46c2: 8294699: Launcher causes lingering busy cursor
• e1f8f83: 8316460: 4 javax/management tests ignore VM flags
• ... and 3 more: https://git.openjdk.org/jdk21u-dev/compare/b80fb5e6d4c5fa5bd0df31ae2d52bd872880c16e...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit d5f44dc.

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