8212084: G1: Implement UseGCOverheadLimit

[tschatzl]

Hi all,

please review these changes to implement the UseGCOverheadLimit functionality for G1 (and make the implementation for Parallel GC have similar output).

The UseGCOverheadLimit feature prematurely returns null from a GC if GC cpu usage limits and heap usage limits are met for some time. This is to avoid a VM limping along if garbage collection gets into an endless cycle of garbage collections or until a "real" OOME is thrown.

What is important here is how this works (derived from the Parallel GC implementation):

• check overheads at the end of the (initial) garbage collection (before upgrading) to see whether we are over the limits for a sequence of GCs.
• keep doing GCs without actually allocating memory for the allocation request to keep on measuring gc CPU usage. This is important for measuring the correct cpu usage in case of the application being able to free memory on the OOME.

Testing: tier1-5 without any OOMEs due to this feature, test case

Thanks,
Thomas

---

Progress

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Issue

• JDK-8212084: G1: Implement UseGCOverheadLimit (Enhancement - P4)

Reviewers

• Ivan Walulya (@walulyai - Reviewer) Review applies to ac3223fa
• Francesco Andreuzzi (@fandreuz - Author) Review applies to ac3223fa
• Albert Mingkun Yang (@albertnetymk - Reviewer)

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[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 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:

8212084: G1: Implement UseGCOverheadLimit

Reviewed-by: ayang, iwalulya, fandreuzzi

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At the time when this comment was updated there had been 22 new commits pushed to the master branch:

• cc9483b: 8366182: Some PKCS11Tests are being skipped when they shouldn't
• 470eedb: 8370511: test/jdk/javax/swing/JSlider/bug4382876.java does not release previously pressed keys
• f73e56e: 8361894: sun/security/krb5/config/native/TestDynamicStore.java ensure that the test is run with sudo
• ... and 19 more: https://git.openjdk.org/jdk/compare/027aea9d2e0dff29fcd00fa7074ca955066929ec...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.

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[openjdk]

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

• hotspot-gc

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[mlbridge]

Webrevs

• 04: Full - Incremental (bdc9663b)
• 03: Full - Incremental (03334385)
• 02: Full - Incremental (ac3223fa)
• 01: Full - Incremental (a8663e1b)
• 00: Full (389e5a26)

[walulyai]

Some suggestions

[walulyai]

Looks good!

[tschatzl]

Also ran up to tier8 in our CI with no additional issues afaict.

[tschatzl]

Thanks for all the reviews!
/integrate

[openjdk]

Going to push as commit 3d2ce80.
Since your change was applied there have been 32 commits pushed to the master branch:

• bfc1db7: 8370560: Remove non-public API reference from public API javadoc
• e7c7892: 8370197: Add missing @OverRide annotations in com.sun.beans package
• c3449de: 8360395: sun/security/tools/keytool/i18n.java user country is current user location instead of the language
• ... and 29 more: https://git.openjdk.org/jdk/compare/027aea9d2e0dff29fcd00fa7074ca955066929ec...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tschatzl Pushed as commit 3d2ce80.

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