8170817: G1: Returning MinTLABSize from unsafe_max_tlab_alloc causes TLAB flapping

[walulyai]

Hi all,

Please review this small change to return the maximum allowed TLAB size from unsafe_max_tlab_alloc in case the current region does not have enough free space to allocate MinTLABSize. We assume that the next TLAB allocation will happen in a new region.

Testing: Tier 1-3.

Thanks

---

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Issue

• JDK-8170817: G1: Returning MinTLABSize from unsafe_max_tlab_alloc causes TLAB flapping (Enhancement - P3)

Reviewers

• Thomas Schatzl (@tschatzl - Reviewer)
• Albert Mingkun Yang (@albertnetymk - Reviewer)

Reviewing

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[openjdk]

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[mlbridge]

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[tschatzl]

Lgtm. Thanks for the documentation

[openjdk]

@walulyai 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:

8170817: G1: Returning MinTLABSize from unsafe_max_tlab_alloc causes TLAB flapping

Reviewed-by: tschatzl, ayang

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 98 new commits pushed to the master branch:

• d95b548: 8315850: Improve AbstractMap anonymous Iterator classes
• 424de29: 8317866: replace NET_SocketAvailable
• 6d6c900: 8038244: (fs) Check return value of malloc in Java_sun_nio_fs_AixNativeDispatcher_getmntctl()
• eca6ea4: 8317873: Add @sealedGraph to IllegalFormatException
• 2edf9c3: 8317763: Follow-up to AVX512 intrinsics for Arrays.sort() PR
• 839cb19: 8317581: [s390x] Multiple test failure with LockingMode=2
• 387896f: 8309621: [XWayland][Screencast] screen capture failure with sun.java2d.uiScale other than 1
• 8d2ad2b: 8317977: update problemlist to include MacOS for sun/security/tools/keytool/NssTest.java
• b92de54: 8317964: java/awt/Mouse/MouseModifiersUnitTest/MouseModifiersUnitTest_Standard.java fails on macosx-all after JDK-8317751
• 2a80160: 8314283: Support for NSS tests on aarch64 platforms
• ... and 88 more: https://git.openjdk.org/jdk/compare/287b24322135b54641f013970c4545ce069c4350...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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[walulyai]

Thanks for the reviews.

/integrate

[openjdk]

Going to push as commit 4c79e7d.
Since your change was applied there have been 101 commits pushed to the master branch:

• 7633a76: 8317998: Temporarily disable malformed control flow assert to reduce noise in testing
• 00ef9f9: 8316947: Write a test to check textArea triggers MouseEntered/MouseExited events properly
• 77dc891: 8317963: Serial: Remove unused GenerationIsInReservedClosure
• d95b548: 8315850: Improve AbstractMap anonymous Iterator classes
• 424de29: 8317866: replace NET_SocketAvailable
• 6d6c900: 8038244: (fs) Check return value of malloc in Java_sun_nio_fs_AixNativeDispatcher_getmntctl()
• eca6ea4: 8317873: Add @sealedGraph to IllegalFormatException
• 2edf9c3: 8317763: Follow-up to AVX512 intrinsics for Arrays.sort() PR
• 839cb19: 8317581: [s390x] Multiple test failure with LockingMode=2
• 387896f: 8309621: [XWayland][Screencast] screen capture failure with sun.java2d.uiScale other than 1
• ... and 91 more: https://git.openjdk.org/jdk/compare/287b24322135b54641f013970c4545ce069c4350...master

Your commit was automatically rebased without conflicts.

[openjdk]

@walulyai Pushed as commit 4c79e7d.

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