8339162: [REDO] JDK-8338440 Parallel: Improve fragmentation mitigation in Full GC

[albertnetymk]

This PR consists of two commits, the original and bug-fix.

The original patch calculates the dest-count for the preceding live words incorrectly -- preceding_destination can be on region-boundary.

Test: TEST=gc/TestSoftReferencesBehaviorOnOOME.java fails ~4/100 without the fix but passes with the fix.

---

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Issue

• JDK-8339162: [REDO] JDK-8338440 Parallel: Improve fragmentation mitigation in Full GC (Enhancement - P4)

Reviewers

• Ivan Walulya (@walulyai - Reviewer) Review applies to fbba74ae
• Guoxiong Li (@lgxbslgx - Reviewer) Review applies to fbba74ae
• Zhengyu Gu (@zhengyu123 - Reviewer)

Contributors

• Guoxiong Li <gli@openjdk.org>

Reviewing

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Using Webrev

Link to Webrev Comment

[albertnetymk]

@lgxbslgx @zhengyu123 @walulyai Could you take a look?

[bridgekeeper]

👋 Welcome back ayang! 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]

@albertnetymk 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:

8339162: [REDO] JDK-8338440 Parallel: Improve fragmentation mitigation in Full GC

Co-authored-by: Guoxiong Li <gli@openjdk.org>
Reviewed-by: zgu, iwalulya, gli

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 1 new commit pushed to the master branch:

• 2614c99: 8343793: Test java/foreign/TestMemorySession.java is timing out

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[openjdk]

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

• hotspot-gc

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[mlbridge]

Webrevs

• 01: Full (d1e69020)
• 00: Full (fbba74ae)

[walulyai]

LGTM!

Shouldn't the contributors in the original be added to this redo?

[albertnetymk]

/contributor add gli

[openjdk]

@albertnetymk
Contributor Guoxiong Li <gli@openjdk.org> successfully added.

[lgxbslgx]

Looks good. Nice found. The region_align_up is not the next_region_start_address.

[lgxbslgx]

The region_align_up is not the next_region_start_address.

Even an experienced developer would misuse the function region_align_up, it may be good to add comment (in another PR?) to region_align_up to clarify its usage.

[zhengyu123]

LGTM

[albertnetymk]

Thanks for review.

/integrate

[openjdk]

Going to push as commit 423e8e0.
Since your change was applied there have been 3 commits pushed to the master branch:

• f400896: 8342442: Static ACVP sample tests
• 325a2c3: 8343848: Fix typo of property name in TestOAEPPadding after 8341927
• 2614c99: 8343793: Test java/foreign/TestMemorySession.java is timing out

Your commit was automatically rebased without conflicts.

[openjdk]

@albertnetymk Pushed as commit 423e8e0.

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