8329223: Parallel: Parallel GC resizes heap even if -Xms = -Xmx

[benty-amzn]

Clean backport of a low-risk change to address unexpected behavior with Parallel GC when Xms == Xmx
Passes local tier-1 testing on linux x86_64

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8329223 needs maintainer approval

Issue

• JDK-8329223: Parallel: Parallel GC resizes heap even if -Xms = -Xmx (Bug - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk17u-dev.git pull/2480/head:pull/2480
$ git checkout pull/2480

Update a local copy of the PR:
$ git checkout pull/2480
$ git pull https://git.openjdk.org/jdk17u-dev.git pull/2480/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 2480

View PR using the GUI difftool:
$ git pr show -t 2480

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk17u-dev/pull/2480.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back btaylor! 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]

@benty-amzn 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:

8329223: Parallel: Parallel GC resizes heap even if -Xms = -Xmx

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 6 new commits pushed to the master branch:

• 060c250: 8177107: Reduce memory footprint of java.lang.reflect.Constructor/Method
• 4071b8c: 8286781: Replace the deprecated/obsolete gethostbyname and inet_addr calls
• a640001: 8312194: test/hotspot/jtreg/applications/ctw/modules/jdk_crypto_ec.java cannot handle empty modules
• a632247: 8319338: tools/jpackage/share/RuntimeImageTest.java fails with -XX:+UseZGC
• e00211b: 8321107: Add more test cases for JDK-8319372
• 6264c70: 8273153: Consolidate file_exists into os:file_exists

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

[openjdk]

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

[openjdk]

⚠️ @benty-amzn This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[mlbridge]

Webrevs

• 00: Full (74a225dc)

[benty-amzn]

/approval request Clean backport of a low-risk change to address unexpected behavior with Parallel GC when Xms == Xmx.

[openjdk]

@benty-amzn
8329223: The approval request has been created successfully.

[benty-amzn]

/integrate

[openjdk]

Going to push as commit f4da0e7.
Since your change was applied there have been 9 commits pushed to the master branch:

• d1e31f6: 8289643: File descriptor leak with ProcessBuilder.startPipeline
• 69e6736: 8314835: gtest wrappers should be marked as flagless
• 6c3a188: 8320681: [macos] Test tools/jpackage/macosx/MacAppStoreJlinkOptionsTest.java timed out on macOS
• 060c250: 8177107: Reduce memory footprint of java.lang.reflect.Constructor/Method
• 4071b8c: 8286781: Replace the deprecated/obsolete gethostbyname and inet_addr calls
• a640001: 8312194: test/hotspot/jtreg/applications/ctw/modules/jdk_crypto_ec.java cannot handle empty modules
• a632247: 8319338: tools/jpackage/share/RuntimeImageTest.java fails with -XX:+UseZGC
• e00211b: 8321107: Add more test cases for JDK-8319372
• 6264c70: 8273153: Consolidate file_exists into os:file_exists

Your commit was automatically rebased without conflicts.

[openjdk]

@benty-amzn Pushed as commit f4da0e7.

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