8338136: Hotspot should support multiple large page sizes on Windows

[dhanalla]

This pull request introduces enhancements to the handling of large page sizes in the OpenJDK for Windows systems, aiming to align its capabilities with those observed on Linux platforms. Investigation through SPECJBB benchmarks across various platforms revealed a 16-year-old limitation in handling large pages over 4MB for IA32/AMD64 architectures, with no such constraints for Windows on ARM64.

JBS issue https://bugs.openjdk.org/browse/JDK-8338136

The goal of this change is to overcome the 4MB large page size limitation, thereby enhancing Windows' large page support to match Linux's more flexible handling capabilities. This decision to remove 4MB constraint was influenced by insights from Linux's implementation strategies. The implementation supports multiple large page sizes , specifically excluding the IA32 architecture.

Key changes and bug fixes include enabling Windows support for multiple huge page sizes with -XX:LargePageSizeInBytes, and utilizing logic from JDK-8271195 to use the largest available large page size smaller than LargePageSizeInBytes when available.

This update removes the 4MB limit on AMD64 for Windows, populating the shared array to enable fallback options on all architectures except IA32. The implementation introduces an experimental flag, defaulting to FALSE, to facilitate testing and gradual adoption of these changes. The flag allows users to opt-in to the new large page handling logic, with a warning mechanism implemented for cases where the requested large page size is not a multiple of the OS minimum page size.

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Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change requires CSR request JDK-8343896 to be approved
• JDK-8338136 needs maintainer approval

Issues

• JDK-8338136: Hotspot should support multiple large page sizes on Windows (Enhancement - P3 - Approved)
• JDK-8343896: Hotspot should support multiple large page sizes on Windows (CSR)

Reviewing

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$ git checkout pull/1547

Update a local copy of the PR:
$ git checkout pull/1547
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/1547/head

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$ git pr checkout 1547

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https://git.openjdk.org/jdk21u-dev/pull/1547.diff

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[bridgekeeper]

👋 Welcome back dhanalla! 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]

@dhanalla 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:

8338136: Hotspot should support multiple large page sizes on Windows

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 39 new commits pushed to the master branch:

• 7d8b97f: 8332506: SIGFPE In ObjectSynchronizer::is_async_deflation_needed()
• a373866: 8336042: Caller/callee param size mismatch in deoptimization causes crash
• 73f9206: 8337981: ShenandoahHeap::is_in should check for alive regions
• ca8d6af: 8333890: Fatal error in auto-vectorizer with float16 kernel.
• e4bdf76: 8331088: Incorrect TraceLoopPredicate output
• c7fccfe: 8330106: C2: VectorInsertNode::make() shouldn't call ConINode::make() directly
• 1d5d3d8: 8330158: C2: Loop strip mining uses ABS with min int
• 2cbb283: 8351665: Remove unused UseNUMA in os_aix.cpp
• c662d7d: 8339538: Wrong timeout computations in DnsClient
• 983307e: 8343342: java/io/File/GetXSpace.java fails on Windows with CD-ROM drive
• ... and 29 more: https://git.openjdk.org/jdk21u-dev/compare/cfbfbca131f78be6a452dea4e8ddc899913ce515...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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➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[openjdk]

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

[openjdk]

⚠️ @dhanalla 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 (964e0a42)

[dhanalla]

/integrate

[openjdk]

@dhanalla
Your change (at version 964e0a4) is now ready to be sponsored by a Committer.

[phohensee]

/sponsor

[openjdk]

Going to push as commit 7ef1881.
Since your change was applied there have been 95 commits pushed to the master branch:

• 6236ffb: 8327370: (ch) sun.nio.ch.Poller.register throws AssertionError
• 7141b97: 8341072: Open source several AWT Canvas and Rectangle related tests
• c36b84a: 8341257: Open source few DND tests - Set1
• ... and 92 more: https://git.openjdk.org/jdk21u-dev/compare/cfbfbca131f78be6a452dea4e8ddc899913ce515...master

Your commit was automatically rebased without conflicts.

[openjdk]

@phohensee @dhanalla Pushed as commit 7ef1881.

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