8343205: CompileBroker::possibly_add_compiler_threads excessively polls available memory

[TheRealMDoerr]

Backport of JDK-8343205 from jdk21u-dev.

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Progress

• JDK-8343205 needs maintainer approval
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8343205: CompileBroker::possibly_add_compiler_threads excessively polls available memory (Bug - P4 - Requested)

Reviewing

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$ git fetch https://git.openjdk.org/jdk17u-dev.git pull/3106/head:pull/3106
$ git checkout pull/3106

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$ git checkout pull/3106
$ git pull https://git.openjdk.org/jdk17u-dev.git pull/3106/head

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[bridgekeeper]

👋 Welcome back mdoerr! 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]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

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

[openjdk]

⚠️ @TheRealMDoerr 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 (a320a4b7)

[TheRealMDoerr]

/approval request JDK17 is affected by this performance issue, too. The fix is not complicated and the backport from 21u-dev applies cleanly. Tier1-4 plus extra tests have passed many times. No regression observed.

[openjdk]

@TheRealMDoerr
8343205: The approval request has been created successfully.

[GoeLin]

Hi, the bug says this applies only to linux x86_64, why is this so?
Also, this is at the edge of being applicable to stable 17u. I would like to defer this to the next release to give it some time in 24/21.

[TheRealMDoerr]

All platforms are affected, but it is only problematic in environments in which os::free_memory() is slow. That was reported for some kind of container environment on linux x64. I think we should have this fix in 17u because JDK 17u is probably used in such environments, too. I think the risk is low, but we could also ship it one release later.