8293019: [JVMCI] change ratio of libgraal to C1 threads and use one isolate per libgraal thread

[dougxc]

JDK-8242440 allows the VM to use one isolate per libgraal thread (OIPLT). This has a number of benefits such better isolation of compiler crashes and avoids GC interference between isolates. Experimentation has shown that reducing the ratio of libgraal threads to C1 threads also helps keep the max RSS down. This PR makes OIPLT the default and adds a JVMCINativeLibraryThreadFraction flag for configuring the libgraal to C1 thread ratio. The default value for JVMCINativeLibraryThreadFraction is 0.33 which means there are 2 C1 threads per libgraal thread.

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Progress

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Issue

• JDK-8293019: [JVMCI] change ratio of libgraal to C1 threads and use one isolate per libgraal thread

Reviewers

• Tom Rodriguez (@tkrodriguez - Reviewer)
• Igor Veresov (@veresov - Reviewer)

Reviewing

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (42a7db88)

[openjdk]

@dougxc 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:

8293019: [JVMCI] change ratio of libgraal to C1 threads and use one isolate per libgraal thread

Reviewed-by: never, iveresov

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At the time when this comment was updated there had been 5 new commits pushed to the master branch:

• 0d51f63: 8293008: Replace uses of StringBuffer with StringBuilder in MergeCollation
• 5d6779f: 8292681: Add JMH for ProtectionDomain
• 38e6706: 8293050: RISC-V: Remove redundant non-null assertions about macro-assembler
• 4c90e87: 8290781: Segfault at PhaseIdealLoop::clone_loop_handle_data_uses
• 9e3176b: 8293035: Cleanup MacroAssembler::movoop code patching logic aarch64 riscv

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.

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[veresov]

LGTM

[dougxc]

Thanks for the reviews @veresov and @tkrodriguez .

[dougxc]

/integrate

[openjdk]

Going to push as commit 3c1bda4.
Since your change was applied there have been 5 commits pushed to the master branch:

• 0d51f63: 8293008: Replace uses of StringBuffer with StringBuilder in MergeCollation
• 5d6779f: 8292681: Add JMH for ProtectionDomain
• 38e6706: 8293050: RISC-V: Remove redundant non-null assertions about macro-assembler
• 4c90e87: 8290781: Segfault at PhaseIdealLoop::clone_loop_handle_data_uses
• 9e3176b: 8293035: Cleanup MacroAssembler::movoop code patching logic aarch64 riscv

Your commit was automatically rebased without conflicts.

[openjdk]

@dougxc Pushed as commit 3c1bda4.

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