design: TiDB Global Memory Arbitrator

[solotzg]

What problem does this PR solve?

Issue Number: ref #58194

Problem Summary: shown in #58194

What changed and how does it work?

• add design doc to introduce the new global memory control mechanism

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[tiprow]

Hi @solotzg. Thanks for your PR.

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[Copilot]

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

[solotzg]

/cc @gengliqi

[solotzg]

/cc @windtalker @wshwsh12

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-06-19 09:17:46.410538082 +0000 UTC m=+349719.133717064: ☑️ agreed by guo-shaoge.
• 2025-06-26 08:21:07.774174907 +0000 UTC m=+951120.497353889: ☑️ agreed by XuHuaiyu.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: guo-shaoge, wshwsh12, XuHuaiyu

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Needs approval from an approver in each of these files:

• OWNERS [XuHuaiyu,guo-shaoge,wshwsh12]

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[tiprow]

@solotzg: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
tidb_parser_test	bc51ab7	link	true	/test tidb_parser_test

Full PR test history. Your PR dashboard.

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