*: recalculate the threshold of gctuner when ServerMemoryLimit is updated

[hawkingrei]

What problem does this PR solve?

Issue Number: close #48180

Problem Summary:

What changed and how does it work?

recalculate the threshold of gctuner when ServerMemoryLimit is updated.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

I have tested in the production cluster. When I set ServerMemoryLimit , the GOGC will update.

• 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

[codecov]

Codecov Report

Merging #51197 (25422db) into master (1fc92b3) will decrease coverage by 15.7448%.
Report is 7 commits behind head on master.
The diff coverage is 100.0000%.

Additional details and impacted files

@@                Coverage Diff                @@
##             master     #51197         +/-   ##
=================================================
- Coverage   70.5999%   54.8551%   -15.7448%     
=================================================
  Files          1467       1576        +109     
  Lines        434849     603225     +168376     
=================================================
+ Hits         307003     330900      +23897     
- Misses       108598     249349     +140751     
- Partials      19248      22976       +3728     

Flag	Coverage Δ
integration	36.9427% <100.0000%> (?)
unit	70.4613% <100.0000%> (+0.0624%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	53.9957% <ø> (ø)
parser	∅ <ø> (∅)
br	51.4834% <ø> (+5.5876%)	⬆️

[hawkingrei]

/retest

[hawkingrei]

/retest

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-02-20 09:35:02.884467822 +0000 UTC m=+349791.632090931: ☑️ agreed by wshwsh12.
• 2024-02-21 02:38:00.635300873 +0000 UTC m=+411169.382923983: ☑️ agreed by AilinKid.

[easonn7]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AilinKid, easonn7, wshwsh12, XuHuaiyu

The full list of commands accepted by this bot can be found here.

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• pkg/sessionctx/variable/OWNERS [easonn7]

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[hawkingrei]

/retest

[hawkingrei]

/cherrypick release-7.5
/cherrypick release-7.1
/cherrypick release-6.5

[ti-chi-bot]

@hawkingrei: new pull request created to branch release-6.5: #51213.

In response to this:

/cherrypick release-7.5
/cherrypick release-7.1
/cherrypick release-6.5

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

@hawkingrei: new pull request created to branch release-7.1: #51214.

In response to this:

/cherrypick release-7.5
/cherrypick release-7.1
/cherrypick release-6.5

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

@hawkingrei: new pull request created to branch release-7.5: #51215.

In response to this:

/cherrypick release-7.5
/cherrypick release-7.1
/cherrypick release-6.5

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.