Remove the swappiness parameter (#5987)

[ti-chi-bot]

This is an automated cherry-pick of #5987

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• This PR is translated from: Remove the swappiness parameter docs-cn#6377
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• Delete files
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• Might cause conflicts after applied to another branch

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• TomShawn

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[TomShawn]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 2a29a18