in-memory-engine: OLTP-insert has more than 10% regression when in-memory-engine is enabled in a test environment

[tonyxuqqi]

Bug Report

What version of TiKV are you using?

master branch [c36886a]

What operating system and CPU are you using?

Steps to reproduce

enable in-memory-engine and run sysbench oltp-insert
And then disable it and restart the tikv, sysbench oltp-insert again (with same prepared data).

What did you expect?

The insert TPS has less than 5% regression when in-memory-engine is enabled.

What did happened?

It shows that with in-memory-engine, the TPS has 10%+ regression.

clinic: https://clinic.pingcap.com/portal/#/orgs/1372813089196921458/clusters/7361927152612425097?from=1715034298&to=1715041498