Performance degradation and unstable observed on 10.6.19

I plan to migrate our MariaDB instances from `10.2.10` to `10.6.19`, and have run some performance benchmarks. And I observed performance is not stable compared to `10.2.10`, especially for in-memory workload.

Here is my test setup.
Test tool: sysbench 1.0.X
OS: CentOS 7.9 X86_64
MariaDB version: 10.2.10 10.6.19
Dataset: create 10 tables and each with 5M rows, each table ~ 1.2GB, the total size is ~ 12GB
Almost all config options are the same, except I removed some options which is deprecated/removed in 10.6, e.g. `innodb_buffer_pool_instances`, `innodb_page_cleaners`,`innodb-thread-concurrency`,`innodb_checksum_algorithm` etc.

Test 1.
In-memory workset, with `innodb_buffer_pool_size`=188GB
> NOTE:
> TPS-X means using X threads run sysbench `oltp_read_write.lua` test

10.2.10

10.6.19

We can see there are performance drops periodically with version `10.6.19`. The `10.6.19` can keep stable only in `4` threads case, while `10.2.10` 's performance is always stable with threads `4, 8, 16, and 32`.

Test 2:
Disk io bund test with `innodb_buffer_pool_size=2G`

10.2.10

10.6.19

you can see `10.2.10` is also more stable compared to `10.6.19`.