ClickHouse/tests/performance/small_block_contention.xml

<test>
    <query>select sum(number) from numbers_mt(200000) settings max_threads=100, max_block_size = 1 format Null</query>
</test>
Remove lock from the ReadProgressCallback It looks redundant (added in 5ef51ed), though it has "fix tests" in the log message, but CI reports is not available for the commits from that PR [1], so let's try. [1]: https://github.com/ClickHouse/ClickHouse/pull/37543 Also this can be a big problem, since the code under that lock (throttling or quotas with previous implementation that uses boost::atomic_shared_ptr) may sleep. Some numbers: run \| time ------------------------\|------ max_threads=100 before \| 23.1 max_threads=100 after \| 15.1 max_threads=4500 before \| 4.5 max_threads=4500 after \| 2.3 Query: select sum(number) from numbers_mt(2000000) settings max_threads=X, max_block_size = 1 Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com> 2024-01-13 15:48:47 +00:00			`<test>`
			`<query>select sum(number) from numbers_mt(200000) settings max_threads=100, max_block_size = 1 format Null</query>`
			`</test>`