Re: Benchmarking: How to identify bottleneck (limiting factor) and achieve "linear scalability"?

> Do you know which of the settings is causing lower TPS ?

> I suggest to check shared_buffers.
>

I'm trying to find this, but it's taking a lot of time in re-running the
benchmarks changing one config setting at a time. Thanks for the tip
related to shared_buffers.

>
> If you haven't done it, disabling THP and KSM can resolve performance
> issues,
> esp. with large RAM like shared_buffers, at least with older kernels.
>
> https://www.postgresql.org/message-id/20170718180152.GE17566%40telsasoft.com

Is this a well-known performance "hack"? Is there any reason why it is not
mentioned at https://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server
? Are the stability implications of fiddling with THP and KSM well-known?
Also, wrt KSM, my understand was that when a process forks the process'
memory is anyways "copy on write", right? What other kind of pages would
end-up being de-duplicated by ksmd? (Caveat: This is the first time I'm
hearing about KSM and my knowledge is based off a single reading of
https://www.kernel.org/doc/html/latest/admin-guide/mm/ksm.html )

-- Saurabh.