Consider a different version of jemalloc
Based on this article: https://www.speedshop.co/2017/12/04/malloc-doubles-ruby-memory.html
Do not use jemalloc 4.x with Ruby. It has a bad interaction with Transparent Huge Pages that reduces the memory savings you’ll see. Instead, use jemalloc 3.6. 5.0’s performance with Ruby is currently unknown.
They suggest we may have better memory footprint by either going back to 3.6 or moving up to 5.x
We are currently bundling 4.2.1 (check changes here: https://github.com/jemalloc/jemalloc/releases).