"I was considering using #LMDB (which uses mmap) in a NodeJS server but page faults would block the event loop stopping it from processing requests. Benchmarks can be misleading."

https://xcancel.com/Amr__Elmohamady/status/2014672445244895449#m

Pretty sure that pagefault handling is still at least an order of magnitude faster than anything a Node.JS server can process. People always worrying about the wrong things in their code...