A big part of it is because they're repeatedly walking the same path while reading and writing it. I got a 20% performance improvement on FreeBSD+ZFS with this

A big part of it is because they're repeatedly walking the same path while reading and writing it. I got a 20% performance improvement on FreeBSD+ZFS with this change, which merely opens an fd, and uses that to stat and write, cutting the number of path traversals in half: https://eigenstate.org/paste/d41e3b69d258e3b52f7cee7a9921f027 https://eigenstate.org/paste/d41e3b69d258e3b52f7cee7a9921f02...