Increasing max_connections on Postgresql 9.5

Currently I'm running Postgresql 9.5 on Debian 8 on Linode. The OS crashed on me a few times and I need to get it on a stable system ASAP as the database is being used in production.

I'm researching to make the switch to FreeBSD as it sounds like it's one of the most stable operating systems out there.

I will need to increase the max_connections in postgresql.conf. Increasing the max_connections also requires increasing the shared_buffers in postgresql.conf and in versions after Postgresql 9.4, a kernel recompile is not needed on Linux, but in prior versions of Postgresql 9.4 a linux kernel recompile was needed. Is it the same case with FreeBSD? no recompile is needed to increase the shared_buffers after postgresql 9.4?