The kernel is custom built, with the following added (relevant) options:
options PMAP_SHPGPERPROC=4096
options ACCEPT_FILTER_HTTP
/boot/loader.conf:
kern.maxproc=32768
kern.ipc.shmmni=4096
kern.ipc.shmseg=2048
kern.ipc.semmns=960
kern.ipc.semmni=160
kern.ipc.semume=160
kern.ipc.semmnu=480