Most of the OpenBSD kernel is under a big lock but they are adding more fine grained locking. OpenBSD didn't add kernel threads until 2012. A bit late in compar

Most of the OpenBSD kernel is under a big lock but they are adding more fine grained locking. OpenBSD didn't add kernel threads until 2012. A bit late in comparison to freebsd and linux but it wasn't a priority to them. It also allowed them to benefit from the lessons everybody else learned the hard way.