[1] Accordingly, the giant-lock approach is commonly seen as a preliminary means of bringing SMP support to an operating system, yielding benefits only in user space.
As of September 2022[update], Linux kernel still has console_lock and rtnl_lock, which are sometimes referred as BKL, and its removal is in progress.
[11] FreeBSD still has support for the Giant mutex,[12] which provides semantics akin to the old spl interface, but performance-critical core components have long been converted to use finer-grained locking.
[1] It is claimed by Matthew Dillon that out of the open-source software general-purpose operating systems, only Linux, DragonFly BSD and FreeBSD have modern SMP support, with OpenBSD and NetBSD falling behind.
[11] The NetBSD Foundation views modern SMP support as vital to the direction of The NetBSD Project, and has offered grants to developers willing to work on SMP improvements; NPF (firewall) was one of the projects that arose as a result of these financial incentives, but further improvements to the core networking stack may still be necessary.