Source for those interested: https://github.com/torvalds/linux/blob/master/lib/refcount.c https://github.com/torvalds/linux/blob/master/lib/refcount.c I'm kin

Source for those interested: https://github.com/torvalds/linux/blob/master/lib/refcount.c https://github.com/torvalds/linux/blob/master/lib/refcount.c I'm kind of surprised that the authors went with compare-and-exchange for their ref count, rather than get-and-increment. Even if the counter does overflow, it's usually detectable, and reversible. This is true even in the face of concurrent updates. The benefit is that there is only one atomic operation in the fast path.