An example of how not to use bitfields: https://lwn.net/Articles/478657/ https://lwn.net/Articles/478657/ I am not sure whether the underlying spinlock_t struc

An example of how not to use bitfields: https://lwn.net/Articles/478657/ https://lwn.net/Articles/478657/ I am not sure whether the underlying spinlock_t struct is something in memory or mapped to a hardware register. But it seems like this was being used to save space rather than to access hardware.