On 01/20/2015 02:53 PM, Michael Kerrisk (man-pages) wrote: > This is an enormous and complex API. Why is the API ioctl() based, > rather than system-call-based? Have we learned nothing from the hydra > that the futex() multiplexing syscall became? (And kdbus is an order > of magnitude more complex, by the look of things.) At the very least, > a *good* justification of why the API is ioctl()-based should be part > of this documentation file. I think the simplest reason is because we want to be able to build kdbus as a module. It's rather an optional driver than a core kernel feature. IMO, kernel primitives should be syscalls, but kdbus is not a primitive but an elaborate subsystem. Also, the context the kdbus commands operate on originate from a mountable special-purpose file system. Hence, we decided not to use a global kernel interface but specific ioctls on the nodes exposed by kdbusfs. Thanks, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
