I was revising Linux system calls. I found that a few calls are unimplemented system calls. For example: afs_syscall. I don't understand why they are included in man pages if they are not yet available.
They are not implemented in the kernel. So who will implement them? Will they be available in future kernel releases? Or does the user have to implement them? Or will distributions implement them?
Are they really necessary? What is the use of unimplemented system calls?
If some one implemented these calls, how can I know they are implemented, what arguments do I have to pass and what will they return?