Re: [PATCH V3][for-next] mm: add a new vector based madvise syscall

+	if (behavior != MADV_DONTNEED && behavior != MADV_FREE)
+		return -EINVAL;

This limitations is kind of lame and makes it a special purpose hack.

It will also cause backwards compatibility issues if it needs
to be extended later.

How hard would it be to support all of madvise vectored?

That would also give much cleaner documentation.

-Andi