What new system calls do you want in BSD?

[Eliot &]

Another system call (that I feel any virtual memory system ought to support)
is one to move a range of pages from one location in the address space to
another. This is sometimes desirable for garbage collectors, etc. Note that
one need not move the *data*, only the page table entries (though it is
certainly more complicated than just a block move within the OS). Note that
the call should work even if the range overlaps with itself. It is the page
level analog of memcpy. The size of the region should probably *not* be
specified in terms of pages, but rather bytes, and the source and destination
addresses as byte addresses, too. The call should fail if the addresses are
not page aligned and the quantity to move is not a multiple of the page size.

If one allows additional arguments for adjusting the protection, and allows
the source and/or destination to be associated with different processes and/or
files, a general move/messaging operator results.
								Eliot
--

		J. Eliot B. Moss, Assistant Professor
		Department of Computer and Information Science
		Lederle Graduate Research Center
		University of Massachusetts
		Amherst, MA  01003
		(413) 545-4206; Moss at cs.umass.edu