Re: just curious

[Peter da Silva <peter-dragonfly@xxxxxxxxxxx>]

Matthew Dillon wrote:
>     Since the in-kernel storage format is VM Objects, offsets, and ranges,
>     now actual shadowing or copy-on-write is really needed.  The target
>     process would have the option of using lseek/read/write on the descriptor,
>     or mmapping() it.  mmap()ing it would result in the data being shared,
>     but with mmap() one can also make things copy-on-write (MAP_PRIVATE), and
>     so forth.  We already have the VM object layering model in place in the
>     kernel to make it all possible so it would not require any special effort.

So you'll be able to use the normal UNIX system calls to access 
arbitrary VM objects? So if I have a VM object that represents a buffer 
in another user process, it'll just look like a file to me? What happens 
if I overrun the end of the buffer, ENOSPC?

That's got some amazingly cool possibilities.