> 2. I understand where chuq is coming from and I think I agree with him. I
>    think that the uio_ is a process wide struct and not an lwp specific one.
>    For example, what happens when the lwp exits before the uio is completed?

for aio-like things, i think uio_proc should be changed to vmspace,
and reference to the vmspace should be kept.

>    On the other hand, keeping it as uio_proc, would require us to call
>    proc_representative_lwp(uio->uio_proc) in a bunch of places; not very
>    attractive either.

where is "a bunch of places" for example?
using uio_proc for other than address space is evil, IMO.
if proc (or lwp, or ucred, etc) is really necessary,
it should be passed as another argument.  (or curlwp, where appropriate.)

YAMAMOTO Takashi