"partial" container checkpoint

[Dave Hansen <dave@linux.vnet.ibm.com>]

On Tue, 2009-04-14 at 10:29 -0500, Serge E. Hallyn wrote:
> I think the perceived need for it comes, as above, from the pure
> checkpoint-a-whole-container-only view.  So long as you will
> checkpoint/restore a whole container, then you'll end up doing
> something requiring privilege anyway.  But that is not all of
> the use cases.

Yeah, there are certainly a lot of shades of gray here.  I've been
talking to some HPC guys in the last couple of days.  They certainly
have a need for checkpoint/restart, but much less of a need for doing
entire containers.  

It also occurs to me that we have the potential to pull some
long-out-of-tree users back in.  VMADump users, for instance:

	http://bproc.sourceforge.net/c268.html

If we could do *just* a selective checkpoint of a single process's VMAs,
the bproc users could probably use sys_checkpoint() in some way.  That's
*way* less than an entire container, but it would be really useful to
some people.   

-- Dave