[PATCH 0/4] um: suspend/resume

[Johannes Berg]

Hi,

So I've been playing with suspend/resume in my time-travel
environment, and things are actually quite decent with just
minimal effort (these patches).

Eventually, I think I'd like to implement proper hooks so
even kernel services are suspended properly, but that will
be a separate patch anyway.

Also, since virtqueues on virtio (vhost-user) devices are
just completely suspended, I don't have a way to wake up
from an external source, which would obviously be the most
interesting thing to do ... I suspect that to really do it
right we'd need another vhost-user spec extension to have a
new file descriptor, and then use a new UML interrupt that
can be marked as a wakeup source.

In any case, with this I can already do e.g.

	rtcwake -m mem -s 30

inside a system, in any kind of (non) time-travel mode, so
that's a start.

johannes