Re: suspend2 merge (was Re: [Suspend2-devel] Re: CFS and suspend2: hang in atomic copy)

Alan Cox
2007-04-25T22:55:44Z

> Tell me, what does "suspend" do, and what does "freeze" (snapshot) do?
>
> And name *one* thing that have in common.

Both of them have to ensure you can make a consistent snapshot. Doing
that means you've got to be able to define a single "point" at which the
snapshot is made and is internally self-consistent. That in both cases
tends to mean you've got to ensure nothing occurs which pees on the image
while you are making that snapshot (such as outstanding O_DIRECT I/O to
user pages).

Alan