Re: Snapshot customizing

[Peter Maydell]

On Wed, 27 Jul 2022 at 18:45, Jayakrishna Vadayath <jay@forallsecure.com> wrote:
> Yes I did profile it afterwards and found that the majority of time is being 
> spent on loading the RAM.
> I'm running QEMU with "-m 1G" and I do see that there's close to 1 gigabyte 
> of memory being loaded from the snapshot.
>
> In my use case, I need to repeatedly revert back to a snapshot after 
> executing a small user-space program.
> I was wondering if it would be possible to identify the dirty pages in RAM 
> after this execution and only restore those pages from the snapshot when a 
> restore is encountered.
>
> I understand that this scenario might be very unique, but I just wanted to 
> know if such an idea would be feasible or not.

Potentially most of the machinery is present for that (tracking dirty
pages); but it would probably be a moderate development effort to
get it connected up to handle the snapshot revert case correctly,
and as you say it's for an extremely niche use case.

thanks
-- PMM