[dm-devel] [PATCH] announcing the dm-update target

[Akilesh Kailash]

On Wed, Nov 24, 2021 at 8:10 AM Mikulas Patocka <mpatocka at redhat.com> wrote:
>
>
>
> On Tue, 23 Nov 2021, David Anderson wrote:
>
> > In our ecosystem, the OTA generation and on-device application process
> > has evolved continually, in every release, for over 10 years now. So
> > we think it's unlikely that we'll stop making improvements to it. Our
> > current roadmap has other changes in the pipeline too. It's not just
> > us trying to eek out diminishing returns. Other parts of the system
> > change around us, and the OTA system needs to adapt.
> >
> > The performance penalty is something we've been working on, and have
> > improved a lot since our first iteration. We're currently
> > experimenting with io_uring as well.
> >
> > Best,
> >
> > -David
>
> Hi
>
> I understand that an update format developed over 10 years will have
> better compression ratio than my format developed in 2 months.
>
> I'd be interested in extending dm-update to handle your your update format
> and possibly add some abstraction, so that it can work with multiple
> formats.
>
> You say that you have "COPY" and "XOR" operations.
>
> How do you search for blocks that are similar, so that the "XOR" method is
> benefical for them? How do you make sure that you don't perform the "XOR"
> operation twice, if there's system crash when performing it?

CC: Kelvin and Tianjie who are familiar with the  OTA generation.

> Could it be possible for you to give us two Android images and a program
> that calculates difference between them? So that we could see how well we
> are performing compared to the existing solution.
>
> Mikulas
>