Re: [FYI] DAMON and virtio-balloon in DeepSeek's DSec paper

[Lian Wang <lianux.mm@gmail.com>]

Hi Lance,

Thank you very much for sharing this and for your interest in the related
work. It is great to see DAMON and virtio-balloon being used together in
another real, large-scale system.

One scenario we have recently been studying came from Sangfor. In a KVM/QEMU
deployment with guest memory backed by shared tmpfs and host THP enabled,
host-side DAMON can report a much larger hot-memory proportion than the
guest's fine-grained activity suggests. The related discussion is here:

https://lore.kernel.org/all/20260915025514.2434-1-lianux.mm@gmail.com/

We are preparing more complete experiments and improvements around this
scenario, and we plan to discuss it in more depth at LPC.

I am still actively running experiments based in part on SJ's earlier
introductions and our discussions. After LPC, we hope to share results on a
more regular basis, together with discussion outcomes and reports from more
scenarios. I believe DAMON will continue to become even better as these users
and perspectives come together.

I am also contacting the authors of the DeepSeek paper to learn more about
their setup and experience. We hope they can join the discussion so that we
can work together to improve this area further.

Kairui is also very interested in this DAMON use case and may already have
discussed related ideas with SJ, so I have kept him in Cc.

Thank you again, Lance, and thanks everyone!

Best,
Lian

On Fri, 25 Sep 2026 13:44:08 +0800 Lance Yang <lance.yang@linux.dev> wrote:

> I was reading DeepSeek's new DSec paper[1] and found a nice use of DAMON
> and virtio-balloon:
>
> And it worked: time-integrated host memory use fell by 21.2%, while peak
> usage stayed about the same, with no significant CPU overhead.