Hi Lance, On Fri, 25 Sep 2026 13:44:08 +0800 Lance Yang <[email protected]> wrote:
> Hi all, > > I was reading DeepSeek's new DSec paper[1] and found a nice use of DAMON > and virtio-balloon: > > With this kind of workload, an agent may read a file once and never touch > it again, while those pages remain in the guest page cache. Without memory > pressure in the guest, they can stay cached even though the host would > like that memory back ... > > The trick is DAMON + virtio-balloon free-page reporting :) DAMON reclaims > cold file pages from the guest page cache; buddy gets a chance to coalesce > them into reportable blocks, and virtio-balloon passes those blocks to > Firecracker. Firecracker can then drop the host backing with MADV_DONTNEED. > > And it worked: time-integrated host memory use fell by 21.2%, while peak > usage stayed about the same, with no significant CPU overhead. Pretty cool > to see these pieces show up in another real, large-scale system :) Thank you for sharing this, Lance! > > Kernel work still changes the world. Cheers to that! Indeed, the community is making the work a great place. > > Anyhow, I still don't know DAMON and virtio-balloon as well as I should > (mostly I just know the people who built them) :P Please feel free to ask any question to DAMON community and me, whenever you get :) > > [1] https://arxiv.org/html/2609.22978 I only briefly read the paper. But it looks like DeepSeek's DAMON usage is similar to AWS' DAMON usage [1] for their serverless service. While I was in AWS, I proposed [2] a more advanced version called Access/Contiguity-aware Memory Autoscaling (ACMA). After the RFC idea v2 [2], no progress is made so far, though. I shortly covered it in LSFMMBPF'25 [3], but all I mentioned was that the project is suspended. Recently a useer has personally reached out to me asking the status of ACMA. It is too early stage of the discussion to say or promise something in my humble perspective, though. [1] https://cdn.amazon.science/ee/a4/41ff11374f2f865e5e24de11bd17/resource-management-in-aurora-serverless.pdf [2] https://lore.kernel.org/all/[email protected]/ [3] https://lore.kernel.org/all/[email protected]/ Thanks, SJ [...]
