Re: [LSF/MM/BPF TOPIC] DAMON Updates and Plans: Automation of DAMON tuning, tiering, and VM guest scaling
From: SeongJae Park
Date: Sun May 12 2024 - 15:44:12 EST
On Mon, 29 Jan 2024 12:47:49 -0800 SeongJae Park <sj@xxxxxxxxxx> wrote:
> Hi all,
>
>
> Thanks to the discussions and feedback that we received last year from the
> LSF/MM/BPF 2023's DAMON updates and future plans session[1], DAMON made many
> advances and yet more future plans. I'd like to again share/discuss the
> followup changes and status we made so far after the last year's session, and
> the future development plans on LSF/MM/BPF 2024.
>
> A few topics would be shared, including below.
>
[...]
>
> Access/Contiguity-aware Memory Auto-scaling
> -------------------------------------------
>
> This is a new idea which was not discussed in last year's LSF/MM/BPF. The main
> purpose is to implement an access-aware, efficient, reliable, and simple to use
> memory over-subscribed VM guest kernels. Specifically, it will steal guest
> memory based on access patterns in a contiguity-aware manner and report those
> to the host as free to use. The PSI-based stealing aggressiveness auto-tuning
> may be used. It will also apply a 'struct page' overhead reduction mechanism
> to the stolen memory. We're currently thinking about memory hotplugging and
> vmemmap remapping as candidate mechanisms. For simple usage, the interface
> will be similar to that of virtio-balloon, which is widely adopted. The first
> version of the more detailed idea[7] has been shared before.
>
> Because it is still at a pure idea level, not much progress until LSF/MM/BPF is
> expected. This item would be primarily for the future plans part. That said,
> at least a second version of the design will be shared before. Also hopefully
> early proof-of-concepts level implementation or some test results will be
> shared. Since this is expected to be more for future plans than status update,
> I hope to have more discussions for getting design level concerns and possible
> collaboration chances.
I just posted the RFC IDEA v2 of this with pseudo-code level implementation
example: https://lore.kernel.org/all/20240512193657.79298-1-sj@xxxxxxxxxx/
Hopefully it will help the idea success or fail faster :)
Thanks,
SJ
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