Re: [LSF/MM/BPF TOPIC] DAMON Requirements for Access-aware MM of Future

Gregory Price
2025-01-02T15:22:18Z

On Thu, Jan 02, 2025 at 04:09:38AM +0000, Matthew Wilcox wrote:
> On Wed, Jan 01, 2025 at 02:20:39PM -0800, SeongJae Park wrote:
> > Hi all,
> >
> >
> > I find a few interesting and promising projects that aim to do efficient access
> > pattern-aware memory management of near future, including below (alphabetically
> > sorted).
> >
> > - CXL hotness monitoring unit
> > (https://lore.kernel.org/20241121101845.1815660-1-Jonathan.Cameron@huawei.com)
> > - Memory tiering fainess by per-cgroup control of promotion and demotion
> > (https://lore.kernel.org/20241108190152.3587484-1-kaiyang2@cs.cmu.edu)
> > - Promotion of unmapped page cache folios
> > (https://lore.kernel.org/20241210213744.2968-1-gourry@gourry.net)
>
> I'm not sure how DAMON can help with this one. As I understand DAMON,
> it monitors accesses to user addresses. This patchset is trying to solve
> the problem for file pages which aren't mapped to userspace at all.
> ie only accessed through read() and write().

DAMON can monitor physical addresses to, though the mechanism is
different. I haven't assessed this as a solution, yet.

~Gregory