Re: [RFC PATCH v2 0/4] mm/damon: Introduce a huge page collapsing mechanism using auto tuning

From: SeongJae Park

Date: Mon May 25 2026 - 12:50:31 EST


On Mon, 25 May 2026 16:53:17 +0300 Gutierrez Asier <gutierrez.asier@xxxxxxxxxxxxxxxxxxx> wrote:

> Hi SJ,
>
> On 5/23/2026 8:17 PM, SeongJae Park wrote:
> > On Fri, 22 May 2026 14:55:14 +0000 <gutierrez.asier@xxxxxxxxxxxxxxxxxxx> wrote:
[...]
> >> A new module is introduced to demonstrate the use of huge pages
> >> collapse autotuning. The goal is to collapse hot regions of a given
> >> process into huge pages. The module launches a kdamond thread for a
> >> certain task provided by the user through monitored_pid module argument.
> >> Hugepage goal autotuning will automatically adjust the aggressiveness
> >> of hot region collapses.
> >
> > Having a module for the demonstration purpose sounds good. But, for the
> > demonstration purpose, as I previousoly commented, making it as a sample module
> > (put under /samples/damon/) or just drop when you drop RFC tag would be better.
> >
> > Let me know if this module is aimed to be as is even after you drop RFC tag.
> I'll move it to samples. I'll keep the RFC in the next version still,
> so I make sure that the major details are polished before I drop RFC tag.

Makes sense. In the case, I think we can further reduce the number of
parameters of the sample module and make the code simpler.

[...]
> >> TODO
> >> ====
> >> - Support page splitting for cold hugepages.
> >
> > Sounds good! By using two DAMOS schemes that doing collapsing and splitting, I
> > think we can make more complete access-aware THP system.
> My thought was to add cold page splitting as a separate RFC in the future.

Makes sense :)


Thanks,
SJ

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