Re: [PATCH] mm/damon: update expired description of damos_action

[SeongJae Park <sj@kernel.org>]

On Sat, 2 Aug 2025 01:11:09 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:

> Hi, Honggyu
> 
> On Fri, Aug 1, 2025 at 8:35 PM Honggyu Kim <honggyu.kim@sk.com> wrote:
> >
> > Hi Sang-Heon and SeongJae,
> >
> > On 8/1/2025 2:58 AM, SeongJae Park wrote:
> > > Hello Sang-Heon,
> > >
> > > On Thu, 31 Jul 2025 22:22:30 +0900 Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> > >
> > >> Nowadays, damos operation actions support more various operation set.
> > >> But comments(also, generated documentation) doesn't updated.
> > >> So, fix the comments with current support status.
[...]
> > >> diff --git a/include/linux/damon.h b/include/linux/damon.h
[...]
> > >>    * @DAMOS_WILLNEED:  Call ``madvise()`` for the region with MADV_WILLNEED.
> > >>    * @DAMOS_COLD:              Call ``madvise()`` for the region with MADV_COLD.
> > >> - * @DAMOS_PAGEOUT:   Call ``madvise()`` for the region with MADV_PAGEOUT.
> > >> + * @DAMOS_PAGEOUT:   Reclaim the region.
> > >
> > > Nice!
> >
> > But doesn't it make confusion about whether this pages out to disk or does
> > demotion to the lower tier memory?  It's because PAGEOUT action doesn't do
> > demotion, but it looks "reclaim" includes pageout and demotion together in my
> > understanding since /sys/kernel/mm/numa/demotion_enabled was introduced.

To my understanding, DAMOS_PAGEOUT can also do demotion when demotion_enabled
is set.  Am I missing something?

> 
> My intention was just to synchronize with the Design documentation.
> 
> So how about changing the description to `Page out the region`, Would
> this be also confusing?
> I feel like it would be clearer than using word "reclaim"

In my opinion, "reclaim" is good.


Thanks,
SJ

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