Re: [PATCH] mm: mark folio as workingset in lru_deactivate_fn

[Zhaoyang Huang]

On Thu, Mar 30, 2023 at 5:32 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
>
> On Thu, Mar 30, 2023 at 09:38:48AM +0800, Zhaoyang Huang wrote:
> > On Wed, Mar 29, 2023 at 10:55 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> > >
> > > On Wed, Mar 29, 2023 at 06:47:35PM +0800, zhaoyang.huang wrote:
> > > > From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
> > > >
> > > > folio will skip of being set as workingset in lru_deactivate_fn.
> > >
> > > Can you please elaborate why that's undesirable? What's the problem
> > > you're fixing?
> > If I am correct, folio will skip being set as workingset when moving
> > from active lru to inactive lru, which is performed on every folio in
> > shrink_active_list during normal reclaim.
>
> shrink_active_list directly calls folio_set_workingset(). The function
> you're editing is used for things like MADV_COLD and truncate().
Yes.
>
> It sounds like there is just a misunderstanding of the code, not an
> actual problem.
Isn't that a problem? As my understanding, MADV_COLD could be deemed
as a stimulation of normal reclaiming which turbo the folio towards
eviction, while the page moving by it should be also delt in the same
way(PG_active has been cleaned)