Re: [PATCH v3] mm: add thp_utilization metrics to /proc/thp_utilization

[Yang Shi <shy828301@gmail.com>]

On Tue, Aug 9, 2022 at 4:36 PM Yu Zhao <yuzhao@google.com> wrote:
>
> On Tue, Aug 9, 2022 at 11:16 AM Alex Zhu (Kernel) <alexlzhu@fb.com> wrote:
> >
> >
> > > OK, it is hard to tell what it looks like now. But the THPs on the
> > > deferred split list may be on the "low utilization split" list too?
> > > IIUC the major difference is to replace zero-filled subpage to special
> > > zero page, so you implemented another THP split function to handle it?
> > >
> > > Anyway the code should answer the most questions.
> >
> > They can indeed end up on both lists. This did have to be handled when
> > implementing the shrinker.
> >
> > We free the zero filled subpages, while modifying the existing split_huge_page()
> > function. Will follow up that change in another patch.
>
> FYI. This series does it:
>
> https://lore.kernel.org/r/20210731063938.1391602-1-yuzhao@google.com/
>
> And this one:
>
> https://lore.kernel.org/r/1635422215-99394-1-git-send-email-ningzhang@linux.alibaba.com/

Thanks, Yu. I totally forgot about these series. It is time to refresh
my memory.