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

[Yu Zhao]

On Tue, Aug 9, 2022 at 11:16 AM Alex Zhu (Kernel) <alexlzhu@xxxxxx> 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@xxxxxxxxxx/

And this one:

https://lore.kernel.org/r/1635422215-99394-1-git-send-email-ningzhang@xxxxxxxxxxxxxxxxx/