Re: [PATCH v2 1/1] mm: skip mlocked THPs that are underused early in deferred_split_scan()

Kiryl Shutsemau
2025-09-08T10:38:32Z

On Mon, Sep 08, 2025 at 05:07:41PM +0800, Lance Yang wrote:
> From: Lance Yang <lance.yang@linux.dev>
>
> When we stumble over a fully-mapped mlocked THP in the deferred shrinker,
> it does not make sense to try to detect whether it is underused, because
> try_to_map_unused_to_zeropage(), called while splitting the folio, will not
> actually replace any zeroed pages by the shared zeropage.

It makes me think, does KSM follows the same logic as
try_to_map_unused_to_zeropage()?

I cannot immediately find what prevents KSM from replacing zeroed mlocked
folio with ZERO_PAGE().

Hm?

--
Kiryl Shutsemau / Kirill A. Shutemov