Re: [PATCH v2 1/2] mm/huge_memory.c: skip zero-page remapping when underused THP shrinker is disabled

[Barry Song]

On Mon, Oct 26, 2026 at 1:40 AM Nico Pache (Red Hat)
<nico.pache@xxxxxxxxx> wrote:
>
> The zero-page remapping in __folio_split() was added to support the
> underused THP shrinker. When the shrinker is disabled via
> shrink_underused, gate TTU_USE_SHARED_ZEROPAGE on split_underused_thp
> to avoid scanning subpages for zero content unnecessarily.
>
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
> Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp")
> Signed-off-by: Nico Pache <nico.pache@xxxxxxxxx>

is b1f202060afe a correct fixes tag? as
commit b1f202060afe has no even "split_underused_thp" there.

it was introduced by 81d3ff3c6f7 ("mm: add sysfs entry to disable
splitting underused THPs").