Re: [PATCH v2 08/17] mm/sparse-vmemmap: support section-based vmemmap optimization

[Muchun Song]

> On Jul 20, 2026, at 17:31, Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote:
> 
> Teach sparse-vmemmap population code to use the compound page order
> when deciding whether a vmemmap page can be optimized.
> 
> With this information, the common sparse-vmemmap population path can
> allocate or reuse shared tail vmemmap pages directly instead of relying
> on HugeTLB-specific handling.
> 
> This centralizes vmemmap optimization logic in the sparse-vmemmap code,
> based on section metadata, and prepares for sharing the same mechanism
> across different users of vmemmap optimization, including HugeTLB and
> DAX.
> 
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>

Sashiko reported four issues [1] regarding memory hotplug, but the entire
series doesn't actually support applying HVO via memory hotplug. Therefore,
all four of these issues are false positives.

[1] https://sashiko.dev/#/patchset/20260720093127.540540-1-songmuchun%40bytedance.com?part=8