Re: [PATCH v4 6/6] mm/mm_init: add zone mismatch warning during page init

[Mike Rapoport]

On Sat, Oct 10, 2026 at 05:32:59PM +0800, Muchun Song wrote:
> 
> 
> > On Oct 10, 2026, at 15:57, Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote:
> > 
> > For vmemmap-optimized sections, tail struct pages may be backed by
> > shared vmemmap pages. Those shared pages must carry the same page zone
> > ID as the struct pages initialized for the section.
> > 
> > Warn in __init_single_page() if the shared tail page has a different
> > page_zone_id(), which would indicate inconsistent initialization.
> 
> Please ignore Sashiko's report [1], both are false positive. It didn't
> realize that shared vmemmap pages are initialized early before __init_single_page().

I didn't realize it too when I read this first :)
 
How about a short comment above vmemmap_optimization_verify_zone()?

> [1] https://sashiko.dev/#/patchset/20261010075755.83339-1-songmuchun%40bytedance.com?part=6
> 
> Thanks.

-- 
Sincerely yours,
Mike.