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

On Oct 10, 2026, at 17:58, Mike Rapoport [off-list ref] wrote:

On Sat, Oct 10, 2026 at 05:32:59PM +0800, Muchun Song wrote:

quoted

quoted

On Oct 10, 2026, at 15:57, Muchun Song [off-list ref] 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()?

Good point. A short comment there would be helpful.

Thanks,
Muchun

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

Thanks.

-- 
Sincerely yours,
Mike.