mm/mm_init: add zone mismatch warning during page init

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.

[muchun.song@linux.dev: document ordering of shared and retained struct page initialization]
  Link: https://lore.kernel.org/20261010115523.4005071-1-songmuchun@bytedance.com
Link: https://lore.kernel.org/20261010075755.83339-7-songmuchun@bytedance.com
Signed-off-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <chleroy@kernel.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>

0 files changed, 0 insertions, 0 deletions