This are no users since commit 40d707f33db5 ("mm/ksm: use folio in
write_protect_page"), so remove DEFINE_PAGE_VMA_WALK().
Link: https://lkml.kernel.org/r/20240524053618.208895-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Alex Shi <alexs@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>