Commit c7f84b57 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm: use entire_mapcount in __page_dup_rmap() 

Remove the use of the compound_mapcount_ptr() wrapper, and add an
assertion that we're not passing a tail page if we're duplicating a PMD.

Link: https://lkml.kernel.org/r/20230111142915.1001531-12-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent db4e5dbd

include/linux/rmap.h

+8 −1
Original line number Diff line number Diff line
@@ -208,7 +208,14 @@ void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *, 


static inline void __page_dup_rmap(struct page *page, bool compound)

{

	atomic_inc(compound ? compound_mapcount_ptr(page) : &page->_mapcount);

	if (compound) {

		struct folio *folio = (struct folio *)page;



		VM_BUG_ON_PAGE(compound && !PageHead(page), page);

		atomic_inc(&folio->_entire_mapcount);

	} else {

		atomic_inc(&page->_mapcount);

	}

}



static inline void page_dup_file_rmap(struct page *page, bool compound)