Commit e5e75892 authored by Wei Yang's avatar Wei Yang Committed by Andrew Morton
Browse files

mm/rmap: not necessary to mask off FOLIO_PAGES_MAPPED 

At this point, we are in an if branch conditional on (nr <
ENTIRELY_MAPPED), and FOLIO_PAGES_MAPPED is equal to (ENTIRELY_MAPPED -
1).  This means the upper bits are already cleared.

It is not necessary to mask it off.

Link: https://lkml.kernel.org/r/20250817032647.29147-2-richard.weiyang@gmail.com


Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Reviewed-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 658fa653

mm/rmap.c

+1 −1
Original line number Diff line number Diff line
@@ -1748,7 +1748,7 @@ static __always_inline void __folio_remove_rmap(struct folio *folio, 
				nr_pages = folio_large_nr_pages(folio);

				if (level == PGTABLE_LEVEL_PMD)

					nr_pmdmapped = nr_pages;

				nr = nr_pages - (nr & FOLIO_PAGES_MAPPED);

				nr = nr_pages - nr;

				/* Raced ahead of another remove and an add? */

				if (unlikely(nr < 0))

					nr = 0;