The quilt patch titled
Subject: mm/migrate: use folio_likely_mapped_shared() in add_page_for_migration()
has been removed from the -mm tree. Its filename was
mm-migrate-use-folio_likely_mapped_shared-in-add_page_for_migration.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/migrate: use folio_likely_mapped_shared() in add_page_for_migration()
Date: Tue, 9 Apr 2024 21:22:54 +0200
We want to limit the use of page_mapcount() to the places where it is
absolutely necessary. In add_page_for_migration(), we actually want to
check if the folio is mapped shared, to reject such folios. So let's use
folio_likely_mapped_shared() instead.
For small folios, fully mapped THP, and hugetlb folios, there is no change.
For partially mapped, shared THP, we should now do a better job at
rejecting such folios.
Link: https://lkml.kernel.org/r/20240409192301.907377-12-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Richard Chang <richardycc@xxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/migrate.c~mm-migrate-use-folio_likely_mapped_shared-in-add_page_for_migration
+++ a/mm/migrate.c
@@ -2140,7 +2140,7 @@ static int add_page_for_migration(struct
goto out_putfolio;
err = -EACCES;
- if (page_mapcount(page) > 1 && !migrate_all)
+ if (folio_likely_mapped_shared(folio) && !migrate_all)
goto out_putfolio;
err = -EBUSY;
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
