mm-migrate-exclude-hugetlb-folios-from-mthp_stat_nr_anon-accounting.patch removed from -mm tree

The quilt patch titled
Subject: mm/migrate: exclude hugetlb folios from MTHP_STAT_NR_ANON accounting
has been removed from the -mm tree. Its filename was
mm-migrate-exclude-hugetlb-folios-from-mthp_stat_nr_anon-accounting.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Nico Pache <[email protected]>
Subject: mm/migrate: exclude hugetlb folios from MTHP_STAT_NR_ANON accounting
Date: Fri, 17 Jul 2026 00:45:00 -0600

__folio_migrate_mapping() increments MTHP_STAT_NR_ANON for the destination folio when folio_test_anon(folio) && folio_test_large(folio) is true. However, hugetlb folios satisfy both conditions despite having a completely separate accounting system — they use hugetlb_add_anon_rmap() which does not touch mTHP stats, and their free path also bypasses the mTHP decrement in __free_pages_prepare().

This causes MTHP_STAT_NR_ANON to be incremented on each hugetlb migration without a corresponding decrement, permanently inflating the nr_anon counter.

Add a !folio_test_hugetlb() check to __folio_migrate_mapping() so that only actual mTHP folios are counted.

---

 mm/migrate.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -590,7 +590,8 @@ static int __folio_migrate_mapping(struc
 		/* No turning back from here */
 		newfolio->index = folio->index;
 		newfolio->mapping = folio->mapping;
-		if (folio_test_anon(folio) && folio_test_large(folio))
+		if (folio_test_anon(folio) && folio_test_large(folio) &&
+		    !folio_test_hugetlb(folio))
 			mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1);
 		if (folio_test_swapbacked(folio))
 			__folio_set_swapbacked(newfolio);

_

Patches currently in -mm which might be from [email protected] are