The quilt patch titled
Subject: mm: migrate: remove PageHead() check for HugeTLB in add_page_for_migration()
has been removed from the -mm tree. Its filename was
mm-migrate-remove-pagehead-check-for-hugetlb-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: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: mm: migrate: remove PageHead() check for HugeTLB in add_page_for_migration()
Date: Wed, 13 Sep 2023 17:51:30 +0800
There is some different between hugeTLB and THP behave when passed the
address of a tail page, for THP, it will migrate the entire THP page, but
for HugeTLB, it will return -EACCES, or -ENOENT before commit e66f17ff7177
("mm/hugetlb: take page table lock in follow_huge_pmd()"),
-EACCES The page is mapped by multiple processes and can be moved
only if MPOL_MF_MOVE_ALL is specified.
-ENOENT The page is not present.
But when check manual[1], both of the two errnos are not suitable, it is
better to keep the same behave between hugetlb and THP when passed the
address of a tail page, so let's just remove the PageHead() check for
HugeTLB.
[1] https://man7.org/linux/man-pages/man2/move_pages.2.html
Link: https://lkml.kernel.org/r/20230913095131.2426871-8-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Suggested-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Acked-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/mm/migrate.c~mm-migrate-remove-pagehead-check-for-hugetlb-in-add_page_for_migration
+++ a/mm/migrate.c
@@ -2096,10 +2096,8 @@ static int add_page_for_migration(struct
goto out_putfolio;
if (folio_test_hugetlb(folio)) {
- if (PageHead(page)) {
- isolated = isolate_hugetlb(folio, pagelist);
- err = isolated ? 1 : -EBUSY;
- }
+ isolated = isolate_hugetlb(folio, pagelist);
+ err = isolated ? 1 : -EBUSY;
} else {
isolated = folio_isolate_lru(folio);
if (!isolated) {
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-memory-add-vm_normal_folio_pmd.patch
mm-huge_memory-use-a-folio-in-do_huge_pmd_numa_page.patch
mm-memory-use-a-folio-in-do_numa_page.patch
mm-memory-make-numa_migrate_prep-to-take-a-folio.patch
mm-mempolicy-make-mpol_misplaced-to-take-a-folio.patch
sched-numa-mm-make-numa-migrate-functions-to-take-a-folio.patch
