The quilt patch titled Subject: migrate_pages(): fix failure counting for THP on -ENOSYS has been removed from the -mm tree. Its filename was migrate_pages-fix-failure-counting-for-thp-on-enosys.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: Huang Ying <ying.huang@xxxxxxxxx> Subject: migrate_pages(): fix failure counting for THP on -ENOSYS Date: Wed, 17 Aug 2022 16:14:05 +0800 If THP or hugetlbfs page migration isn't supported, unmap_and_move() or unmap_and_move_huge_page() will return -ENOSYS. For THP, splitting will be tried, but if splitting doesn't succeed, the THP will be left in "from" list wrongly. If some other pages are retried, the THP migration failure will counted again. This is fixed via moving the failure THP from "from" to "ret_pages". Another issue of the original code is that the unsupported failure processing isn't consistent between THP and hugetlbfs page. Make them consistent in this patch to make the code easier to be understood too. Link: https://lkml.kernel.org/r/20220817081408.513338-6-ying.huang@xxxxxxxxx Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/migrate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/migrate.c~migrate_pages-fix-failure-counting-for-thp-on-enosys +++ a/mm/migrate.c @@ -1260,10 +1260,8 @@ static int unmap_and_move_huge_page(new_ * tables or check whether the hugepage is pmd-based or not before * kicking migration. */ - if (!hugepage_migration_supported(page_hstate(hpage))) { - list_move_tail(&hpage->lru, ret); + if (!hugepage_migration_supported(page_hstate(hpage))) return -ENOSYS; - } if (page_count(hpage) == 1) { /* page was freed from under us. So we are done. */ @@ -1460,6 +1458,7 @@ retry: * page will be put back * -EAGAIN: stay on the from list * -ENOMEM: stay on the from list + * -ENOSYS: stay on the from list * Other errno: put on ret_pages list then splice to * from list */ @@ -1489,6 +1488,7 @@ retry: } nr_failed_pages += nr_subpages; + list_move_tail(&page->lru, &ret_pages); break; case -ENOMEM: /* _ Patches currently in -mm which might be from ying.huang@xxxxxxxxx are