The patch titled
Subject: migrate_pages(): fix failure counting for THP on -ENOSYS
has been added to the -mm mm-unstable branch. Its filename is
migrate_pages-fix-failure-counting-for-thp-on-enosys.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/migrate_pages-fix-failure-counting-for-thp-on-enosys.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
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
memory-tiering-hot-page-selection-with-hint-page-fault-latency.patch
memory-tiering-rate-limit-numa-migration-throughput.patch
memory-tiering-adjust-hot-threshold-automatically.patch
migrate-fix-syscall-move_pages-return-value-for-failure.patch
migrate_pages-remove-unnecessary-list_safe_reset_next.patch
migrate_pages-fix-thp-failure-counting-for-enomem.patch
migrate_pages-fix-failure-counting-for-thp-subpages-retrying.patch
migrate_pages-fix-failure-counting-for-thp-on-enosys.patch
migrate_pages-fix-failure-counting-for-thp-splitting.patch
migrate_pages-fix-failure-counting-for-retry.patch
