From: Yang Shi <shy828301@xxxxxxxxx>
Subject: mm: hwpoison: remove the unnecessary THP check
When handling THP hwpoison checked if the THP is in allocation or free
stage since hwpoison may mistreat it as hugetlb page. After commit
415c64c1453a ("mm/memory-failure: split thp earlier in memory error
handling") the problem has been fixed, so this check is no longer needed.
Remove it. The side effect of the removal is hwpoison may report unsplit
THP instead of unknown error for shmem THP. It seems not like a big deal.
The following patch "mm: filemap: check if THP has hwpoisoned subpage for
PMD page fault" depends on this, which fixes shmem THP with hwpoisoned
subpage(s) are mapped PMD wrongly. So this patch needs to be backported
to -stable as well.
Link: https://lkml.kernel.org/r/20211020210755.23964-2-shy828301@xxxxxxxxx
Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 14 --------------
1 file changed, 14 deletions(-)
--- a/mm/memory-failure.c~mm-hwpoison-remove-the-unnecessary-thp-check
+++ a/mm/memory-failure.c
@@ -1147,20 +1147,6 @@ static int __get_hwpoison_page(struct pa
if (!HWPoisonHandlable(head))
return -EBUSY;
- if (PageTransHuge(head)) {
- /*
- * Non anonymous thp exists only in allocation/free time. We
- * can't handle such a case correctly, so let's give it up.
- * This should be better than triggering BUG_ON when kernel
- * tries to touch the "partially handled" page.
- */
- if (!PageAnon(head)) {
- pr_err("Memory failure: %#lx: non anonymous thp\n",
- page_to_pfn(page));
- return 0;
- }
- }
-
if (get_page_unless_zero(head)) {
if (head == compound_head(page))
return 1;
_
