The patch titled
Subject: mm, hwpoison: do not lock page again when me_huge_page() successfully recovers
has been added to the -mm tree. Its filename is
mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch
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------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Subject: mm, hwpoison: do not lock page again when me_huge_page() successfully recovers
Currently me_huge_page() temporary unlocks page to perform some actions
then locks it again later. My testcase (which calls hard-offline on some
tail page in a hugetlb, then accesses the address of the hugetlb range)
showed that page allocation code detects the page lock on buddy page and
printed out "BUG: Bad page state" message. PG_hwpoison does not prevent
it because PG_hwpoison flag is set on any subpage of the hugetlb page but
the 2nd page lock is on the head page.
This patch suggests to drop the 2nd page lock to fix the issue.
Link: https://lkml.kernel.org/r/20210304064437.962442-1-nao.horiguchi@xxxxxxxxx
Fixes: commit 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/memory-failure.c~mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers
+++ a/mm/memory-failure.c
@@ -834,7 +834,6 @@ static int me_huge_page(struct page *p,
page_ref_inc(p);
res = MF_RECOVERED;
}
- lock_page(hpage);
}
return res;
@@ -1290,7 +1289,8 @@ static int memory_failure_hugetlb(unsign
res = identify_page_state(pfn, p, page_flags);
out:
- unlock_page(head);
+ if (PageLocked(head))
+ unlock_page(head);
return res;
}
_
Patches currently in -mm which might be from naoya.horiguchi@xxxxxxx are
mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch
