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... and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-do-not-lock-page-again...

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------------------------------------------------------ From: Naoya Horiguchi naoya.horiguchi@nec.com 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@gmail.com Fixes: commit 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error") Signed-off-by: Naoya Horiguchi naoya.horiguchi@nec.com Cc: Michal Hocko mhocko@kernel.org Cc: Oscar Salvador osalvador@suse.de Cc: Tony Luck tony.luck@intel.com Cc: "Aneesh Kumar K.V" aneesh.kumar@linux.vnet.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

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@nec.com are

mm-hwpoison-do-not-lock-page-again-when-me_huge_page-successfully-recovers.patch