From: Naoya Horiguchi naoya.horiguchi@nec.com Subject: mm/hwpoison: retry with shake_page() for unhandlable pages
HWPoisonHandlable() sometimes returns false for typical user pages due to races with average memory events like transfers over LRU lists. This causes failures in hwpoison handling.
There's retry code for such a case but does not work because the retry loop reaches the retry limit too quickly before the page settles down to handlable state. Let get_any_page() call shake_page() to fix it.
[naoya.horiguchi@nec.com: get_any_page(): return -EIO when retry limit reached] Link: https://lkml.kernel.org/r/20210819001958.2365157-1-naoya.horiguchi@linux.dev Link: https://lkml.kernel.org/r/20210817053703.2267588-1-naoya.horiguchi@linux.dev Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") Signed-off-by: Naoya Horiguchi naoya.horiguchi@nec.com Reported-by: Tony Luck tony.luck@intel.com Reviewed-by: Yang Shi shy828301@gmail.com Cc: Oscar Salvador osalvador@suse.de Cc: Muchun Song songmuchun@bytedance.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Michal Hocko mhocko@suse.com Cc: stable@vger.kernel.org [5.13+] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/memory-failure.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
--- a/mm/memory-failure.c~mm-hwpoison-retry-with-shake_page-for-unhandlable-pages +++ a/mm/memory-failure.c @@ -1146,7 +1146,7 @@ static int __get_hwpoison_page(struct pa * unexpected races caused by taking a page refcount. */ if (!HWPoisonHandlable(head)) - return 0; + return -EBUSY;
if (PageTransHuge(head)) { /* @@ -1199,9 +1199,15 @@ try_again: } goto out; } else if (ret == -EBUSY) { - /* We raced with freeing huge page to buddy, retry. */ - if (pass++ < 3) + /* + * We raced with (possibly temporary) unhandlable + * page, retry. + */ + if (pass++ < 3) { + shake_page(p, 1); goto try_again; + } + ret = -EIO; goto out; } } _