mm/hwpoison: check the subpage, not the head page

Hardware poison is tracked on a per-page basis, not on the head page.

Link: https://lkml.kernel.org/r/20220130013042.1906881-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/rmap.c b/mm/rmap.c
index 6a1e8c7..09b0888 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1553,7 +1553,7 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                /* Update high watermark before we lower rss */
                update_hiwater_rss(mm);
 
-               if (PageHWPoison(page) && !(flags & TTU_IGNORE_HWPOISON)) {
+               if (PageHWPoison(subpage) && !(flags & TTU_IGNORE_HWPOISON)) {
                        pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
                        if (PageHuge(page)) {
                                hugetlb_count_sub(compound_nr(page), mm);
@@ -1873,7 +1873,7 @@ static bool try_to_migrate_one(struct page *page, struct vm_area_struct *vma,
                         * memory are supported.
                         */
                        subpage = page;
-               } else if (PageHWPoison(page)) {
+               } else if (PageHWPoison(subpage)) {
                        pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
                        if (PageHuge(page)) {
                                hugetlb_count_sub(compound_nr(page), mm);