[PATCH] mm/hwpoison: Check the subpage, not the head page

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

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

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/rmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index 6a1e8c7f6213..09b08888120e 100644
--- 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);
-- 
2.34.1