mm, hugetlb, hwpoison: separate branch for free and in-use hugepage
We know that HPageFreed pages should have page refcount 0, so
get_page_unless_zero() always fails and returns 0. So explicitly separate
the branch based on page state for minor optimization and better
readability.
Link: https://lkml.kernel.org/r/20220415041848.GA3034499@ik1-406-35019.vs.sakura.ne.jp
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e01a2da..9711c0e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1517,7 +1517,9 @@ int __get_huge_page_for_hwpoison(unsigned long pfn, int flags)
if (flags & MF_COUNT_INCREASED) {
ret = 1;
count_increased = true;
- } else if (HPageFreed(head) || HPageMigratable(head)) {
+ } else if (HPageFreed(head)) {
+ ret = 0;
+ } else if (HPageMigratable(head)) {
ret = get_page_unless_zero(head);
if (ret)
count_increased = true;
