[PATCH v2] mm: hwpoison: remove incorrect comment

[Naoya Horiguchi]

dequeue_hwpoisoned_huge_page() can be called without page lock hold,
so let's remove incorrect comment.

The reason why the page lock is not really needed is that
dequeue_hwpoisoned_huge_page() checks page_huge_active() inside hugetlb_lock,
which allows us to avoid trying to dequeue a hugepage that are just allocated
but not linked to active list yet, even without taking page lock.

Reported-by: Zhan Chen <zhanc1@xxxxxxxxxxxxxx>
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
 mm/hugetlb.c        | 1 -
 mm/memory-failure.c | 2 --
 2 files changed, 3 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c1f3c0be150a..26f735cc7478 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4401,7 +4401,6 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address,
 
 /*
  * This function is called from memory failure code.
- * Assume the caller holds page lock of the head page.
  */
 int dequeue_hwpoisoned_huge_page(struct page *hpage)
 {
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 2fcca6b0e005..7532c3a8a39c 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -741,8 +741,6 @@ static int me_huge_page(struct page *p, unsigned long pfn)
 	 * page->lru because it can be used in other hugepage operations,
 	 * such as __unmap_hugepage_range() and gather_surplus_pages().
 	 * So instead we use page_mapping() and PageAnon().
-	 * We assume that this function is called with page lock held,
-	 * so there is no race between isolation and mapping/unmapping.
 	 */
 	if (!(page_mapping(hpage) || PageAnon(hpage))) {
 		res = dequeue_hwpoisoned_huge_page(hpage);
-- 
2.7.4