[PATCH 6/6] mm: hugetlb: remove VM_BUG_ON_PAGE from page_huge_active

From: Muchun Song
Date: Mon Jan 04 2021 - 02:05:53 EST


The page_huge_active() can be called from scan_movable_pages() which
do not hold a reference count to the HugeTLB page. So when we call
page_huge_active() from scan_movable_pages(), the HugeTLB page can
be freed parallel. Then we will trigger a BUG_ON which is in the
page_huge_active() when CONFIG_DEBUG_VM is enabled. Just remove the
VM_BUG_ON_PAGE.

Fixes: 7e1f049efb86 ("mm: hugetlb: cleanup using paeg_huge_active()")
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
mm/hugetlb.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5c2f64f53177..4c8631114e88 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1360,7 +1360,6 @@ struct hstate *size_to_hstate(unsigned long size)
*/
bool page_huge_active(struct page *page)
{
- VM_BUG_ON_PAGE(!PageHuge(page), page);
return PageHead(page) && PagePrivate(&page[1]);
}

--
2.11.0