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From:   Zi Yan <zi.yan@sent.com>
To:     David Hildenbrand <david@redhat.com>, linux-mm@kvack.org
Cc:     Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Michal Hocko <mhocko@kernel.org>,
        John Hubbard <jhubbard@nvidia.com>,
        linux-kernel@vger.kernel.org, Zi Yan <ziy@nvidia.com>
Subject: [RFC PATCH 07/15] mm: hugetlb: use PAGES_PER_SECTION to check mem_map discontiguity
Date:   Thu,  5 Aug 2021 15:02:45 -0400
Message-Id: <20210805190253.2795604-8-zi.yan@sent.com>
In-Reply-To: <20210805190253.2795604-1-zi.yan@sent.com>
References: <20210805190253.2795604-1-zi.yan@sent.com>
Reply-To: Zi Yan <ziy@nvidia.com>
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From: Zi Yan <ziy@nvidia.com>

mem_map is only guaranteed to be virtually contiguous within a section.
Use PAGES_PER_SECTION to check the condition properly.

Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ce79d76c42ce..7f78203d6feb 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1784,7 +1784,7 @@ pgoff_t hugetlb_basepage_index(struct page *page)
 	pgoff_t index =3D page_index(page_head);
 	unsigned long compound_idx;
=20
-	if (compound_order(page_head) >=3D MAX_ORDER)
+	if (compound_order(page_head) >=3D PAGES_PER_SECTION)
 		compound_idx =3D page_to_pfn(page) - page_to_pfn(page_head);
 	else
 		compound_idx =3D page - page_head;
--=20
2.30.2