X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mm%2Fhugetlb.c;h=c41b2a0ee2736e4f7df74c440ceb90bd5fcceecb;hb=c420f19b9cdc59662dbb56677417487efc1729ec;hp=0a9ac6c268325a6ca9096bfc784cfbf68ac6a65e;hpb=c18fafc89c38251f4ddabfa2c9e0be90169c0e59;p=firefly-linux-kernel-4.4.55.git

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0a9ac6c26832..c41b2a0ee273 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -917,7 +917,6 @@ static void prep_compound_gigantic_page(struct page *page, unsigned long order)
 	__SetPageHead(page);
 	__ClearPageReserved(page);
 	for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
-		__SetPageTail(p);
 		/*
 		 * For gigantic hugepages allocated through bootmem at
 		 * boot, it's safer to be consistent with the not-gigantic
@@ -933,6 +932,9 @@ static void prep_compound_gigantic_page(struct page *page, unsigned long order)
 		__ClearPageReserved(p);
 		set_page_count(p, 0);
 		p->first_page = page;
+		/* Make sure p->first_page is always valid for PageTail() */
+		smp_wmb();
+		__SetPageTail(p);
 	}
 }