[PATCH extra ] mm: hugetlb: add description for alloc_gigantic_page()

[Huang Shijie]

This patch adds the description for function alloc_gigantic_page().

Signed-off-by: Huang Shijie <shijie.huang at arm.com>
---
 mm/hugetlb.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 3faec05..0d4bb8a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1089,6 +1089,12 @@ static bool zone_spans_last_pfn(const struct zone *zone,
 	return zone_spans_pfn(zone, last_pfn);
 }
 
+/*
+ * Allocate a gigantic page from @nid node.
+ *
+ * Scan the zones of @nid node, and try to allocate a number of contiguous
+ * pages (1 << order).
+ */
 static struct page *alloc_gigantic_page(int nid, unsigned int order)
 {
 	unsigned long nr_pages = 1 << order;
-- 
2.5.5