hugetlb: move all the in use pages to active list

When we fail to allocate pages from the reserve pool, hugetlb tries to
allocate huge pages using alloc_buddy_huge_page.  Add these to the active
list.  We also need to add the huge page we allocate when we soft offline
the oldpage to active list.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c

@@ -928,8 +928,14 @@ struct page *alloc_huge_page_node(struct hstate *h, int nid)
 	page = dequeue_huge_page_node(h, nid);
 	spin_unlock(&hugetlb_lock);
 
-	if (!page)
+	if (!page) {
 		page = alloc_buddy_huge_page(h, nid);
+		if (page) {
+			spin_lock(&hugetlb_lock);
+			list_move(&page->lru, &h->hugepage_activelist);
+			spin_unlock(&hugetlb_lock);
+		}
+	}
 
 	return page;
 }
@@ -1155,6 +1161,9 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
 			hugepage_subpool_put_pages(spool, chg);
 			return ERR_PTR(-ENOSPC);
 		}
+		spin_lock(&hugetlb_lock);
+		list_move(&page->lru, &h->hugepage_activelist);
+		spin_unlock(&hugetlb_lock);
 	}
 
 	set_page_private(page, (unsigned long)spool);