page_cgroup should ignore empty nodes

Fix a total bootup freeze on ia64.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 0b3cbf090a674a1424cb1d7cc9e4cd4f3bfa4c02..ab27ff75051958fb992417ddcf675a296b96176e 100644 (file)
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -49,6 +49,9 @@ static int __init alloc_node_page_cgroup(int nid)
        start_pfn = NODE_DATA(nid)->node_start_pfn;
        nr_pages = NODE_DATA(nid)->node_spanned_pages;
 
+       if (!nr_pages)
+               return 0;
+
        table_size = sizeof(struct page_cgroup) * nr_pages;
 
        base = __alloc_bootmem_node_nopanic(NODE_DATA(nid),