[PATCH] fix oom killer kills current every time if there is memory-less-node take2

constrained_alloc(), which is called to detect where oom is from, checks
passed zone_list().  If zone_list doesn't include all nodes, it thinks oom
is from mempolicy.

But there is memory-less-node.  memory-less-node's zones are never included
in zonelist[].

contstrained_alloc() should get memory_less_node into count.  Otherwise, it
always thinks 'oom is from mempolicy'.  This means that current process
dies at any time.  This patch fix it.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/oom_kill.c

@@ -174,7 +174,12 @@ static inline int constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask)
 {
 #ifdef CONFIG_NUMA
 	struct zone **z;
-	nodemask_t nodes = node_online_map;
+	nodemask_t nodes;
+	int node;
+	/* node has memory ? */
+	for_each_online_node(node)
+		if (NODE_DATA(node)->node_present_pages)
+			node_set(node, nodes);
 
 	for (z = zonelist->zones; *z; z++)
 		if (cpuset_zone_allowed_softwall(*z, gfp_mask))