From: Larry Woodman <lwoodman@redhat.com>
Subject: [RHEL5.1 patch] oom-killer from *always* kills current process on  memoryless node.
Date: Mon, 09 Apr 2007 14:57:12 -0400
Bugzilla: 222491
Message-Id: <461A8C88.2030001@redhat.com>
Changelog: [mm] oom kills current process on memoryless node.


An OOM-kill will always kill the current process if its running on a 
memory-less NUMA node.
This is because memory-less node is online but is not included in 
zonelist[] so constrained_alloc()
returns CONSTRAINT_MEMORY_POLICY and that causes out_of_memory to kill 
current.
The following upstream fixes this:

In addition, while we are at it, out_of_memory() should panic if 
sysctl_panic_on_oom is set
before even bothering to call constrained_alloc(), otherwise it can kill 
current rather than
panic'ng even though /proc/vm/kernel/panic_on_oom is set to non-zero.

Fixes Bug 222491



--- linux-2.6.18.noarch/mm/oom_kill.c.orig
+++ linux-2.6.18.noarch/mm/oom_kill.c
@@ -171,7 +171,13 @@ static inline int constrained_alloc(stru
 {
 #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(*z, gfp_mask))