[PATCH] NUMA: Add zone_to_nid function

There are many places where we need to determine the node of a zone.
Currently we use a difficult to read sequence of pointer dereferencing.
Put that into an inline function and use throughout VM.  Maybe we can find
a way to optimize the lookup in the future.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index f1c0ef1fd21f..bada3d03119f 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -177,8 +177,7 @@ static inline int constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask)
 
         for (z = zonelist->zones; *z; z++)
                 if (cpuset_zone_allowed(*z, gfp_mask))
-                        node_clear((*z)->zone_pgdat->node_id,
-                                        nodes);
+                        node_clear(zone_to_nid(*z), nodes);
                 else
                         return CONSTRAINT_CPUSET;