[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, 2 insertions, 2 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 76940361273e..cff41511269f 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2245,7 +2245,7 @@ int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl)
         int i;
 
         for (i = 0; zl->zones[i]; i++) {
-                int nid = zl->zones[i]->zone_pgdat->node_id;
+                int nid = zone_to_nid(zl->zones[i]);
 
                 if (node_isset(nid, current->mems_allowed))
                         return 1;
@@ -2318,7 +2318,7 @@ int __cpuset_zone_allowed(struct zone *z, gfp_t gfp_mask)
 
         if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
                 return 1;
-        node = z->zone_pgdat->node_id;
+        node = zone_to_nid(z);
         might_sleep_if(!(gfp_mask & __GFP_HARDWALL));
         if (node_isset(node, current->mems_allowed))
                 return 1;