[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, 3 insertions, 3 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 8002e1faccda..38f89650bc84 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -487,7 +487,7 @@ static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
         switch (p->policy) {
         case MPOL_BIND:
                 for (i = 0; p->v.zonelist->zones[i]; i++)
-                        node_set(p->v.zonelist->zones[i]->zone_pgdat->node_id,
+                        node_set(zone_to_nid(p->v.zonelist->zones[i]),
                                 *nodes);
                 break;
         case MPOL_DEFAULT:
@@ -1145,7 +1145,7 @@ unsigned slab_node(struct mempolicy *policy)
                  * Follow bind policy behavior and start allocation at the
                  * first node.
                  */
-                return policy->v.zonelist->zones[0]->zone_pgdat->node_id;
+                return zone_to_nid(policy->v.zonelist->zones[0]);
 
         case MPOL_PREFERRED:
                 if (policy->v.preferred_node >= 0)
@@ -1649,7 +1649,7 @@ void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
 
                 nodes_clear(nodes);
                 for (z = pol->v.zonelist->zones; *z; z++)
-                        node_set((*z)->zone_pgdat->node_id, nodes);
+                        node_set(zone_to_nid(*z), nodes);
                 nodes_remap(tmp, nodes, *mpolmask, *newmask);
                 nodes = tmp;