[PATCH] use NODES_SHIFT to calculate ZONE_SHIFT

[jbarnes@sgi.com (Jesse Barnes)]

Now that we have a proper NODES_SHIFT value, we need to use it to define
ZONE_SHIFT otherwise we'll spill over 8 bits if we have more than 85
nodes.  How does this look?  The '+2' should really be
log2(MAX_NR_NODES), but I think this is an improvement over what was
there.

Thanks,
Jesse

===== include/linux/mm.h 1.133 vs edited =====
--- 1.133/include/linux/mm.h	Sun Oct  5 01:07:49 2003
+++ edited/include/linux/mm.h	Tue Nov  4 16:45:33 2003
@@ -322,8 +322,10 @@
 /*
  * The zone field is never updated after free_area_init_core()
  * sets it, so none of the operations on it need to be atomic.
+ * We'll have up to log2(MAX_NUMNODES * MAX_NR_ZONES) zones
+ * total, so we use NODES_SHIFT here to get enough bits.
  */
-#define ZONE_SHIFT (BITS_PER_LONG - 8)
+#define ZONE_SHIFT (BITS_PER_LONG - (NODES_SHIFT + 2))
 
 struct zone;
 extern struct zone *zone_table[];