[PATCH] fix show_mem on discontig machines

Dave Hansen recently did some bootmem and paging init cleanups, but I
missed this little bit when I tested his original patches.  We need to
initialize pgdat->node_mem_map correctly since a) we're using vmem_map, and
b) the core won't do it for us since we have a valid node_start_pfn I
believe.
Signed-off-by: Jesse Barnes <jbarnes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ia64/mm/discontig.c

@@ -664,6 +664,7 @@ void paging_init(void)
 
 		pfn_offset = mem_data[node].min_pfn;
 
+		NODE_DATA(node)->node_mem_map = vmem_map + pfn_offset;
 		free_area_init_node(node, NODE_DATA(node), zones_size,
 				    pfn_offset, zholes_size);
 	}