mm: introduce node_zonelist() for accessing the zonelist for a GFP mask

Introduce a node_zonelist() helper function.  It is used to lookup the
appropriate zonelist given a node and a GFP mask.  The patch on its own is a
cleanup but it helps clarify parts of the two-zonelist-per-node patchset.  If
necessary, it can be merged with the next patch in this set without problems.

Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1bda771a072a..63ff71830ea4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1713,10 +1713,9 @@ EXPORT_SYMBOL(free_pages);
 static unsigned int nr_free_zone_pages(int offset)
 {
         /* Just pick one node, since fallback list is circular */
-        pg_data_t *pgdat = NODE_DATA(numa_node_id());
         unsigned int sum = 0;
 
-        struct zonelist *zonelist = pgdat->node_zonelists + offset;
+        struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
         struct zone **zonep = zonelist->zones;
         struct zone *zone;