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, 3 insertions, 3 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index 1dae94acb3fe..71358499bc57 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -361,13 +361,13 @@ void invalidate_bdev(struct block_device *bdev)
 static void free_more_memory(void)
 {
         struct zonelist *zonelist;
-        pg_data_t *pgdat;
+        int nid;
 
         wakeup_pdflush(1024);
         yield();
 
-        for_each_online_pgdat(pgdat) {
-                zonelist = &pgdat->node_zonelists[gfp_zone(GFP_NOFS)];
+        for_each_online_node(nid) {
+                zonelist = node_zonelist(nid, GFP_NOFS);
                 if (zonelist->zones[0])
                         try_to_free_pages(zonelist, 0, GFP_NOFS);
         }