mm: introduce for_each_populated_zone() macro
Impact: cleanup
In almost cases, for_each_zone() is used with populated_zone(). It's
because almost function doesn't need memoryless node information.
Therefore, for_each_populated_zone() can help to make code simplify.
This patch has no functional change.
[akpm@linux-foundation.org: small cleanup]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 1aca6ce..26ef240 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -806,6 +806,14 @@
zone; \
zone = next_zone(zone))
+#define for_each_populated_zone(zone) \
+ for (zone = (first_online_pgdat())->node_zones; \
+ zone; \
+ zone = next_zone(zone)) \
+ if (!populated_zone(zone)) \
+ ; /* do nothing */ \
+ else
+
static inline struct zone *zonelist_zone(struct zoneref *zoneref)
{
return zoneref->zone;