mm/highmem: simplify is_highmem()

is_highmem() can be simplified by use of is_highmem_idx().  This patch
removes redundant code and will make it easier to maintain if the zone
policy is changed or a new zone is added.

(akpm: saves me 25 bytes of text per is_highmem() callsite)

Signed-off-by: Chanho Min <[email protected]>
Reviewed-by: Dan Williams <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index c60df9257cc7c751dedcdb46f7ffc06d63677703..150c6049f961407b82c75d5b7fe3bef0976f0993 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -828,10 +828,7 @@ static inline int is_highmem_idx(enum zone_type idx)
 static inline int is_highmem(struct zone *zone)
 {
 #ifdef CONFIG_HIGHMEM
-       int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
-       return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
-              (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
-               zone_movable_is_highmem());
+       return is_highmem_idx(zone_idx(zone));
 #else
        return 0;
 #endif