[PATCH] mm/vmscan: sc->reclaim_idx must be a valid zone index

[Wei Yang <richard.weiyang@xxxxxxxxx>]

Function lruvec_lru_size() is only used in get_scan_count(), so the only
possible zone_idx is sc->reclaim_idx. Since sc->reclaim_idx is ensured
to be a valid zone idex, we can remove the extra check for zone
iteration.

Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
---
 mm/vmscan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6e4f0e1e9cea..443c75a9d092 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -586,7 +586,7 @@ unsigned long zone_reclaimable_pages(struct zone *zone)
  * lruvec_lru_size -  Returns the number of pages on the given LRU list.
  * @lruvec: lru vector
  * @lru: lru to use
- * @zone_idx: zones to consider (use MAX_NR_ZONES for the whole LRU list)
+ * @zone_idx: zones to consider (use MAX_NR_ZONES - 1 for the whole LRU list)
  */
 static unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru,
 				     int zone_idx)
@@ -594,7 +594,7 @@ static unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru,
 	unsigned long size = 0;
 	int zid;
 
-	for (zid = 0; zid <= zone_idx && zid < MAX_NR_ZONES; zid++) {
+	for (zid = 0; zid <= zone_idx; zid++) {
 		struct zone *zone = &lruvec_pgdat(lruvec)->node_zones[zid];
 
 		if (!managed_zone(zone))
-- 
2.33.1