mm, vmscan: avoid passing in classzone_idx unnecessarily to shrink_node

shrink_node receives all information it needs about classzone_idx from
sc->reclaim_idx so remove the aliases.

Link: http://lkml.kernel.org/r/1467970510-21195-25-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1013f37..7bfc0fe 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2428,8 +2428,7 @@ static inline bool should_continue_reclaim(struct pglist_data *pgdat,
        return true;
 }
 
-static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc,
-                       enum zone_type classzone_idx)
+static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc)
 {
        struct reclaim_state *reclaim_state = current->reclaim_state;
        unsigned long nr_reclaimed, nr_scanned;
@@ -2658,7 +2657,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
                if (zone->zone_pgdat == last_pgdat)
                        continue;
                last_pgdat = zone->zone_pgdat;
-               shrink_node(zone->zone_pgdat, sc, classzone_idx);
+               shrink_node(zone->zone_pgdat, sc);
        }
 
        /*
@@ -3082,7 +3081,6 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining,
  * This is used to determine if the scanning priority needs to be raised.
  */
 static bool kswapd_shrink_node(pg_data_t *pgdat,
-                              int classzone_idx,
                               struct scan_control *sc)
 {
        struct zone *zone;
@@ -3090,7 +3088,7 @@ static bool kswapd_shrink_node(pg_data_t *pgdat,
 
        /* Reclaim a number of pages proportional to the number of zones */
        sc->nr_to_reclaim = 0;
-       for (z = 0; z <= classzone_idx; z++) {
+       for (z = 0; z <= sc->reclaim_idx; z++) {
                zone = pgdat->node_zones + z;
                if (!populated_zone(zone))
                        continue;
@@ -3102,7 +3100,7 @@ static bool kswapd_shrink_node(pg_data_t *pgdat,
         * Historically care was taken to put equal pressure on all zones but
         * now pressure is applied based on node LRU order.
         */
-       shrink_node(pgdat, sc, classzone_idx);
+       shrink_node(pgdat, sc);
 
        /*
         * Fragmentation may mean that the system cannot be rebalanced for
@@ -3164,7 +3162,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
                                if (!populated_zone(zone))
                                        continue;
 
-                               classzone_idx = i;
+                               sc.reclaim_idx = i;
                                break;
                        }
                }
@@ -3177,12 +3175,12 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
                 * zone was balanced even under extreme pressure when the
                 * overall node may be congested.
                 */
-               for (i = classzone_idx; i >= 0; i--) {
+               for (i = sc.reclaim_idx; i >= 0; i--) {
                        zone = pgdat->node_zones + i;
                        if (!populated_zone(zone))
                                continue;
 
-                       if (zone_balanced(zone, sc.order, classzone_idx))
+                       if (zone_balanced(zone, sc.order, sc.reclaim_idx))
                                goto out;
                }
 
@@ -3213,7 +3211,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
                 * enough pages are already being scanned that that high
                 * watermark would be met at 100% efficiency.
                 */
-               if (kswapd_shrink_node(pgdat, classzone_idx, &sc))
+               if (kswapd_shrink_node(pgdat, &sc))
                        raise_priority = false;
 
                /*
@@ -3676,7 +3674,7 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in
                 * priorities until we have enough memory freed.
                 */
                do {
-                       shrink_node(pgdat, &sc, classzone_idx);
+                       shrink_node(pgdat, &sc);
                } while (sc.nr_reclaimed < nr_pages && --sc.priority >= 0);
        }