memcg,vmscan: do not break out targeted reclaim without reclaimed pages

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 292f50a..4639909 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1973,18 +1973,17 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc)
                        shrink_lruvec(lruvec, sc);
 
                        /*
-                        * Limit reclaim has historically picked one
-                        * memcg and scanned it with decreasing
-                        * priority levels until nr_to_reclaim had
-                        * been reclaimed.  This priority cycle is
-                        * thus over after a single memcg.
-                        *
-                        * Direct reclaim and kswapd, on the other
-                        * hand, have to scan all memory cgroups to
-                        * fulfill the overall scan target for the
+                        * Direct reclaim and kswapd have to scan all memory
+                        * cgroups to fulfill the overall scan target for the
                         * zone.
+                        *
+                        * Limit reclaim, on the other hand, only cares about
+                        * nr_to_reclaim pages to be reclaimed and it will
+                        * retry with decreasing priority if one round over the
+                        * whole hierarchy is not sufficient.
                         */
-                       if (!global_reclaim(sc)) {
+                       if (!global_reclaim(sc) &&
+                                       sc->nr_reclaimed >= sc->nr_to_reclaim) {
                                mem_cgroup_iter_break(root, memcg);
                                break;
                        }