+static void shrink_zone(int priority, struct zone *zone,
+ struct scan_control *sc)
+{
+ struct mem_cgroup *root = sc->target_mem_cgroup;
+ struct mem_cgroup_reclaim_cookie reclaim = {
+ .zone = zone,
+ .priority = priority,
+ };
+ struct mem_cgroup *memcg;
+
+ memcg = mem_cgroup_iter(root, NULL, &reclaim);
+ do {
+ struct mem_cgroup_zone mz = {
+ .mem_cgroup = memcg,
+ .zone = zone,
+ };
+
+ shrink_mem_cgroup_zone(priority, &mz, 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 zone.
+ */
+ if (!global_reclaim(sc)) {
+ mem_cgroup_iter_break(root, memcg);
+ break;
+ }
+ memcg = mem_cgroup_iter(root, memcg, &reclaim);
+ } while (memcg);
+}
+