1 files changed, 21 insertions, 142 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fe6b9f96abdd..6c32271a31c5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2004,57 +2004,28 @@ static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
 }
 #endif
 
-static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
-				   struct zone *zone,
-				   gfp_t gfp_mask,
-				   unsigned long *total_scanned)
-{
-	struct mem_cgroup *victim = NULL;
-	int total = 0;
-	int loop = 0;
-	unsigned long excess;
-	unsigned long nr_scanned;
-	struct mem_cgroup_reclaim_cookie reclaim = {
-		.zone = zone,
-		.priority = 0,
-	};
-
-	excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
-
-	while (1) {
-		victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
-		if (!victim) {
-			loop++;
-			if (loop >= 2) {
-				/*
-				 * If we have not been able to reclaim
-				 * anything, it might because there are
-				 * no reclaimable pages under this hierarchy
-				 */
-				if (!total)
-					break;
-				/*
-				 * We want to do more targeted reclaim.
-				 * excess >> 2 is not to excessive so as to
-				 * reclaim too much, nor too less that we keep
-				 * coming back to reclaim from this cgroup
-				 */
-				if (total >= (excess >> 2) ||
-					(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
-					break;
-			}
-			continue;
-		}
-		if (!mem_cgroup_reclaimable(victim, false))
-			continue;
-		total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
-						     zone, &nr_scanned);
-		*total_scanned += nr_scanned;
-		if (!res_counter_soft_limit_excess(&root_memcg->res))
-			break;
+/*
+ * A group is eligible for the soft limit reclaim if it is
+ * 	a) is over its soft limit
+ * 	b) any parent up the hierarchy is over its soft limit
+ */
+bool mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg)
+{
+	struct mem_cgroup *parent = memcg;
+
+	if (res_counter_soft_limit_excess(&memcg->res))
+		return true;
+
+	/*
+	 * If any parent up the hierarchy is over its soft limit then we
+	 * have to obey and reclaim from this group as well.
+	 */
+	while((parent = parent_mem_cgroup(parent))) {
+		if (res_counter_soft_limit_excess(&parent->res))
+			return true;
 	}
-	mem_cgroup_iter_break(root_memcg, victim);
-	return total;
+
+	return false;
 }
 
 /*
@@ -4727,98 +4698,6 @@ static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
 	return ret;
 }
 
-unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
-					    gfp_t gfp_mask,
-					    unsigned long *total_scanned)
-{
-	unsigned long nr_reclaimed = 0;
-	struct mem_cgroup_per_zone *mz, *next_mz = NULL;
-	unsigned long reclaimed;
-	int loop = 0;
-	struct mem_cgroup_tree_per_zone *mctz;
-	unsigned long long excess;
-	unsigned long nr_scanned;
-
-	if (order > 0)
-		return 0;
-
-	mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
-	/*
-	 * This loop can run a while, specially if mem_cgroup's continuously
-	 * keep exceeding their soft limit and putting the system under
-	 * pressure
-	 */
-	do {
-		if (next_mz)
-			mz = next_mz;
-		else
-			mz = mem_cgroup_largest_soft_limit_node(mctz);
-		if (!mz)
-			break;
-
-		nr_scanned = 0;
-		reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
-						    gfp_mask, &nr_scanned);
-		nr_reclaimed += reclaimed;
-		*total_scanned += nr_scanned;
-		spin_lock(&mctz->lock);
-
-		/*
-		 * If we failed to reclaim anything from this memory cgroup
-		 * it is time to move on to the next cgroup
-		 */
-		next_mz = NULL;
-		if (!reclaimed) {
-			do {
-				/*
-				 * Loop until we find yet another one.
-				 *
-				 * By the time we get the soft_limit lock
-				 * again, someone might have aded the
-				 * group back on the RB tree. Iterate to
-				 * make sure we get a different mem.
-				 * mem_cgroup_largest_soft_limit_node returns
-				 * NULL if no other cgroup is present on
-				 * the tree
-				 */
-				next_mz =
-				__mem_cgroup_largest_soft_limit_node(mctz);
-				if (next_mz == mz)
-					css_put(&next_mz->memcg->css);
-				else /* next_mz == NULL or other memcg */
-					break;
-			} while (1);
-		}
-		__mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
-		excess = res_counter_soft_limit_excess(&mz->memcg->res);
-		/*
-		 * One school of thought says that we should not add
-		 * back the node to the tree if reclaim returns 0.
-		 * But our reclaim could return 0, simply because due
-		 * to priority we are exposing a smaller subset of
-		 * memory to reclaim from. Consider this as a longer
-		 * term TODO.
-		 */
-		/* If excess == 0, no tree ops */
-		__mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess);
-		spin_unlock(&mctz->lock);
-		css_put(&mz->memcg->css);
-		loop++;
-		/*
-		 * Could not reclaim anything and there are no more
-		 * mem cgroups to try or we seem to be looping without
-		 * reclaiming anything.
-		 */
-		if (!nr_reclaimed &&
-			(next_mz == NULL ||
-			loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
-			break;
-	} while (!nr_reclaimed);
-	if (next_mz)
-		css_put(&next_mz->memcg->css);
-	return nr_reclaimed;
-}
-
 /**
  * mem_cgroup_force_empty_list - clears LRU of a group
  * @memcg: group to clear