On Wed, Sep 13, 2017 at 01:46:51PM -0700, David Rientjes wrote:

On Mon, 11 Sep 2017, Roman Gushchin wrote:

quoted

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 15af3da5af02..da2b12ea4667 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -2661,6 +2661,231 @@ static inline bool memcg_has_children(struct mem_cgroup *memcg)
 	return ret;
 }
 
+static long memcg_oom_badness(struct mem_cgroup *memcg,
+			      const nodemask_t *nodemask,
+			      unsigned long totalpages)
+{
+	long points = 0;
+	int nid;
+	pg_data_t *pgdat;
+
+	/*
+	 * We don't have necessary stats for the root memcg,
+	 * so we define it's oom_score as the maximum oom_score
+	 * of the belonging tasks.
+	 */
+	if (memcg == root_mem_cgroup) {
+		struct css_task_iter it;
+		struct task_struct *task;
+		long score, max_score = 0;
+
+		css_task_iter_start(&memcg->css, 0, &it);
+		while ((task = css_task_iter_next(&it))) {
+			score = oom_badness(task, memcg, nodemask,
+					    totalpages);
+			if (max_score > score)

score > max_score

Ups. Fixed. Thanks!