X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=mm%2Fmemcontrol.c;h=b58d4fbe6c480d57be40a822713ea790c38772c6;hb=034c4b3e832b22ec83e7bd409cf1ad3efba18f45;hp=5b6b0039f725032de5d63376aa0388e49bd3192d;hpb=8c35743fdc3c013cbb9832dc9c5eb04362b86cbb;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5b6b003..b58d4fb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -292,6 +292,9 @@ struct mem_cgroup {
 	/* vmpressure notifications */
 	struct vmpressure vmpressure;
 
+	/* css_online() has been completed */
+	int initialized;
+
 	/*
 	 * the counter to account for mem+swap usage.
 	 */
@@ -1127,9 +1130,21 @@ skip_node:
 	 * skipping css reference should be safe.
 	 */
 	if (next_css) {
-		if ((next_css == &root->css) ||
-		    ((next_css->flags & CSS_ONLINE) && css_tryget(next_css)))
-			return mem_cgroup_from_css(next_css);
+		struct mem_cgroup *memcg = mem_cgroup_from_css(next_css);
+
+		if (next_css == &root->css)
+			return memcg;
+
+		if (css_tryget(next_css)) {
+			/*
+			 * Make sure the memcg is initialized:
+			 * mem_cgroup_css_online() orders the the
+			 * initialization against setting the flag.
+			 */
+			if (smp_load_acquire(&memcg->initialized))
+				return memcg;
+			css_put(next_css);
+		}
 
 		prev_css = next_css;
 		goto skip_node;
@@ -5670,8 +5685,12 @@ static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
 {
 	struct mem_cgroup_eventfd_list *ev;
 
+	spin_lock(&memcg_oom_lock);
+
 	list_for_each_entry(ev, &memcg->oom_notify, list)
 		eventfd_signal(ev->eventfd, 1);
+
+	spin_unlock(&memcg_oom_lock);
 	return 0;
 }
 
@@ -6534,6 +6553,7 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
 	struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css));
+	int ret;
 
 	if (css->cgroup->id > MEM_CGROUP_ID_MAX)
 		return -ENOSPC;
@@ -6570,7 +6590,18 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
 	}
 	mutex_unlock(&memcg_create_mutex);
 
-	return memcg_init_kmem(memcg, &mem_cgroup_subsys);
+	ret = memcg_init_kmem(memcg, &mem_cgroup_subsys);
+	if (ret)
+		return ret;
+
+	/*
+	 * Make sure the memcg is initialized: mem_cgroup_iter()
+	 * orders reading memcg->initialized against its callers
+	 * reading the memcg members.
+	 */
+	smp_store_release(&memcg->initialized, 1);
+
+	return 0;
 }
 
 /*