---

yaml
---
r: 318399
b: refs/heads/master
c: 80d1fa6
h: refs/heads/master
i:
  318397: 50fc4cc
  318395: f59c712
  318391: ab78aaa
  318383: 8494a5a
  318367: 3e7726c
  318335: d9de250
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d35be8bab9b0ce44bed4b9453f86ebf64062721e
+refs/heads/master: 80d1fa6463d934969b7aebf04107fc133463f0f6

trunk/kernel/cpuset.c

@@ -1989,6 +1989,32 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
 	move_member_tasks_to_cpuset(cs, parent);
 }
 
+/*
+ * Helper function to traverse cpusets.
+ * It can be used to walk the cpuset tree from top to bottom, completing
+ * one layer before dropping down to the next (thus always processing a
+ * node before any of its children).
+ */
+static struct cpuset *cpuset_next(struct list_head *queue)
+{
+	struct cpuset *cp;
+	struct cpuset *child;	/* scans child cpusets of cp */
+	struct cgroup *cont;
+
+	if (list_empty(queue))
+		return NULL;
+
+	cp = list_first_entry(queue, struct cpuset, stack_list);
+	list_del(queue->next);
+	list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
+		child = cgroup_cs(cont);
+		list_add_tail(&child->stack_list, queue);
+	}
+
+	return cp;
+}
+
+
 /*
  * Walk the specified cpuset subtree and look for empty cpusets.
  * The tasks of such cpuset must be moved to a parent cpuset.
@@ -2008,19 +2034,11 @@ static void scan_for_empty_cpusets(struct cpuset *root)
 {
 	LIST_HEAD(queue);
 	struct cpuset *cp;	/* scans cpusets being updated */
-	struct cpuset *child;	/* scans child cpusets of cp */
-	struct cgroup *cont;
 	static nodemask_t oldmems;	/* protected by cgroup_mutex */
 
 	list_add_tail((struct list_head *)&root->stack_list, &queue);
 
-	while (!list_empty(&queue)) {
-		cp = list_first_entry(&queue, struct cpuset, stack_list);
-		list_del(queue.next);
-		list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
-			child = cgroup_cs(cont);
-			list_add_tail(&child->stack_list, &queue);
-		}
+	while ((cp = cpuset_next(&queue)) != NULL) {
 
 		/* Continue past cpusets with all cpus, mems online */
 		if (cpumask_subset(cp->cpus_allowed, cpu_active_mask) &&