1 files changed, 48 insertions, 23 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 91cf85b36dd5..d5ab79cf516d 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -54,7 +54,6 @@
 #include <asm/uaccess.h>
 #include <asm/atomic.h>
 #include <linux/mutex.h>
-#include <linux/kfifo.h>
 #include <linux/workqueue.h>
 #include <linux/cgroup.h>
 
@@ -486,13 +485,38 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b)
 static void
 update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c)
 {
-	if (!dattr)
-		return;
 	if (dattr->relax_domain_level < c->relax_domain_level)
 		dattr->relax_domain_level = c->relax_domain_level;
 	return;
 }
 
+static void
+update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
+{
+	LIST_HEAD(q);
+
+	list_add(&c->stack_list, &q);
+	while (!list_empty(&q)) {
+		struct cpuset *cp;
+		struct cgroup *cont;
+		struct cpuset *child;
+
+		cp = list_first_entry(&q, struct cpuset, stack_list);
+		list_del(q.next);
+
+		if (cpus_empty(cp->cpus_allowed))
+			continue;
+
+		if (is_sched_load_balance(cp))
+			update_domain_attr(dattr, cp);
+
+		list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
+			child = cgroup_cs(cont);
+			list_add_tail(&child->stack_list, &q);
+		}
+	}
+}
+
 /*
  * rebuild_sched_domains()
  *
@@ -532,7 +556,7 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c)
  * So the reverse nesting would risk an ABBA deadlock.
  *
  * The three key local variables below are:
- *    q  - a kfifo queue of cpuset pointers, used to implement a
+ *    q  - a linked-list queue of cpuset pointers, used to implement a
  *	   top-down scan of all cpusets.  This scan loads a pointer
  *	   to each cpuset marked is_sched_load_balance into the
  *	   array 'csa'.  For our purposes, rebuilding the schedulers
@@ -567,7 +591,7 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c)
 
 void rebuild_sched_domains(void)
 {
-	struct kfifo *q;	/* queue of cpusets to be scanned */
+	LIST_HEAD(q);		/* queue of cpusets to be scanned*/
 	struct cpuset *cp;	/* scans q */
 	struct cpuset **csa;	/* array of all cpuset ptrs */
 	int csn;		/* how many cpuset ptrs in csa so far */
@@ -577,7 +601,6 @@ void rebuild_sched_domains(void)
 	int ndoms;		/* number of sched domains in result */
 	int nslot;		/* next empty doms[] cpumask_t slot */
 
-	q = NULL;
 	csa = NULL;
 	doms = NULL;
 	dattr = NULL;
@@ -591,35 +614,42 @@ void rebuild_sched_domains(void)
 		dattr = kmalloc(sizeof(struct sched_domain_attr), GFP_KERNEL);
 		if (dattr) {
 			*dattr = SD_ATTR_INIT;
-			update_domain_attr(dattr, &top_cpuset);
+			update_domain_attr_tree(dattr, &top_cpuset);
 		}
 		*doms = top_cpuset.cpus_allowed;
 		goto rebuild;
 	}
 
-	q = kfifo_alloc(number_of_cpusets * sizeof(cp), GFP_KERNEL, NULL);
-	if (IS_ERR(q))
-		goto done;
 	csa = kmalloc(number_of_cpusets * sizeof(cp), GFP_KERNEL);
 	if (!csa)
 		goto done;
 	csn = 0;
 
-	cp = &top_cpuset;
-	__kfifo_put(q, (void *)&cp, sizeof(cp));
-	while (__kfifo_get(q, (void *)&cp, sizeof(cp))) {
+	list_add(&top_cpuset.stack_list, &q);
+	while (!list_empty(&q)) {
 		struct cgroup *cont;
 		struct cpuset *child;   /* scans child cpusets of cp */
 
+		cp = list_first_entry(&q, struct cpuset, stack_list);
+		list_del(q.next);
+
 		if (cpus_empty(cp->cpus_allowed))
 			continue;
 
-		if (is_sched_load_balance(cp))
+		/*
+		 * All child cpusets contain a subset of the parent's cpus, so
+		 * just skip them, and then we call update_domain_attr_tree()
+		 * to calc relax_domain_level of the corresponding sched
+		 * domain.
+		 */
+		if (is_sched_load_balance(cp)) {
 			csa[csn++] = cp;
+			continue;
+		}
 
 		list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
 			child = cgroup_cs(cont);
-			__kfifo_put(q, (void *)&child, sizeof(cp));
+			list_add_tail(&child->stack_list, &q);
 		}
   	}
 
@@ -686,7 +716,7 @@ restart:
 					cpus_or(*dp, *dp, b->cpus_allowed);
 					b->pn = -1;
 					if (dattr)
-						update_domain_attr(dattr
+						update_domain_attr_tree(dattr
 								   + nslot, b);
 				}
 			}
@@ -702,8 +732,6 @@ rebuild:
 	put_online_cpus();
 
 done:
-	if (q && !IS_ERR(q))
-		kfifo_free(q);
 	kfree(csa);
 	/* Don't kfree(doms) -- partition_sched_domains() does that. */
 	/* Don't kfree(dattr) -- partition_sched_domains() does that. */
@@ -1833,24 +1861,21 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
  */
 static void scan_for_empty_cpusets(const struct cpuset *root)
 {
+	LIST_HEAD(queue);
 	struct cpuset *cp;	/* scans cpusets being updated */
 	struct cpuset *child;	/* scans child cpusets of cp */
-	struct list_head queue;
 	struct cgroup *cont;
 	nodemask_t oldmems;
 
-	INIT_LIST_HEAD(&queue);
-
 	list_add_tail((struct list_head *)&root->stack_list, &queue);
 
 	while (!list_empty(&queue)) {
-		cp = container_of(queue.next, struct cpuset, stack_list);
+		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);
 		}
-		cont = cp->css.cgroup;
 
 		/* Continue past cpusets with all cpus, mems online */
 		if (cpus_subset(cp->cpus_allowed, cpu_online_map) &&