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) &&