Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  sched: fix new task startup crash
  sched: fix !SYSFS build breakage
  sched: fix improper load balance across sched domain
  sched: more robust sd-sysctl entry freeing

4 files changed, 49 insertions, 20 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3de5aa210feb..c204ab0d4df1 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -535,10 +535,12 @@ struct user_struct {
 
 #ifdef CONFIG_FAIR_USER_SCHED
         struct task_group *tg;
+#ifdef CONFIG_SYSFS
         struct kset kset;
         struct subsys_attribute user_attr;
         struct work_struct work;
 #endif
+#endif
 };
 
 #ifdef CONFIG_FAIR_USER_SCHED
diff --git a/kernel/sched.c b/kernel/sched.c
index c4889abc00b6..92721d1534b8 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1712,7 +1712,7 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 
         p->prio = effective_prio(p);
 
-        if (!p->sched_class->task_new || !current->se.on_rq || !rq->cfs.curr) {
+        if (!p->sched_class->task_new || !current->se.on_rq) {
                 activate_task(rq, p, 0);
         } else {
                 /*
@@ -2336,7 +2336,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
         unsigned long max_pull;
         unsigned long busiest_load_per_task, busiest_nr_running;
         unsigned long this_load_per_task, this_nr_running;
-        int load_idx;
+        int load_idx, group_imb = 0;
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
         int power_savings_balance = 1;
         unsigned long leader_nr_running = 0, min_load_per_task = 0;
@@ -2355,9 +2355,10 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
                 load_idx = sd->idle_idx;
 
         do {
-                unsigned long load, group_capacity;
+                unsigned long load, group_capacity, max_cpu_load, min_cpu_load;
                 int local_group;
                 int i;
+                int __group_imb = 0;
                 unsigned int balance_cpu = -1, first_idle_cpu = 0;
                 unsigned long sum_nr_running, sum_weighted_load;
 
@@ -2368,6 +2369,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 
                 /* Tally up the load of all CPUs in the group */
                 sum_weighted_load = sum_nr_running = avg_load = 0;
+                max_cpu_load = 0;
+                min_cpu_load = ~0UL;
 
                 for_each_cpu_mask(i, group->cpumask) {
                         struct rq *rq;
@@ -2388,8 +2391,13 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
                                 }
 
                                 load = target_load(i, load_idx);
-                        } else
+                        } else {
                                 load = source_load(i, load_idx);
+                                if (load > max_cpu_load)
+                                        max_cpu_load = load;
+                                if (min_cpu_load > load)
+                                        min_cpu_load = load;
+                        }
 
                         avg_load += load;
                         sum_nr_running += rq->nr_running;
@@ -2415,6 +2423,9 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
                 avg_load = sg_div_cpu_power(group,
                                 avg_load * SCHED_LOAD_SCALE);
 
+                if ((max_cpu_load - min_cpu_load) > SCHED_LOAD_SCALE)
+                        __group_imb = 1;
+
                 group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
 
                 if (local_group) {
@@ -2423,11 +2434,12 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
                         this_nr_running = sum_nr_running;
                         this_load_per_task = sum_weighted_load;
                 } else if (avg_load > max_load &&
-                           sum_nr_running > group_capacity) {
+                           (sum_nr_running > group_capacity || __group_imb)) {
                         max_load = avg_load;
                         busiest = group;
                         busiest_nr_running = sum_nr_running;
                         busiest_load_per_task = sum_weighted_load;
+                        group_imb = __group_imb;
                 }
 
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
@@ -2499,6 +2511,9 @@ group_next:
                 goto out_balanced;
 
         busiest_load_per_task /= busiest_nr_running;
+        if (group_imb)
+                busiest_load_per_task = min(busiest_load_per_task, avg_load);
+
         /*
          * We're trying to get all the cpus to the average_load, so we don't
          * want to push ourselves above the average load, nor do we wish to
@@ -5282,11 +5297,20 @@ static struct ctl_table *sd_alloc_ctl_entry(int n)
 
 static void sd_free_ctl_entry(struct ctl_table **tablep)
 {
-        struct ctl_table *entry = *tablep;
+        struct ctl_table *entry;
 
-        for (entry = *tablep; entry->procname; entry++)
+        /*
+         * In the intermediate directories, both the child directory and
+         * procname are dynamically allocated and could fail but the mode
+         * will always be set.  In the lowest directory the names are
+         * static strings and all have proc handlers.
+         */
+        for (entry = *tablep; entry->mode; entry++) {
                 if (entry->child)
                         sd_free_ctl_entry(&entry->child);
+                if (entry->proc_handler == NULL)
+                        kfree(entry->procname);
+        }
 
         kfree(*tablep);
         *tablep = NULL;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index a17b785d7000..166ed6db600b 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1031,12 +1031,8 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
                 swap(curr->vruntime, se->vruntime);
         }
 
-        update_stats_enqueue(cfs_rq, se);
-        check_spread(cfs_rq, se);
-        check_spread(cfs_rq, curr);
-        __enqueue_entity(cfs_rq, se);
-        account_entity_enqueue(cfs_rq, se);
         se->peer_preempt = 0;
+        enqueue_task_fair(rq, p, 0);
         resched_task(rq->curr);
 }
 
diff --git a/kernel/user.c b/kernel/user.c
index 9cb6f6403561..e91331c457e2 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -84,9 +84,6 @@ static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
 
 #ifdef CONFIG_FAIR_USER_SCHED
 
-static struct kobject uids_kobject; /* represents /sys/kernel/uids directory */
-static DEFINE_MUTEX(uids_mutex);
-
 static void sched_destroy_user(struct user_struct *up)
 {
         sched_destroy_group(up->tg);
@@ -108,6 +105,19 @@ static void sched_switch_user(struct task_struct *p)
         sched_move_task(p);
 }
 
+#else   /* CONFIG_FAIR_USER_SCHED */
+
+static void sched_destroy_user(struct user_struct *up) { }
+static int sched_create_user(struct user_struct *up) { return 0; }
+static void sched_switch_user(struct task_struct *p) { }
+
+#endif  /* CONFIG_FAIR_USER_SCHED */
+
+#if defined(CONFIG_FAIR_USER_SCHED) && defined(CONFIG_SYSFS)
+
+static struct kobject uids_kobject; /* represents /sys/kernel/uids directory */
+static DEFINE_MUTEX(uids_mutex);
+
 static inline void uids_mutex_lock(void)
 {
         mutex_lock(&uids_mutex);
@@ -254,11 +264,8 @@ static inline void free_user(struct user_struct *up, unsigned long flags)
         schedule_work(&up->work);
 }
 
-#else   /* CONFIG_FAIR_USER_SCHED */
+#else   /* CONFIG_FAIR_USER_SCHED && CONFIG_SYSFS */
 
-static void sched_destroy_user(struct user_struct *up) { }
-static int sched_create_user(struct user_struct *up) { return 0; }
-static void sched_switch_user(struct task_struct *p) { }
 static inline int user_kobject_create(struct user_struct *up) { return 0; }
 static inline void uids_mutex_lock(void) { }
 static inline void uids_mutex_unlock(void) { }
@@ -277,7 +284,7 @@ static inline void free_user(struct user_struct *up, unsigned long flags)
         kmem_cache_free(uid_cachep, up);
 }
 
-#endif  /* CONFIG_FAIR_USER_SCHED */
+#endif
 
 /*
  * Locate the user_struct for the passed UID.  If found, take a ref on it.  The