sched: fix SCHED_OTHER balance iterator to include all tasks

The currently logic inadvertently skips the last task on the run-queue,
resulting in missed balance opportunities.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: David Bahi <dbahi@novell.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 12 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 08ae848b71d4..1fe4c65a8170 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1275,23 +1275,18 @@ __load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
         struct task_struct *p = NULL;
         struct sched_entity *se;
 
-        if (next == &cfs_rq->tasks)
-                return NULL;
-
-        /* Skip over entities that are not tasks */
-        do {
+        while (next != &cfs_rq->tasks) {
                 se = list_entry(next, struct sched_entity, group_node);
                 next = next->next;
-        } while (next != &cfs_rq->tasks && !entity_is_task(se));
 
-        if (next == &cfs_rq->tasks)
-                return NULL;
+                /* Skip over entities that are not tasks */
+                if (entity_is_task(se)) {
+                        p = task_of(se);
+                        break;
+                }
+        }
 
         cfs_rq->balance_iterator = next;
-
-        if (entity_is_task(se))
-                p = task_of(se);
-
         return p;
 }