[PATCH] sched: reset loop counters if all tasks are pinned and we need to redo load balance

[Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>]

While load balancing, if all tasks on the source runqueue are pinned,
we retry after excluding the corresponding source cpu. However, loop counters
env.loop and env.loop_break are not reset before retrying, which can lead
to failure in moving the tasks. In this patch we reset env.loop and
env.loop_break to their inital values before we retry.

Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 939fd63..60f8b66 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4520,8 +4520,11 @@ more_balance:
 		/* All tasks on this runqueue were pinned by CPU affinity */
 		if (unlikely(env.flags & LBF_ALL_PINNED)) {
 			cpumask_clear_cpu(cpu_of(busiest), cpus);
-			if (!cpumask_empty(cpus))
+			if (!cpumask_empty(cpus)) {
+				env.loop = 0;
+				env.loop_break = sched_nr_migrate_break;
 				goto redo;
+			}
 			goto out_balanced;
 		}
 	}