Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar.

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix migration thread runtime bogosity
  sched,rt: fix isolated CPUs leaving root_task_group indefinitely throttled
  sched,cgroup: Fix up task_groups list
  sched: fix divide by zero at {thread_group,task}_times
  sched, cgroup: Reduce rq->lock hold times for large cgroup hierarchies

1 files changed, 9 insertions, 2 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d0cc03b3e70b..c219bf8d704c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3387,6 +3387,14 @@ static int tg_load_down(struct task_group *tg, void *data)
 
 static void update_h_load(long cpu)
 {
+        struct rq *rq = cpu_rq(cpu);
+        unsigned long now = jiffies;
+
+        if (rq->h_load_throttle == now)
+                return;
+
+        rq->h_load_throttle = now;
+
         rcu_read_lock();
         walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
         rcu_read_unlock();
@@ -4293,11 +4301,10 @@ redo:
                 env.src_rq    = busiest;
                 env.loop_max  = min(sysctl_sched_nr_migrate, busiest->nr_running);
 
+                update_h_load(env.src_cpu);
 more_balance:
                 local_irq_save(flags);
                 double_rq_lock(this_rq, busiest);
-                if (!env.loop)
-                        update_h_load(env.src_cpu);
 
                 /*
                  * cur_ld_moved - load moved in current iteration