Merge branch 'linus' into sched/core

Merge reason: Move from the -rc3 to the almost-rc6 base.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 17 insertions, 5 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 7b443ee27be4..16f3f77f71be 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1277,6 +1277,12 @@ static void sched_avg_update(struct rq *rq)
         s64 period = sched_avg_period();
 
         while ((s64)(rq->clock - rq->age_stamp) > period) {
+                /*
+                 * Inline assembly required to prevent the compiler
+                 * optimising this loop into a divmod call.
+                 * See __iter_div_u64_rem() for another example of this.
+                 */
+                asm("" : "+rm" (rq->age_stamp));
                 rq->age_stamp += period;
                 rq->rt_avg /= 2;
         }
@@ -1680,9 +1686,6 @@ static void update_shares(struct sched_domain *sd)
 
 static void update_h_load(long cpu)
 {
-        if (root_task_group_empty())
-                return;
-
         walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
 }
 
@@ -2564,7 +2567,16 @@ void sched_fork(struct task_struct *p, int clone_flags)
         if (p->sched_class->task_fork)
                 p->sched_class->task_fork(p);
 
+        /*
+         * The child is not yet in the pid-hash so no cgroup attach races,
+         * and the cgroup is pinned to this child due to cgroup_fork()
+         * is ran before sched_fork().
+         *
+         * Silence PROVE_RCU.
+         */
+        rcu_read_lock();
         set_task_cpu(p, cpu);
+        rcu_read_unlock();
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
         if (likely(sched_info_on()))
@@ -2934,9 +2946,9 @@ unsigned long nr_iowait(void)
         return sum;
 }
 
-unsigned long nr_iowait_cpu(void)
+unsigned long nr_iowait_cpu(int cpu)
 {
-        struct rq *this = this_rq();
+        struct rq *this = cpu_rq(cpu);
         return atomic_read(&this->nr_iowait);
 }