Merge branch 'linus' into sched/core

[android-x86/kernel.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 7b443ee..16f3f77 100644 (file)
--- 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);
 }