X-Git-Url: http://git.osdn.net/view?a=blobdiff_plain;f=kernel%2Fsched.c;h=16f3f77f71beccb828d47e3870a3650a9db255c5;hb=dca45ad8af54963c005393a484ad117b8ba6150f;hp=7b443ee27be4aba135c66c4b3a7071f0b8b269c5;hpb=68c38fc3cb4e5a60f502ee9c45f3dfe70e5165ad;p=android-x86%2Fkernel.git

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);
 }