Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue
  sched: CPU hotplug events must not destroy scheduler domains created by the cpusets
  sched: rt-group: fix RR buglet
  sched: rt-group: heirarchy aware throttle
  sched: rt-group: fix hierarchy
  sched: NULL pointer dereference while setting sched_rt_period_us
  sched: fix defined-but-unused warning

1 files changed, 25 insertions, 2 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index eaf6751e761..4a3cb061415 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1127,6 +1127,7 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer)
 	return HRTIMER_NORESTART;
 }
 
+#ifdef CONFIG_SMP
 static void hotplug_hrtick_disable(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
@@ -1182,6 +1183,7 @@ static void init_hrtick(void)
 {
 	hotcpu_notifier(hotplug_hrtick, 0);
 }
+#endif /* CONFIG_SMP */
 
 static void init_rq_hrtick(struct rq *rq)
 {
@@ -7236,6 +7238,18 @@ void __attribute__((weak)) arch_update_cpu_topology(void)
 }
 
 /*
+ * Free current domain masks.
+ * Called after all cpus are attached to NULL domain.
+ */
+static void free_sched_domains(void)
+{
+	ndoms_cur = 0;
+	if (doms_cur != &fallback_doms)
+		kfree(doms_cur);
+	doms_cur = &fallback_doms;
+}
+
+/*
  * Set up scheduler domains and groups. Callers must hold the hotplug lock.
  * For now this just excludes isolated cpus, but could be used to
  * exclude other special cases in the future.
@@ -7382,6 +7396,7 @@ int arch_reinit_sched_domains(void)
 	get_online_cpus();
 	mutex_lock(&sched_domains_mutex);
 	detach_destroy_domains(&cpu_online_map);
+	free_sched_domains();
 	err = arch_init_sched_domains(&cpu_online_map);
 	mutex_unlock(&sched_domains_mutex);
 	put_online_cpus();
@@ -7467,6 +7482,7 @@ static int update_sched_domains(struct notifier_block *nfb,
 	case CPU_DOWN_PREPARE:
 	case CPU_DOWN_PREPARE_FROZEN:
 		detach_destroy_domains(&cpu_online_map);
+		free_sched_domains();
 		return NOTIFY_OK;
 
 	case CPU_UP_CANCELED:
@@ -7485,8 +7501,16 @@ static int update_sched_domains(struct notifier_block *nfb,
 		return NOTIFY_DONE;
 	}
 
+#ifndef CONFIG_CPUSETS
+	/*
+	 * Create default domain partitioning if cpusets are disabled.
+	 * Otherwise we let cpusets rebuild the domains based on the
+	 * current setup.
+	 */
+
 	/* The hotplug lock is already held by cpu_up/cpu_down */
 	arch_init_sched_domains(&cpu_online_map);
+#endif
 
 	return NOTIFY_OK;
 }
@@ -7626,7 +7650,6 @@ static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
 	else
 		rt_se->rt_rq = parent->my_q;
 
-	rt_se->rt_rq = &rq->rt;
 	rt_se->my_q = rt_rq;
 	rt_se->parent = parent;
 	INIT_LIST_HEAD(&rt_se->run_list);
@@ -8348,7 +8371,7 @@ static unsigned long to_ratio(u64 period, u64 runtime)
 #ifdef CONFIG_CGROUP_SCHED
 static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
 {
-	struct task_group *tgi, *parent = tg->parent;
+	struct task_group *tgi, *parent = tg ? tg->parent : NULL;
 	unsigned long total = 0;
 
 	if (!parent) {