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:
  cpusets, hotplug, scheduler: fix scheduler domain breakage

Author: torvalds

kernel/cpuset.c

@@ -1882,7 +1882,7 @@ static void scan_for_empty_cpusets(const struct cpuset *root)
  * in order to minimize text size.
  */
 
-static void common_cpu_mem_hotplug_unplug(void)
+static void common_cpu_mem_hotplug_unplug(int rebuild_sd)
 {
 	cgroup_lock();
 
@@ -1894,7 +1894,8 @@ static void common_cpu_mem_hotplug_unplug(void)
 	 * Scheduler destroys domains on hotplug events.
 	 * Rebuild them based on the current settings.
 	 */
-	rebuild_sched_domains();
+	if (rebuild_sd)
+		rebuild_sched_domains();
 
 	cgroup_unlock();
 }
@@ -1912,11 +1913,22 @@ static void common_cpu_mem_hotplug_unplug(void)
 static int cpuset_handle_cpuhp(struct notifier_block *unused_nb,
 				unsigned long phase, void *unused_cpu)
 {
-	if (phase == CPU_DYING || phase == CPU_DYING_FROZEN)
+	switch (phase) {
+	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
+	case CPU_DOWN_FAILED:
+	case CPU_DOWN_FAILED_FROZEN:
+	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		common_cpu_mem_hotplug_unplug(1);
+		break;
+	default:
 		return NOTIFY_DONE;
+	}
 
-	common_cpu_mem_hotplug_unplug();
-	return 0;
+	return NOTIFY_OK;
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
@@ -1929,7 +1941,7 @@ static int cpuset_handle_cpuhp(struct notifier_block *unused_nb,
 
 void cpuset_track_online_nodes(void)
 {
-	common_cpu_mem_hotplug_unplug();
+	common_cpu_mem_hotplug_unplug(0);
 }
 #endif