1 files changed, 50 insertions, 17 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 552faf8d358c..2b942e49d0fa 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5804,17 +5804,46 @@ static struct notifier_block __cpuinitdata migration_notifier = {
         .priority = CPU_PRI_MIGRATION,
 };
 
+static int __cpuinit sched_cpu_active(struct notifier_block *nfb,
+                                      unsigned long action, void *hcpu)
+{
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_ONLINE:
+        case CPU_DOWN_FAILED:
+                set_cpu_active((long)hcpu, true);
+                return NOTIFY_OK;
+        default:
+                return NOTIFY_DONE;
+        }
+}
+
+static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb,
+                                        unsigned long action, void *hcpu)
+{
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_DOWN_PREPARE:
+                set_cpu_active((long)hcpu, false);
+                return NOTIFY_OK;
+        default:
+                return NOTIFY_DONE;
+        }
+}
+
 static int __init migration_init(void)
 {
         void *cpu = (void *)(long)smp_processor_id();
         int err;
 
-        /* Start one for the boot CPU: */
+        /* Initialize migration for the boot CPU */
         err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
         BUG_ON(err == NOTIFY_BAD);
         migration_call(&migration_notifier, CPU_ONLINE, cpu);
         register_cpu_notifier(&migration_notifier);
 
+        /* Register cpu active notifiers */
+        cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE);
+        cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE);
+
         return 0;
 }
 early_initcall(migration_init);
@@ -7273,29 +7302,35 @@ int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
 }
 #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
 
-#ifndef CONFIG_CPUSETS
 /*
- * Add online and remove offline CPUs from the scheduler domains.
- * When cpusets are enabled they take over this function.
+ * Update cpusets according to cpu_active mask.  If cpusets are
+ * disabled, cpuset_update_active_cpus() becomes a simple wrapper
+ * around partition_sched_domains().
  */
-static int update_sched_domains(struct notifier_block *nfb,
-                                unsigned long action, void *hcpu)
+static int __cpuexit cpuset_cpu_active(struct notifier_block *nfb,
+                                       unsigned long action, void *hcpu)
 {
-        switch (action) {
+        switch (action & ~CPU_TASKS_FROZEN) {
         case CPU_ONLINE:
-        case CPU_ONLINE_FROZEN:
-        case CPU_DOWN_PREPARE:
-        case CPU_DOWN_PREPARE_FROZEN:
         case CPU_DOWN_FAILED:
-        case CPU_DOWN_FAILED_FROZEN:
-                partition_sched_domains(1, NULL, NULL);
+                cpuset_update_active_cpus();
                 return NOTIFY_OK;
+        default:
+                return NOTIFY_DONE;
+        }
+}
 
+static int __cpuexit cpuset_cpu_inactive(struct notifier_block *nfb,
+                                         unsigned long action, void *hcpu)
+{
+        switch (action & ~CPU_TASKS_FROZEN) {
+        case CPU_DOWN_PREPARE:
+                cpuset_update_active_cpus();
+                return NOTIFY_OK;
         default:
                 return NOTIFY_DONE;
         }
 }
-#endif
 
 static int update_runtime(struct notifier_block *nfb,
                                 unsigned long action, void *hcpu)
@@ -7341,10 +7376,8 @@ void __init sched_init_smp(void)
         mutex_unlock(&sched_domains_mutex);
         put_online_cpus();
 
-#ifndef CONFIG_CPUSETS
-        /* XXX: Theoretical race here - CPU may be hotplugged now */
-        hotcpu_notifier(update_sched_domains, 0);
-#endif
+        hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
+        hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);
 
         /* RT runtime code needs to handle some hotplug events */
         hotcpu_notifier(update_runtime, 0);