1 files changed, 93 insertions, 65 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 25bba73b1be3..63e8de13c948 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -20,6 +20,20 @@
 /* Serializes the updates to cpu_online_mask, cpu_present_mask */
 static DEFINE_MUTEX(cpu_add_remove_lock);
 
+/*
+ * The following two API's must be used when attempting
+ * to serialize the updates to cpu_online_mask, cpu_present_mask.
+ */
+void cpu_maps_update_begin(void)
+{
+        mutex_lock(&cpu_add_remove_lock);
+}
+
+void cpu_maps_update_done(void)
+{
+        mutex_unlock(&cpu_add_remove_lock);
+}
+
 static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain);
 
 /* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
@@ -27,6 +41,8 @@ static __cpuinitdata RAW_NOTIFIER_HEAD(cpu_chain);
  */
 static int cpu_hotplug_disabled;
 
+#ifdef CONFIG_HOTPLUG_CPU
+
 static struct {
         struct task_struct *active_writer;
         struct mutex lock; /* Synchronizes accesses to refcount, */
@@ -41,8 +57,6 @@ static struct {
         .refcount = 0,
 };
 
-#ifdef CONFIG_HOTPLUG_CPU
-
 void get_online_cpus(void)
 {
         might_sleep();
@@ -67,22 +81,6 @@ void put_online_cpus(void)
 }
 EXPORT_SYMBOL_GPL(put_online_cpus);
 
-#endif  /* CONFIG_HOTPLUG_CPU */
-
-/*
- * The following two API's must be used when attempting
- * to serialize the updates to cpu_online_mask, cpu_present_mask.
- */
-void cpu_maps_update_begin(void)
-{
-        mutex_lock(&cpu_add_remove_lock);
-}
-
-void cpu_maps_update_done(void)
-{
-        mutex_unlock(&cpu_add_remove_lock);
-}
-
 /*
  * This ensures that the hotplug operation can begin only when the
  * refcount goes to zero.
@@ -124,6 +122,12 @@ static void cpu_hotplug_done(void)
         cpu_hotplug.active_writer = NULL;
         mutex_unlock(&cpu_hotplug.lock);
 }
+
+#else /* #if CONFIG_HOTPLUG_CPU */
+static void cpu_hotplug_begin(void) {}
+static void cpu_hotplug_done(void) {}
+#endif  /* #esle #if CONFIG_HOTPLUG_CPU */
+
 /* Need to know about CPUs going up/down? */
 int __ref register_cpu_notifier(struct notifier_block *nb)
 {
@@ -134,6 +138,30 @@ int __ref register_cpu_notifier(struct notifier_block *nb)
         return ret;
 }
 
+static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
+                        int *nr_calls)
+{
+        int ret;
+
+        ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
+                                        nr_calls);
+
+        return notifier_to_errno(ret);
+}
+
+static int cpu_notify(unsigned long val, void *v)
+{
+        return __cpu_notify(val, v, -1, NULL);
+}
+
+static void cpu_notify_nofail(unsigned long val, void *v)
+{
+        int err;
+
+        err = cpu_notify(val, v);
+        BUG_ON(err);
+}
+
 #ifdef CONFIG_HOTPLUG_CPU
 
 EXPORT_SYMBOL(register_cpu_notifier);
@@ -164,6 +192,7 @@ static inline void check_for_tasks(int cpu)
 }
 
 struct take_cpu_down_param {
+        struct task_struct *caller;
         unsigned long mod;
         void *hcpu;
 };
@@ -172,6 +201,7 @@ struct take_cpu_down_param {
 static int __ref take_cpu_down(void *_param)
 {
         struct take_cpu_down_param *param = _param;
+        unsigned int cpu = (unsigned long)param->hcpu;
         int err;
 
         /* Ensure this CPU doesn't handle any more interrupts. */
@@ -179,9 +209,10 @@ static int __ref take_cpu_down(void *_param)
         if (err < 0)
                 return err;
 
-        raw_notifier_call_chain(&cpu_chain, CPU_DYING | param->mod,
-                                param->hcpu);
+        cpu_notify(CPU_DYING | param->mod, param->hcpu);
 
+        if (task_cpu(param->caller) == cpu)
+                move_task_off_dead_cpu(cpu, param->caller);
         /* Force idle task to run as soon as we yield: it should
            immediately notice cpu is offline and die quickly. */
         sched_idle_next();
@@ -192,10 +223,10 @@ static int __ref take_cpu_down(void *_param)
 static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 {
         int err, nr_calls = 0;
-        cpumask_var_t old_allowed;
         void *hcpu = (void *)(long)cpu;
         unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
         struct take_cpu_down_param tcd_param = {
+                .caller = current,
                 .mod = mod,
                 .hcpu = hcpu,
         };
@@ -206,38 +237,26 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         if (!cpu_online(cpu))
                 return -EINVAL;
 
-        if (!alloc_cpumask_var(&old_allowed, GFP_KERNEL))
-                return -ENOMEM;
-
         cpu_hotplug_begin();
         set_cpu_active(cpu, false);
-        err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
-                                        hcpu, -1, &nr_calls);
-        if (err == NOTIFY_BAD) {
+        err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
+        if (err) {
                 set_cpu_active(cpu, true);
 
                 nr_calls--;
-                __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
-                                          hcpu, nr_calls, NULL);
+                __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
                 printk("%s: attempt to take down CPU %u failed\n",
                                 __func__, cpu);
-                err = -EINVAL;
                 goto out_release;
         }
 
-        /* Ensure that we are not runnable on dying cpu */
-        cpumask_copy(old_allowed, &current->cpus_allowed);
-        set_cpus_allowed_ptr(current, cpu_active_mask);
-
         err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
         if (err) {
                 set_cpu_active(cpu, true);
                 /* CPU didn't die: tell everyone.  Can't complain. */
-                if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
-                                            hcpu) == NOTIFY_BAD)
-                        BUG();
+                cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
 
-                goto out_allowed;
+                goto out_release;
         }
         BUG_ON(cpu_online(cpu));
 
@@ -249,22 +268,14 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         __cpu_die(cpu);
 
         /* CPU is completely dead: tell everyone.  Too late to complain. */
-        if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod,
-                                    hcpu) == NOTIFY_BAD)
-                BUG();
+        cpu_notify_nofail(CPU_DEAD | mod, hcpu);
 
         check_for_tasks(cpu);
 
-out_allowed:
-        set_cpus_allowed_ptr(current, old_allowed);
 out_release:
         cpu_hotplug_done();
-        if (!err) {
-                if (raw_notifier_call_chain(&cpu_chain, CPU_POST_DEAD | mod,
-                                            hcpu) == NOTIFY_BAD)
-                        BUG();
-        }
-        free_cpumask_var(old_allowed);
+        if (!err)
+                cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
         return err;
 }
 
@@ -272,9 +283,6 @@ int __ref cpu_down(unsigned int cpu)
 {
         int err;
 
-        err = stop_machine_create();
-        if (err)
-                return err;
         cpu_maps_update_begin();
 
         if (cpu_hotplug_disabled) {
@@ -286,7 +294,6 @@ int __ref cpu_down(unsigned int cpu)
 
 out:
         cpu_maps_update_done();
-        stop_machine_destroy();
         return err;
 }
 EXPORT_SYMBOL(cpu_down);
@@ -303,13 +310,11 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
                 return -EINVAL;
 
         cpu_hotplug_begin();
-        ret = __raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu,
-                                                        -1, &nr_calls);
-        if (ret == NOTIFY_BAD) {
+        ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
+        if (ret) {
                 nr_calls--;
                 printk("%s: attempt to bring up CPU %u failed\n",
                                 __func__, cpu);
-                ret = -EINVAL;
                 goto out_notify;
         }
 
@@ -322,12 +327,11 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
         set_cpu_active(cpu, true);
 
         /* Now call notifier in preparation. */
-        raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
+        cpu_notify(CPU_ONLINE | mod, hcpu);
 
 out_notify:
         if (ret != 0)
-                __raw_notifier_call_chain(&cpu_chain,
-                                CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
+                __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
         cpu_hotplug_done();
 
         return ret;
@@ -336,6 +340,12 @@ out_notify:
 int __cpuinit cpu_up(unsigned int cpu)
 {
         int err = 0;
+
+#ifdef  CONFIG_MEMORY_HOTPLUG
+        int nid;
+        pg_data_t       *pgdat;
+#endif
+
         if (!cpu_possible(cpu)) {
                 printk(KERN_ERR "can't online cpu %d because it is not "
                         "configured as may-hotadd at boot time\n", cpu);
@@ -346,6 +356,28 @@ int __cpuinit cpu_up(unsigned int cpu)
                 return -EINVAL;
         }
 
+#ifdef  CONFIG_MEMORY_HOTPLUG
+        nid = cpu_to_node(cpu);
+        if (!node_online(nid)) {
+                err = mem_online_node(nid);
+                if (err)
+                        return err;
+        }
+
+        pgdat = NODE_DATA(nid);
+        if (!pgdat) {
+                printk(KERN_ERR
+                        "Can't online cpu %d due to NULL pgdat\n", cpu);
+                return -ENOMEM;
+        }
+
+        if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
+                mutex_lock(&zonelists_mutex);
+                build_all_zonelists(NULL);
+                mutex_unlock(&zonelists_mutex);
+        }
+#endif
+
         cpu_maps_update_begin();
 
         if (cpu_hotplug_disabled) {
@@ -367,9 +399,6 @@ int disable_nonboot_cpus(void)
 {
         int cpu, first_cpu, error;
 
-        error = stop_machine_create();
-        if (error)
-                return error;
         cpu_maps_update_begin();
         first_cpu = cpumask_first(cpu_online_mask);
         /*
@@ -400,7 +429,6 @@ int disable_nonboot_cpus(void)
                 printk(KERN_ERR "Non-boot CPUs are not disabled\n");
         }
         cpu_maps_update_done();
-        stop_machine_destroy();
         return error;
 }
 
@@ -467,7 +495,7 @@ void __cpuinit notify_cpu_starting(unsigned int cpu)
         if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
                 val = CPU_STARTING_FROZEN;
 #endif /* CONFIG_PM_SLEEP_SMP */
-        raw_notifier_call_chain(&cpu_chain, val, (void *)(long)cpu);
+        cpu_notify(val, (void *)(long)cpu);
 }
 
 #endif /* CONFIG_SMP */