1 files changed, 25 insertions, 17 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index f6e726f18491..12b7458f23b1 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -126,7 +126,7 @@ static void cpu_hotplug_done(void)
 #else /* #if CONFIG_HOTPLUG_CPU */
 static void cpu_hotplug_begin(void) {}
 static void cpu_hotplug_done(void) {}
-#endif  /* #esle #if CONFIG_HOTPLUG_CPU */
+#endif  /* #else #if CONFIG_HOTPLUG_CPU */
 
 /* Need to know about CPUs going up/down? */
 int __ref register_cpu_notifier(struct notifier_block *nb)
@@ -160,7 +160,6 @@ static void cpu_notify_nofail(unsigned long val, void *v)
 {
         BUG_ON(cpu_notify(val, v));
 }
-
 EXPORT_SYMBOL(register_cpu_notifier);
 
 void __ref unregister_cpu_notifier(struct notifier_block *nb)
@@ -189,7 +188,6 @@ static inline void check_for_tasks(int cpu)
 }
 
 struct take_cpu_down_param {
-        struct task_struct *caller;
         unsigned long mod;
         void *hcpu;
 };
@@ -198,7 +196,6 @@ 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. */
@@ -207,12 +204,6 @@ static int __ref take_cpu_down(void *_param)
                 return err;
 
         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();
         return 0;
 }
 
@@ -223,7 +214,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         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,
         };
@@ -235,6 +225,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
                 return -EINVAL;
 
         cpu_hotplug_begin();
+
         err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
         if (err) {
                 nr_calls--;
@@ -253,9 +244,15 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         }
         BUG_ON(cpu_online(cpu));
 
-        /* Wait for it to sleep (leaving idle task). */
+        /*
+         * The migration_call() CPU_DYING callback will have removed all
+         * runnable tasks from the cpu, there's only the idle task left now
+         * that the migration thread is done doing the stop_machine thing.
+         *
+         * Wait for the stop thread to go away.
+         */
         while (!idle_cpu(cpu))
-                yield();
+                cpu_relax();
 
         /* This actually kills the CPU. */
         __cpu_die(cpu);
@@ -306,7 +303,7 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
         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",
+                printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
                                 __func__, cpu);
                 goto out_notify;
         }
@@ -386,6 +383,14 @@ out:
 #ifdef CONFIG_PM_SLEEP_SMP
 static cpumask_var_t frozen_cpus;
 
+void __weak arch_disable_nonboot_cpus_begin(void)
+{
+}
+
+void __weak arch_disable_nonboot_cpus_end(void)
+{
+}
+
 int disable_nonboot_cpus(void)
 {
         int cpu, first_cpu, error = 0;
@@ -397,6 +402,7 @@ int disable_nonboot_cpus(void)
          * with the userspace trying to use the CPU hotplug at the same time
          */
         cpumask_clear(frozen_cpus);
+        arch_disable_nonboot_cpus_begin();
 
         printk("Disabling non-boot CPUs ...\n");
         for_each_online_cpu(cpu) {
@@ -412,6 +418,8 @@ int disable_nonboot_cpus(void)
                 }
         }
 
+        arch_disable_nonboot_cpus_end();
+
         if (!error) {
                 BUG_ON(num_online_cpus() > 1);
                 /* Make sure the CPUs won't be enabled by someone else */
@@ -441,14 +449,14 @@ void __ref enable_nonboot_cpus(void)
         if (cpumask_empty(frozen_cpus))
                 goto out;
 
-        printk("Enabling non-boot CPUs ...\n");
+        printk(KERN_INFO "Enabling non-boot CPUs ...\n");
 
         arch_enable_nonboot_cpus_begin();
 
         for_each_cpu(cpu, frozen_cpus) {
                 error = _cpu_up(cpu, 1);
                 if (!error) {
-                        printk("CPU%d is up\n", cpu);
+                        printk(KERN_INFO "CPU%d is up\n", cpu);
                         continue;
                 }
                 printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
@@ -500,7 +508,7 @@ void __cpuinit notify_cpu_starting(unsigned int cpu)
  */
 
 /* cpu_bit_bitmap[0] is empty - so we can back into it */
-#define MASK_DECLARE_1(x)       [x+1][0] = 1UL << (x)
+#define MASK_DECLARE_1(x)       [x+1][0] = (1UL << (x))
 #define MASK_DECLARE_2(x)       MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
 #define MASK_DECLARE_4(x)       MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
 #define MASK_DECLARE_8(x)       MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)