cpu_hotplug.refcount = 0;
}
+cpumask_t cpu_active_map;
+
#ifdef CONFIG_HOTPLUG_CPU
void get_online_cpus(void)
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
- struct task_struct *p;
cpumask_t old_allowed, tmp;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
cpu_clear(cpu, tmp);
set_cpus_allowed_ptr(current, &tmp);
- p = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
-
- if (IS_ERR(p) || cpu_online(cpu)) {
+ err = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
+ if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
hcpu) == NOTIFY_BAD)
BUG();
- if (IS_ERR(p)) {
- err = PTR_ERR(p);
- goto out_allowed;
- }
- goto out_thread;
+ goto out_allowed;
}
+ BUG_ON(cpu_online(cpu));
/* Wait for it to sleep (leaving idle task). */
while (!idle_cpu(cpu))
check_for_tasks(cpu);
-out_thread:
- err = kthread_stop(p);
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();
+ }
return err;
}
int err = 0;
cpu_maps_update_begin();
- if (cpu_hotplug_disabled)
+
+ if (cpu_hotplug_disabled) {
err = -EBUSY;
- else
- err = _cpu_down(cpu, 0);
+ goto out;
+ }
+
+ cpu_clear(cpu, cpu_active_map);
+ /*
+ * Make sure the all cpus did the reschedule and are not
+ * using stale version of the cpu_active_map.
+ * This is not strictly necessary becuase stop_machine()
+ * that we run down the line already provides the required
+ * synchronization. But it's really a side effect and we do not
+ * want to depend on the innards of the stop_machine here.
+ */
+ synchronize_sched();
+
+ err = _cpu_down(cpu, 0);
+
+ if (cpu_online(cpu))
+ cpu_set(cpu, cpu_active_map);
+
+out:
cpu_maps_update_done();
return err;
}
}
cpu_maps_update_begin();
- if (cpu_hotplug_disabled)
+
+ if (cpu_hotplug_disabled) {
err = -EBUSY;
- else
- err = _cpu_up(cpu, 0);
+ goto out;
+ }
+
+ err = _cpu_up(cpu, 0);
+ if (cpu_online(cpu))
+ cpu_set(cpu, cpu_active_map);
+
+out:
cpu_maps_update_done();
return err;
}
goto out;
printk("Enabling non-boot CPUs ...\n");
- for_each_cpu_mask(cpu, frozen_cpus) {
+ for_each_cpu_mask_nr(cpu, frozen_cpus) {
error = _cpu_up(cpu, 1);
if (!error) {
printk("CPU%d is up\n", cpu);