Re: [Bug fix PATCH] numa, cpu hotplug: Change links of CPU and nodewhen changing node number by onlining CPU

[Yasuaki Ishimatsu]

2013/04/19 1:32, KOSAKI Motohiro wrote:
> >   #ifdef CONFIG_HOTPLUG_CPU
> > +static void change_cpu_under_node(struct cpu *cpu,
> > +                       unsigned int from_nid, unsigned int to_nid)
> > +{
> > +       int cpuid = cpu->dev.id;
> > +       unregister_cpu_under_node(cpuid, from_nid);
> > +       register_cpu_under_node(cpuid, to_nid);
> > +       cpu->node_id = to_nid;
> > +}
> > +

> Where is stub for !CONFIG_HOTPLUG_CPU?

This function is called by only store_online(). And the store_online() is
defined only when CONFIG_HOTPLUG_CPU enables. Thus change_cpu_under_node()
is not necessary for !CONFIG_HOTPLUG_CPU.

> >   static ssize_t show_online(struct device *dev,
> >                             struct device_attribute *attr,
> >                             char *buf)
> > @@ -39,17 +48,23 @@ static ssize_t __ref store_online(struct device *dev,
> >                                    const char *buf, size_t count)
> >   {
> >          struct cpu *cpu = container_of(dev, struct cpu, dev);
> > +       int num = cpu->dev.id;

> "num" is wrong name. cpuid may be better.

I'll update it.

> > +       int from_nid, to_nid;
> >          ssize_t ret;
> >
> >          cpu_hotplug_driver_lock();
> >          switch (buf[0]) {
> >          case '0':
> > -               ret = cpu_down(cpu->dev.id);
> > +               ret = cpu_down(num);
> >                  if (!ret)
> >                          kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
> >                  break;
> >          case '1':
> > -               ret = cpu_up(cpu->dev.id);
> > +               from_nid = cpu_to_node(num);
> > +               ret = cpu_up(num);
> > +               to_nid = cpu_to_node(num);
> > +               if (from_nid != to_nid)
> > +                       change_cpu_under_node(cpu, from_nid, to_nid);
>
> You need to add several comments. this code is not straightforward.

O.K. I'll update it.

Thanks,
Yasuaki Ishimatsu


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