On Mon, Aug 13, 2012 at 5:52 AM, Huacai Chen <chenhc@xxxxxxxxxx> wrote:
> When poweroff machine, kernel_power_off() call disable_nonboot_cpus().
> And if we have HOTPLUG_CPU configured, disable_nonboot_cpus() is not an
> empty function but attempt to actually disable the nonboot cpus. Since
> system state is SYSTEM_POWER_OFF, play_dead() won't be called and thus
> disable_nonboot_cpus() hangs. Therefore, we make this patch to avoid
> poweroff failure.
I have seen the same problem; sometimes it causes a kernel oops too.
> #ifdef CONFIG_HOTPLUG_CPU
> - if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map) &&
> - (system_state == SYSTEM_RUNNING ||
> - system_state == SYSTEM_BOOTING))
> + if (!cpu_online(cpu) && !cpu_isset(cpu, cpu_callin_map))
> play_dead();
This fix works for me.
Acked-by: Kevin Cernekee <cernekee@xxxxxxxxx>
I do see SMP boot problems ("Attempted to kill the idle task!" panic)
on a 4-way box if the !cpu_isset() check is removed.
