On Mon, Aug 13, 2012 at 5:52 AM, Huacai Chen <che...@lemote.com> 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 <cerne...@gmail.com> 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/