Re: [RFC][PATCH 2/5] cpu-hotplug: Allow get_online_cpus() to nest

[Thomas Gleixner]

On Fri, 12 May 2017, Steven Rostedt wrote:
>  void get_online_cpus(void)
>  {
> +#ifdef CONFIG_LOCKDEP
> +     if (current->goc_depth++)
> +             return;

This must be unconditional and not depend on lockdep. The percpu rwsem is
going to deadlock silently otherwise when a writer is waiting ....

Thanks,

        tglx