Re: [PATCH] device: separate all subsys mutexes (was: Re: [BUG] potential deadlock led by cpu_hotplug lock (memcg involved))

Greg Kroah-Hartman
2013-03-12T15:43:41Z

On Tue, Mar 12, 2013 at 04:28:25PM +0100, Peter Zijlstra wrote:
> On Tue, 2013-03-12 at 14:05 +0100, Michal Hocko wrote:
> > @@ -111,17 +111,17 @@ struct bus_type {
> > struct iommu_ops *iommu_ops;
> >
> > struct subsys_private *p;
> > + struct lock_class_key __key;
> > };
>
> Is struct bus_type constrained to static storage or can people go an
> allocate this stuff dynamically? If so, this patch is broken.

I don't think anyone is creating this dynamically, it should be static.
Why does this matter, does the lockdep code care about where the
variable is declared (heap vs. static)?

thanks,

greg k-h