Re: pmu_dev_alloc; warning at at kernel/locking/lockdep.c:3002 lockdep_init_map

[Peter Zijlstra <peterz@infradead.org>]

On Thu, May 07, 2015 at 07:06:26PM +0200, Peter Zijlstra wrote:
> On Thu, May 07, 2015 at 05:29:57PM +0100, Tvrtko Ursulin wrote:
> > >>> May  7 11:58:20 skl kernel: [    6.066696] futex hash table entries: 1024 (order: 5, 131072 bytes)
> 
> > >>> May  7 11:58:20 skl kernel: [    6.329549] HugeTLB registered 2 MB page size, pre-allocated 0 pages
> 
> 
> > > sysfs by default uses lockdep key embedded in attrs.  It looks like
> > > somebody is making on-heap copies of attrs and using them as the group
> > > attrs.  What's the offending pmu type?
> > 
> > I am not familiar with this area, is this the answer?
> 
> Nope, that's way before you get the fail. initcall_debug might get you
> the right answer, but I suspect its the intel_uncore driver.
> 
> I see arch/x86/kernel/cpu/perf_event_intel_uncore.c:uncore_type_init()
> do exactly what TJ says, its dynamically allocating struct attribute.
> 
> Now, let me try and trigger that locally, that should not be skylake
> specific at all.

4.1-rc2+ with lockdep enabled boots without issue on my ivb-ep, no idea
what's going on on your skylake thingy.