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

Peter Zijlstra
2015-05-07T17:06:47Z

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.