Re: Lockdep splat in -next

From: Paul E. McKenney
Date: Mon Jun 28 2021 - 18:16:01 EST


On Mon, Jun 28, 2021 at 01:08:41PM -0300, Jason Gunthorpe wrote:
> On Mon, Jun 28, 2021 at 08:37:46AM -0700, Paul E. McKenney wrote:
> > Hello, Yixian Liu,
> >
> > The following -next commit results in a lockdep splat:
> >
> > 591f762b2750 ("RDMA/hns: Remove the condition of light load for posting DWQE")
> >
> > The repeat-by is as follows:
> >
> > tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --trust-make --duration 1 --configs TASKS01
> >
> > The resulting splat is as shown below. This appears to have been either
> > fixed or obscured by a later commit, but it does affect bisectability.
> > Which I found out about the hard way. ;-)
>
> I'm confused, the hns driver is causing this, and you are able to test
> with the hns hardware???

Apparently I am as well, apologies for the noise. I incorrectly assumed
that v5.13-rc1 was clean, but this deadlock really is present in v5.13-rc.

And here I thought I was handling the heat relatively well...

Thanx, Paul