Re: possible deadlock in xfrm_policy_delete

[peterz]

On Thu, Sep 24, 2020 at 06:44:12AM +0200, Dmitry Vyukov wrote:
> On Thu, Sep 24, 2020 at 6:36 AM Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
> > >  (k-slock-AF_INET6){+.-.}-{2:2}

That's a seqlock.

> > What's going on with all these bogus lockdep reports?
> >
> > These are two completely different locks, one is for TCP and the
> > other is for SCTP.  Why is lockdep suddenly beoming confused about
> > this?
> >
> > FWIW this flood of bogus reports started on 16/Sep.
> 
> 
> FWIW one of the dups of this issue was bisected to:
> 
> commit 1909760f5fc3f123e47b4e24e0ccdc0fc8f3f106
> Author: Ahmed S. Darwish <a.darwish@xxxxxxxxxxxxx>
> Date:   Fri Sep 4 15:32:31 2020 +0000
> 
>     seqlock: PREEMPT_RT: Do not starve seqlock_t writers
> 
> Can it be related?

Did that tree you're testing include 267580db047e ("seqlock: Unbreak
lockdep") ?