[PATCH] hotplug lockdep splat (tip)

[Peter Zijlstra]

On Mon, Oct 02, 2017 at 09:51:23AM +0300, Marta Lofstedt wrote:
> From: Peter Zijlstra <peterz at infradead.org>
> 
> On Mon, Sep 04, 2017 at 09:55:02AM +0200, Peter Zijlstra wrote:
> > On Sun, Sep 03, 2017 at 08:59:35AM +0200, Mike Galbraith wrote:
> > >
> > > [  126.626908] Unregister pv shared memory for cpu 1
> > > [  126.631041]
> > > [  126.631269] ======================================================
> > > [  126.632442] WARNING: possible circular locking dependency detected
> > > [  126.633599] 4.13.0.g06260ca-tip-lockdep #2 Tainted: G            E
> > > [  126.634380] ------------------------------------------------------
> > > [  126.635124] stress-cpu-hotp/3156 is trying to acquire lock:
> > > [  126.635804]  ((complete)&st->done){+.+.}, at: [<ffffffff8108d19a>] takedown_cpu+0x8a/0xf0
> > > [  126.636809]
> > > [  126.636809] but task is already holding lock:
> > > [  126.637567]  (sparse_irq_lock){+.+.}, at: [<ffffffff81107ac7>] irq_lock_sparse+0x17/0x20
> > > [  126.638665]
> >
> > https://lkml.kernel.org/r/20170829193416.GC32112@worktop.programming.kicks-ass.net
> >
> > I still need to write a coherent Changelog and comments for that :/
> 
> How's this?

See:

  https//lkml.kernel.org/r/20170920170014.548896195 at infradead.org

Those patches landed in tip and this splat should no longer happen.