Re: next: suspicious RCU usage message since commit 'rcu: Remove superfluous versions of rcu_read_lock_sched_held()'

[Guenter Roeck]

On 04/25/2016 01:49 PM, Paul E. McKenney wrote:
> On Mon, Apr 25, 2016 at 01:25:10PM -0700, Guenter Roeck wrote:
> > On Mon, Apr 25, 2016 at 10:12:39AM -0700, Paul E. McKenney wrote:
> > > On Sun, Apr 24, 2016 at 11:26:41PM -0700, Guenter Roeck wrote:
> > > > On 04/24/2016 10:49 PM, Paul E. McKenney wrote:
> > > > > On Sun, Apr 24, 2016 at 10:37:25PM -0700, Guenter Roeck wrote:
> > > > > > On 04/24/2016 10:28 PM, Paul E. McKenney wrote:
> > > > > > > On Sun, Apr 24, 2016 at 04:56:38PM -0700, Guenter Roeck wrote:
> > >
> > > [ . . . ]
> > >
> > > > > > > > After making the same change in _pwrdm_state_switch(), the traceback is gone
> > > > > > > >from my tests (beagle, beagle-xm, and overo-tobi).
> > > > > > >
> > > > > > > Very good!
> > > > > > >
> > > > > > > (And yes, you normally find these one at a time...)
> > > > > > Are you going to submit a formal patch ?
> > > > >
> > > > > I can, but please feel free to send mine along with yours, if you wish.
> > > > I think it would be best if you send a single patch which fixes both calls.
> > >
> > > Like this one?
> > >
> > > If so, could you please run it to make sure that it actually fixes the
> > > problem?  And if it does, would you be willing to give me a Tested-by?
> > It does. Tested-by: inline below.
>
> Got it, thank you!
>
> If the ARM guys are willing to take this, it might hit the next merge
> window, or perhaps they will take it as an exception.  If I push it
> up my usual route, it will be a bit later.
>
> I just now sent it out, so hopefully they will grab it.  ;-)
Hi Paul,

Either it fixes a zero-day bug which was exposed by 'rcu: Remove superfluous
versions ...", or it fixes a problem with that commit, so I would hope that
_someone_ will pick it up.

Anyway, thanks a lot for looking into it, and for the patch!

Guenter