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

From: Paul E. McKenney
Date: Mon May 16 2016 - 13:09:50 EST


On Sat, May 14, 2016 at 08:42:46AM -0700, Guenter Roeck wrote:
> 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. ;-)
> >
> The problem is still seen in next-20160513, so it looks like the patch was not accepted.
>
> I recently learned that arm has a special way of submitting patches. See
> http://www.arm.linux.org.uk/developer/patches/ for details. If I understand correctly,
> you'll have to send the patch to patches@xxxxxxxxxxxxxxxx, and it has to be formatted
> correctly (eg no "[PATCH]" in the subject line, and some other information added).
> I never tried it myself, so I don't really know how exactly it works.

Nor have I. But Tony Lindgren asked me to send them via -tip. which I
can do. But I do need to straighten out the commit logs a bit beforehand.
So I will send an updated series to LKML later today and if there are no
objections, send a pull request to Ingo.

Thanx, Paul