Re: next: Commit 'mm: Prevent __alloc_pages_nodemask() RCU CPU stall ...' causing hang on sparc32 qemu

[Guenter Roeck]

On 12/01/2016 04:34 AM, Paul E. McKenney wrote:
> On Wed, Nov 30, 2016 at 10:56:57PM -0800, Guenter Roeck wrote:
> > Hi Paul,
> >
> > On Wed, Nov 30, 2016 at 05:19:50PM -0800, Paul E. McKenney wrote:
> > [ ... ]
> >
> > > > > > BUG: sleeping function called from invalid context at mm/page_alloc.c:3775
> > [ ... ]
> > > Whew!  You had me going for a bit there.  ;-)
> >
> > Bisect results are here ... the culprit is, again, commit 2d66cccd73 ("mm:
> > Prevent __alloc_pages_nodemask() RCU CPU stall warnings"), and reverting that
> > patch fixes the problem. Good that you dropped it already :-).
>
> "My work is done."  ;-)
>
> And apologies for the hassle.  I have no idea what I was thinking when
> I put the cond_resched_rcu_qs() there!

No worries.

Cheers,
Guenter