Re: suspicious RCU usage warnings in 3.3.0

From: Paul E. McKenney
Date: Fri Apr 13 2012 - 12:33:54 EST


On Fri, Apr 13, 2012 at 10:55:56AM -0400, David Miller wrote:
> From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
> Date: Fri, 13 Apr 2012 06:35:13 -0700
>
> DANGER WILL ROBINSON, McKenney is hacking sparc64 assembler!
> :-))))

;-) ;-) ;-)

> > My main concern about my patch is my removal of this line:
> >
> > bne,pn %icc, __handle_softirq
> >
> > It is quite possible that this should instead change to look as follows:
> >
> > bne,pn %icc, __handle_preemption
> >
>
> I would say it should not, because the __handle_softirq code path,
> if taken, unconditionally branches to the very next instruction
> after this branch and it's delay slot.

Beginners luck beats skill. Now I just have to be very careful to
avoid ever submitting a second sparc64 assembler patch. ;-)

> > Anyway, patch with updated changelog below.
>
> Great work, I'll apply this after I test it out a bit myself.

Cool!!!

Thanx, Paul

> Thanks a lot Paul!
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/