On Fri, Mar 18, 2016 at 12:11:28AM +0100, Peter Zijlstra wrote:
> On Thu, Mar 17, 2016 at 03:55:57PM -0700, Paul E. McKenney wrote:
> > The RCU stall-warn stack traces can be ugly, agreed.
>
> Ugly isn't the problem, completely random bollocks that puts you on the
> wrong path was more the problem.
>
> It uses a stack pointer saved at some random time in the past to start
> unwinding an active stack from. Completely and utter misery.
Yep, its accuracy does depend on what is going on, which was also my
experience with the NMI-based approach's reliablity.
Perhaps a boot-time parameter enabling the sysadm to pick the desired
flavor of poison?
Thanx, Paul
