Occasionally losing the tick_sched_timer

[Thomas Gleixner]

On Tue, 10 Apr 2018, Nicholas Piggin wrote:
> On Tue, 10 Apr 2018 09:42:29 +0200 (CEST)
> Thomas Gleixner <tglx at linutronix.de> wrote:
> > > Thomas do you have any ideas on what we might look for, or if we can add
> > > some BUG_ON()s to catch this at its source?  
> > 
> > Not really. Tracing might be a more efficient tool that random BUG_ONs.
> 
> Sure, we could try that. Any suggestions? timer events?

timer, hrtimer and the tick-sched stuff should be a good start. And make
sure to freeze the trace once you hit the fault case. tracing_off() is your
friend.

Thanks,

	tglx