Re: [patch 2/9] LTTng instrumentation - irq

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> 
> * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> 
> > If we want to do this logically, without thinking about tracer 
> > performance impact, we could/should do :
> > 
> > trace_irq_entry(irqno, pt_regs)
> >   for_each_handler() {
> >     trace_irq_handler_entry(action)
> >     action->handler()
> >     trace_irq_handler_exit(ret)
> >   }
> > trace_irq_exit(retval)
> 
> Not really.

Put differently: we seem to agree on handler invocation entry/exit 
events (and those are handled by Jason's patch already), and that's 
good.

I dont think we need two events for physical IRQ events though. One 
is enough: entry event. What meaning does 'retval' have in your 
pseudo-code above? None typically.

	Ingo