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

Ingo Molnar
2009-03-25T08:48:38Z

* 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