Re: [PATCH V3] trace/events: add chip name and hwirq to irq entry tracepoint

From: Thomas Gleixner
Date: Sun Jul 05 2015 - 17:29:27 EST


On Wed, 24 Jun 2015, Steven Rostedt wrote:
> > +
> > +#define show_chip_name(irq) \
> > + (irq_get_irq_data(irq) \
> > + ? irq_get_irq_data(irq)->chip->name \
> > + : "NULL")
> > +
> > +#define show_hwirq(irq) \
> > + (irq_get_irq_data(irq) \
> > + ? irq_get_irq_data(irq)->hwirq \
> > + : -ENODEV)
>
> Note these magic functions will only be useful for the tracefs reads of
> the trace files. Userspace tools that extract the data (like perf and
> trace-cmd), will have no idea of how to parse it.
>
> I'm not against doing this, but I'm just letting you know what the
> effect of this change will be.

What's worse is, that they are racy against a concurrent teardown of
the interrupt. Not a good idea ...

Thanks,

tglx


--
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/