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

From: Ankit Gupta
Date: Wed Jul 08 2015 - 13:56:39 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 ...
>

Agree, I'll save the chip-name and hwirq in the struct. This technique
using the same macros to save the chip-name and hwirq in the struct also
works well with trace-cmd.

Thanks,
Ankit and Gilad

> Thanks,
>
> tglx
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