Re: [PATCH] genirq/irqaction: Move dev_id and percpu_dev_id in a union

[Thomas Gleixner]

On Sat, Apr 10 2021 at 13:00, Marc Zyngier wrote:
> dev_id and percpu_dev_id are mutually exclusive in struct irqaction,
> as they conceptually represent the same thing, only in a per-cpu
> fashion.
>
> Move them into an anonymous union, saving a few bytes on the way.

The reason why they are not in an anomymous union is that any misuse of
interfaces will result in an instantaneous explosion while with your
variant it will cause hard to diagnose side effects.

I rather waste the extra 4/8 bytes unless there is a compelling reason
not to do so.

Thanks,

        tglx