Re: [Intel-gfx] [PATCH v3 2/4] drm/i915/pmu: Use kstat_irqs to get interrupt count

[Tvrtko Ursulin]

On 10/12/2020 17:44, Thomas Gleixner wrote:
> On Thu, Dec 10 2020 at 17:09, Tvrtko Ursulin wrote:
> > On 10/12/2020 16:35, Thomas Gleixner wrote:
> > > I'll send out a series addressing irq_to_desc() (ab)use all over the
> > > place shortly. i915 is in there...
> >
> > Yep we don't need atomic, my bad. And we would care about the shared
> > interrupt line. And without atomic the extra accounting falls way below
> > noise.
>
> You have to be careful though. If you make the accumulated counter 64
> bit wide then you need to be careful vs. 32bit machines.

Yep, thanks, I am bad jumping from one thing to another. Forgot about 
the read side atomicity completely..

> > So in the light of it all, it sounds best I just quickly replace our
> > abuse with private counting and then you don't have to deal with it in
> > your series.
>
> I mostly have it. Still chewing on the 32bit vs. 64bit thing. And
> keeping it in my series allows me to remove the export of irq_to_desc()
> at the end without waiting for your tree to be merged.
>
> Give me a few.

Ok.

Regards,

Tvrtko