Re: [PATCH] genirq: Fix race on spurious interrupt detection

From: Thomas Gleixner
Date: Fri Oct 19 2018 - 11:26:33 EST


On Fri, 19 Oct 2018, Lukas Wunner wrote:
> On Fri, Oct 19, 2018 at 04:31:30PM +0200, Thomas Gleixner wrote:
> > I doubt that this can happen in reality, so I'd rather reword that
> > paragraph slightly:
> >
> > In theory high CPU load and in the presence of higher priority tasks, the
> > number of incorrectly detected spurious interrupts might increase beyond
> > the 99,900 threshold and cause disablement of the interrupt.
> >
> > In practice it just increments the spurious interrupt count. But that can
> > cause people to waste time investigating it over and over.
> >
> > Hmm?
>
> Sure, fine by me. Would you prefer me to resend with that change or
> can you fold it in when applying?

I'll fold it. No problem.

> FWIW I did manage to reach the 99,900 threshold once because I had
> added copious amounts of printk() to the hi3110 IRQ thread to debug
> another issue. But I never experienced that without those printk()'s.

Cute.

Thanks

tglx