Re: question about the limited interrupt vector resource on a single cpu

From: Thomas Gleixner
Date: Wed Jun 06 2018 - 05:34:52 EST

On Wed, 6 Jun 2018, Pingfan Liu wrote:

> On Wed, Jun 6, 2018 at 5:15 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > On Wed, 6 Jun 2018, Pingfan Liu wrote:
> >
> >> For x86, there is around 200 vectors left for external device on a
> >> single logic cpu.
> >>
> >> Is there any case that we exhaust them in real world, and is it worth to fix?
> >
> > Exhaustion is unlikely, but how would you fix it? The vector space per CPU
> > is limited by hardware not software.
> >
> Playing some trick on iommu, we can use it to identify the irq requester.

But what's the point? If you have more than 200 device interrupts on a
single CPU, then you surely have other problems than that.

What kind of problem are you trying to solve?