On Wed, Jun 6, 2018 at 5:34 PM, Thomas Gleixner <[email protected]> wrote: > On Wed, 6 Jun 2018, Pingfan Liu wrote: > >> On Wed, Jun 6, 2018 at 5:15 PM, Thomas Gleixner <[email protected]> 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? > In kdump case, normally we set nr_cpus=1 by default, and in some huge system, it can exhaust vector space. By this is easily to resolve by inc nr_cpus. Hence I post this question to see whether there are other requirements to resolve such case
Thanks, Pingfan
