lkml.org 
[lkml]   [2018]   [Jun]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: question about the limited interrupt vector resource on a single cpu
On Wed, Jun 6, 2018 at 5:34 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Wed, 6 Jun 2018, Pingfan Liu wrote:
>
>> On Wed, Jun 6, 2018 at 5:15 PM, Thomas Gleixner <tglx@linutronix.de> 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

\
 
 \ /
  Last update: 2018-06-06 13:45    [W:0.033 / U:2.864 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site