[USRP-users] Installing PCIE drivers for x310

James Humphries james.humphries at ettus.com
Thu Oct 29 21:32:59 EDT 2015


Ok, so it looks like the default update rate for dstat is 1 second. In that
case, I was seeing 30k interrupts per second on my machine. It would made
sense that you should be seeing a similar number.

Could you post the output of (or just the output that concerns the NI
adaptor):

$ sudo lspci -vv

I'm curious if, as you pointed out, that the PCIe slot is negotiating a 1x
bus for some reason. Are there any other devices on the PCIe bus? Video
card or other adaptors?

-Trip

On Thu, Oct 29, 2015 at 9:06 PM, Jared Dulmage via USRP-users <
usrp-users at lists.ettus.com> wrote:

> Trip,
>
> When I run
> > benchmark_rate --rx_rate 50e6
>
> dstat -crimp shows around 7500 interrupts/sec.  I get no overflows but
> this is much lower than the rate Marcus predicted.  Perhaps due to a 4 lane
> PCIe interface instead of 1 lane?
>
> When I run
> > benchmark_rate --rx_rate 100e6
>
> I get around 5500 interrupts/sec.  So I think that might be something I
> need to investigate.  Can you tell me what
>
> > cat /proc/irq/<# niusrpriok irq>/smp_affinity
> > cat /proc/irq/<# niusrpriok irq>/smp_affinity_list
>
> where <# niusrpriok irq> is the interrupt for niusrpiok in
> /proc/interrupts on your setup?
>
> Mine says
> > cat /proc/irq/90/smp_affinity
> fff
> > cat /proc/irq/90/smp_affinity_list
> 0-11
>
> which I think might be causing the problem.  Nope, just checked in
> /proc/interrupts, all of the interrupts for 90 are serviced by core 0.
> Perhaps I need to get multiple cores servicing the interrupts?  Scratching
> my head again.
>
> Thanks for all the help guys,
> Jared.
> ------------------------------------------------------
> Jared Dulmage
> Engineering Specialist
> Digital Comm. and Implementation Dept.
> Aerospace Corporation
> 310-336-3140
>
> _______________________________________________
> USRP-users mailing list
> USRP-users at lists.ettus.com
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
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