mlx5 irq

[Olivier Cochard-Labbé]

On Thu, Oct 1, 2020 at 12:28 PM Hans Petter Selasky <hps at selasky.org> wrote:

> On 2020-10-01 11:13, Michal Vančo via freebsd-net wrote:
> > On 01/10/2020 10:52, Hans Petter Selasky wrote:
> >> On 2020-10-01 10:24, Michal Vančo wrote:
> >>> But why is the actual number of IRQ lines bigger than number of CPU
> >>> cores?
> >>
> >> There are some dedicated IRQ's used for firmware management.
> >>
> >> Else the driver will use the number of online CPU's by default as the
> >> number of rings, if the hardware supports it.
> >
> > Thanks for clarification. Is there any way to optimize this? In my case
> > I have 2 CPU sockets with 8 cores each (SMT is disabled). NIC is
> > connected via PCIe to the first CPU socket (numa domain 0). In this
> > case, wouldn't it be better if all interrupts were firing only on cores
> > of first socket?
> >
>
> Hi,
>
> You can use "cpuset" to bind those IRQ threads to the right core.
>
>
> You could try this RC script to bind them:

https://github.com/ocochard/BSDRP/blob/master/BSDRP/Files/usr/local/etc/rc.d/mlx5en_affinity

Regards,

Olivier